US20040266284A1 - Engine output control for watercraft - Google Patents
Engine output control for watercraft Download PDFInfo
- Publication number
- US20040266284A1 US20040266284A1 US10/812,290 US81229004A US2004266284A1 US 20040266284 A1 US20040266284 A1 US 20040266284A1 US 81229004 A US81229004 A US 81229004A US 2004266284 A1 US2004266284 A1 US 2004266284A1
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- US
- United States
- Prior art keywords
- canceled
- watercraft
- opening degree
- throttle valve
- throttle
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63H—MARINE PROPULSION OR STEERING
- B63H21/00—Use of propulsion power plant or units on vessels
- B63H21/22—Use of propulsion power plant or units on vessels the propulsion power units being controlled from exterior of engine room, e.g. from navigation bridge; Arrangements of order telegraphs
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B61/00—Adaptations of engines for driving vehicles or for driving propellers; Combinations of engines with gearing
- F02B61/04—Adaptations of engines for driving vehicles or for driving propellers; Combinations of engines with gearing for driving propellers
- F02B61/045—Adaptations of engines for driving vehicles or for driving propellers; Combinations of engines with gearing for driving propellers for outboard marine engines
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/30—Controlling fuel injection
- F02D41/32—Controlling fuel injection of the low pressure type
- F02D41/34—Controlling fuel injection of the low pressure type with means for controlling injection timing or duration
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D2200/00—Input parameters for engine control
- F02D2200/02—Input parameters for engine control the parameters being related to the engine
- F02D2200/04—Engine intake system parameters
- F02D2200/0404—Throttle position
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D2200/00—Input parameters for engine control
- F02D2200/50—Input parameters for engine control said parameters being related to the vehicle or its components
- F02D2200/501—Vehicle speed
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/40—Engine management systems
Definitions
- This invention relates to a control system for an engine of a watercraft.
- a hull of the personal watercraft commonly defines a rider's area above an engine compartment.
- An internal combustion engine powers a jet propulsion unit that propels the watercraft by discharging water rearward.
- the engine lies within the engine compartment in front of a tunnel, which is formed on an underside of the hull.
- the jet propulsion unit is placed within the tunnel and includes an impeller that is driven by the engine.
- a deflector or steering nozzle is mounted on a rear end of the jet propulsion unit for steering the watercraft.
- a steering mast with a handlebar is linked with the deflector through a linkage. The steering mast extends upwardly in front of the rider's area. The rider remotely steers the watercraft using the handlebar.
- the engine typically includes a throttle valve disposed in an air intake passage of the engine.
- the throttle valve regulates an air amount supplied to the engine.
- the engine output also increases.
- a throttle lever or control is attached to the handlebar and is linked with the throttle valve usually through a throttle linkage and cable. The rider thus can control the throttle valve remotely by operating the throttle lever on the handlebar.
- a watercraft comprises a water propulsion device and an engine powering the water propulsion device.
- An engine output control mechanism is arranged to control the engine's output.
- a steering mechanism is arranged to the watercraft.
- a first sensor is arranged to sense a state of the engine output control mechanism.
- a second sensor is arranged to sense a state of the steering mechanism.
- a control device is configured to control the engine output control mechanism based upon a first control parameter corresponding to an output of the first sensor and a second control parameter corresponding to an output of the second sensor. The control device causes the engine output control mechanism to increase the engine output when the first control parameter is less than a first reference magnitude and the second control parameter is greater than a second reference magnitude.
- a watercraft comprises a water propulsion device and an engine powering the water propulsion device.
- An engine output control mechanism is arranged to control the engine's output.
- a steering mechanism is arranged to steer the watercraft.
- a first sensor is arranged to sense a state of the steering mechanism.
- a second sensor is arranged to sense a velocity of the watercraft.
- a control device is configured to control the engine output control mechanism based upon a first control parameter corresponding to an output of the first sensor and a second control parameter corresponding to an output of the second sensor. The control device causes the engine output control mechanism to increase the engine output when the first control parameter is greater than a first reference magnitude and the second control parameter is greater than a second reference magnitude.
- a watercraft comprises a water propulsion device and an engine powering the water propulsion device.
- a steering mechanism is arranged to steer a thrust direction of the water propulsion device.
- the thrust direction is quickly changed under a first condition when the water propulsion device produces a thrust force greater than a predetermined thrust force.
- Means are provided for recognizing that the steering mechanism is steered under a second condition in which the water propulsion device does not produce a thrust force greater than the predetermined thrust force. Additional means are provided for increasing an output of the engine when the recognizing means recognizes that the steering mechanism is steered under the second condition.
- a watercraft comprises a water propulsion device and an engine powering the water propulsion device.
- the engine has at least one combustion chamber and an air induction system arranged to provide air to the combustion chamber.
- a throttle valve is disposed in the air induction system for regulating an amount of the air flowing into the combustion chamber.
- a steering assembly is arranged to steer the watercraft.
- a first sensor is arranged to sense an opening degree of the throttle valve.
- a second sensor is arranged to sense an angular position of the steering assembly.
- An electrically operated control device is provided.
- a throttle valve actuator is arranged to operate the opening degree of the throttle valve. The control device is configured to control the throttle valve actuator based upon an output of the first sensor and an output of the second sensor.
- the control device causes the throttle valve actuator to operate the throttle valve to increase the opening degree when the output of the first sensor indicates that the sensed opening degree less than a reference opening degree and the output of the second sensor indicates that the sensed angular position is greater than a reference angular position.
- a control method for an engine of a watercraft.
- the watercraft has a water propulsion device, an engine output control mechanism, a steering mechanism, at least two sensors and a control device.
- the method comprises sensing a state of the engine output control mechanism by one sensor, sensing a state of the steering mechanism by another sensor, determining whether a first control parameter corresponding to a sensed state of the engine output is less than a first reference magnitude, determining whether a second control parameter corresponding to a sensed state of the steering mechanism is greater than a second reference magnitude, and increasing engine output by the control device if the results of both determinations are affirmative (i.e., are true).
- a control method for an engine of a watercraft.
- the watercraft has a water propulsion device, a steering assembly, at least two sensors and a control device.
- the engine includes a throttle valve and a throttle valve actuator.
- the method comprises sensing an opening degree of the throttle valve by one sensor, sensing an angular position of the steering assembly by another sensor, determining whether the sensed opening degree is less than a reference opening degree, determining whether the sensed angular position is greater than a reference angular position, and increasing the opening degree by the control device if the results of both determinations are affirmative (i.e., are true).
- FIG. 1 is a side elevational view of a personal watercraft and schematically illustrates an engine control system configured in accordance with a preferred embodiment of the present invention.
- FIG. 2 is a block diagram showing the control system of an engine for the watercraft.
- FIG. 3(A) is a graph showing a way of increase of an engine output versus time.
- FIG. 3(B) is a graph showing another way of increase of the engine output versus time.
- FIG. 3(C) is a graph showing a further way of increase of the engine output versus time.
- FIG. 4 is a control routine of an ECU of the control system.
- FIG. 5 is a sub-routine provided for the control routine.
- FIG. 6 is a schematic front view of the engine. A large part of the engine except for an air induction system and a throttle valve control mechanism is illustrated in phantom.
- FIG. 7 is a schematic view of the throttle valve control mechanism.
- FIG. 8 is a sectional view of an air intake conduit having the throttle valve and a bypass. A portion of the engine where the intake conduit is connected is also shown in phantom.
- FIG. 9 is a sectional view of a bypass control mechanism. The intake passage in part and the throttle valve is shown in phantom.
- FIG. 10 is a perspective view of a steering mast and a handlebar disposed atop thereof. Both the steering mast and handlebar are part of the personal watercraft. A steering position sensing mechanism is schematically shown in this figure. A lanyard switch unit configured in accordance with the present embodiment is also shown in the figure.
- FIG. 11 is a schematic view of the lanyard switch unit including a switch section and a pair of lanyard sections selectively combined with the switch section.
- FIG. 12(A) is a side view of another throttle valve control mechanism configured in accordance with another preferred embodiment of the present invention.
- FIG. 12(B) is a sectional view of the throttle valve control mechanism taken along the line 12 - 12 of FIG. 12(A).
- FIG. 12(C) is a front view of the throttle valve control mechanism.
- FIG. 13(A) is a side view of an additional throttle valve control mechanism configured in accordance with an additional preferred embodiment of the present invention.
- FIG. 13(B) is a sectional view of the throttle valve control mechanism taken along the line 13 - 13 of FIG. 13(A).
- FIG. 13(C) is a front view of a control structure including a solenoid actuator looked in the direction of the arrow H.
- FIG. 14(A) is a side view of another throttle valve control mechanism configured in accordance with a further preferred embodiment of the present invention.
- FIG. 14(B) is a sectional view of the throttle valve control mechanism taken along the line 14 - 14 of FIG. 14(A).
- FIG. 15 is a side view of the watercraft having a trim control mechanism.
- the trim control mechanism is not activated in this figure.
- FIG. 16 is the same side view of the watercraft of FIG. 15, and the trim control mechanism is activated in this figure.
- FIG. 17(A) is a schematic view of preferred embodiment of the steering position sensing mechanism.
- FIG. 17(B) is a time chart of sensed signals.
- FIG. 18(A) is a schematic view of preferred embodiment of the steering position sensing mechanism.
- FIG. 18(B) is a time chart of sensed signals.
- FIG. 19(A) is a schematic view of a further preferred embodiment of the steering position sensing mechanism.
- FIG. 19(B) is a graph showing a partial voltage ratio of the steering position sensing mechanism
- FIG. 20(A) is a schematic view of a still further preferred embodiment of the steering position sensing mechanism.
- FIG. 20(B) is a time chart of sensed signals.
- FIG. 21(A) is a schematic view of a yet further preferred embodiment of the steering position sensing mechanism.
- FIG. 21(B) is a time chart of sensed signals.
- FIG. 22 is a schematic view showing another embodiment of the control system.
- FIG. 23 is a control routine of an ECU of the control system shown in FIG. 22.
- the watercraft 30 employs an internal combustion engine 32 and an engine control system 34 configured in accordance with a preferred embodiment of the present invention.
- This engine control system 34 has particular utility with a personal watercraft, and thus is described in the context of the personal watercraft.
- the control system can be applied to other types of watercraft as well, such as, for example, small jet boats.
- the personal watercraft 30 includes a hull 36 generally formed with a lower hull section 38 and an upper hull section or deck 40 .
- the lower hull section may include one or more inner liner sections to strengthen the hull or to provide mounting platforms for various internal components of the watercraft.
- Both the hull sections 38 , 40 are made of, for example, a molded fiberglass reinforced resin or a sheet molding compound.
- the lower hull section 38 and the upper hull section 40 are coupled together to define an internal cavity.
- a gunnel or bulwark 42 defines an intersection of both the hull sections 38 , 40 .
- a steering mast 46 extends generally upwardly almost atop the upper hull section 40 to support a handlebar 48 .
- the handlebar 48 is provided primarily for a rider to control the steering mast 46 so that a thrust direction of the watercraft 30 is properly changed.
- grips 50 are formed at both ends of the bar 48 . The rider can hold them for steering the watercraft 30 .
- the handlebar 48 also carries other control devices such as, for example, a throttle lever 52 for manually operating throttle valves 54 (FIGS. 6-9) of the engine 32 .
- the steering must 46 is covered with a padded steering cover member 56 .
- a seat 60 extends longitudinally fore to aft along a centerline of the hull 36 at a location behind the steering mast 46 .
- This area, in which the seat 60 is positioned, is a rider's area.
- the seat 60 has generally a saddle shape so that the rider can straddle it. Foot areas are defined on both sides of the seat 60 and at the top surface of the upper hull section 40 .
- a cushion, which has a rigid backing and is supported by a pedestal section of the upper hull section 40 forms part of the seat 60 .
- the pedestal forms the other portion of the seat.
- the seat cushion is detachably attached to the pedestal of the upper hull section 40 .
- An access opening is defined on the top surface of the pedestal, under the seat cushion, through which the rider can access an engine compartment defined in an internal cavity formed between the lower and upper hull sections 38 , 40 .
- the engine 32 is placed in the engine compartment.
- the engine compartment may be an area within the internal cavity or may be divided for one or more other areas of internal cavity by one or more bulkheads.
- a fuel tank is placed in the cavity under the upper hull section 40 and preferably in front of the engine compartment.
- the fuel tank is coupled with a fuel inlet port positioned at a top surface of the upper hull section 40 through a filler duct.
- a closure cap closes the fuel inlet port.
- At least a pair of air ducts or ventilation ducts is provided on both sides of the upper hull section 40 so that the ambient air can enter the internal cavity through the ducts. Except for the air ducts, the engine compartment is substantially sealed so as to protect the engine 32 and a fuel supply system (including the fuel tank) from water.
- a jet pump unit 64 propels the watercraft 30 .
- the jet pump assembly 64 includes a tunnel 66 formed on the underside of the lower hull section 38 . In some hull designs, the tunnel is isolated from the engine compartment by a bulkhead.
- the tunnel 66 has a downward facing inlet port 68 opening toward the body of water.
- a jet pump housing 70 is disposed within a portion of the tunnel 66 and communicates with the inlet port 68 .
- An impeller 72 is rotatably supported within the housing 70 .
- An impeller shaft extends forwardly from the impeller 72 and is coupled with a crankshaft of the engine 32 so as to be driven by the crankshaft.
- the rear end of the housing 70 defines a discharge nozzle 74 .
- a deflector or steering nozzle 76 is affixed to the discharge nozzle 74 for pivotal movement about a steering axis 78 extending generally vertically.
- a cable connects the deflector 76 with the steering mast 46 so that the rider can steer the deflector 76 .
- a steering mechanism 80 for the watercraft thus preferably comprises the steering mast 46 , the handlebar 48 , the cable and the deflector 76 .
- the engine control system 34 preferably includes an ECU (electronic control unit) or control device 86 , a steering position sensor 88 , a throttle position sensor 90 and a watercraft velocity sensor 92 .
- the ECU 86 is preferably mounted on the engine 32 or disposed in proximity to the engine 32 .
- the steering position sensor 88 is preferably positioned adjacent to the steering mast 46 so as to sense an angle of the steering mast 46 when the rider operates it.
- the throttle position sensor 90 is preferably affixed at one end of throttle valve shafts 94 (FIGS. 6 and 7) so as to sense a position of the throttle valves 54 .
- the watercraft velocity sensor 92 is preferably located at a rear bottom portion of the watercraft 30 , which is submerged during a normal running condition of the watercraft 30 .
- the respective sensors 88 , 90 , 92 are connected to the ECU 86 through signal lines 96 , 98 , 100 , respectively.
- the signals can be sent through hard-wired connections, emitter and detector pairs, infrared radiation, radio waves or the like.
- the type of signal and the type of connection can be varied between sensors or the same type can be used with all sensors.
- the illustrated control system 34 preferably operates in accordance with a control routine shown in FIGS. 4 and 5, although other control routines are applicable inasmuch as complying with the control strategy of the present invention.
- the exemplary control routine as well as the control system 34 will be described in greater detail shortly.
- the engine 32 preferably operates on a two-cycle crankcase compression principle and has three cylinders spaced apart from one another along the longitudinal centerline.
- the illustrated engine merely exemplifies one type of engine on which various aspects and features of the present invention can be used.
- the invention can be used with engines having other number of cylinders, having other cylinder arrangements, other cylinder orientations (e.g., upright cylinder banks) and operating on other combustion principles (e.g., four cycle or rotary).
- the engine 32 generally has a typical and conventional construction. That is, the engine 32 includes a cylinder block defining three cylinder bores in which pistons reciprocate. At least one cylinder head member is affixed to the upper end of the cylinder block to close respective upper ends of the cylinder bores and defines combustion chambers with the cylinder bores and the pistons.
- crankcase member is also affixed to the lower end of the cylinder block to close the respective lower ends of the cylinder bores and to define a crankcase chamber with the cylinder block.
- the crankshaft is rotatably connected to the pistons through connecting rods and is journaled for rotation within the crankcase.
- the cylinder block, the cylinder head and the crankcase member preferably are made of aluminum alloy and together define an engine body 102 .
- Engine mounts 104 extend from both sides of the engine body 102 .
- the engine mounts 104 preferably include resilient portions made of, for example, rubber material.
- the engine body 102 is mounted on the lower hull section 38 (or possibly on the hull liner) by the engine mounts 104 so that vibration of the engine body 102 is inhibited from conducting to the hull section 38 .
- the engine 32 preferably includes an air induction system 108 to introduce air to the combustion chambers.
- the air induction system is disposed on the starboard side of the engine body 102 .
- the induction system 108 includes throttle bodies 110 affixed to the crankcase member, and a plenum chamber member or air intake box 112 .
- the plenum chamber member 112 defines a plenum chamber 114 into which the air in the engine compartment enters.
- the plenum chamber 114 smoothes the intake air and attenuates intake noise.
- the throttle bodies 110 each communicate with a respective individual chamber within the crankcase chamber that communicates with one of the combustion chambers through scavenge passages defined within the engine body 102 .
- the throttle bodies 110 define intake passages 116 through which the air flows to the individual crankcase chambers.
- the respective throttle valves 54 are disposed within the intake passages 116 so as to regulate the amount of air passing through the intake passages 116 . Because the throttle valve shafts 94 are journaled on the throttle bodies 110 for pivotal movement about axes of the respective valve shafts 94 , the respective throttle valves 54 can pivot to change opening degrees thereof.
- the foregoing throttle lever 52 preferably is connected to the throttle valve shafts 94 through a throttle wire or cable 118 . In the illustrated embodiment, the entire throttle valve shafts 94 are linked together so that the throttle wire 118 can be connected with only one of the shafts 94 . As seen in FIG.
- the throttle valve shaft 94 has a pulley 120 and the throttle wire 118 is affixed to the pulley 120 so as to coil around it.
- the opening degrees of the respective throttle valves 54 change so as to regulate proper amounts of air to the combustion chambers.
- one of the throttle valve shafts 94 has the throttle position sensor 90 at one end thereof.
- the throttle position sensor 90 thus can sense an angular position of each throttle valve 54 , i.e., an opening degree of each throttle valve 54 .
- the throttle valves 54 can be closed so as to bring the engine 32 to an idle state. Even at this idle state, the engine 32 still needs a small amount of air to maintain the idle state.
- An idle air supply mechanism thus is provided such as a sub-passage bypassing the throttle valves 54 .
- a control valve for controlling the idle air amount can be provided at the sub-passage.
- the engine 32 also includes a fuel supply system.
- the fuel supply system includes the fuel tank, a charge forming device and a fuel delivery mechanism that connects the fuel tank with the charge forming device.
- the charge forming device can take various structures such as a carburetor, a fuel injection mechanism or the like. If the fuel injection mechanism is employed, fuel can be sprayed either directly or indirectly to the combustion chambers. In the illustrated embodiment, an indirect fuel injection mechanism is employed.
- the fuel injection mechanism includes one or more fuel injectors directed toward the respective intake passages and one or more fuel pumps to pressurize the fuel delivered to the fuel injectors.
- Each fuel injector has an injection nozzle that is exposed to the intake passage.
- the injection nozzle preferably is opened and closed by an electromagnetic unit that is slideable within an injection body.
- the electromagnetic unit has a solenoid coil controlled by electrical signals. When the nozzle is opened, pressurized fuel is sprayed to the intake passage. The sprayed fuel is drawn to the combustion chambers with the air passing through the intake passages.
- the ECU 86 controls an amount of fuel sprayed into each intake passage 116 . Because a pressure regulator strictly regulates the fuel pressure, the ECU 86 can vary the fuel amount by varying the duration of each injection. The ECU also can advance injection timing and initiation timing in order to increase the engine output.
- the engine 32 further includes an ignition or firing system. Spark plugs of the ignition system are affixed to the cylinder head. A spark gap of each spark plug is exposed within an associated combustion chamber. Each spark plug ignites an air/fuel charge at an ignition timing controlled by the ECU.
- the ignition system preferably has an ignition mechanism including an ignition coil and an igniter.
- the ignition coil preferably is a combination of a primary coil element and a secondary coil element that are wound around a common core.
- the secondary coil element is connected to the spark plugs while the primary coil element is connected to the igniter.
- the primary coil element also is coupled with a power source (e.g. a battery).
- the igniter abruptly cuts off the current flow in response to an ignition timing control signal from the ECU. A high voltage current flow consequently occurs in the secondary coil element.
- the high voltage current flow forms a spark at each spark plug.
- the ECU 86 controls an ignition timing of the spark plugs in this manner.
- the engine 32 further includes an exhaust system to discharge burnt charges, i.e., exhaust gases, from the combustion chambers.
- Exhaust ports are defined in the cylinder block and communicate with the associated combustion chambers.
- An exhaust manifold is connected to the cylinder block and communicates with the exhaust ports.
- Multiple exhaust conduits 122 (FIG. 1) are further coupled with the exhaust manifold in series so as to extend around the engine body 102 and then toward the tunnel 66 .
- a discharge exhaust conduit 122 is connected to the tunnel 66 so that the exhaust gases are discharged into the tunnel 66 in a known manner.
- control system 34 may be in the form of a hard wired feedback control circuit or may be constructed of a dedicated processor and a memory for storing a computer program and data. Additionally, the control system 34 may be constructed of a general purpose computer having a general purpose processor and the memory for storing the computer program for performing the control routine. Preferably, however, the control system 34 utilizes the engine ECU 86 , which may be constructed in any of the above-mentioned forms.
- FIG. 2 illustrates a block diagram of the control system 34 in which the ECU 86 controls an engine output control mechanism 130 .
- the engine output control mechanism 130 comprises the throttle valves 54 and a throttle valve actuator 132 .
- the throttle valve actuator 132 actuates the throttle valves 54
- the ECU 86 controls the actuator 132 to control the opening degree of the throttle valves 54 .
- the throttle valve actuator 132 is mounted on one of the throttle bodies 110 and is connected with one of the throttle shafts 94 .
- a linkage causes all of the throttle shafts 94 to move together, and thus, the actuator 132 can move all of the throttle shafts 94 even though it is coupled only to one.
- the actuator 132 is coupled to the throttle shaft 94 to which the throttle valve position sensor 90 is also connected.
- the actuator 132 is disposed on one end of the shaft 94 (e.g., on an outer end relative to the engine body) and the sensor 90 is disposed on an opposite end of the shaft 94 (e.g., on an inner end).
- the throttle valve actuator 132 preferably is a step motor or an electric motor employed in a feedback system.
- a servomotor 132 a also can be used in place of the step motor. Although a servomotor is usually larger than the step motor, the servomotor 132 a may be desirable in some applications because it eliminates the need for the throttle valve position sensor 90 .
- the servomotor 132 a preferably is disposed apart from the engine body 102 .
- the servomotor 132 a has a pulley 136 on a shaft 138 that rotates about an axis (e.g., a vertical axis), while the throttle valve 54 has a corresponding pulley 140 on its shaft 94 next to the pulley 120 that is coupled to the throttle wire 118 .
- a control wire 142 connects the pulleys 136 , 140 with each other.
- the servomotor 132 a moves the throttle shaft 94 in a controlled manner through this pulley system.
- the pulleys 140 , 120 which are connected to the servomotor 132 a and the throttle wire 118 , respectively, can of course be positioned on different throttle shafts 94 .
- the throttle valve actuator 132 i.e., the step motor 132 or the servomotor 132 a , is connected to the ECU 86 by a control line. Normally, the operator operates the throttle valves 54 by the throttle lever 52 . The ECU 86 , however, overrides the control of the throttle lever 52 and causes the throttle valve actuator 132 to increase or maintain the opening degree of the throttle valves 54 under certain conditions.
- three sensors or sensing mechanisms i.e., the throttle valve position sensor 90 , the steering position sensor 88 and a watercraft velocity sensor 92 , are employed for sensing the respective states or velocity of the watercraft and its engine.
- the throttle valve position sensor 90 preferably is a potentiometer. As schematically shown in FIG. 10, the sensor 90 can be alternatively positioned next to the throttle lever 52 or any other place where the throttle opening degree can be sensed. Other sensors or sensing mechanisms such as a proximity sensor can also be used.
- the steering position sensor 88 preferably is a proximity sensor positioned adjacent to the steering mast 46 and senses an angular position of the steering mast 46 .
- Other types of sensors or sensing mechanisms also can be used.
- the velocity sensor 92 of the watercraft 30 preferably is a paddle-wheel type sensor positioned at a bottom portion or a submerged stern portion of the watercraft 30 .
- Any other sensors acting as velocity sensors such as a dynamic pressure sensor disposed with the tunnel 66 or a Pitot tube type sensor disposed toward the body of water can replace the paddle-wheel type sensor 92 .
- the ECU 86 has stored in its memory a reference watercraft velocity (Vs).
- Vs watercraft velocity
- the reference velocity (Vs) is selected from velocities greater than a velocity where the watercraft 30 starts planing.
- the jet type watercraft 30 transfers from a displacement (trolling) range to a transient range at a velocity of 10-15 Km/h (at an engine speed of 2,000-2,500 rpm) and then transfers to the planing range at a velocity of 30-35 Km/h (at an engine speed of 4,500 rpm).
- the watercraft 30 can stay in a complete planing range when the velocity is 35 Km/h or more (at the engine speed is 4,500 rpm or more).
- the maximum speed of the engine 32 is about 7,000 rpm.
- the present invention can be used with engines having greater or lesser top-end speeds.
- the velocity of the watercraft when it starts planing also depends upon the size and shape of its hull, the weight of the watercraft, the location of the watercraft's center of gravity, and the performance of the jet propulsion unit, to name a few additional factors.
- the reference velocity (Vs) can be determined empirically for a particular watercraft design and then stored in the ECU of each watercraft made in accordance with such design.
- the predetermined reference velocity (Vs) of 15 Km/h in this embodiment thus is merely an example.
- a reference throttle opening degree (Th ⁇ s) preferably is selected to correspond to a watercraft velocity that generates a thrust force sufficient to change sharply the direction of travel of the watercraft 30 .
- the reference throttle opening degree (Th ⁇ s) increases with watercraft velocity.
- the reference throttle opening degree (Th ⁇ s) preferably is not less than 30 degrees and increases with increasing watercraft speed. At throttle angles less than 30 degrees, the engine output may not be sufficient to produce enough thrust to turn the watercraft 30 sharply.
- a reference steering position (Sds) also is preferably selected to correspond to a watercraft velocity. Unless the reference steering position (Sds) is large enough relative to the watercraft velocity, the watercraft 30 may not be as responsive as the rider would like at low speeds.
- the reference steering position (Sds) is variable and generally increases with increasing watercraft velocity. In the illustrated embodiment, the steering mast 46 rotates from a neutral position (for straight-ahead travel) by forty degrees (40°) to a fully turned position to each side.
- the steering mast 46 rotates from its neutral position (0°) by plus forty degrees (40°) when moved from the neutral position to a fully turned position to the right and by minus forty degrees ( ⁇ 40°) when moved from the neutral position to a fully turned position to the left.
- the reference steering position (Sds) preferably is not less than twenty degrees (20°) and varies relative to watercraft speed.
- the ECU 86 has stored in its memory at least one map that relates the reference throttle opening degrees (Th ⁇ s) to watercraft velocities (V) and at least another map that relates the reference steering positions (Sds) to the watercraft velocities (V). These maps are used for selecting the reference throttle opening degree (Th ⁇ s) and the steering positions (Sds) in response to a continually sensed watercraft velocity (V).
- the present control system 32 thus is adapted to maintain or increase the throttle angle to a desired throttle opening degree in order to enhance the responsiveness of the watercraft 30 and to ease watercraft operations during such turns.
- the ECU 86 has stored in its memory a map of objective throttle opening degrees (Th ⁇ m), i.e., desired throttle opening degrees, versus watercraft speed.
- Th ⁇ m objective throttle opening degrees
- the throttle opening degree (Th ⁇ m) increases with increases in watercraft speed.
- Step S 1 the ECU 86 reads a current throttle valve opening degree (Th ⁇ ), a current steering position (Sd) and a current watercraft velocity (V) based upon the signals sent from the throttle position sensor 90 , the steering position sensor 88 and the watercraft velocity sensor 92 , respectively, and stores these values in memory as current data. While the sensed signals of the throttle position sensor 90 and the watercraft velocity sensor 92 are stored without alteration, the sensed signal of the steering sensor 88 is altered to be an absolute value (
- the ECU recalls the reference watercraft velocity (Vs) from its memory.
- the program also determines from the stored maps the reference throttle valve opening degree (Th ⁇ s) and the reference steering position (Sds) that correspond to the current watercraft velocity (V).
- the ECU determines whether the watercraft velocity (V) is equal to or greater than the reference velocity (Vs), i.e., 15 Km/h (Step S 3 ). If the watercraft velocity (V) is less than the reference velocity (Vs), the routine returns to its start (Step S 6 ). If the watercraft velocity (V) is equal to or greater than the reference velocity (Vs), then the watercraft 30 is operating under a planing mode. Of course it is understood that the routine could be written such that the routine would proceed to Step S 6 if the watercraft velocity were less than the reference velocity.
- Step S 4 the ECU determines whether the throttle opening degree (Th ⁇ ) is equal to or less than the reference opening degree (Th ⁇ s), which is selected to correspond to the current watercraft velocity (V) and is at least 30 degrees. If not, the program returns to its start (Step S 6 ). If yes, then the program proceeds to Step S 5 .
- Step S 5 the ECU determines whether the steering position (
- the steering position
- Sds the reference steering position
- Step S 7 the ECU performs an engine output control sub-routine illustrated in FIG. 5.
- the ECU 86 reads a current throttle valve opening degree (Th ⁇ ), a current steering position (Sd) and a current watercraft velocity (V) based upon the signals sent from the throttle position sensor 90 , the steering position sensor 88 and the watercraft velocity sensor 92 , respectively, and stores these values in memory as current data.
- Th ⁇ current throttle valve opening degree
- Sd current steering position
- V current watercraft velocity
- the ECU determines from the stored map(s) an objective throttle opening degree (Th ⁇ m) that corresponds to the current watercraft velocity (V).
- the ECU drives the throttle valve actuator 132 (Step S 10 ) to actuate the throttle valves 54 until the opening degree (Th ⁇ ) of the throttle valves 54 becomes equal to the objective opening degree (Th ⁇ m).
- the opening degree (Th ⁇ ) reaches the objective opening degree (Th ⁇ m)
- the ECU proceeds to the next step.
- Step S 11 the ECU determines whether the steering mast 46 is at the neutral position, i.e., whether the steering position (
- the ECU can likewise cease its engine output control mode if ECU determines that the steering mast 46 is less than the reference steering position (Sds) or is around zero (e.g., less than 10 degrees or more preferably less than 5 degrees). If not, however, the ECU proceeds to Step S 12 .
- Step S 12 the ECU determines whether the throttle opening degree (Th ⁇ ) is increasing, i.e., whether the differential value of the throttle opening degree (Th ⁇ ) is greater than zero. If yes, the rider is increasing the throttle opening degree to an opening greater than the objective opening degree (Th ⁇ m) on his or her own. The program thus proceeds to Step S 14 so as to return to Step S 1 of the main routine. If not, the ECU proceeds to Step S 13 .
- the ECU determines whether the watercraft velocity (V) is equal or less than another reference velocity (Vs2).
- the reference velocity (Vs2) is also stored in the memory of the ECU 86 and is preferably selected to be slightly slower than the reference velocity (Vs) used in Step S 3 .
- the second reference velocity (Vs2) is equal to 10 Km/h, which is less than 15 Km/h (the first reference velocity (Vs)). If the watercraft velocity (V) is equal to or less than the second reference velocity (Vs2), then the power assistance provided by the engine output control mode is no longer provided.
- the ECU then moves to Step S 14 to return to the first step of the main routine (Step S 1 ).
- the ECU If, however, the watercraft velocity (V) is greater than the second reference velocity (Vs2), the ECU returns to Step S 11 and proceeds in accordance with the above description.
- the ECU continues to control the engine's output by instructing the actuator 132 to continue to hold the throttle valves 54 open to the objective opening degree (Th ⁇ m).
- the reference throttle opening degree (Th ⁇ s) and the reference steering position (Sds) need not necessarily correspond to the watercraft velocity. That is, the reference throttle opening degree (Th ⁇ s) can be a fixed degree (e.g., 30 degrees). Also, the reference steering position (Sds) can be a fixed degree (e.g., 20 degrees).
- the ECU can stop the engine control routine based upon other parameters than those of the quires of Steps S 11 , S 12 and S 13 .
- the program can return to the main routine after the elapse of a predetermined time period following the completion of Step S 10 .
- the predetermined time could be constant or variable. If variable, the time period preferably would be longer for higher speeds.
- Step S 3 or Step S 4 can be omitted, provided that at least one of these steps remains. Also, two of the Steps S 11 , S 12 , and S 13 can be omitted if at least one of them remains.
- the engine output control mechanism 130 can comprise other components or can take on other forms.
- an alternative control mechanism 130 A includes a bypass passage 148 that bypasses one of the throttle valves 54 and an electromagnetic type control valve 150 that selectively opens and closes the bypass passage 148 under control of the ECU 86 .
- This bypass mechanism supplies increased air to the combustion chamber when the control valve 150 opens the bypass passage 148 to increase engine speed.
- This type of engine output control mechanism 130 A also can be used as the idle air supply mechanism described above.
- the engine output control mechanism 130 also can include components of other systems whose operations affect engine output.
- the engine output control mechanism 130 can also include the ignition system and/or the fuel supply system. If the ignition system is used as part of the control mechanism 130 , then the ECU 86 can control the ignition mechanism 156 to advance ignition timing of the spark plug(s) 156 . If the fuel supply system is used as part of the control mechanism 130 , then the ECU can control the fuel injectors to increase the injected fuel amount under the engine output control mode by advancing and/or increasing the duration of the fuel injection cycle.
- FIG. 3(A) illustrates a pattern in which the engine output increases linearly.
- FIG. 3(B) illustrates another pattern in which the engine output increases non-linearly.
- the rate of change of the engine output can decrease over time as shown by the solid line in FIG. 3(B) or can increase over time as shown by the dotted line in the same figure.
- FIG. 3(C) illustrates a further pattern in which the engine output increases in a stepped manner.
- the watercraft can also include a switchover mechanism to selectively activate or disable the ECU's engine output control mode.
- a switchover mechanism to selectively activate or disable the ECU's engine output control mode.
- Personal watercraft typically are provided with a lanyard switch unit 168 that permits the engine to be started when inserted and kills the engine when it is removed.
- the lanyard switch unit 168 includes a switch section 170 and a lanyard or tether section 172 .
- the switchover mechanism can be incorporated into the lanyard switch unit 168 .
- the switch section 170 is formed on the handlebar 48 and defines a main power switch of the watercraft 30 .
- the switch section 170 can be disposed at other locations on the watercraft (e.g., disposed on the deck just forward of the seat and beneath the handlebar 48 ), and can function simply as a switch in the start and kill circuits of the watercraft rather than as the main power switch of the watercraft 30 .
- the switch section 170 has a combination 174 of a fixed contact and a moveable contact, which is schematically illustrated in FIG. 11. When the moveable contact is connected to the fixed contact, a battery is connected to the electrical equipment of the engine and the engine can be started.
- the switch section 170 also has a knob 176 that is moveable along an extending axis thereof.
- the knob 176 moves in a direction indicated by the arrow 178 and is biased in the opposite direction.
- the knob 176 is moved in the direction of arrow 178 and held in a connected position, the movable contact mates with the fixed contact. But when the knob 176 is biased in the direction of arrow 180 back to a disconnected position, the movable and fixed contacts no longer mate.
- the lanyard section 172 has a forked member 184 and a lanyard 186 .
- the forked member 184 is connected with one end of the lanyard 186 and acts as a spacer that is disposed in a space defined between a switch body 188 , which contains the contact combination 174 , and the knob 176 so as to hold the contact combination 174 in the connected position.
- the other end of the lanyard 186 defines a closed circle portion 190 so that the rider can put it around his or her wrist or attach to a belt loop or the like. In the event the rider falls into the water while the lanyard is inserted, the forked member 184 is pulled from the space and the knob 176 moves back to the disconnected position. Engine operation accordingly stops.
- the switch body 188 in the illustrated embodiment has another switch mechanism 194 , next to the contact combination 174 , that can selectively activate and disable the ECU 86 .
- This switch mechanism 194 defines a proximity switch that senses magnetism.
- the switch mechanism 194 can of course use other switch constructions, such as, for example, but without limitation, a contact switch construction including a fixed contact and a moveable contact.
- Another lanyard section 196 is provided.
- This second lanyard section 196 has a forked member 184 a , which is similar to the forked member 184 of the first lanyard section 172 but includes a magnet piece 198 .
- a lanyard 186 a which has the same configuration as the lanyard 186 of the first lanyard section 172 , is connected to the second lanyard section 196 . If the second lanyard section 196 replaces the first lanyard section 172 , the magnetic piece 198 of the forked member 184 a exists adjacent to the proximity switch mechanism 194 so that the ECU 86 is activated and the main switch turned on (i.e., the knob 176 is held in the connected position).
- the rider can select one of the first lanyard section 172 and the second lanyard section 196 at his or her own choice. If the rider selects the first lanyard section 172 , the ECU's engine output control mode control is disabled and the rider can control the engine output without restriction.
- the ECU can cap engine output. If the maximum output of the engine is 100 h.p. (engine speed 7,000 rpm), the ECU can restrict the engine's output to 80 h.p. (engine speed 6,000-6,500 rpm), for example.
- FIGS. 12 (A)-(C) another embodiment of the throttle valve control mechanism, i.e., a further engine output control mechanism 130 B, will be described below.
- the same reference numerals will be assigned to the same components and members that have been already described and further detailed description of such components and members will be omitted.
- the engine in this embodiment also operates on a two cycle crankcase compression principle and has three cylinders.
- Three throttle bodies 110 a , 110 b , 110 c are separately formed and coupled together by a lower linkage rail 210 and an upper linkage rail 212 . That is, each throttle body 110 a , 110 b , 110 c has a lower flange 214 that extends downward from the bottom thereof and defines a vertical face.
- Each throttle body 110 a , 110 b , 110 c also includes an upper flange 216 that extends upward and defines a horizontal face.
- the respective lower flanges 214 are affixed to the vertical faces of the lower linkage rail 210 by screws 218
- the respective upper flanges 216 are affixed to the respective horizontal faces of the upper linkage rail 212 by screws 220 .
- the linked throttle bodies 110 a , 110 b , 110 c are affixed to the crankcase member of the engine body one side of the engine (e.g., the starboard side).
- One end 222 of each throttle body 110 a , 110 b , 110 c communicates with the crankcase chamber through an appropriate intake manifold and the other end 224 communicates the plenum chamber via an appropriate sleeve.
- the throttle valve shafts 94 a , 94 b , 94 c which support the throttle valves 54 a , 54 b , 54 c , are journaled by bearing portions 228 of the throttle bodies 110 a , 110 b , 110 c for pivotal movement.
- Coupling members 230 couple the throttle valve shafts 94 a , 94 b , 94 c with one another so that all of the valve shafts 94 a , 94 b , 94 c rotate together.
- Return springs are provided around the respective throttle valve shafts 94 a , 94 b , 94 c in the bearing portions 228 to bias the shafts 94 a , 94 b , 94 c toward a position in which the throttle valves 54 a , 54 b , 54 c are closed.
- the throttle valves 54 a , 54 b , 54 c are urged toward the closed position unless an actuation force acts on the valve shafts 94 a , 94 b , 94 c.
- the fuel injectors 232 are affixed to the throttle bodies 94 a , 94 b , 94 c so that each nozzle portion of the injector 232 is directed to the intake passage 116 a , 116 b , 116 c downstream of the throttle valve 54 b .
- a fuel rail 234 is affixed to the throttle bodies 94 a , 94 b , 94 c so as to support the fuel injectors 232 and also to form a fuel passage 236 therein through which the fuel sprayed by the injectors 232 is delivered.
- lubricant oil 238 is also injected toward the journaled portions of the valve shafts 94 a , 94 b , 94 c in the intake passages 116 a , 116 b , 116 c through oil injection nozzles 240 . Lubricant injection at this point tends to inhibit salt water from depositing on the valve shafts and at the journaled portions of the valve shaft.
- a motor flange 244 is unitarily formed with the most forward portion of the throttle body 110 c and a valve control motor 246 is affixed thereto.
- the throttle valve shafts 94 a , 94 b , 94 c in this arrangement are actuated only by this motor 246 in either a manual control mode by the rider or the engine output control mode by the ECU 86 .
- No mechanical control wire or cable connects the throttle lever 52 and the valve shafts 94 a , 94 b , 94 c .
- the throttle lever 52 is connected to a throttle lever position sensor that sends a signal to the ECU 86 through a signal line.
- the engine output control mechanism 130 B needs no throttle position sensor because the motor 246 has a built-in position sensor by which a signal indicating a position of the shafts 94 a , 9 b , 94 c is sent to the ECU 86 .
- a watertight cover protects the motor 246 . Because of the arrangements and constructions of the throttle bodies and valve control motor, the engine output control mechanism 130 B is simple, accurate and durable.
- a pulley 250 is affixed to the middle throttle shaft 94 b and a throttle wire 252 is affixed to the pulley 250 .
- the throttle wire 252 also is connected to the throttle lever 52 so that the rider can manually operate the valve shafts 94 a , 94 b , 94 c through the throttle wire 252 .
- the pulley 250 is disposed between the front throttle body and the middle throttle body.
- the pulley 250 can be disposed between the middle throttle body and the rear throttle body, and can be connected to any of the throttle shafts.
- the coupling 230 is positioned between the middle throttle body 110 b and the rear throttle body 110 a and has a lever portion 254 extending outward.
- the coupling 230 preferably lies on one side of the middle throttle body and the pulley 250 lies on the other side in order to simplify construction and provide a compact arrangement of these components.
- a solenoid actuator 256 is disposed in a space between the middle throttle body 110 b and the rear throttle body 110 a .
- the solenoid actuator 256 depends from the upper linkage 212 and is affixed thereto.
- a bracket 258 which is affixed to the rear throttle body 110 a , extends forwardly from the rear throttle body to support a body of the actuator 256 .
- the solenoid actuator 256 has a plunger 260 that extends toward the lever portion 254 of the coupling 230 . The plunger 260 extends when a solenoid of the actuator 256 is activated to push or hold the lever portion 254 downward under control of the ECU 86 .
- the throttle position sensor 90 is affixed to a forward end of the throttle valve shaft 94 c that is placed at the most forward position.
- the position sensor 90 senses the opening degree of the throttle valves 54 a , 54 b , 54 c and send a signal to the ECU 86 as described above.
- the rider manually operates the throttle shafts 94 a , 94 b , 94 c through the wire 252 and the pulley 250 .
- the plunger 260 pushes the lever portion 254 .
- the throttle valve shafts 94 a , 94 b , 94 c rotate to increase the throttle opening degree.
- the manual operation of the shafts 94 a , 94 b , 94 c is regulated not to decrease the opening degree and is only allowed to increase further the opening degree.
- the plunger 260 also can be extended to prevent closing rotation of the throttle valves beyond the objective opening degree.
- the engine output control mechanism 130 C is durable and is protected, particularly against water.
- the pulley 250 is affixed to the middle throttle shaft 94 b and the throttle wire 252 is affixed to the pulley 250 .
- the throttle wire 252 is connected to the throttle lever 52 so that the rider can manually operate the valve shafts 94 a , 94 b , 94 c through the throttle wire 252 .
- the throttle position sensor 90 is affixed to the forward end of the throttle valve shaft 94 c to sense the opening degree of the throttle valves 54 a , 54 b , 54 c and is connected to the ECU 86 .
- each throttle body 110 a , 110 b , 110 c has a projection 270 with a flange 272 .
- the projection 270 is positioned at a bottom surface of the throttle body 110 a , 110 b , 110 c to define an air inlet pathway 274 therein disposed directly downstream of the throttle valve 54 a , 54 b , 54 c.
- An air delivery conduit 276 which defines an air delivery passage 278 therein, is attached to the respective projections 270 so that the delivery passage 278 communicates with the respective inlet pathways 274 .
- the air delivery conduit 276 has flanges 280 shaped to be the same configuration as the flanges 272 of the throttle bodies 110 a , 110 b , 110 c and the flanges 271 , 280 are affixed together by screws 282 so as to rigidly fix the delivery conduit 276 to the respective throttle bodies 110 a , 110 b , 110 c .
- the delivery conduit 276 has an inlet projection 284 extending downward and defining an air inlet port 286 therein at the most forward portion.
- the air inlet port 286 communicates with the plenum chamber 114 by an external conduit so that the air in the plenum chamber 114 is supplied to the delivery passage 278 . Because the delivery conduit 276 links the throttle bodies 110 a , 110 b , 110 c , the foregoing lower linkage rail 210 is not provided and the resulting construction is simple and is easily manufactured.
- a solenoid valve device 300 is affixed to the delivery conduit 276 and is disposed next to the inlet projection 284 .
- the solenoid valve device 300 has a piston valve 302 that is disposed within the delivery passage 278 and is reciprocally moveable along an axis of the delivery passage 278 .
- the piston valve 302 is normally positioned at a cross section of the inlet port 286 with the delivery passage 278 to inhibit communication therebetween.
- the solenoid valve device 300 has a solenoid that actuates the piston valve 302 under control of the ECU 86 . When the solenoid is activated, the piston valve 302 retreats to allow the air from the plenum chamber 114 to flow into the delivery passage 278 .
- the ECU 86 activates the solenoid to pull back the piston valve 302 .
- the inlet port 286 thus can communicate with the delivery passage 278 and the air, which is allowed to flow through the delivery passage 278 , is added to the air that passes through the main intake passages 116 a , 116 b , 116 c .
- the total air amount delivered to the crankcase increases and hence the engine output also increases.
- FIGS. 15 and 16 illustrate a preferred embodiment of the watercraft in which the watercraft 30 additionally incorporates a trim control mechanism 310 .
- the same reference numerals will be assigned to the same components and members that have been already described and further detailed description of such components and members will be omitted.
- the deflector 76 in this arrangement is pivotal not only in a horizontal plane about the axis 78 (FIG. 1) extending generally vertically but also in a vertical plane about an axis 312 extending generally horizontally.
- a trim cable or rod 314 is connected to a portion of the deflector 76 positioned atop thereof.
- the other end of the cable 314 is connected to a trim actuator or winch 316 .
- the actuator 316 has an appropriate pulley and the cable 314 is affixed to the pulley so as to coil around it.
- the ECU 86 controls the actuator 316 through a control line 318 . While in the illustrated embodiment the actuator 316 is disposed toward a fore end of the watercraft, it is understood that the actuator can 316 be disposed at other locations on the watercraft (e.g., within the interior cavity above the tunnel or within the tunnel).
- the deflector 76 is normally positioned in a neutral trim position as generally illustrated in FIG. 15 and the watercraft 30 lies generally along the water line L.
- the ECU 86 also controls the actuator 316 so that the deflector 76 inclines to direct the resulting water jet oblique downward as shown in FIG. 16.
- the thrust force produced by the water jet under this condition raises the stem of the watercraft 30 and forces the watercraft's bow downward relative to the water line L, as schematically illustrated in FIG. 16.
- a bucket is additionally affixed to the deflector 76 for pivotal movement about a horizontal axis.
- the cable 314 is connected with the bucket to move the bucket up and down.
- the deflector 76 in this form may be configured to rotate only about the steering axis.
- FIG. 17(A) illustrates four steering position sensors 88 A 1 - 4 disposed around the steering mast 46 .
- the position sensors 88 A- 4 are electromagnetic type proximity sensors. Each sensor is configured to generate a pulse signal when a metallic substance such as iron approaches the sensor.
- a single projection 334 A which is such a metallic substance, is formed on a side surface of the steering mast 46 .
- the projection 334 A approaches the sensors 88 A 2 , 88 A 1 and the sensors generate pulses 336 , 338 , respectively, as shown in FIG. 17(B).
- the time difference (t1) between the pulses 336 , 338 depends upon how fast the rider operates the steering mast 46 . The faster the operation, the shorter the time difference. Because the pulses 336 , 338 reach the ECU 86 in this order with the time difference (t1), the ECU 86 recognizes that the steering mast 46 is steered to make a right turn and how slowly or quickly the steering mast 46 is operated.
- the ECU 86 recognizes with the sensors 88 A 3 and 88 A 4 that the steering mast 46 is steered to make a left turn and how quickly the steering mast 46 is turned in the same manner. It should be noted, however, the recognition of steering direction is not necessary for the control of ECU 86 .
- the ECU may, however, use the time difference (t1) as another parameter in determining whether to initiate its engine output control mode.
- FIG. 18(A) illustrates a combination of a single steering position sensor 88 B, which is also the electromagnetic type, and four projections 334 B 1 - 4 disposed around the steering mast 46 .
- the projections 334 B 3 , 334 B 4 approach the sensor 88 B in this order and generate pulse 340 , 342 also in this order as shown in FIG. 18(B).
- the time difference (t2) between the pulses 340 , 342 is long. If, however, the operation is quick, the time difference (t3) therebetween is short.
- FIG. 19(A) illustrates a potentiometer type sensor 344 .
- This sensor 344 comprises a resister 346 having an appropriate length (c-e) disposed around the steering mast 46 and an output pin or wiper 348 extending from a side surface of the mast 46 . A tip portion of the pin 348 abuts on the resister 346 .
- the pin 348 is adjusted to be positioned at a point (d), which is a mid point of the length (c-e) when the steering mast 46 is in a neutral position. If the steering mast 46 is operated and the output pin 348 slides over the resister 346 , the sensor 344 outputs a signal having a partial voltage corresponding to an angular position of the steering mast 46 as shown in FIG. 19(B).
- the ECU 86 thus recognizes the steering position by receiving the signal. Also, a differentiated value of the partial voltage by time is a change rate of the steering position.
- FIG. 20(A) illustrates a photo-coupler type sensor 350 .
- the steering mast 46 has a flange 352 extending around and a plurality of slits 354 are provided at the flange 352 .
- the section of the flange 352 with the slits is interposed between elements of the sensor 350 , i.e., between a light source and a phototransistor or diode.
- the sensor 350 When the steering mast 46 is operated, the sensor 350 generates pulses 356 , as shown in FIG. 20(B).
- the ECU 86 recognizes a magnitude of the position (angular) change by the number of the pulses 356 and also recognizes a speed of the change by the density of the pulses 356 .
- FIG. 21(A) illustrates an electromagnetic pickup type sensor 360 .
- the steering mast 46 also has a flange 362 extending around its periphery and a plurality of projections 364 is provided at the outer periphery of the flange 362 .
- the sensor 360 is disposed adjacent to the flange 362 .
- the output is rectified and shaped to be pulses 358 .
- the ECU 86 recognizes a magnitude of the change by the number of the pulses 358 and also recognizes a speed of the change by the density of the pulses 358 .
- the sensors described above are merely examples and other types of sensors such as a contact type, a capacitor type and a Hall integrated circuit type are all available. Also, the sensors or sensing mechanism can be used not only for sensing the steering position but also for sensing other angular positions such as the throttle valve position and the throttle lever position.
- FIG. 22 illustrates a further control system 34 A.
- the steering mast 46 includes a steering shaft 380 , the handlebar 48 , a steering arm 382 and a tubular steering column 384 . While the handlebar 48 is formed atop the steering shaft 380 , the steering arm 382 is rigidly affixed to the bottom portion of the steering shaft 380 .
- the steering column 384 is affixed to the upper hull section 40 .
- the steering column 384 supports the steering shaft 380 for steering movement. With the rider steering with the handlebar 48 , the steering arm 382 moves generally in a plane normal to the steering shaft 380 .
- the steering arm 382 is connected to the deflector 76 through a deflector cable 386 , and the deflector 76 pivots about the vertical axis 78 with the movement of the steering arm 382 in a known manner.
- a sensor arm 388 on which the steering position sensor 88 is disposed is rigidly affixed to the steering column 384 .
- a lever 390 extends from the sensor 88 and a linkage member 392 couples the lever 390 with the steering arm 382 . Because the lever 390 pivots with the movement of the steering arm 382 , the steering position sensor 88 senses an angular position of the steering shaft 380 . The sensed signal is set to the ECU 86 through a signal line 396 .
- the throttle lever 52 on the handlebar 48 is connected to a pulley 400 affixed to a shaft of a throttle lever position sensor 402 through a throttle wire 404 .
- This throttle position sensor 402 is not affixed to the throttle valve shafts 94 but rather is separately provided for remotely sensing a position of the throttle lever 52 .
- the sensed signal is sent to the ECU 86 through a signal line 406 .
- the throttle valves 54 desirably are controlled by the throttle lever 52 , the position of the throttle valves 54 should generally correspond to the position of this lever 52 .
- a return spring 408 is provided at the throttle position sensor 402 so as to return the shaft of the position sensor 402 to an initial position unless the rider operates the throttle lever 52 .
- the control system 34 A employs another engine output control mechanism 130 E.
- This control mechanism 130 E includes an electric motor 412 having a motor shaft 414 .
- a first gear 416 is coupled with the motor shaft 414 via a clutch 418 .
- the clutch 418 is activated, the motor 412 does not rotate the first gear 416 and the first gear 416 merely idles.
- the first gear 414 meshes with a second gear 420 that in turn is coupled to a second shaft 422 . Because a diameter of the second gear 420 is larger than a diameter of the first gear 414 , a rotational speed of the second shaft 422 will be reduced relative to the rotational speed of the motor shaft 414 .
- a pulley 426 is affixed to the second shaft 422 .
- the throttle bodies 110 (schematically illustrated in FIG. 22) also have a pulley 424 that actuates the throttle shafts.
- An actuator cable 426 connects together the pulleys 422 , 424 .
- a return spring 428 is affixed to one end of the second shaft 422 so as to return the first and second gears 416 , 420 to their initial positions unless the clutch 418 is connected.
- a position sensor 430 is affixed to the other end of the reduction shaft 422 to sense an angular position of the shaft 422 .
- the position sensor 430 sends a signal, which is indicative of the angular position of the shaft 422 , to the ECU 86 through a signal line 432 for feedback control of the clutch 418 and/or the motor 412 .
- the signal sensed by the position sensor 430 corresponds to the position of the throttle valves 54 .
- the position sensor 430 as well as the throttle lever position sensor 402 can be any type of angular position sensors such as a potentiometer type like the sensor 90 used in the preceding embodiments or a Hall IC type sensor.
- the ECU 86 controls the motor 412 through a control line 434 .
- a pulse width modulator or power amplifier 436 preferably is provided between the ECU 86 and the motor 412 to directly control the motor 412 .
- the ECU 86 also controls the clutch 418 through a control line 438 .
- a switch 440 e.g., FET switch, preferably is provided between the ECU 86 and the clutch 418 to actuate the clutch 418 .
- a power switch i.e., main switch
- the switch 440 is biased off and accordingly the clutch 418 is disconnected so that the throttle valves 54 can be manually operated.
- the ECU 86 has a ROM to store at least a reference position of the steering shaft 380 and also has a RAM to store at least a current position signal of the throttle lever 52 and a change rate of the position signal.
- the ECU 86 also has a timer.
- FIG. 23 illustrates a control routine of the control system 34 A.
- the control routine starts at Step S 21 when the rider turns on the main power switch.
- Step S 22 the ECU initializes stored data of the RAM and proceeds to Step S 23 .
- the timer starts to count time (To) at Step S 23 .
- Step S 24 the ECU 86 determines a closed position of the throttle valves 54 from the signal of the throttle valve position sensor 430 .
- the ECU determines whether the time (To) counted by the timer exceeds 0.25 seconds (Step S 25 ). If 0.25 seconds has not elapsed, the ECU returns to Step S 24 to repeat this step. If the time has elapsed, the ECU instructs the switch 440 to connect the clutch 418 (Step S 26 ).
- Steps S 21 through S 26 comprise an initializing phase of the routine and are not repeated until engine is stopped and restarted.
- Step S 27 the ECU 86 reads a current throttle lever position from the signal sensed by the throttle lever position sensor 402 .
- the ECU then calculates the rate of change of the throttle lever position (Step S 28 ). If the rate of change is zero, the rider wants to maintain the current throttle position. A large rate of change indicates quick movement of the throttle lever (e.g., when accelerating from rest) and a small rate of change indicates slow movement of the throttle lever (e.g., when docking the watercraft at which time the rider may more precisely control the throttle lever for slow speed maneuvering).
- the ECU 86 determines (at Step S 29 ) whether the closed position of the throttle valves, which was read and stored into memory at Step S 24 , falls within a range defined between a reference upper limit (RUL) and a reference lower limit (RLL). If it does, the ECU proceeds to Step S 31 . If not, the ECU performs Step S 30 .
- RUL reference upper limit
- RLL reference lower limit
- the ECU 86 selects either the reference upper limit (RUL) or the reference lower limit (RLL) as a hypothetical closed position. For example, the ECU may be programmed to determine which one of the RUL or RLL is closer to measured value, and then use the closest one as the hypothetical closed position. The ECU then proceeds to the Step 31 .
- RUL reference upper limit
- RLL reference lower limit
- Step S 31 the ECU 86 determines whether the engine 32 is in an idle state, i.e., whether the throttle valves 54 are closed. This determination uses either the actual closed position sensed by the throttle valve position sensor 430 or the hypothetical closed position replaced at the step S 30 , depending upon the conclusion reached at Step S 29 .
- the idle engine speed of the engine 32 is, for example, 1,200 rpm. If the engine is operating above idle, the ECU proceeds to Step S 39 to instruct the pulse width modulator 436 to practice a normal control mode for controlling the throttle drive motor 412 . If, however, the engine is at idle, the ECU proceeds to Step S 32 .
- the pulse width modulator 436 practices the following two controls at the step S 39 .
- the first control i.e., Control (1)
- the first control involves bringing the actual throttle opening degree sensed by the throttle valve position sensor 430 close to the desired throttle opening sensed by the throttle lever position sensor 402 .
- any deviation between these two sensed values preferably is minimized to the extent possible by actuating the motor 412 to move the throttle valves.
- the second control involves controlling the motor 412 through the pulse width modulator 436 in response to the change rate calculated at Step S 28 . If the rate of change is large, the modulator 436 supplies the motor 412 with a relatively high power level so that the motor 412 rotates at a relatively high speed. If the rate of change is small, then the modulator 436 supplies the motor 412 with a relatively low power level so that the motor 412 rotates at a relatively low speed. After performing Step S 39 , the program returns to Step S 27 .
- Step S 31 the ECU 86 determines at Step S 32 whether the steering position sensed by the steering position sensor 88 is greater than a reference steering position (RS). If no, the ECU does not begin its engine output control mode and proceeds to control the modulator 436 in its normal manner (Step S 39 ). If, however, the sensed steering position is greater than the reference steering position (RS), i.e., the rider has turned the steering bar 48 by more than a predetermined degree, the ECU proceeds to Step S 33 for a further calculation before deciding whether to begin its engine output control mode.
- RS reference steering position
- the ECU 86 at Step S 33 determines whether the throttle valve opening, and consequently the engine output, is increasing. The assessment of this situation can be determined from whether the actual throttle opening degree is increasing from the closed position under the rider's own control. If yes, the program proceeds to Step S 39 . If not, the ECU begins its engine output control mode (Step S 34 ). This step S 33 is advantageous if a manual control or an independent control of the throttle valves is employed. This step S 33 , however, can be omitted in the illustrated control system 34 A.
- Step S 34 the ECU 86 instructs the pulse width modulator 436 to drive the motor 412 in a direction that increases the throttle valve opening degree.
- the throttle valves are opened to a predetermined throttle opening that corresponds with a desired engine speed.
- the engine speed preferably is increased to 3,000 rpm.
- the desired engine speed preferably is sufficient to effect sharp turning of the watercraft.
- the ECU 86 then starts the timer (Step S 35 ) to count off a predetermined amount of time (i.e., starts a count down).
- Step S 36 the ECU 86 determines whether the throttle lever position is greater than the idle position. If yes, the rider is operating the throttle lever 52 to increase the engine output and the program proceeds to Step S 38 to stop the engine output control mode. If no, the ECU proceeds to Step S 37 .
- Step S 37 the ECU determines whether the timer has finished the count down.
- the time period of this count down preferably is about 3 seconds. If this time has not elapsed, the ECU repeats Step S 36 . If the time has expired, the ECU ceases the engine output control mode (Step S 38 ), and returns to the main control routine at Step S 27 .
- the output of the throttle valve position sensor in the described embodiments can be directly or indirectly used as a control parameter of the ECU. That is, for example, a sensed throttle opening degree, an absolute value of the sensed opening degree, an increase or decrease amount of the opening degree and a rate of change of the opening degree can all be used as the control parameter(s).
- the output of the steering position sensor can be directly or indirectly used as another control parameter of the ECU. That is, for example, a sensed angular position, an absolute value of the sensed angular position, an increase or decrease amount of the angular position and a rate of change of the angular position are all applicable as the control parameter(s).
- the output of the velocity sensor can be directly or indirectly used as a further control parameter of the ECU. That is, for example, a sensed velocity, an absolute value of the velocity, an increase or decrease amount of the velocity and a change rate of the velocity are all applicable as the control parameter.
- the sensors can be positioned not only in close proximity to thing that they are measuring but also at a remote place. If the sensors are remotely disposed, an appropriate mechanical, electrical or optical linkage mechanism can be applied.
Abstract
A watercraft includes an improved engine control system that enhances the responsiveness of the watercraft and eases watercraft operation. The watercraft includes a propulsion device, such as a jet propulsion unit, and an engine that powers the propulsion device. The engine control system is configured to maintain or increase engine speed under certain operating conditions.
Description
- This invention is based on and claims priority to Japanese Patent Application Nos. 2000-077084 and 2001-029961, filed Mar. 17, 2000 and Feb. 6, 2001, respectively, the entire contents of which are hereby expressly incorporated by reference.
- 1. Field of the Invention
- This invention relates to a control system for an engine of a watercraft.
- 2. Description of Related Art
- Personal watercraft have become very popular in recent years. This type of watercraft is quite sporting in nature and carries one or more riders. A hull of the personal watercraft commonly defines a rider's area above an engine compartment. An internal combustion engine powers a jet propulsion unit that propels the watercraft by discharging water rearward. The engine lies within the engine compartment in front of a tunnel, which is formed on an underside of the hull. The jet propulsion unit is placed within the tunnel and includes an impeller that is driven by the engine.
- A deflector or steering nozzle is mounted on a rear end of the jet propulsion unit for steering the watercraft. A steering mast with a handlebar is linked with the deflector through a linkage. The steering mast extends upwardly in front of the rider's area. The rider remotely steers the watercraft using the handlebar.
- The engine typically includes a throttle valve disposed in an air intake passage of the engine. The throttle valve regulates an air amount supplied to the engine. Typically, as the amount of air increases, the engine output also increases. A throttle lever or control is attached to the handlebar and is linked with the throttle valve usually through a throttle linkage and cable. The rider thus can control the throttle valve remotely by operating the throttle lever on the handlebar.
- When docking, the rider operates the handlebar to make a right or left turn toward the dock. Under some conditions, the rider may have a little difficulty in slowly guiding the watercraft into a docking position. A need therefore exists for an improved engine output control for a watercraft that can enhance maneuverability of the watercraft under at least slow speed conditions.
- In accordance with one aspect of the present invention, a watercraft comprises a water propulsion device and an engine powering the water propulsion device. An engine output control mechanism is arranged to control the engine's output. A steering mechanism is arranged to the watercraft. A first sensor is arranged to sense a state of the engine output control mechanism. A second sensor is arranged to sense a state of the steering mechanism. A control device is configured to control the engine output control mechanism based upon a first control parameter corresponding to an output of the first sensor and a second control parameter corresponding to an output of the second sensor. The control device causes the engine output control mechanism to increase the engine output when the first control parameter is less than a first reference magnitude and the second control parameter is greater than a second reference magnitude.
- In accordance with another aspect of the present invention, a watercraft comprises a water propulsion device and an engine powering the water propulsion device. An engine output control mechanism is arranged to control the engine's output. A steering mechanism is arranged to steer the watercraft. A first sensor is arranged to sense a state of the steering mechanism. A second sensor is arranged to sense a velocity of the watercraft. A control device is configured to control the engine output control mechanism based upon a first control parameter corresponding to an output of the first sensor and a second control parameter corresponding to an output of the second sensor. The control device causes the engine output control mechanism to increase the engine output when the first control parameter is greater than a first reference magnitude and the second control parameter is greater than a second reference magnitude.
- In accordance with a further aspect of the present invention, a watercraft comprises a water propulsion device and an engine powering the water propulsion device. A steering mechanism is arranged to steer a thrust direction of the water propulsion device. The thrust direction is quickly changed under a first condition when the water propulsion device produces a thrust force greater than a predetermined thrust force. Means are provided for recognizing that the steering mechanism is steered under a second condition in which the water propulsion device does not produce a thrust force greater than the predetermined thrust force. Additional means are provided for increasing an output of the engine when the recognizing means recognizes that the steering mechanism is steered under the second condition.
- In accordance with a further aspect of the present invention, a watercraft comprises a water propulsion device and an engine powering the water propulsion device. The engine has at least one combustion chamber and an air induction system arranged to provide air to the combustion chamber. A throttle valve is disposed in the air induction system for regulating an amount of the air flowing into the combustion chamber. A steering assembly is arranged to steer the watercraft. A first sensor is arranged to sense an opening degree of the throttle valve. A second sensor is arranged to sense an angular position of the steering assembly. An electrically operated control device is provided. A throttle valve actuator is arranged to operate the opening degree of the throttle valve. The control device is configured to control the throttle valve actuator based upon an output of the first sensor and an output of the second sensor. The control device causes the throttle valve actuator to operate the throttle valve to increase the opening degree when the output of the first sensor indicates that the sensed opening degree less than a reference opening degree and the output of the second sensor indicates that the sensed angular position is greater than a reference angular position.
- In accordance with an additional aspect of the present invention, a control method is provided for an engine of a watercraft. The watercraft has a water propulsion device, an engine output control mechanism, a steering mechanism, at least two sensors and a control device. The method comprises sensing a state of the engine output control mechanism by one sensor, sensing a state of the steering mechanism by another sensor, determining whether a first control parameter corresponding to a sensed state of the engine output is less than a first reference magnitude, determining whether a second control parameter corresponding to a sensed state of the steering mechanism is greater than a second reference magnitude, and increasing engine output by the control device if the results of both determinations are affirmative (i.e., are true).
- In accordance with a still another aspect of the present invention, a control method is provided for an engine of a watercraft. The watercraft has a water propulsion device, a steering assembly, at least two sensors and a control device. The engine includes a throttle valve and a throttle valve actuator. The method comprises sensing an opening degree of the throttle valve by one sensor, sensing an angular position of the steering assembly by another sensor, determining whether the sensed opening degree is less than a reference opening degree, determining whether the sensed angular position is greater than a reference angular position, and increasing the opening degree by the control device if the results of both determinations are affirmative (i.e., are true).
- Further aspects, features and advantages of this invention will become apparent from the detailed description of the preferred embodiments which follow.
- These and other features, aspects and advantages of the present invention will now be described with reference to the drawings of preferred embodiments, which are intended to illustrate and not to limit the invention. The drawings comprise 23 figures.
- FIG. 1 is a side elevational view of a personal watercraft and schematically illustrates an engine control system configured in accordance with a preferred embodiment of the present invention.
- FIG. 2 is a block diagram showing the control system of an engine for the watercraft.
- FIG. 3(A) is a graph showing a way of increase of an engine output versus time. FIG. 3(B) is a graph showing another way of increase of the engine output versus time. FIG. 3(C) is a graph showing a further way of increase of the engine output versus time.
- FIG. 4 is a control routine of an ECU of the control system.
- FIG. 5 is a sub-routine provided for the control routine.
- FIG. 6 is a schematic front view of the engine. A large part of the engine except for an air induction system and a throttle valve control mechanism is illustrated in phantom.
- FIG. 7 is a schematic view of the throttle valve control mechanism.
- FIG. 8 is a sectional view of an air intake conduit having the throttle valve and a bypass. A portion of the engine where the intake conduit is connected is also shown in phantom.
- FIG. 9 is a sectional view of a bypass control mechanism. The intake passage in part and the throttle valve is shown in phantom.
- FIG. 10 is a perspective view of a steering mast and a handlebar disposed atop thereof. Both the steering mast and handlebar are part of the personal watercraft. A steering position sensing mechanism is schematically shown in this figure. A lanyard switch unit configured in accordance with the present embodiment is also shown in the figure.
- FIG. 11 is a schematic view of the lanyard switch unit including a switch section and a pair of lanyard sections selectively combined with the switch section.
- FIG. 12(A) is a side view of another throttle valve control mechanism configured in accordance with another preferred embodiment of the present invention. FIG. 12(B) is a sectional view of the throttle valve control mechanism taken along the line12-12 of FIG. 12(A). FIG. 12(C) is a front view of the throttle valve control mechanism.
- FIG. 13(A) is a side view of an additional throttle valve control mechanism configured in accordance with an additional preferred embodiment of the present invention. FIG. 13(B) is a sectional view of the throttle valve control mechanism taken along the line13-13 of FIG. 13(A). FIG. 13(C) is a front view of a control structure including a solenoid actuator looked in the direction of the arrow H.
- FIG. 14(A) is a side view of another throttle valve control mechanism configured in accordance with a further preferred embodiment of the present invention. FIG. 14(B) is a sectional view of the throttle valve control mechanism taken along the line14-14 of FIG. 14(A).
- FIG. 15 is a side view of the watercraft having a trim control mechanism. The trim control mechanism is not activated in this figure.
- FIG. 16 is the same side view of the watercraft of FIG. 15, and the trim control mechanism is activated in this figure.
- FIG. 17(A) is a schematic view of preferred embodiment of the steering position sensing mechanism. FIG. 17(B) is a time chart of sensed signals.
- FIG. 18(A) is a schematic view of preferred embodiment of the steering position sensing mechanism. FIG. 18(B) is a time chart of sensed signals.
- FIG. 19(A) is a schematic view of a further preferred embodiment of the steering position sensing mechanism. FIG. 19(B) is a graph showing a partial voltage ratio of the steering position sensing mechanism
- FIG. 20(A) is a schematic view of a still further preferred embodiment of the steering position sensing mechanism. FIG. 20(B) is a time chart of sensed signals.
- FIG. 21(A) is a schematic view of a yet further preferred embodiment of the steering position sensing mechanism. FIG. 21(B) is a time chart of sensed signals.
- FIG. 22 is a schematic view showing another embodiment of the control system.
- FIG. 23 is a control routine of an ECU of the control system shown in FIG. 22.
- With primary reference to FIG. 1 and additionally to FIGS. 2-10, an overall configuration of a
personal watercraft 30 will be described. - The
watercraft 30 employs aninternal combustion engine 32 and anengine control system 34 configured in accordance with a preferred embodiment of the present invention. Thisengine control system 34 has particular utility with a personal watercraft, and thus is described in the context of the personal watercraft. The control system, however, can be applied to other types of watercraft as well, such as, for example, small jet boats. - The
personal watercraft 30 includes ahull 36 generally formed with alower hull section 38 and an upper hull section ordeck 40. The lower hull section may include one or more inner liner sections to strengthen the hull or to provide mounting platforms for various internal components of the watercraft. Both thehull sections lower hull section 38 and theupper hull section 40 are coupled together to define an internal cavity. A gunnel orbulwark 42 defines an intersection of both thehull sections - A steering mast46 (FIG. 10) extends generally upwardly almost atop the
upper hull section 40 to support ahandlebar 48. Thehandlebar 48 is provided primarily for a rider to control thesteering mast 46 so that a thrust direction of thewatercraft 30 is properly changed. As seen in FIG. 10, grips 50 are formed at both ends of thebar 48. The rider can hold them for steering thewatercraft 30. Thehandlebar 48 also carries other control devices such as, for example, athrottle lever 52 for manually operating throttle valves 54 (FIGS. 6-9) of theengine 32. In the illustrated arrangement, the steering must 46 is covered with a paddedsteering cover member 56. - A
seat 60 extends longitudinally fore to aft along a centerline of thehull 36 at a location behind thesteering mast 46. This area, in which theseat 60 is positioned, is a rider's area. Theseat 60 has generally a saddle shape so that the rider can straddle it. Foot areas are defined on both sides of theseat 60 and at the top surface of theupper hull section 40. A cushion, which has a rigid backing and is supported by a pedestal section of theupper hull section 40, forms part of theseat 60. The pedestal forms the other portion of the seat. The seat cushion is detachably attached to the pedestal of theupper hull section 40. An access opening is defined on the top surface of the pedestal, under the seat cushion, through which the rider can access an engine compartment defined in an internal cavity formed between the lower andupper hull sections engine 32 is placed in the engine compartment. The engine compartment may be an area within the internal cavity or may be divided for one or more other areas of internal cavity by one or more bulkheads. - A fuel tank is placed in the cavity under the
upper hull section 40 and preferably in front of the engine compartment. The fuel tank is coupled with a fuel inlet port positioned at a top surface of theupper hull section 40 through a filler duct. A closure cap closes the fuel inlet port. - At least a pair of air ducts or ventilation ducts is provided on both sides of the
upper hull section 40 so that the ambient air can enter the internal cavity through the ducts. Except for the air ducts, the engine compartment is substantially sealed so as to protect theengine 32 and a fuel supply system (including the fuel tank) from water. - A
jet pump unit 64 propels thewatercraft 30. Thejet pump assembly 64 includes atunnel 66 formed on the underside of thelower hull section 38. In some hull designs, the tunnel is isolated from the engine compartment by a bulkhead. Thetunnel 66 has a downward facinginlet port 68 opening toward the body of water. Ajet pump housing 70 is disposed within a portion of thetunnel 66 and communicates with theinlet port 68. Animpeller 72 is rotatably supported within thehousing 70. An impeller shaft extends forwardly from theimpeller 72 and is coupled with a crankshaft of theengine 32 so as to be driven by the crankshaft. The rear end of thehousing 70 defines adischarge nozzle 74. A deflector or steeringnozzle 76 is affixed to thedischarge nozzle 74 for pivotal movement about a steeringaxis 78 extending generally vertically. A cable connects thedeflector 76 with thesteering mast 46 so that the rider can steer thedeflector 76. Asteering mechanism 80 for the watercraft thus preferably comprises thesteering mast 46, thehandlebar 48, the cable and thedeflector 76. - When the crankshaft of the
engine 32 drives the impeller shaft and hence theimpeller 72 rotates, water is drawn from the surrounding body of water through theinlet port 68. The pressure generated in thehousing 70 by theimpeller 72 produces a jet of water that is discharged through thedischarge nozzle 74 and thedeflector 76. The water jet produces thrust to propel thewatercraft 30. Maneuver of thedeflector 76 changes the direction of the water jet. The rider thus can turn thewatercraft 30 in either a right or a left direction by operating thesteering mechanism 80. - As schematically shown in FIG. 1, the
engine control system 34 preferably includes an ECU (electronic control unit) orcontrol device 86, asteering position sensor 88, athrottle position sensor 90 and awatercraft velocity sensor 92. TheECU 86 is preferably mounted on theengine 32 or disposed in proximity to theengine 32. Thesteering position sensor 88 is preferably positioned adjacent to thesteering mast 46 so as to sense an angle of thesteering mast 46 when the rider operates it. Thethrottle position sensor 90 is preferably affixed at one end of throttle valve shafts 94 (FIGS. 6 and 7) so as to sense a position of thethrottle valves 54. Thewatercraft velocity sensor 92 is preferably located at a rear bottom portion of thewatercraft 30, which is submerged during a normal running condition of thewatercraft 30. Therespective sensors ECU 86 throughsignal lines - The illustrated
control system 34 preferably operates in accordance with a control routine shown in FIGS. 4 and 5, although other control routines are applicable inasmuch as complying with the control strategy of the present invention. The exemplary control routine as well as thecontrol system 34 will be described in greater detail shortly. - The
engine 32 preferably operates on a two-cycle crankcase compression principle and has three cylinders spaced apart from one another along the longitudinal centerline. The illustrated engine, however, merely exemplifies one type of engine on which various aspects and features of the present invention can be used. The invention can be used with engines having other number of cylinders, having other cylinder arrangements, other cylinder orientations (e.g., upright cylinder banks) and operating on other combustion principles (e.g., four cycle or rotary). - The
engine 32 generally has a typical and conventional construction. That is, theengine 32 includes a cylinder block defining three cylinder bores in which pistons reciprocate. At least one cylinder head member is affixed to the upper end of the cylinder block to close respective upper ends of the cylinder bores and defines combustion chambers with the cylinder bores and the pistons. - Separate cylinder heads for each cylinder bore also can be used. A crankcase member is also affixed to the lower end of the cylinder block to close the respective lower ends of the cylinder bores and to define a crankcase chamber with the cylinder block. The crankshaft is rotatably connected to the pistons through connecting rods and is journaled for rotation within the crankcase. The cylinder block, the cylinder head and the crankcase member preferably are made of aluminum alloy and together define an
engine body 102. - Engine mounts104 (FIG. 6) extend from both sides of the
engine body 102. The engine mounts 104 preferably include resilient portions made of, for example, rubber material. Theengine body 102 is mounted on the lower hull section 38 (or possibly on the hull liner) by the engine mounts 104 so that vibration of theengine body 102 is inhibited from conducting to thehull section 38. - The
engine 32 preferably includes anair induction system 108 to introduce air to the combustion chambers. As seen in FIG. 6, in the illustrated embodiment, the air induction system is disposed on the starboard side of theengine body 102. Theinduction system 108 includesthrottle bodies 110 affixed to the crankcase member, and a plenum chamber member orair intake box 112. Theplenum chamber member 112 defines aplenum chamber 114 into which the air in the engine compartment enters. Preferably, theplenum chamber 114 smoothes the intake air and attenuates intake noise. Thethrottle bodies 110 each communicate with a respective individual chamber within the crankcase chamber that communicates with one of the combustion chambers through scavenge passages defined within theengine body 102. Thethrottle bodies 110 defineintake passages 116 through which the air flows to the individual crankcase chambers. - The
respective throttle valves 54 are disposed within theintake passages 116 so as to regulate the amount of air passing through theintake passages 116. Because thethrottle valve shafts 94 are journaled on thethrottle bodies 110 for pivotal movement about axes of therespective valve shafts 94, therespective throttle valves 54 can pivot to change opening degrees thereof. The foregoingthrottle lever 52 preferably is connected to thethrottle valve shafts 94 through a throttle wire orcable 118. In the illustrated embodiment, the entirethrottle valve shafts 94 are linked together so that thethrottle wire 118 can be connected with only one of theshafts 94. As seen in FIG. 7, thethrottle valve shaft 94 has apulley 120 and thethrottle wire 118 is affixed to thepulley 120 so as to coil around it. By operating thethrottle lever 52, the opening degrees of therespective throttle valves 54 change so as to regulate proper amounts of air to the combustion chambers. - As described above, one of the
throttle valve shafts 94 has thethrottle position sensor 90 at one end thereof. Thethrottle position sensor 90 thus can sense an angular position of eachthrottle valve 54, i.e., an opening degree of eachthrottle valve 54. - The
throttle valves 54 can be closed so as to bring theengine 32 to an idle state. Even at this idle state, theengine 32 still needs a small amount of air to maintain the idle state. An idle air supply mechanism thus is provided such as a sub-passage bypassing thethrottle valves 54. A control valve for controlling the idle air amount can be provided at the sub-passage. - The
engine 32 also includes a fuel supply system. The fuel supply system includes the fuel tank, a charge forming device and a fuel delivery mechanism that connects the fuel tank with the charge forming device. The charge forming device can take various structures such as a carburetor, a fuel injection mechanism or the like. If the fuel injection mechanism is employed, fuel can be sprayed either directly or indirectly to the combustion chambers. In the illustrated embodiment, an indirect fuel injection mechanism is employed. - The fuel injection mechanism includes one or more fuel injectors directed toward the respective intake passages and one or more fuel pumps to pressurize the fuel delivered to the fuel injectors. Each fuel injector has an injection nozzle that is exposed to the intake passage. The injection nozzle preferably is opened and closed by an electromagnetic unit that is slideable within an injection body. The electromagnetic unit has a solenoid coil controlled by electrical signals. When the nozzle is opened, pressurized fuel is sprayed to the intake passage. The sprayed fuel is drawn to the combustion chambers with the air passing through the intake passages.
- The
ECU 86 controls an amount of fuel sprayed into eachintake passage 116. Because a pressure regulator strictly regulates the fuel pressure, theECU 86 can vary the fuel amount by varying the duration of each injection. The ECU also can advance injection timing and initiation timing in order to increase the engine output. - The
engine 32 further includes an ignition or firing system. Spark plugs of the ignition system are affixed to the cylinder head. A spark gap of each spark plug is exposed within an associated combustion chamber. Each spark plug ignites an air/fuel charge at an ignition timing controlled by the ECU. The ignition system preferably has an ignition mechanism including an ignition coil and an igniter. The ignition coil preferably is a combination of a primary coil element and a secondary coil element that are wound around a common core. The secondary coil element is connected to the spark plugs while the primary coil element is connected to the igniter. The primary coil element also is coupled with a power source (e.g. a battery). The igniter abruptly cuts off the current flow in response to an ignition timing control signal from the ECU. A high voltage current flow consequently occurs in the secondary coil element. The high voltage current flow forms a spark at each spark plug. TheECU 86 controls an ignition timing of the spark plugs in this manner. - The
engine 32 further includes an exhaust system to discharge burnt charges, i.e., exhaust gases, from the combustion chambers. Exhaust ports are defined in the cylinder block and communicate with the associated combustion chambers. An exhaust manifold is connected to the cylinder block and communicates with the exhaust ports. Multiple exhaust conduits 122 (FIG. 1) are further coupled with the exhaust manifold in series so as to extend around theengine body 102 and then toward thetunnel 66. Adischarge exhaust conduit 122 is connected to thetunnel 66 so that the exhaust gases are discharged into thetunnel 66 in a known manner. - With reference to FIGS. 1-10, and especially to FIGS. 2-5, the
control system 34 and an exemplary control routine will now be described. It is to be noted that thecontrol system 34 may be in the form of a hard wired feedback control circuit or may be constructed of a dedicated processor and a memory for storing a computer program and data. Additionally, thecontrol system 34 may be constructed of a general purpose computer having a general purpose processor and the memory for storing the computer program for performing the control routine. Preferably, however, thecontrol system 34 utilizes theengine ECU 86, which may be constructed in any of the above-mentioned forms. - FIG. 2 illustrates a block diagram of the
control system 34 in which theECU 86 controls an engineoutput control mechanism 130. In the illustrated embodiment, the engineoutput control mechanism 130 comprises thethrottle valves 54 and athrottle valve actuator 132. Thethrottle valve actuator 132 actuates thethrottle valves 54, and theECU 86 controls theactuator 132 to control the opening degree of thethrottle valves 54. As seen in FIG. 6, thethrottle valve actuator 132 is mounted on one of thethrottle bodies 110 and is connected with one of thethrottle shafts 94. A linkage causes all of thethrottle shafts 94 to move together, and thus, theactuator 132 can move all of thethrottle shafts 94 even though it is coupled only to one. In the illustrated embodiment, theactuator 132 is coupled to thethrottle shaft 94 to which the throttlevalve position sensor 90 is also connected. Theactuator 132 is disposed on one end of the shaft 94 (e.g., on an outer end relative to the engine body) and thesensor 90 is disposed on an opposite end of the shaft 94 (e.g., on an inner end). - The
throttle valve actuator 132 preferably is a step motor or an electric motor employed in a feedback system. Aservomotor 132 a also can be used in place of the step motor. Although a servomotor is usually larger than the step motor, theservomotor 132 a may be desirable in some applications because it eliminates the need for the throttlevalve position sensor 90. - In this variation, as illustrated in FIGS. 6 and 7, the
servomotor 132 a preferably is disposed apart from theengine body 102. Theservomotor 132 a has apulley 136 on ashaft 138 that rotates about an axis (e.g., a vertical axis), while thethrottle valve 54 has acorresponding pulley 140 on itsshaft 94 next to thepulley 120 that is coupled to thethrottle wire 118. Acontrol wire 142 connects thepulleys servomotor 132 a moves thethrottle shaft 94 in a controlled manner through this pulley system. Thepulleys servomotor 132 a and thethrottle wire 118, respectively, can of course be positioned ondifferent throttle shafts 94. - The
throttle valve actuator 132, i.e., thestep motor 132 or theservomotor 132 a, is connected to theECU 86 by a control line. Normally, the operator operates thethrottle valves 54 by thethrottle lever 52. TheECU 86, however, overrides the control of thethrottle lever 52 and causes thethrottle valve actuator 132 to increase or maintain the opening degree of thethrottle valves 54 under certain conditions. - In the illustrated embodiment, three sensors or sensing mechanisms, i.e., the throttle
valve position sensor 90, thesteering position sensor 88 and awatercraft velocity sensor 92, are employed for sensing the respective states or velocity of the watercraft and its engine. The throttlevalve position sensor 90 preferably is a potentiometer. As schematically shown in FIG. 10, thesensor 90 can be alternatively positioned next to thethrottle lever 52 or any other place where the throttle opening degree can be sensed. Other sensors or sensing mechanisms such as a proximity sensor can also be used. - The
steering position sensor 88 preferably is a proximity sensor positioned adjacent to thesteering mast 46 and senses an angular position of thesteering mast 46. Other types of sensors or sensing mechanisms also can be used. - The
velocity sensor 92 of thewatercraft 30 preferably is a paddle-wheel type sensor positioned at a bottom portion or a submerged stern portion of thewatercraft 30. Any other sensors acting as velocity sensors such as a dynamic pressure sensor disposed with thetunnel 66 or a Pitot tube type sensor disposed toward the body of water can replace the paddle-wheel type sensor 92. It would also be possible to use a GPS (global positioning system) that uses an artificial satellite and includes a GPS antenna comprises a velocity sensing mechanism. The sensing mechanism using the GPS is described in, for example, Japanese Laid Open Publication No. Hei 11-43093. - The
ECU 86 has stored in its memory a reference watercraft velocity (Vs). In the illustrated embodiment, the reference velocity (Vs) is selected from velocities greater than a velocity where thewatercraft 30 starts planing. In general, thejet type watercraft 30 transfers from a displacement (trolling) range to a transient range at a velocity of 10-15 Km/h (at an engine speed of 2,000-2,500 rpm) and then transfers to the planing range at a velocity of 30-35 Km/h (at an engine speed of 4,500 rpm). Thewatercraft 30 can stay in a complete planing range when the velocity is 35 Km/h or more (at the engine speed is 4,500 rpm or more). In the illustrated embodiment, the maximum speed of theengine 32 is about 7,000 rpm. The present invention, however, can be used with engines having greater or lesser top-end speeds. The velocity of the watercraft when it starts planing also depends upon the size and shape of its hull, the weight of the watercraft, the location of the watercraft's center of gravity, and the performance of the jet propulsion unit, to name a few additional factors. The reference velocity (Vs) can be determined empirically for a particular watercraft design and then stored in the ECU of each watercraft made in accordance with such design. The predetermined reference velocity (Vs) of 15 Km/h in this embodiment thus is merely an example. - A reference throttle opening degree (Thθs) preferably is selected to correspond to a watercraft velocity that generates a thrust force sufficient to change sharply the direction of travel of the
watercraft 30. The reference throttle opening degree (Thθs) increases with watercraft velocity. In the illustrated embodiment, where the throttle opening degree ranges from 0 to 90 degrees, the reference throttle opening degree (Thθs) preferably is not less than 30 degrees and increases with increasing watercraft speed. At throttle angles less than 30 degrees, the engine output may not be sufficient to produce enough thrust to turn thewatercraft 30 sharply. - A reference steering position (Sds) also is preferably selected to correspond to a watercraft velocity. Unless the reference steering position (Sds) is large enough relative to the watercraft velocity, the
watercraft 30 may not be as responsive as the rider would like at low speeds. The reference steering position (Sds) is variable and generally increases with increasing watercraft velocity. In the illustrated embodiment, thesteering mast 46 rotates from a neutral position (for straight-ahead travel) by forty degrees (40°) to a fully turned position to each side. In other words, thesteering mast 46 rotates from its neutral position (0°) by plus forty degrees (40°) when moved from the neutral position to a fully turned position to the right and by minus forty degrees (−40°) when moved from the neutral position to a fully turned position to the left. For such an embodiment, the reference steering position (Sds) preferably is not less than twenty degrees (20°) and varies relative to watercraft speed. - The
ECU 86 has stored in its memory at least one map that relates the reference throttle opening degrees (Thθs) to watercraft velocities (V) and at least another map that relates the reference steering positions (Sds) to the watercraft velocities (V). These maps are used for selecting the reference throttle opening degree (Thθs) and the steering positions (Sds) in response to a continually sensed watercraft velocity (V). - More thrust generally is required to turn the
watercraft 30 sharply at higher speeds. Thepresent control system 32 thus is adapted to maintain or increase the throttle angle to a desired throttle opening degree in order to enhance the responsiveness of thewatercraft 30 and to ease watercraft operations during such turns. For this purpose, theECU 86 has stored in its memory a map of objective throttle opening degrees (Thθm), i.e., desired throttle opening degrees, versus watercraft speed. In general, the throttle opening degree (Thθm) increases with increases in watercraft speed. - With reference to FIGS. 4 and 5, an exemplary control routine for the
ECU 86 will now be described below. At the start of the control routine (Step S1), theECU 86 reads a current throttle valve opening degree (Thθ), a current steering position (Sd) and a current watercraft velocity (V) based upon the signals sent from thethrottle position sensor 90, thesteering position sensor 88 and thewatercraft velocity sensor 92, respectively, and stores these values in memory as current data. While the sensed signals of thethrottle position sensor 90 and thewatercraft velocity sensor 92 are stored without alteration, the sensed signal of thesteering sensor 88 is altered to be an absolute value (|Sd|) and then is stored. The data is renewed every cycle, i.e., when the routine returns to its start (Step S1). - At the step S2, the ECU recalls the reference watercraft velocity (Vs) from its memory. The program also determines from the stored maps the reference throttle valve opening degree (Thθs) and the reference steering position (Sds) that correspond to the current watercraft velocity (V).
- The ECU then determines whether the watercraft velocity (V) is equal to or greater than the reference velocity (Vs), i.e., 15 Km/h (Step S3). If the watercraft velocity (V) is less than the reference velocity (Vs), the routine returns to its start (Step S6). If the watercraft velocity (V) is equal to or greater than the reference velocity (Vs), then the
watercraft 30 is operating under a planing mode. Of course it is understood that the routine could be written such that the routine would proceed to Step S6 if the watercraft velocity were less than the reference velocity. - At Step S4, the ECU determines whether the throttle opening degree (Thθ) is equal to or less than the reference opening degree (Thθs), which is selected to correspond to the current watercraft velocity (V) and is at least 30 degrees. If not, the program returns to its start (Step S6). If yes, then the program proceeds to Step S5.
- At Step S5, the ECU determines whether the steering position (|Sd|) is equal to or greater than the reference steering position (Sds), which is selected to correspond to the current watercraft velocity (V) and is at least 20 degrees. If not, the ECU returns to its start (Step S6) and repeats because at this time the rider is not steering the watercraft to turn sharply. If yes, the program proceeds to the Step S7 to assist the rider with the engine's control during the turn.
- At this point (i.e., Step S7), the ECU performs an engine output control sub-routine illustrated in FIG. 5. At the start of the sub-routine (Step S8), the
ECU 86 reads a current throttle valve opening degree (Thθ), a current steering position (Sd) and a current watercraft velocity (V) based upon the signals sent from thethrottle position sensor 90, thesteering position sensor 88 and thewatercraft velocity sensor 92, respectively, and stores these values in memory as current data. - At the Step S9, the ECU determines from the stored map(s) an objective throttle opening degree (Thθm) that corresponds to the current watercraft velocity (V).
- The ECU drives the throttle valve actuator132 (Step S10) to actuate the
throttle valves 54 until the opening degree (Thθ) of thethrottle valves 54 becomes equal to the objective opening degree (Thθm). When the opening degree (Thθ) reaches the objective opening degree (Thθm), the ECU proceeds to the next step. - At Step S11, the ECU determines whether the
steering mast 46 is at the neutral position, i.e., whether the steering position (|Sd|) is zero. If yes, the rider no longer wishes to turn sharply, and theECU 86 returns (at Step S14) to the first step (Step S1) of the main routine. In doing so, the ECU ceases its engine output control mode. Theactuator 132 no longer holds thethrottle valves 54 to the objective opening degree (Thθm) under this condition and the rider can operate thethrottle valves 54 without restriction. In accordance with other variations of the control routine, the ECU can likewise cease its engine output control mode if ECU determines that thesteering mast 46 is less than the reference steering position (Sds) or is around zero (e.g., less than 10 degrees or more preferably less than 5 degrees). If not, however, the ECU proceeds to Step S12. - At Step S12, the ECU determines whether the throttle opening degree (Thθ) is increasing, i.e., whether the differential value of the throttle opening degree (Thθ) is greater than zero. If yes, the rider is increasing the throttle opening degree to an opening greater than the objective opening degree (Thθm) on his or her own. The program thus proceeds to Step S14 so as to return to Step S1 of the main routine. If not, the ECU proceeds to Step S13.
- At Step S13, the ECU determines whether the watercraft velocity (V) is equal or less than another reference velocity (Vs2). The reference velocity (Vs2) is also stored in the memory of the
ECU 86 and is preferably selected to be slightly slower than the reference velocity (Vs) used in Step S3. In the illustrated embodiment, the second reference velocity (Vs2) is equal to 10 Km/h, which is less than 15 Km/h (the first reference velocity (Vs)). If the watercraft velocity (V) is equal to or less than the second reference velocity (Vs2), then the power assistance provided by the engine output control mode is no longer provided. The ECU then moves to Step S14 to return to the first step of the main routine (Step S1). If, however, the watercraft velocity (V) is greater than the second reference velocity (Vs2), the ECU returns to Step S11 and proceeds in accordance with the above description. Thus, unless the rider has stopped turning, the rider has increased the throttle position independent of the control system, or the watercraft has slowed to a speed within the displacement or transitional ranges, the ECU continues to control the engine's output by instructing theactuator 132 to continue to hold thethrottle valves 54 open to the objective opening degree (Thθm). - In order to simplify the
control system 34, the reference throttle opening degree (Thθs) and the reference steering position (Sds) need not necessarily correspond to the watercraft velocity. That is, the reference throttle opening degree (Thθs) can be a fixed degree (e.g., 30 degrees). Also, the reference steering position (Sds) can be a fixed degree (e.g., 20 degrees). - The ECU can stop the engine control routine based upon other parameters than those of the quires of Steps S11, S12 and S13. For instance, the program can return to the main routine after the elapse of a predetermined time period following the completion of Step S10. The predetermined time could be constant or variable. If variable, the time period preferably would be longer for higher speeds.
- In order to further simplify and increase the speed of performing the control routine, either Step S3 or Step S4 can be omitted, provided that at least one of these steps remains. Also, two of the Steps S11, S12, and S13 can be omitted if at least one of them remains.
- The engine
output control mechanism 130 can comprise other components or can take on other forms. For instance, as seen in FIGS. 8 and 9, analternative control mechanism 130A includes abypass passage 148 that bypasses one of thethrottle valves 54 and an electromagnetictype control valve 150 that selectively opens and closes thebypass passage 148 under control of theECU 86. This bypass mechanism supplies increased air to the combustion chamber when thecontrol valve 150 opens thebypass passage 148 to increase engine speed. Preferably at least two of the throttle bodies include such a bypass mechanism. This type of engineoutput control mechanism 130A also can be used as the idle air supply mechanism described above. - The engine
output control mechanism 130 also can include components of other systems whose operations affect engine output. For instance, as additionally illustrated in FIG. 2, the engineoutput control mechanism 130 can also include the ignition system and/or the fuel supply system. If the ignition system is used as part of thecontrol mechanism 130, then theECU 86 can control theignition mechanism 156 to advance ignition timing of the spark plug(s) 156. If the fuel supply system is used as part of thecontrol mechanism 130, then the ECU can control the fuel injectors to increase the injected fuel amount under the engine output control mode by advancing and/or increasing the duration of the fuel injection cycle. - The increase of the engine output can take a variety of patterns under the engine output control mode. FIG. 3(A) illustrates a pattern in which the engine output increases linearly. FIG. 3(B) illustrates another pattern in which the engine output increases non-linearly. The rate of change of the engine output can decrease over time as shown by the solid line in FIG. 3(B) or can increase over time as shown by the dotted line in the same figure. FIG. 3(C) illustrates a further pattern in which the engine output increases in a stepped manner.
- If desired, the watercraft can also include a switchover mechanism to selectively activate or disable the ECU's engine output control mode. An exemplary switchover mechanism will be described below with reference to FIGS. 10 and 11.
- Personal watercraft typically are provided with a
lanyard switch unit 168 that permits the engine to be started when inserted and kills the engine when it is removed. Thelanyard switch unit 168 includes aswitch section 170 and a lanyard ortether section 172. The switchover mechanism can be incorporated into thelanyard switch unit 168. - In the illustrated embodiment, the
switch section 170 is formed on thehandlebar 48 and defines a main power switch of thewatercraft 30. Theswitch section 170, however, can be disposed at other locations on the watercraft (e.g., disposed on the deck just forward of the seat and beneath the handlebar 48), and can function simply as a switch in the start and kill circuits of the watercraft rather than as the main power switch of thewatercraft 30. Theswitch section 170 has acombination 174 of a fixed contact and a moveable contact, which is schematically illustrated in FIG. 11. When the moveable contact is connected to the fixed contact, a battery is connected to the electrical equipment of the engine and the engine can be started. When the moveable contact is disconnected from the fixed contact, however, the battery is disconnected from at least some of the electrical equipment and a kill circuit is activated. Theswitch section 170 also has aknob 176 that is moveable along an extending axis thereof. Theknob 176 moves in a direction indicated by thearrow 178 and is biased in the opposite direction. When theknob 176 is moved in the direction ofarrow 178 and held in a connected position, the movable contact mates with the fixed contact. But when theknob 176 is biased in the direction ofarrow 180 back to a disconnected position, the movable and fixed contacts no longer mate. - The
lanyard section 172 has a forkedmember 184 and alanyard 186. The forkedmember 184 is connected with one end of thelanyard 186 and acts as a spacer that is disposed in a space defined between aswitch body 188, which contains thecontact combination 174, and theknob 176 so as to hold thecontact combination 174 in the connected position. The other end of thelanyard 186 defines aclosed circle portion 190 so that the rider can put it around his or her wrist or attach to a belt loop or the like. In the event the rider falls into the water while the lanyard is inserted, the forkedmember 184 is pulled from the space and theknob 176 moves back to the disconnected position. Engine operation accordingly stops. - The
switch body 188 in the illustrated embodiment has anotherswitch mechanism 194, next to thecontact combination 174, that can selectively activate and disable theECU 86. Thisswitch mechanism 194 defines a proximity switch that senses magnetism. Theswitch mechanism 194 can of course use other switch constructions, such as, for example, but without limitation, a contact switch construction including a fixed contact and a moveable contact. - Another
lanyard section 196 is provided. Thissecond lanyard section 196 has a forkedmember 184 a, which is similar to the forkedmember 184 of thefirst lanyard section 172 but includes amagnet piece 198. Alanyard 186 a, which has the same configuration as thelanyard 186 of thefirst lanyard section 172, is connected to thesecond lanyard section 196. If thesecond lanyard section 196 replaces thefirst lanyard section 172, themagnetic piece 198 of the forkedmember 184 a exists adjacent to theproximity switch mechanism 194 so that theECU 86 is activated and the main switch turned on (i.e., theknob 176 is held in the connected position). - The rider can select one of the
first lanyard section 172 and thesecond lanyard section 196 at his or her own choice. If the rider selects thefirst lanyard section 172, the ECU's engine output control mode control is disabled and the rider can control the engine output without restriction. - Another control strategy is practicable with the interchangeable switch mechanism. For instance, when the
second lanyard section 196 is selected, the ECU can cap engine output. If the maximum output of the engine is 100 h.p. (engine speed 7,000 rpm), the ECU can restrict the engine's output to 80 h.p. (engine speed 6,000-6,500 rpm), for example. - With reference to FIGS.12(A)-(C), another embodiment of the throttle valve control mechanism, i.e., a further engine
output control mechanism 130B, will be described below. The same reference numerals will be assigned to the same components and members that have been already described and further detailed description of such components and members will be omitted. - The engine in this embodiment also operates on a two cycle crankcase compression principle and has three cylinders. Three
throttle bodies lower linkage rail 210 and anupper linkage rail 212. That is, eachthrottle body lower flange 214 that extends downward from the bottom thereof and defines a vertical face. Eachthrottle body upper flange 216 that extends upward and defines a horizontal face. The respectivelower flanges 214 are affixed to the vertical faces of thelower linkage rail 210 byscrews 218, while the respectiveupper flanges 216 are affixed to the respective horizontal faces of theupper linkage rail 212 byscrews 220. The linkedthrottle bodies end 222 of eachthrottle body other end 224 communicates the plenum chamber via an appropriate sleeve. Thethrottle valve shafts throttle valves 54 a, 54 b, 54 c, are journaled by bearingportions 228 of thethrottle bodies members 230 couple thethrottle valve shafts valve shafts throttle valve shafts portions 228 to bias theshafts throttle valves 54 a, 54 b, 54 c are closed. In other words, thethrottle valves 54 a, 54 b, 54 c are urged toward the closed position unless an actuation force acts on thevalve shafts - The
fuel injectors 232 are affixed to thethrottle bodies injector 232 is directed to theintake passage throttle valve 54 b. Afuel rail 234 is affixed to thethrottle bodies fuel injectors 232 and also to form afuel passage 236 therein through which the fuel sprayed by theinjectors 232 is delivered. - In the illustrated embodiment,
lubricant oil 238 is also injected toward the journaled portions of thevalve shafts intake passages oil injection nozzles 240. Lubricant injection at this point tends to inhibit salt water from depositing on the valve shafts and at the journaled portions of the valve shaft. - A
motor flange 244 is unitarily formed with the most forward portion of thethrottle body 110 c and avalve control motor 246 is affixed thereto. Thethrottle valve shafts motor 246 in either a manual control mode by the rider or the engine output control mode by theECU 86. No mechanical control wire or cable connects thethrottle lever 52 and thevalve shafts throttle lever 52 is connected to a throttle lever position sensor that sends a signal to theECU 86 through a signal line. - The engine
output control mechanism 130B needs no throttle position sensor because themotor 246 has a built-in position sensor by which a signal indicating a position of theshafts ECU 86. A watertight cover protects themotor 246. Because of the arrangements and constructions of the throttle bodies and valve control motor, the engineoutput control mechanism 130B is simple, accurate and durable. - With reference to FIGS.13(A)-(C), a further embodiment of the throttle valve control mechanism 130C, i.e., engine output control mechanism, will be described below. The same reference numerals will also be assigned to the same components and members that have been already described and further detailed description of these components and members will be omitted.
- In this arrangement, a
pulley 250 is affixed to themiddle throttle shaft 94 b and athrottle wire 252 is affixed to thepulley 250. Thethrottle wire 252 also is connected to thethrottle lever 52 so that the rider can manually operate thevalve shafts throttle wire 252. In the illustrated embodiment, thepulley 250 is disposed between the front throttle body and the middle throttle body. Thepulley 250, however, can be disposed between the middle throttle body and the rear throttle body, and can be connected to any of the throttle shafts. - In the illustrated embodiment, the
coupling 230 is positioned between themiddle throttle body 110 b and therear throttle body 110 a and has alever portion 254 extending outward. Thecoupling 230 preferably lies on one side of the middle throttle body and thepulley 250 lies on the other side in order to simplify construction and provide a compact arrangement of these components. - A
solenoid actuator 256 is disposed in a space between themiddle throttle body 110 b and therear throttle body 110 a. Thesolenoid actuator 256 depends from theupper linkage 212 and is affixed thereto. Also, abracket 258, which is affixed to therear throttle body 110 a, extends forwardly from the rear throttle body to support a body of theactuator 256. Thesolenoid actuator 256 has aplunger 260 that extends toward thelever portion 254 of thecoupling 230. Theplunger 260 extends when a solenoid of theactuator 256 is activated to push or hold thelever portion 254 downward under control of theECU 86. - The
throttle position sensor 90 is affixed to a forward end of thethrottle valve shaft 94 c that is placed at the most forward position. Theposition sensor 90 senses the opening degree of thethrottle valves 54 a, 54 b, 54 c and send a signal to theECU 86 as described above. - Normally, the rider manually operates the
throttle shafts wire 252 and thepulley 250. When theECU 86 starts the engine output control mode, theplunger 260 pushes thelever portion 254. Under this condition, thethrottle valve shafts shafts plunger 260 also can be extended to prevent closing rotation of the throttle valves beyond the objective opening degree. - Because the
solenoid actuator 256 is disposed between thethrottle bodies - With reference to FIGS.14(A) and (B), another embodiment of the throttle
valve control mechanism 130D (i.e., the engine output control mechanism) will be described below. The same reference numerals will again be assigned to the same components and members that have been already described and further detailed description of such components and members will be omitted. - Like the engine output control mechanism130C, the
pulley 250 is affixed to themiddle throttle shaft 94 b and thethrottle wire 252 is affixed to thepulley 250. Thethrottle wire 252 is connected to thethrottle lever 52 so that the rider can manually operate thevalve shafts throttle wire 252. Thethrottle position sensor 90 is affixed to the forward end of thethrottle valve shaft 94 c to sense the opening degree of thethrottle valves 54 a, 54 b, 54 c and is connected to theECU 86. - In this arrangement, each
throttle body projection 270 with aflange 272. Theprojection 270 is positioned at a bottom surface of thethrottle body air inlet pathway 274 therein disposed directly downstream of thethrottle valve 54 a, 54 b, 54 c. - An
air delivery conduit 276, which defines anair delivery passage 278 therein, is attached to therespective projections 270 so that thedelivery passage 278 communicates with therespective inlet pathways 274. Theair delivery conduit 276 hasflanges 280 shaped to be the same configuration as theflanges 272 of thethrottle bodies flanges 271, 280 are affixed together byscrews 282 so as to rigidly fix thedelivery conduit 276 to therespective throttle bodies delivery conduit 276 has aninlet projection 284 extending downward and defining an air inlet port 286 therein at the most forward portion. The air inlet port 286 communicates with theplenum chamber 114 by an external conduit so that the air in theplenum chamber 114 is supplied to thedelivery passage 278. Because thedelivery conduit 276 links thethrottle bodies lower linkage rail 210 is not provided and the resulting construction is simple and is easily manufactured. - A
solenoid valve device 300 is affixed to thedelivery conduit 276 and is disposed next to theinlet projection 284. Thesolenoid valve device 300 has apiston valve 302 that is disposed within thedelivery passage 278 and is reciprocally moveable along an axis of thedelivery passage 278. Thepiston valve 302 is normally positioned at a cross section of the inlet port 286 with thedelivery passage 278 to inhibit communication therebetween. Thesolenoid valve device 300 has a solenoid that actuates thepiston valve 302 under control of theECU 86. When the solenoid is activated, thepiston valve 302 retreats to allow the air from theplenum chamber 114 to flow into thedelivery passage 278. - In order to increase engine speed, the
ECU 86 activates the solenoid to pull back thepiston valve 302. The inlet port 286 thus can communicate with thedelivery passage 278 and the air, which is allowed to flow through thedelivery passage 278, is added to the air that passes through themain intake passages - FIGS. 15 and 16 illustrate a preferred embodiment of the watercraft in which the
watercraft 30 additionally incorporates atrim control mechanism 310. Again the same reference numerals will be assigned to the same components and members that have been already described and further detailed description of such components and members will be omitted. - The
deflector 76 in this arrangement is pivotal not only in a horizontal plane about the axis 78 (FIG. 1) extending generally vertically but also in a vertical plane about anaxis 312 extending generally horizontally. A trim cable orrod 314 is connected to a portion of thedeflector 76 positioned atop thereof. The other end of thecable 314 is connected to a trim actuator orwinch 316. Specifically, theactuator 316 has an appropriate pulley and thecable 314 is affixed to the pulley so as to coil around it. TheECU 86 controls theactuator 316 through acontrol line 318. While in the illustrated embodiment theactuator 316 is disposed toward a fore end of the watercraft, it is understood that the actuator can 316 be disposed at other locations on the watercraft (e.g., within the interior cavity above the tunnel or within the tunnel). - The
deflector 76 is normally positioned in a neutral trim position as generally illustrated in FIG. 15 and thewatercraft 30 lies generally along the water line L. During the engine output control mode, theECU 86 also controls theactuator 316 so that thedeflector 76 inclines to direct the resulting water jet oblique downward as shown in FIG. 16. The thrust force produced by the water jet under this condition raises the stem of thewatercraft 30 and forces the watercraft's bow downward relative to the water line L, as schematically illustrated in FIG. 16. - In a variation, a bucket is additionally affixed to the
deflector 76 for pivotal movement about a horizontal axis. Thecable 314 is connected with the bucket to move the bucket up and down. Thedeflector 76 in this form may be configured to rotate only about the steering axis. When the bucket is brought into a position that produces a downwardly directed water jet (similar to that produced by thedeflector 76 in FIG. 16), the watercraft's bow is forced down against the water. - With reference to FIGS.17(A)-21(B), exemplary
steering position sensors 88 will now be described below. FIG. 17(A) illustrates four steering position sensors 88A1-4 disposed around thesteering mast 46. The position sensors 88A-4 are electromagnetic type proximity sensors. Each sensor is configured to generate a pulse signal when a metallic substance such as iron approaches the sensor. Asingle projection 334A, which is such a metallic substance, is formed on a side surface of thesteering mast 46. - If the
steering mast 46 is operated clockwise as indicated by the arrow R, theprojection 334A approaches the sensors 88A2, 88A1 and the sensors generatepulses pulses steering mast 46. The faster the operation, the shorter the time difference. Because thepulses ECU 86 in this order with the time difference (t1), theECU 86 recognizes that thesteering mast 46 is steered to make a right turn and how slowly or quickly thesteering mast 46 is operated. If thesteering mast 46 is operated counterclockwise, theECU 86 recognizes with the sensors 88A3 and 88A4 that thesteering mast 46 is steered to make a left turn and how quickly thesteering mast 46 is turned in the same manner. It should be noted, however, the recognition of steering direction is not necessary for the control ofECU 86. The ECU may, however, use the time difference (t1) as another parameter in determining whether to initiate its engine output control mode. - FIG. 18(A) illustrates a combination of a single
steering position sensor 88B, which is also the electromagnetic type, and four projections 334B1-4 disposed around thesteering mast 46. If thesteering mast 46 is operated clockwise as indicated by the arrow R, the projections 334B3, 334B4 approach thesensor 88B in this order and generatepulse pulses - FIG. 19(A) illustrates a
potentiometer type sensor 344. Thissensor 344 comprises aresister 346 having an appropriate length (c-e) disposed around thesteering mast 46 and an output pin orwiper 348 extending from a side surface of themast 46. A tip portion of thepin 348 abuts on theresister 346. Thepin 348 is adjusted to be positioned at a point (d), which is a mid point of the length (c-e) when thesteering mast 46 is in a neutral position. If thesteering mast 46 is operated and theoutput pin 348 slides over theresister 346, thesensor 344 outputs a signal having a partial voltage corresponding to an angular position of thesteering mast 46 as shown in FIG. 19(B). TheECU 86 thus recognizes the steering position by receiving the signal. Also, a differentiated value of the partial voltage by time is a change rate of the steering position. - FIG. 20(A) illustrates a photo-
coupler type sensor 350. Thesteering mast 46 has aflange 352 extending around and a plurality ofslits 354 are provided at theflange 352. The section of theflange 352 with the slits is interposed between elements of thesensor 350, i.e., between a light source and a phototransistor or diode. When thesteering mast 46 is operated, thesensor 350 generatespulses 356, as shown in FIG. 20(B). TheECU 86 recognizes a magnitude of the position (angular) change by the number of thepulses 356 and also recognizes a speed of the change by the density of thepulses 356. - FIG. 21(A) illustrates an electromagnetic
pickup type sensor 360. Thesteering mast 46 also has aflange 362 extending around its periphery and a plurality ofprojections 364 is provided at the outer periphery of theflange 362. Thesensor 360 is disposed adjacent to theflange 362. When thesteering mast 46 is operated, thesensor 360 generatesoutput waveform 366, shown in FIG. 21(B). The output is rectified and shaped to be pulses 358. TheECU 86 recognizes a magnitude of the change by the number of the pulses 358 and also recognizes a speed of the change by the density of the pulses 358. - The sensors described above are merely examples and other types of sensors such as a contact type, a capacitor type and a Hall integrated circuit type are all available. Also, the sensors or sensing mechanism can be used not only for sensing the steering position but also for sensing other angular positions such as the throttle valve position and the throttle lever position.
- With reference to FIGS. 22 and 23, a further embodiment of the control system will now be described. The same reference numerals will again be assigned to the same components and members that have been already described and further detailed description of such components and members will be omitted.
- FIG. 22 illustrates a
further control system 34A. Thesteering mast 46 includes asteering shaft 380, thehandlebar 48, asteering arm 382 and atubular steering column 384. While thehandlebar 48 is formed atop the steeringshaft 380, thesteering arm 382 is rigidly affixed to the bottom portion of thesteering shaft 380. Thesteering column 384 is affixed to theupper hull section 40. Thesteering column 384 supports thesteering shaft 380 for steering movement. With the rider steering with thehandlebar 48, thesteering arm 382 moves generally in a plane normal to thesteering shaft 380. Thesteering arm 382 is connected to thedeflector 76 through adeflector cable 386, and thedeflector 76 pivots about thevertical axis 78 with the movement of thesteering arm 382 in a known manner. Asensor arm 388 on which thesteering position sensor 88 is disposed is rigidly affixed to thesteering column 384. Alever 390 extends from thesensor 88 and alinkage member 392 couples thelever 390 with thesteering arm 382. Because thelever 390 pivots with the movement of thesteering arm 382, thesteering position sensor 88 senses an angular position of thesteering shaft 380. The sensed signal is set to theECU 86 through asignal line 396. - The
throttle lever 52 on thehandlebar 48 is connected to apulley 400 affixed to a shaft of a throttlelever position sensor 402 through athrottle wire 404. Thisthrottle position sensor 402 is not affixed to thethrottle valve shafts 94 but rather is separately provided for remotely sensing a position of thethrottle lever 52. The sensed signal is sent to theECU 86 through asignal line 406. Because thethrottle valves 54 desirably are controlled by thethrottle lever 52, the position of thethrottle valves 54 should generally correspond to the position of thislever 52. Areturn spring 408 is provided at thethrottle position sensor 402 so as to return the shaft of theposition sensor 402 to an initial position unless the rider operates thethrottle lever 52. - The
control system 34A employs another engineoutput control mechanism 130E. Thiscontrol mechanism 130E includes anelectric motor 412 having amotor shaft 414. Afirst gear 416 is coupled with themotor shaft 414 via a clutch 418. Unless the clutch 418 is activated, themotor 412 does not rotate thefirst gear 416 and thefirst gear 416 merely idles. Thefirst gear 414 meshes with asecond gear 420 that in turn is coupled to asecond shaft 422. Because a diameter of thesecond gear 420 is larger than a diameter of thefirst gear 414, a rotational speed of thesecond shaft 422 will be reduced relative to the rotational speed of themotor shaft 414. - A
pulley 426 is affixed to thesecond shaft 422. The throttle bodies 110 (schematically illustrated in FIG. 22) also have apulley 424 that actuates the throttle shafts. Anactuator cable 426 connects together thepulleys return spring 428 is affixed to one end of thesecond shaft 422 so as to return the first andsecond gears position sensor 430 is affixed to the other end of thereduction shaft 422 to sense an angular position of theshaft 422. Theposition sensor 430 sends a signal, which is indicative of the angular position of theshaft 422, to theECU 86 through asignal line 432 for feedback control of the clutch 418 and/or themotor 412. The signal sensed by theposition sensor 430 corresponds to the position of thethrottle valves 54. - The
position sensor 430 as well as the throttlelever position sensor 402 can be any type of angular position sensors such as a potentiometer type like thesensor 90 used in the preceding embodiments or a Hall IC type sensor. - The
ECU 86 controls themotor 412 through acontrol line 434. A pulse width modulator orpower amplifier 436 preferably is provided between theECU 86 and themotor 412 to directly control themotor 412. - The
ECU 86 also controls the clutch 418 through acontrol line 438. Aswitch 440, e.g., FET switch, preferably is provided between theECU 86 and the clutch 418 to actuate the clutch 418. When a power switch, i.e., main switch, of thewatercraft 30 is off, theECU 86 is off and theswitch 440 is disconnected. In the event of malfunction of themotor 412, theswitch 440 is biased off and accordingly the clutch 418 is disconnected so that thethrottle valves 54 can be manually operated. - The
ECU 86 has a ROM to store at least a reference position of thesteering shaft 380 and also has a RAM to store at least a current position signal of thethrottle lever 52 and a change rate of the position signal. TheECU 86 also has a timer. - FIG. 23 illustrates a control routine of the
control system 34A. The control routine starts at Step S21 when the rider turns on the main power switch. At Step S22, the ECU initializes stored data of the RAM and proceeds to Step S23. The timer starts to count time (To) at Step S23. At Step S24, theECU 86 determines a closed position of thethrottle valves 54 from the signal of the throttlevalve position sensor 430. The ECU then determines whether the time (To) counted by the timer exceeds 0.25 seconds (Step S25). If 0.25 seconds has not elapsed, the ECU returns to Step S24 to repeat this step. If the time has elapsed, the ECU instructs theswitch 440 to connect the clutch 418 (Step S26). Steps S21 through S26 comprise an initializing phase of the routine and are not repeated until engine is stopped and restarted. - At Step S27, the
ECU 86 reads a current throttle lever position from the signal sensed by the throttlelever position sensor 402. The ECU then calculates the rate of change of the throttle lever position (Step S28). If the rate of change is zero, the rider wants to maintain the current throttle position. A large rate of change indicates quick movement of the throttle lever (e.g., when accelerating from rest) and a small rate of change indicates slow movement of the throttle lever (e.g., when docking the watercraft at which time the rider may more precisely control the throttle lever for slow speed maneuvering). - The
ECU 86 then determines (at Step S29) whether the closed position of the throttle valves, which was read and stored into memory at Step S24, falls within a range defined between a reference upper limit (RUL) and a reference lower limit (RLL). If it does, the ECU proceeds to Step S31. If not, the ECU performs Step S30. - At the step S30, the
ECU 86 selects either the reference upper limit (RUL) or the reference lower limit (RLL) as a hypothetical closed position. For example, the ECU may be programmed to determine which one of the RUL or RLL is closer to measured value, and then use the closest one as the hypothetical closed position. The ECU then proceeds to theStep 31. - At Step S31, the
ECU 86 determines whether theengine 32 is in an idle state, i.e., whether thethrottle valves 54 are closed. This determination uses either the actual closed position sensed by the throttlevalve position sensor 430 or the hypothetical closed position replaced at the step S30, depending upon the conclusion reached at Step S29. The idle engine speed of theengine 32 is, for example, 1,200 rpm. If the engine is operating above idle, the ECU proceeds to Step S39 to instruct thepulse width modulator 436 to practice a normal control mode for controlling thethrottle drive motor 412. If, however, the engine is at idle, the ECU proceeds to Step S32. - The
pulse width modulator 436 practices the following two controls at the step S39. The first control (i.e., Control (1)) involves bringing the actual throttle opening degree sensed by the throttlevalve position sensor 430 close to the desired throttle opening sensed by the throttlelever position sensor 402. For this purpose, any deviation between these two sensed values preferably is minimized to the extent possible by actuating themotor 412 to move the throttle valves. - The second control (i.e., Control (2)) involves controlling the
motor 412 through thepulse width modulator 436 in response to the change rate calculated at Step S28. If the rate of change is large, themodulator 436 supplies themotor 412 with a relatively high power level so that themotor 412 rotates at a relatively high speed. If the rate of change is small, then themodulator 436 supplies themotor 412 with a relatively low power level so that themotor 412 rotates at a relatively low speed. After performing Step S39, the program returns to Step S27. - If the ECU determines that the throttle valves are closed (Step S31), the
ECU 86 then determines at Step S32 whether the steering position sensed by thesteering position sensor 88 is greater than a reference steering position (RS). If no, the ECU does not begin its engine output control mode and proceeds to control themodulator 436 in its normal manner (Step S39). If, however, the sensed steering position is greater than the reference steering position (RS), i.e., the rider has turned thesteering bar 48 by more than a predetermined degree, the ECU proceeds to Step S33 for a further calculation before deciding whether to begin its engine output control mode. - The
ECU 86 at Step S33 determines whether the throttle valve opening, and consequently the engine output, is increasing. The assessment of this situation can be determined from whether the actual throttle opening degree is increasing from the closed position under the rider's own control. If yes, the program proceeds to Step S39. If not, the ECU begins its engine output control mode (Step S34). This step S33 is advantageous if a manual control or an independent control of the throttle valves is employed. This step S33, however, can be omitted in the illustratedcontrol system 34A. - At Step S34, the
ECU 86 instructs thepulse width modulator 436 to drive themotor 412 in a direction that increases the throttle valve opening degree. Under this control, the throttle valves are opened to a predetermined throttle opening that corresponds with a desired engine speed. In the illustrated embodiment, the engine speed preferably is increased to 3,000 rpm. The desired engine speed preferably is sufficient to effect sharp turning of the watercraft. TheECU 86 then starts the timer (Step S35) to count off a predetermined amount of time (i.e., starts a count down). - At Step S36, the
ECU 86 determines whether the throttle lever position is greater than the idle position. If yes, the rider is operating thethrottle lever 52 to increase the engine output and the program proceeds to Step S38 to stop the engine output control mode. If no, the ECU proceeds to Step S37. - At Step S37, the ECU determines whether the timer has finished the count down. The time period of this count down preferably is about 3 seconds. If this time has not elapsed, the ECU repeats Step S36. If the time has expired, the ECU ceases the engine output control mode (Step S38), and returns to the main control routine at Step S27.
- Although this engine control system has been described in terms of certain preferred embodiments, other embodiments and variations of the foregoing examples will be readily apparent to those of ordinary skill in the art. For example, the output of the throttle valve position sensor in the described embodiments can be directly or indirectly used as a control parameter of the ECU. That is, for example, a sensed throttle opening degree, an absolute value of the sensed opening degree, an increase or decrease amount of the opening degree and a rate of change of the opening degree can all be used as the control parameter(s).
- Additionally, the output of the steering position sensor can be directly or indirectly used as another control parameter of the ECU. That is, for example, a sensed angular position, an absolute value of the sensed angular position, an increase or decrease amount of the angular position and a rate of change of the angular position are all applicable as the control parameter(s).
- The output of the velocity sensor can be directly or indirectly used as a further control parameter of the ECU. That is, for example, a sensed velocity, an absolute value of the velocity, an increase or decrease amount of the velocity and a change rate of the velocity are all applicable as the control parameter.
- The sensors can be positioned not only in close proximity to thing that they are measuring but also at a remote place. If the sensors are remotely disposed, an appropriate mechanical, electrical or optical linkage mechanism can be applied.
- Conventional sensors are all applicable as the sensor described above whether they are given as examples or not. Additionally, conventional actuators using, for example, electrical power or fluid power (e.g., air pressure, water pressure or hydraulic oil pressure) are all applicable as the actuator for the engine output control whether they are exemplified or not.
- Accordingly, the foregoing description is that of preferred embodiments of the present invention, and various changes and modifications may be made without departing from the spirit and scope of the invention, as defined by the appended claims.
Claims (46)
1. (Canceled)
2. (Canceled)
3. (Canceled)
4. (Canceled)
5. (Canceled)
6. (Canceled)
7. (Canceled)
8. (Canceled)
9. (Canceled)
10. (Canceled)
11. (Canceled)
12. (Canceled)
13. (Canceled)
14. (Canceled)
15. (Canceled)
16. (Canceled)
17. (Canceled)
18. (Canceled)
19. (Canceled)
20. (Canceled)
21. (Canceled)
22. (Canceled)
23. (Canceled)
24. (Canceled)
25. (Canceled)
26. (Canceled)
27. (Canceled)
28. (Canceled)
29. (Canceled)
30. (Canceled)
31. (Canceled)
32. (Canceled)
33. A watercraft comprising a water propulsion device, an engine powering the water propulsion device, the engine having at least one combustion chamber and an air induction system arranged to provide air to the combustion chamber, at least one throttle valve disposed in the air induction system for regulating an amount of air supplied to the combustion chamber, a steering assembly arranged to steer the watercraft, a first sensor arranged to sense an opening degree of the throttle valve, a second sensor arranged to sense an angular position of the steering assembly, an electrically operated control device, and a throttle valve actuator arranged to operate the opening degree of the throttle valve, the control device being configured to control the throttle valve actuator based upon an output of the first sensor and an output of the second sensor, the control device causing the throttle valve actuator to operate the at least one throttle valve to increase its opening degree when the output of the first sensor indicates that the sensed opening degree less than a reference opening degree and the output of the second sensor indicates that the sensed angular position is greater than a reference angular position.
34. The watercraft as set forth in claim 33 additionally comprising a third sensor arranged to sense a velocity of the watercraft, wherein the control device coerces the throttle valve actuator into operating the throttle valve to increase the opening degree unless an output of the third sensor indicates that the velocity of the watercraft is less than a reference velocity.
35. The watercraft as set forth in claim 34 , wherein the control device includes a storage to store data of opening degrees of the throttle valve versus velocities of the watercraft, the control device determines one of the opening degrees that corresponds to the sensed output of the third sensor as an objective opening degree, and the control device controls the throttle valve actuator to operate the throttle valve to increase the opening degree to the objective opening degree.
36. The watercraft as set forth in claim 35 , wherein the control device ceases the coercion control when the sensed opening degree of the throttle valve increases to the objective opening degree, the sensed angular position of the steering assembly is generally zero, or the sensed velocity of the watercraft is less than a second reference velocity.
37. The watercraft as set forth in claim 35 , wherein the control device includes a timer, and the control device ceases the coercion control when a predetermined time elapses.
38. The watercraft as set forth in claim 34 , wherein the control device includes a storage to store data of opening degrees of the throttle valve versus velocities of the watercraft and data of the angular positions of the steering assembly versus velocities of the watercraft, the control device determines one of the opening degrees that corresponds to the sensed output of the third sensor as the reference opening degree and also determines one of the angular positions that corresponds to the sensed output of the third sensor as the reference angular position.
39. (Canceled)
40. (Canceled)
41. (Canceled)
42. A control method for an engine of a watercraft having a water propulsion device, a steering assembly, at least two sensors and a control device, the engine including a throttle valve and a throttle valve actuator, the method comprising sensing an opening degree of the throttle valve by one sensor, sensing an angular position of the steering assembly by another sensor, determining whether the sensed opening degree is less than a reference opening degree, determining whether the sensed angular position is greater than a reference angular position, and increasing the opening degree by the control device if the results of both determinations are affirmative.
43. The control method as set forth in claim 42 additionally comprising sensing a velocity of the watercraft, determining whether the sensed velocity is greater than a reference velocity, and increasing the opening degree unless a result of the determination of the velocity is negative.
44. The control method as set forth in claim 43 additionally comprising storing data of opening degrees of the throttle valve versus velocities of the watercraft in a storage of the control device, determining one of the opening degrees that corresponds to the sensed velocity as an objective opening degree, and increasing the opening degree by the throttle valve actuator to the objective opening degree.
45. The control method as set forth in claim 44 additionally comprising judging whether the sensed opening degree increases beyond the objective opening degree, judging whether the sensed angular position is generally zero, judging whether the sensed velocity is less than a second reference velocity, and ceasing the increase of the opening degree if at least one of results of the judgments is affirmative.
46. The control method as set forth in claim 45 additionally comprising storing data of opening degrees of the throttle valve versus velocities of the watercraft in a storage of the control device, storing data of the angular positions of the steering assembly versus velocities of the watercraft in the storage of the control device, determining one of the opening degrees that corresponds to the sensed velocity as the reference opening degree, and determining one of the angular positions that corresponds to the sensed velocity as the reference angular position.
Priority Applications (1)
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US10/812,290 US20040266284A1 (en) | 2000-03-17 | 2004-03-29 | Engine output control for watercraft |
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JP2000077084 | 2000-03-17 | ||
JP2001-029961 | 2001-02-06 | ||
JP2001029961A JP4509406B2 (en) | 2000-03-17 | 2001-02-06 | Engine output control device for water jet propulsion boat |
US09/813,465 US6733350B2 (en) | 2000-03-17 | 2001-03-19 | Engine output control for watercraft |
US10/812,290 US20040266284A1 (en) | 2000-03-17 | 2004-03-29 | Engine output control for watercraft |
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US09/813,465 Division US6733350B2 (en) | 2000-03-17 | 2001-03-19 | Engine output control for watercraft |
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US10/812,290 Abandoned US20040266284A1 (en) | 2000-03-17 | 2004-03-29 | Engine output control for watercraft |
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Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20090095061A1 (en) * | 2007-10-11 | 2009-04-16 | Yamaha Marine Kabushiki Kaisha | Abnormality detection device of fuel pump |
Families Citing this family (61)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4762404B2 (en) * | 2000-09-14 | 2011-08-31 | 川崎重工業株式会社 | Jet-propelled planing boat |
JP4657427B2 (en) * | 2000-08-02 | 2011-03-23 | 川崎重工業株式会社 | Jet-propelled planing boat |
JP4749534B2 (en) * | 2000-09-18 | 2011-08-17 | 川崎重工業株式会社 | Jet-propelled planing boat |
JP4619515B2 (en) * | 2000-10-19 | 2011-01-26 | 川崎重工業株式会社 | Jet-propelled planing boat |
US6390862B1 (en) * | 2000-11-20 | 2002-05-21 | Brunswick Corporation | Pump jet steering method during deceleration |
JP4606571B2 (en) * | 2000-11-30 | 2011-01-05 | 川崎重工業株式会社 | Small planing boat |
JP4035334B2 (en) * | 2001-02-15 | 2008-01-23 | ヤマハ発動機株式会社 | Engine output control device for water jet propulsion boat |
JP2002256928A (en) * | 2001-02-26 | 2002-09-11 | Yamaha Motor Co Ltd | Engine output control device of water jet-propulsion boat |
JP2002303170A (en) * | 2001-04-02 | 2002-10-18 | Kawasaki Heavy Ind Ltd | Jet propelled planing boat |
JP2002371875A (en) | 2001-04-11 | 2002-12-26 | Sanshin Ind Co Ltd | Engine control device of water jet propelled craft |
US7018254B2 (en) * | 2001-04-11 | 2006-03-28 | Yamaha Marine Kabushiki Kaisha | Fuel injection control for marine engine |
JP2003074445A (en) * | 2001-09-03 | 2003-03-12 | Sanshin Ind Co Ltd | Engine output control device for water jet propulsion boat |
CN1264724C (en) * | 2001-09-18 | 2006-07-19 | 本田技研工业株式会社 | Jet prepelling ship |
JP4091307B2 (en) * | 2002-02-04 | 2008-05-28 | 本田技研工業株式会社 | Jet propulsion boat |
US7118431B2 (en) | 2002-09-10 | 2006-10-10 | Yamaha Hatsudoki Kabushiki Kaisha | Watercraft steering assist system |
JP2004162676A (en) * | 2002-11-15 | 2004-06-10 | Yamaha Marine Co Ltd | Engine intake device |
JP3901630B2 (en) | 2002-12-04 | 2007-04-04 | ヤマハ発動機株式会社 | Operation control device for water jet propulsion boat |
JP2004322775A (en) | 2003-04-23 | 2004-11-18 | Honda Motor Co Ltd | Engine controller |
JP4558346B2 (en) * | 2003-04-23 | 2010-10-06 | 本田技研工業株式会社 | Engine output control device |
JP2004346818A (en) * | 2003-05-22 | 2004-12-09 | Yamaha Marine Co Ltd | Throttle valve control device in compact planing boat |
JP2004360651A (en) | 2003-06-06 | 2004-12-24 | Yamaha Marine Co Ltd | Engine output controller of water jet propulsion boat |
JP2005009388A (en) | 2003-06-18 | 2005-01-13 | Yamaha Marine Co Ltd | Engine output control device for water jet propulsion boat |
JP4275572B2 (en) * | 2003-06-30 | 2009-06-10 | ヤマハ発動機株式会社 | Shipboard engine control system |
US6918373B1 (en) * | 2004-03-17 | 2005-07-19 | Visteon Global Technologies, Inc. | Single wire control method for electronic throttle systems |
JP2005329850A (en) * | 2004-05-20 | 2005-12-02 | Yamaha Marine Co Ltd | Water-cooling structure of outboard engine |
JP4420738B2 (en) * | 2004-05-24 | 2010-02-24 | ヤマハ発動機株式会社 | Speed control device for water jet propulsion boat |
US7337739B2 (en) * | 2004-06-07 | 2008-03-04 | Yamaha Marine Kabushiki Kaisha | Steering-force detection device for steering handle of vehicle |
US7430466B2 (en) * | 2004-06-07 | 2008-09-30 | Yamaha Marine Kabushiki Kaisha | Steering force detection device for steering handle of vehicle |
JP2006008044A (en) * | 2004-06-29 | 2006-01-12 | Yamaha Marine Co Ltd | Engine output control device for water jet propulsion vessel |
EP1767763A4 (en) * | 2004-07-12 | 2018-02-14 | Yanmar Co., Ltd. | Fuel control method for multi-cylinder engine, fuel injection amount control method for engine and engine operating state discrimination method using the said method, propelling device for multiple engines, and fuel injection control method at crush astern in engine with speed reducing and reversing |
JP2006194169A (en) | 2005-01-14 | 2006-07-27 | Mitsubishi Electric Corp | Engine controller |
JP2006199136A (en) * | 2005-01-20 | 2006-08-03 | Yamaha Marine Co Ltd | Operation control device for planning boat |
US7513807B2 (en) * | 2005-01-20 | 2009-04-07 | Yamaha Hatsudoki Kabushiki Kaisha | Operation control system for planing boat |
JP2006200442A (en) * | 2005-01-20 | 2006-08-03 | Yamaha Marine Co Ltd | Operation control device for small vessel |
JP2007064162A (en) | 2005-09-02 | 2007-03-15 | Yamaha Marine Co Ltd | Throttle opening control device for small planing boat |
JP2007285229A (en) * | 2006-04-18 | 2007-11-01 | Yamaha Marine Co Ltd | Outboard motor |
JP2007314084A (en) * | 2006-05-26 | 2007-12-06 | Yamaha Marine Co Ltd | Operation control device of hydroplane |
JP2008094256A (en) | 2006-10-12 | 2008-04-24 | Yamaha Marine Co Ltd | Water vehicle |
US7315779B1 (en) | 2006-12-22 | 2008-01-01 | Bombardier Recreational Products Inc. | Vehicle speed limiter |
US7530345B1 (en) | 2006-12-22 | 2009-05-12 | Bombardier Recreational Products Inc. | Vehicle cruise control |
US7380538B1 (en) | 2006-12-22 | 2008-06-03 | Bombardier Recreational Products Inc. | Reverse operation of a vehicle |
JP5046736B2 (en) * | 2007-05-09 | 2012-10-10 | 川崎重工業株式会社 | Jet propulsion boat |
ITGE20070072A1 (en) * | 2007-07-27 | 2009-01-28 | Ultraflex Spa | COMMAND DEVICE FOR BOATS |
JP5424674B2 (en) * | 2009-03-09 | 2014-02-26 | ヤンマー株式会社 | Working machine |
JP2014073790A (en) * | 2012-10-05 | 2014-04-24 | Yamaha Motor Co Ltd | Jet propulsion boat |
GB2506921B (en) | 2012-10-14 | 2015-06-10 | Gibbs Tech Ltd | Enhanced steering |
JP2015157510A (en) * | 2014-02-21 | 2015-09-03 | ヤマハ発動機株式会社 | jet propulsion boat |
US9643698B1 (en) | 2014-12-17 | 2017-05-09 | Brunswick Corporation | Systems and methods for providing notification regarding trim angle of a marine propulsion device |
JP2016169691A (en) * | 2015-03-13 | 2016-09-23 | ヤマハ発動機株式会社 | Jet propulsion watercraft and method for controlling the same |
US9745036B2 (en) | 2015-06-23 | 2017-08-29 | Brunswick Corporation | Systems and methods for automatically controlling attitude of a marine vessel with trim devices |
US9919781B1 (en) | 2015-06-23 | 2018-03-20 | Brunswick Corporation | Systems and methods for automatically controlling attitude of a marine vessel with trim devices |
US10518856B2 (en) | 2015-06-23 | 2019-12-31 | Brunswick Corporation | Systems and methods for automatically controlling attitude of a marine vessel with trim devices |
US9764810B1 (en) | 2015-06-23 | 2017-09-19 | Bruswick Corporation | Methods for positioning multiple trimmable marine propulsion devices on a marine vessel |
US9751605B1 (en) | 2015-12-29 | 2017-09-05 | Brunswick Corporation | System and method for trimming a trimmable marine device with respect to a marine vessel |
US9694892B1 (en) * | 2015-12-29 | 2017-07-04 | Brunswick Corporation | System and method for trimming trimmable marine devices with respect to a marine vessel |
US10011339B2 (en) | 2016-08-22 | 2018-07-03 | Brunswick Corporation | System and method for controlling trim position of propulsion devices on a marine vessel |
US9896174B1 (en) | 2016-08-22 | 2018-02-20 | Brunswick Corporation | System and method for controlling trim position of propulsion device on a marine vessel |
US10118682B2 (en) | 2016-08-22 | 2018-11-06 | Brunswick Corporation | Method and system for controlling trim position of a propulsion device on a marine vessel |
US10000267B1 (en) | 2017-08-14 | 2018-06-19 | Brunswick Corporation | Methods for trimming trimmable marine devices with respect to a marine vessel |
US10351221B1 (en) | 2017-09-01 | 2019-07-16 | Brunswick Corporation | Methods for automatically controlling attitude of a marine vessel during launch |
US10829190B1 (en) | 2018-05-29 | 2020-11-10 | Brunswick Corporation | Trim control system and method |
Citations (50)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1843272A (en) * | 1929-03-08 | 1932-02-02 | Outboard Motors Corp | Control mechanism for outboard motors |
US2332697A (en) * | 1942-06-01 | 1943-10-26 | Gen Motors Corp | Engine governor |
US2627836A (en) * | 1951-05-04 | 1953-02-10 | Nat Pressure Cooker Co | Throttle control for outboard motors |
US2682248A (en) * | 1951-12-27 | 1954-06-29 | Nat Presto Ind | Control mechanism for outboard motors |
US3002487A (en) * | 1961-10-03 | Ignition control for motor boat engine | ||
US3135234A (en) * | 1962-07-30 | 1964-06-02 | Leslie A Turnidge | Device for controlling engine and transmission |
US3795105A (en) * | 1972-05-02 | 1974-03-05 | Twin Disc Inc | Control apparatus for hydraulic jet propulsion water borne craft |
US3918256A (en) * | 1974-06-10 | 1975-11-11 | Boeing Co | Throttle-reverser control system for water jet propelled seacraft |
US4100877A (en) * | 1976-09-27 | 1978-07-18 | The Boeing Company | Protective control system for water-jet propulsion systems |
US4767363A (en) * | 1985-11-30 | 1988-08-30 | Sanshin Koygo Kabushiki Kaisha | Control device for marine engine |
US4778414A (en) * | 1985-10-02 | 1988-10-18 | Sanshin Kogyo Kabushiki Kaisha | Trim angle control device for marine propulsion motors |
US4836809A (en) * | 1988-03-11 | 1989-06-06 | Twin Disc, Incorporated | Control means for marine propulsion system |
US4938721A (en) * | 1987-03-20 | 1990-07-03 | Sanshin Kogyo Kabushiki Kaisha | Alarm device for marine propulsion unit |
US4976636A (en) * | 1986-06-06 | 1990-12-11 | Sanshin Kogyo Kabushiki Kaisha | Trim apparatus for marine propulsion unit |
US5002032A (en) * | 1988-04-09 | 1991-03-26 | Robert Bosch Gmbh | Apparatus to control an internal combustion engine in vehicles |
US5062815A (en) * | 1988-11-28 | 1991-11-05 | Yamaha Hatsudoki Kabushiki Kaisha | Shift control for small watercraft |
US5065723A (en) * | 1987-06-24 | 1991-11-19 | Outboard Marine Corporation | Marine propulsion device with spark timing and fuel supply control mechanism |
US5074810A (en) * | 1990-06-29 | 1991-12-24 | Lakeland Engineering Corporation | Automatic speed control system for boats |
US5127858A (en) * | 1991-07-16 | 1992-07-07 | Twin Disc Incorporated | Control means for marine engines and transmissions |
US5142473A (en) * | 1988-08-12 | 1992-08-25 | Davis Dale R | Speed, acceleration, and trim control system for power boats |
US5203727A (en) * | 1991-04-26 | 1993-04-20 | Mitsubishi Denki Kabushiki Kaisha | Control apparatus for an outboard marine engine with improved cruising performance |
US5261844A (en) * | 1991-02-14 | 1993-11-16 | Sanshin Kogyo Kabushiki Kaisha | Throttle opening control device for marine propulsion device |
US5273016A (en) * | 1992-09-30 | 1993-12-28 | Outboard Marine Corporation | Throttle lever position sensor for two-stroke fuel injected engine |
US5280282A (en) * | 1990-02-28 | 1994-01-18 | Sanshin Kogyo Kabushiki Kaisha | Remote control system |
US5314362A (en) * | 1990-05-31 | 1994-05-24 | Sanshin Kogyo Kabushiki Kaisha | Throttle opening limiting system for a marine propulsion unit |
US5336833A (en) * | 1991-10-25 | 1994-08-09 | Institut Francais Du Petrole | Catalyst based on silica and sulphuric acid and its use for the alkylation of paraffins |
US5368510A (en) * | 1993-06-11 | 1994-11-29 | Richard; Andre L. | Trolling valve safety device |
US5389016A (en) * | 1990-11-23 | 1995-02-14 | Volvo Penta Ab | Steering system for planing watercrafts |
US5413461A (en) * | 1990-10-12 | 1995-05-09 | Johnsen; Oddvard | Method and apparatus for controlling a propulsion engine output based on the net axial force on a propeller shaft |
US5492493A (en) * | 1994-07-07 | 1996-02-20 | Sanshin Kogyo Kabushiki Kaisha | Remote control device for marine propulsion unit |
US5539449A (en) * | 1993-05-03 | 1996-07-23 | At&T Corp. | Integrated television services system |
US5582125A (en) * | 1992-10-24 | 1996-12-10 | Sanshin Kogyo Kabushiki Kaisha | Small jet propelled boat |
US5586535A (en) * | 1993-12-16 | 1996-12-24 | Suzuki Motor Corporation | Engine rotational number controller |
US5607332A (en) * | 1991-05-29 | 1997-03-04 | Yamaha Hatsudoki Kabushiki Kaisha | Control for jet powered watercraft |
US5665025A (en) * | 1994-12-16 | 1997-09-09 | Sanshin Kogyo Kabushuki Kaisha | Engine control linkage |
US5666917A (en) * | 1995-06-06 | 1997-09-16 | Ford Global Technologies, Inc. | System and method for idle speed control |
US5755601A (en) * | 1997-03-17 | 1998-05-26 | Brunswick Corporation | Brake system for personal watercraft |
US5797371A (en) * | 1995-03-09 | 1998-08-25 | Sanshin Kogyo Kabushiki Kaisha | Cylinder-disabling control system for multi-cylinder engine |
US5809436A (en) * | 1996-01-19 | 1998-09-15 | Gregory; John W. | Automatic throttle adjustor |
US5827150A (en) * | 1995-07-27 | 1998-10-27 | Yamaha Hatsudoki Kabushiki Kaisha | Engine control having shift assist with fuel injected during ignition cutoff while shifting |
US5833501A (en) * | 1997-07-15 | 1998-11-10 | Brunswick Corporation | Cavitation control for marine propulsion system |
US5868118A (en) * | 1996-03-26 | 1999-02-09 | Suzuki Motor Corporation | Fuel-injection control device for outboard motors for low-speed operation |
US5906524A (en) * | 1996-12-28 | 1999-05-25 | Yamaha Hatsudoki Kabushiki Kaisha | Throttle position sensor mounting arrangement for personal watercraft engine |
US6015317A (en) * | 1997-07-02 | 2000-01-18 | Sanshin Kogyo Kabushiki Kaisha | Marine engine overheat detection system |
US6015319A (en) * | 1996-12-18 | 2000-01-18 | Sanshin Kogyo Kabushiki Kaisha | Control for marine propulsion |
US6024068A (en) * | 1996-11-22 | 2000-02-15 | Yamaha Hatsudoki Kabushiki Kaisha | Watercraft engine control |
US6030261A (en) * | 1997-02-27 | 2000-02-29 | Sanshin Kogyo Kabushiki Kaisha | Engine control |
US6080075A (en) * | 1999-01-29 | 2000-06-27 | Dana Corporation | Compact actuator for a throttle assembly |
US6159059A (en) * | 1999-11-01 | 2000-12-12 | Arctic Cat Inc. | Controlled thrust steering system for watercraft |
US6336833B1 (en) * | 1997-01-10 | 2002-01-08 | Bombardier Inc. | Watercraft with steer-responsive throttle |
Family Cites Families (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5784297A (en) * | 1980-11-14 | 1982-05-26 | Mitsubishi Heavy Ind Ltd | Turning performance improving equipment on board |
US5538449A (en) | 1993-06-11 | 1996-07-23 | Richard; Andre L. | Boat trolling valve safety device |
JP3693371B2 (en) * | 1994-12-15 | 2005-09-07 | 日本ケーブル・システム株式会社 | Water vehicle spray nozzle angle control device |
JPH08319859A (en) * | 1995-03-23 | 1996-12-03 | Sanshin Ind Co Ltd | Two-cycle engine for ship |
CA2207938A1 (en) | 1997-01-10 | 1998-07-10 | Alain Rheault | Low speed steering system |
JP3928198B2 (en) * | 1997-02-12 | 2007-06-13 | マツダ株式会社 | Engine control device |
JPH1130140A (en) * | 1997-07-11 | 1999-02-02 | Sanshin Ind Co Ltd | Controller of marine engine |
JPH1193720A (en) * | 1997-09-25 | 1999-04-06 | Fuji Heavy Ind Ltd | Failure diagnostic device for small boat |
JPH11270367A (en) * | 1998-03-23 | 1999-10-05 | Denso Corp | Throttle control device of internal combustion engine |
-
2001
- 2001-02-06 JP JP2001029961A patent/JP4509406B2/en not_active Expired - Lifetime
- 2001-03-19 US US09/813,465 patent/US6733350B2/en not_active Expired - Lifetime
-
2004
- 2004-03-29 US US10/812,290 patent/US20040266284A1/en not_active Abandoned
Patent Citations (50)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3002487A (en) * | 1961-10-03 | Ignition control for motor boat engine | ||
US1843272A (en) * | 1929-03-08 | 1932-02-02 | Outboard Motors Corp | Control mechanism for outboard motors |
US2332697A (en) * | 1942-06-01 | 1943-10-26 | Gen Motors Corp | Engine governor |
US2627836A (en) * | 1951-05-04 | 1953-02-10 | Nat Pressure Cooker Co | Throttle control for outboard motors |
US2682248A (en) * | 1951-12-27 | 1954-06-29 | Nat Presto Ind | Control mechanism for outboard motors |
US3135234A (en) * | 1962-07-30 | 1964-06-02 | Leslie A Turnidge | Device for controlling engine and transmission |
US3795105A (en) * | 1972-05-02 | 1974-03-05 | Twin Disc Inc | Control apparatus for hydraulic jet propulsion water borne craft |
US3918256A (en) * | 1974-06-10 | 1975-11-11 | Boeing Co | Throttle-reverser control system for water jet propelled seacraft |
US4100877A (en) * | 1976-09-27 | 1978-07-18 | The Boeing Company | Protective control system for water-jet propulsion systems |
US4778414A (en) * | 1985-10-02 | 1988-10-18 | Sanshin Kogyo Kabushiki Kaisha | Trim angle control device for marine propulsion motors |
US4767363A (en) * | 1985-11-30 | 1988-08-30 | Sanshin Koygo Kabushiki Kaisha | Control device for marine engine |
US4976636A (en) * | 1986-06-06 | 1990-12-11 | Sanshin Kogyo Kabushiki Kaisha | Trim apparatus for marine propulsion unit |
US4938721A (en) * | 1987-03-20 | 1990-07-03 | Sanshin Kogyo Kabushiki Kaisha | Alarm device for marine propulsion unit |
US5065723A (en) * | 1987-06-24 | 1991-11-19 | Outboard Marine Corporation | Marine propulsion device with spark timing and fuel supply control mechanism |
US4836809A (en) * | 1988-03-11 | 1989-06-06 | Twin Disc, Incorporated | Control means for marine propulsion system |
US5002032A (en) * | 1988-04-09 | 1991-03-26 | Robert Bosch Gmbh | Apparatus to control an internal combustion engine in vehicles |
US5142473A (en) * | 1988-08-12 | 1992-08-25 | Davis Dale R | Speed, acceleration, and trim control system for power boats |
US5062815A (en) * | 1988-11-28 | 1991-11-05 | Yamaha Hatsudoki Kabushiki Kaisha | Shift control for small watercraft |
US5280282A (en) * | 1990-02-28 | 1994-01-18 | Sanshin Kogyo Kabushiki Kaisha | Remote control system |
US5314362A (en) * | 1990-05-31 | 1994-05-24 | Sanshin Kogyo Kabushiki Kaisha | Throttle opening limiting system for a marine propulsion unit |
US5074810A (en) * | 1990-06-29 | 1991-12-24 | Lakeland Engineering Corporation | Automatic speed control system for boats |
US5413461A (en) * | 1990-10-12 | 1995-05-09 | Johnsen; Oddvard | Method and apparatus for controlling a propulsion engine output based on the net axial force on a propeller shaft |
US5389016A (en) * | 1990-11-23 | 1995-02-14 | Volvo Penta Ab | Steering system for planing watercrafts |
US5261844A (en) * | 1991-02-14 | 1993-11-16 | Sanshin Kogyo Kabushiki Kaisha | Throttle opening control device for marine propulsion device |
US5203727A (en) * | 1991-04-26 | 1993-04-20 | Mitsubishi Denki Kabushiki Kaisha | Control apparatus for an outboard marine engine with improved cruising performance |
US5607332A (en) * | 1991-05-29 | 1997-03-04 | Yamaha Hatsudoki Kabushiki Kaisha | Control for jet powered watercraft |
US5127858A (en) * | 1991-07-16 | 1992-07-07 | Twin Disc Incorporated | Control means for marine engines and transmissions |
US5336833A (en) * | 1991-10-25 | 1994-08-09 | Institut Francais Du Petrole | Catalyst based on silica and sulphuric acid and its use for the alkylation of paraffins |
US5273016A (en) * | 1992-09-30 | 1993-12-28 | Outboard Marine Corporation | Throttle lever position sensor for two-stroke fuel injected engine |
US5582125A (en) * | 1992-10-24 | 1996-12-10 | Sanshin Kogyo Kabushiki Kaisha | Small jet propelled boat |
US5539449A (en) * | 1993-05-03 | 1996-07-23 | At&T Corp. | Integrated television services system |
US5368510A (en) * | 1993-06-11 | 1994-11-29 | Richard; Andre L. | Trolling valve safety device |
US5586535A (en) * | 1993-12-16 | 1996-12-24 | Suzuki Motor Corporation | Engine rotational number controller |
US5492493A (en) * | 1994-07-07 | 1996-02-20 | Sanshin Kogyo Kabushiki Kaisha | Remote control device for marine propulsion unit |
US5665025A (en) * | 1994-12-16 | 1997-09-09 | Sanshin Kogyo Kabushuki Kaisha | Engine control linkage |
US5797371A (en) * | 1995-03-09 | 1998-08-25 | Sanshin Kogyo Kabushiki Kaisha | Cylinder-disabling control system for multi-cylinder engine |
US5666917A (en) * | 1995-06-06 | 1997-09-16 | Ford Global Technologies, Inc. | System and method for idle speed control |
US5827150A (en) * | 1995-07-27 | 1998-10-27 | Yamaha Hatsudoki Kabushiki Kaisha | Engine control having shift assist with fuel injected during ignition cutoff while shifting |
US5809436A (en) * | 1996-01-19 | 1998-09-15 | Gregory; John W. | Automatic throttle adjustor |
US5868118A (en) * | 1996-03-26 | 1999-02-09 | Suzuki Motor Corporation | Fuel-injection control device for outboard motors for low-speed operation |
US6024068A (en) * | 1996-11-22 | 2000-02-15 | Yamaha Hatsudoki Kabushiki Kaisha | Watercraft engine control |
US6015319A (en) * | 1996-12-18 | 2000-01-18 | Sanshin Kogyo Kabushiki Kaisha | Control for marine propulsion |
US5906524A (en) * | 1996-12-28 | 1999-05-25 | Yamaha Hatsudoki Kabushiki Kaisha | Throttle position sensor mounting arrangement for personal watercraft engine |
US6336833B1 (en) * | 1997-01-10 | 2002-01-08 | Bombardier Inc. | Watercraft with steer-responsive throttle |
US6030261A (en) * | 1997-02-27 | 2000-02-29 | Sanshin Kogyo Kabushiki Kaisha | Engine control |
US5755601A (en) * | 1997-03-17 | 1998-05-26 | Brunswick Corporation | Brake system for personal watercraft |
US6015317A (en) * | 1997-07-02 | 2000-01-18 | Sanshin Kogyo Kabushiki Kaisha | Marine engine overheat detection system |
US5833501A (en) * | 1997-07-15 | 1998-11-10 | Brunswick Corporation | Cavitation control for marine propulsion system |
US6080075A (en) * | 1999-01-29 | 2000-06-27 | Dana Corporation | Compact actuator for a throttle assembly |
US6159059A (en) * | 1999-11-01 | 2000-12-12 | Arctic Cat Inc. | Controlled thrust steering system for watercraft |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20090095061A1 (en) * | 2007-10-11 | 2009-04-16 | Yamaha Marine Kabushiki Kaisha | Abnormality detection device of fuel pump |
US7886586B2 (en) * | 2007-10-11 | 2011-02-15 | Yamaha Hatsudoki Kabushiki Kaisha | Abnormality detection device of fuel pump |
Also Published As
Publication number | Publication date |
---|---|
JP2001329881A (en) | 2001-11-30 |
JP4509406B2 (en) | 2010-07-21 |
US6733350B2 (en) | 2004-05-11 |
US20010036777A1 (en) | 2001-11-01 |
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Legal Events
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Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |