CA1078687A

CA1078687A - Multi-cylinder internal combustion engine having selective cylinder control

Info

Publication number: CA1078687A
Application number: CA273,541A
Authority: CA
Inventors: Bradford Bates
Original assignee: Ford Motor Company of Canada Ltd
Current assignee: Ford Motor Company of Canada Ltd
Priority date: 1976-06-11
Filing date: 1977-03-09
Publication date: 1980-06-03
Also published as: JPS5526285B2; DE2725529A1; GB1578064A; JPS52153019A; AU2228577A; AU504603B2; US4386590A

Abstract

A MULTI-CYLINDER INTERNAL COMBUSTION ENGINE
HAVING SELECTIVE CYLINDER CONTROL

ABSTRACT OF THE DISCLOSURE

A multi-cylinder internal combustion engine having valve train operated intake and exhaust valves for each cylinder and a valve control system adding the capa-bility of automatic selection as to whether or not given cylinders are to be in operation. The cylinders that are to be controlled are identified and movable interposers are installed for both the intake and exhaust valves of the selected cylinders. Control rods interconnect intake inter-posers to each other and exhaust interposers to each other.
A combined actuation arm and interconnection link is provided to transfer motion from a selection actuator to the control rods. A mechanical interlock ensures that exhaust valves are not deactivatable until deactivation of the intake valves occurs.

Description

~7~'7 The pres~nt invention relates to multi-cylinder internal combustion engines.
The concept of operating a multi-cylinder internal combustion engine on less than a total number of the cylinders available is not novel. U.SO Patent 2,166,968 issued July 25, 1939 to K.W. Rohlan entitled an "Apparatus for Controlling the Operation of Internal Combustion Engines of the Multi-Cylinder type" is a rather complete thesis on the advantages of being able to operate-an engine under certain operating conditions on less than the full number of cylinders available. The patent discloses the use of multiple carburetor jets arranged to deliver fuel charges to each of the cylinders independently of the other. The system includes a controlling means including a device respon-sive to increased speed for automatically cutting ofP feed of fuel to one or more of the cylinders~ The disclosed system required a complex array of valves and diaphragms for controlling its operation.
During the early days of gasoline rationing in ~0 the World War II era, it was proposed that fuel consumption could be decreased by permanently deactivating the intake and exhaust valves to one or more of the cylinders of the engine. It was found that the loss of horsepower resulting from ~he deactivation of one or more of the cylinders was not proportional to the number of cylinders that were involved. That is, if half of the cylinders were deactivated the horsepower output under all conditions of operation was substantially less than 50% resulting in poor acceleration characteristics for the vehicle. Once the change is made to the engine there is no way to switch back and forth between full cylinder and part cylinder operation without

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~71~3~87 tearing down the engine and rebuilding it. A recent version of this technique is disclosed in u.S. Pa-tent 3,874,358 ~or an engine conversion system issued to H.D. Crower on April 1, 1975.
The present invention relates to a multi-cylinder internal combustion engine having intake and exhaust valves for each cylinder. Each intake and exhaust valve is operable by a valve train including a rocker arm pivotable about a pedestal-mounted fulcrum means. A control mechanism is provided for controlling the operation of the intake and exhaust valves for selected ones of the cylinders~ The control mechanism comprises an interposer means assembly mounted on the en~ine. The interposer means assembly includes an interposer positioned adjacent the valve train of each intake and exhaust valve of the selected cylinders and shiftable into a valve train disablir~g position to render the latter inoperative to actuate th~ valves. Control rods interconnect the intake interposers to each other and the exhaust interposers to each other. The control mechanism -is coupled to a selection actuator means. A combined actuation and interconnection link is operative by the ;
- selection actuator means to actuate the control rods to shi~t the interposer members into and out of valve train disabling position. A mechanical interlock means coupled to the control rods ensures that the exhaust valves cannot ;;
be deactivated until the intake valves are deactivated.
Preferably, the fulcrum means of each valve train comprises a load transfer means and the support means ~for the movable interposers includes a load bearing plate.
Control of the operation of a given valve is accomplished by moving an interposer into a gap between the fulcrum load ~ i ' ' ~ ~ 3 -~86~7 transfer means and the load bearing plate. This prevents movement of the fulcrum. As the rocker arm roc~s or pivots about the fulcrum, its motion is transferred to the given valve to open and close the latter. With the interposer means out of position~ the load transfer means is free to travel on the pedestal and the fulcrum is free to move with the rocker arm thereby causing the given valve to remain stationary or in a closed pos~tion.
The invention is described further, by way of illustration, with reference to the accompanying drawings, in which:
Figure 1 is a perspective view of a control mechanism adapted to be added to a multi-cylinder internal combustion engine for controlling the selective operation of the cylinders;
Figure 2 is a plan view of Figure 1 with parts cut away to show the internal components o~ the control mechanism;
Figure 3 is a view taken on the line 3-3 of ~ .
Figure 2, Figure 4 is an enlarged view of a portion o~
the valve train for controlling the operation of an intake valve or an exhaust valve and also showing thè relationship of the control mechanism embodying the present invention to the valve train; and Figure 5 is a view in part similar to Figure 4 showing the control mechanism and its relationship to the valve train when the latter is rendered inoperative to actuate a given valve.
Many multi-cylinder internal combustion engines , ~ .
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~ [978687 in current use are valve-in-head engines having the intake and exhaust valves for the several cylinders mounted in the cylinder head. Mounted on the cylinder head are the rocker arm assemblies forming a part of the valve train or valve gear for operating each valve. Each rocker arm assembly comprises a rocker arm having intermediate its ends pivotal bearing engagement with a fulcrum carried on a pedestal.
The rocker arm is engaged at one end by a rocker arm actuator such as a push rod which receives its reciprocatory movement from a follower riding on a cam of a camshaft. At its other end, the rocker arm has operative engagement with a valve or, more specifically, with the valve stem. In the conventional engine the fulcrum provides a fixed pivot axis about which the rocker arm rocks or pivots as it transers motion from the rocker arm actuator, Isuch as the push rod, to the valve.
If the fulcrum is not held in a ~ixed position but is permitted to move up as the push rod moves the one end of the rocker arm upwardly and then to drop back down as the one ~.

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~'~ 5 ,, ~78~;~7 l end of the rocker arm follows the push rod down, no effective 2 movement will be transmitted by the rocker arm to the valve

3 stem. Instead the rocker arm will pivot or rock idly about

4 its point of engagement with the valve stem. If this is permitted to occur with both the intake and exhaust valves for 6 a particular cylinder or cylinders, that cylinder or cylinders 7 ~ill be rendered inoperative.
8 The valve control mechanism embodying the present 9 invention applies the foregoing principle to obtain split-engine operation of a multi-cylinder engine. That is, under ll predetermined operating conditions a V-8 engine could be 12 operated on four cylinders or a six cylinder engine could be 13 operated on three cylinders~ In carryin~ out the present 14 invention this is accomplished by utllizing a modified rocker arm assembly for each intake and exhau~st valve of the cylinders 16 to be selectively rendered operative or inoperative and by 17 mounting a eontrol mechanism in proximity to the modified 18 rocker arm assemblies.
19 Referrlng now to Figs. l to 3, inclusive, a control mechanism embodyin~ the present invention is generally 21 designated lO. A modified rocker arm assembly to be used with 22 the control mechanism lO is shown in Figs. 4 and 5 and is 23 generally designated 11.
24 The modified rocker arm assembly ll depicted in Figs. 4 and 5 comprises a conventional rocker arm 12 adapted 26 to be engaged at one end 13 by a rocker arm actuator shown as 27 the upper end of a push rod 14. At its other end 15, the rocker 28 arm has operatlve engagement with the end of a valve stem 16.
29 Intermediate its ends the rocker arm 12 has bearing engagement with a fulcrum 17 mounted on a ~ulcrum supporting means. The 31 fulcrum supporting means comprises an elongated stud 18 somewhat . . .

378~7 1 longer than a conventional stud. The longitudinal axis of 2 the stud 18 extends in a generally vertical direction to the 3 engine surface 19 on which it is mounted. As in a conventional 4 engine, the rocker arm 12 is provided with an elongated aperture 21 and the fulcrum 17 is provided with a cylindrical aperture 6 through which the center section 22 of the stud 18 pro~ects.
7 The aperture 21 is elongated lengthwise of the rocker arm 12 8 to provide the clearance necessary to permit the rocker arm 9 bearing surface 23 to rock around the opposed bearing surface of the fulcrum 17.
11 In a conventional engine, the fulcrum 17 is held in 12 a down or operative position on the stud center sectlon 22 13 by a nut or retainer threadedly mounted on the stud. In 14 accordance with the present invention the fulcrum 17 has a 1~ load transfer means positioned above it, the superposed 16 load transfer means comprising a tubular member 24 having a 17 flange 25 at its lower end. The tubular member 24 is 18 axlally movable on the stud section 22.
19 The tubular member 24 is encompassed by a compression spring 26 reacting between the flange 25 and a lower support 21 plate 27 that is a part of the control mechanism 10.
22 Referring now to figs. 1 to 3, inclusive, the 23 control mechanism 10 comprises the aforementioned lower support ~4 plate 27 and an upper or load bearing plate 28. Tha two plates 27-28 are bolted to each other in parallel spaced 26 ~elation and ha~e a laterally extending end plates 29 and 31 27 secured to the plate ends.
28 It should be noted that the length of the plates 29 27-28 is such that the control mechanism 10 will span the length of a multi-cylinder engine cylinder head. In the case . . . ~ , .

71~6~37 1 of the V-8 engine, which has two banks of four cylinders and 2 therefore has two cylinder heads, a separate control mechanism 3 10 will extend over each bank of cylinders at each side of the 4 engine and the two units will be operated in synchonism.
The plate 28 of the control mechanism 10 is bored to 6 receive an extension 32 of each fulcrum stud 18, the fulcrum 7 studs being longitudinally aligned lengthwise of the cylinder 8 head. When mounted the upper plate 28 rests on the shoulder 9 33 of the row of studs 18.
(In a prototype installation the control mechanism 11 10 was fitted into the upper panel of a valve cover which 12 normally conceals the rocker arm assemblies of the engine 13 from view.) 14 Between the plates 27-28 are positioned fingers or levers, hereinafter frequently referred to as interposers 34.
16 There are two of these interposers 34 for each intake valve and 17 for each exhaust valve of the cylinders of the engine that are 18 to be capable of being deactivated. With reference to Fig. 2, 19 the two sets of interposers 34 shown at the left end of the control mechanism 10 are associated with one of the cylinders at one 21 end of the bank of four cylinders and the two sets of inter-22 posers 34 located at the other end are associated with the intake 23 and exhaust valves of the cylinder at the other end of the bank 24 of four cylinders, for example, the front and rear cylinders of either bank in a V-8 engine. There are no interposers 34 26 associated with the intake and exhaust valves of theinter-27 mediate cylinders, a suitable spacer (not shown) being permanently 28 inserted between the upper end of the tubular member 24 and 29 the load bearing plate 28 bottom surface 35. In the alternative, conventional rocker arm assemblies could be used at the 31 cylinders not capable of being deactivated.

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1 As indicated, each interposer 34 is a lever. Each 2 lever is pivoted intermediate its ends on a pivot pin 36.
3 Each lever has at its inner end 37 a recess 38 adapted to semi-4 encompass the center section 22 of the stud 18 where the center section o~ the stud projects into the gap between the lower 6 support plate 27 and the upper load bearing plate 28. At its 7 end outwardly of the pivot 36, the interposer has an end 8 portion 39 pro~ecting beyond the side edges of the plates 27-28.
9 At each side of the support plates 27-28 are spaced parallel upper and lower control rods 41 and 42. Each upper 11 control rod 41 is pivotally coupled at 43 to the projecting and 12 portion 39 o~ each intake interposer 34. Each lower control rod 13 42 is similarly pivotally coupled to the pro~ecting end 39 of 14 each e~haust interposer 34.
The control rods 41-42 are slidable in the end plates 16 29 and 31 at each end of the plates 27-28. The control rods 17 41-42 are coupled to an actuation control link 44 mounted in 18 the end plates 29-31 parallel to and outboard of the control 19 rods 41-42 at one side of the p,lates 27-28. The actuation control link 44 is coupled to both sets of control rods 41-42 -21 through coupler levers 45 and 46 which are pivoted intermediate 22 their ends on pivots l17 that extend through the plates 27-28. . .
23 The coupler lever 45 is pivotally connected to each 24 of the exhaust interposer control rods 42 and the coupler lever 46 is pivotally connected to each of the intake interposer . .
26 control rods 41. Each coupler lever 45-46 has an end extension 27 48 through which the actuation control link 44 passes.
28 Separate compression springs 49 extend in opposite directions 29 from the extensions 48 and abut against stops 51 fixed on the control link 44. The springs 49 permit the actuation control 8~

1 link 44 to be shifted in either direction without damage 2 even if the control links 41-42 are blocked against movement 3 for any reason. All that will happen is that the springs 4 49 ~ill be compressed. When the blocking force is removed, the compressed springs 49 will drive the coupler levers 45-46 6 in the direction the control link 44 was trying to move them.
7 This then will cause the desired movement of the control 8 links 41-42.-9 A mechanism for deliberatly blocking movement of the control rods 41-42 is provided. This is a control rod 11 interlock operative to block movement of interposers 34 into 12 a position to cause deactivation of the exhaust valves before 13 the intake valves are deactivated. The interlock comprises 14 a lever member 52 pivoted intermediate its ends on a pivot 53.
One end 54 is pivotally coupled to one of the control rods 16 41 at one side of the support plates 27-28 and the other end 17 55 pro~ects across a control rod 42 on the opposite side of the 18 plates 27-28. This control rod 42 has an upstanding pin 56 19 abuttlng an edge 57 of the projection 55, for a purpose that will become apparent.
21 The actuation control link 44 is sho~n in Fig. 1 as 22 being coupled to a solenoid 58 connected to a switch 59 23 operatively related to an accelerator pedal 61 coupled by a 24 cable 62 to a carburetor (not shown). At a predetermined throttle position, the solenoid 58 becomes energized to shift 26 the actuation control link 44 in a direction to ultimately 27 cause deactivation of the intake and exhaust valves of the 28 cylinders capable of being deactivated. It would be under-29 stood that additional controls on the actuation of the solenoid 58, a vacuum motor or equivalent or control link movement .

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o 1 inducer,can be built into the system as suggested by the 2 prior art. These might include an engine vacuum sensitive 3 control to prevent cylinders being cut-out during vehicle 4 acceleration regardless of throttle position or an engine temperature sensitive device to ensure full power operation 6 until the engine reaches normal operating temperature, or an 7 override switch to present less than full cylinder operation 8 at any time.
9 Operation of the control mechanism 10 in deactivation of selected cylinders may be summarized as follows:
11 Under full power conditions, the interposers 34 12 will be in the positions shown in Fig. 2. That is, each pair 13 f interposers will have their end portions 37 in abutting 14 relation to the stud~section 22 and interposed between the load bearinæ plate 28 and the upper ends of the load transfer 16 tubular members 24, see Fi~. 4. When in this condition, the 17 fulcrum 17 is immovable and provides a fixed axis about 18 which the rocker arm 12 rocks to transfer motion from the 19 push rod 14 to the valve stem 16.
If the sensing device or devices signal that the 21 engine could be operated on half the number of cylinders, 22 which signal is translated into energization of the solenoid 23 58 coupled to the actuation control link 44, the actuation control 24 link 44 will be shifted to the left as viewed in Fig. 2 to swing the couplers levers 45 and 46 in a clockwise direction 26 about their pivots 47.
27 The coupler lever 46 will cause the upper control 28 rods 41 to move in opposite directions. That is, the control 29 rod 41 adjacent the control link 44 will move to the left and the one on the opposite side of the support plates 27-28 will --11~
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1 move to the right. This will cause the interposers 34 2 associated with the intake valves to move clockwise about 3 their pivots 36 and the end portions 37 to move out of 4 abutting position relative the studs 18 to a position beyond the path of upward movement of the load transfer tubular 6 members 24 ( see Fig. 5) . The interposers 34 associated with 7 the exhaust valves will be acting in the same manner as the 8 control rods 42 move in synchronism with the adjacent control 9 rods 41.
With the interposers in the position shown in Fi~. 5, 11 upward movement of the push rod 14 will cause the rocker arm 12 left end 13 to move upward and actually lift the fulcrum 17 13 and load transfer tubular member 24 axially of the stud 18 14 against the resistance of the spring 26. The pivot axis of the rocker arm then in effect is sh'Lfted from the fulcrum 17 16 to the top of the valve stem 16 and the valve remains in a 17 closed condition as the rocker arm rocks about the new pivot 18 axis.
19 To summarize, when the interposers 34 are moved from the Fig. 4 position to the Fig. 5 position the intake and 21 exhaust valves of the selected cylinders are deactivated. The 22 reverse actuation of the actuation control link 44 then ls re-23 quired to move the interposers 34 back into the gap between 24 the surface 35 of the load bearing plate 28 and the upper end of each load transfer tubular member 24 to reactivate the 26 selected cylinders.
27 The ~unction of the control lever 52 iS to ~revent 28 deactivation of the exhaust valves before the intake valves 29 are deactivated. Thus, if the intake control rod 41 coupled to the end 54 of the lever 52 runs into any force blocking - 12 - . .

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~7~7 1 its movement to the left as viewed in Fig. 2, the lever 52 2 will be held against movement in a clockwise direction. Its 3 edge 57 will lie in the path of the pin 56 projecting upwardly 4 from the exhaust control rod 42 lying beneath the end 55 of the lever 52. The exhaust control rod 42 on the one side is 6 tied into the exhaust control rod 42 on the other side of the 7 plates 27-28 by coupler lever 45 so none of the exhaust valve 8 associated interposers 34 can move from the Fig. 4 position to 9 the Fig. 5 position. As soon as the interlock lever 52 swings in a clockwise direction out of the path of pin 56, 11 thus signalling that deactivation of the intake valves is 12 occurring or has occurred, the deactivation of the exhaust 13 valves will occur.
14 It is to be understood this invention is not limited to the exact construction illustrated and described above, 16 but that various changes and modifications may be made without 17 departing from the spirit and scope of the invention as defined 18 by the following claims:

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Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In combination, a multi-cylinder internal combustion engine having intake and exhaust valves for each cylinder, each intake valve and exhaust valve being operable by a valve train including a rocker arm pivotal about a pedestal mounted fulcrum means, and a control mechanism for controlling the operation of the intake and exhaust valves for selected ones of the cylinders, the control mechanism comprising an interposer means assembly mounted on the engine, the interposer means assembly including an interposer member positioned adjacent the valve train of each intake and exhaust valve of the selected cylinders and being shiftable into a valve train disabling position to render the latter inoperative to actuate the valves, control rods interconnecting the intake interpos-ers of the selected cylinders to each other and the exhaust interposers of the selected cylinders to each other, a selection actuator means, a combined actuation and interconnection link operable by the selection actuator means to actuate the control rods to shift the interposer members into and out of valve train disabling position, and mechanical interlock means coupled to the control rods ensuring that the exhaust valves are not deactivated until the intake valves are deactivated.

2. The multi-cylinder internal combustion engine of claim 1, wherein:
the fulcrum means comprises a load transfer means and the interposer means assembly includes a load bearing plate, and control of the operation of a given valve is accomplished by moving an interposer member into a gap between the fulcrum load transfer means and the load bearing plate to prevent movement of the fulcrum in response to operation of the rocker arm and thereby causing motion of the latter to be transferred to the given valve, whereby, with the interposer means out of position, the load transfer means is free to travel on the pedestal and the fulcrum to move with the rocker arm thereby causing the given valve to remain stationary.

3. In combination, a multi-cylinder internal combus-tion engine having intake and exhaust valves for each cylinder, each intake valve and exhaust valve being operable by a valve train including a rocker arm operatively engageable at one end by a rocker arm actuator and having operative engagement at its other end with valve, said rocker arm being pivotal about a pedestal mounted fulcrum means to transmit actuator motion to the valve, said valve train also including fulcrum supporting means positioned intermediate the ends of each rocker arm, each fulcrum supporting means being mounted on a surface of the engine and extending generally perpendicular to the mounting surface, each valve train also including load transfer means superposed on the fulcrum means, the fulcrum means and the superposed load transfer means being slidably supported on the fulcrum supporting means for movement from and toward the engine surface, and a control mechanism for controlling the operation of the intake and exhaust valves for selected ones of the cylinders, the control mechanism comprising an interposer means assembly mounted on the engine, the interposer means assembly including an interposer member positioned adjacent the valve train of each intake and exhaust valve of the selected cylinders, coacting with each load transfer means, and being shiftable into a valve train disabling position to render the latter inoperative to actuate the valves, said interposer member being mounted on support means for movement transversely of the fulcrum supporting means from a non-blocking position in said disabling position of said valve train into a position to block movement of the load transfer means and associated fulcrum means away from the engine surface thereby to maintain the fulcrum means in a substantially stationary position to provide a substantially fixed pivot axis about which each rocker arm is pivotable, said interposer member for each load transfer means when in non-blocking position with respect thereto permitting the latter and its related fulcrum means to reciprocate relative to the engine surface and render the rocker arm inoperative to transmit motion from the actuator to the valve, biasing means urging each load transfer means towards a position in which each interposer member is movable into blocking position contiguous to the load transfer means, control rods interconnecting the intake interposers of selected cylinders to each other and the exhaust inter-posers of the selected cylinders to each other, a selection actuator means, a combined actuation and interconnection link operable by the selection actuator means to actuate the control rods to shift the interposer member transversely of the fulcrum supporting means into and out of blocking position relative to the related load bearing means and thereby into and out of valve train disabling position, and mechanical interlock means coupled to the control rods ensuring that the exhaust valves are not deactivated until the intake valves are deactivated.

4. The multi-cylinder internal combustion engine of claim 3, wherein:
each fulcrum supporting means comprises an elongated stud having its longitudinal axis extending in a generally vertical direction to the engine surface, the rocker arm and fulcrum means have apertures through which the stud projects, the load transfer means comprises a tubular member encompassing the stud, and the load transfer means and the fulcrum means are constrained by the stud to movement along the longitudinal axis of the latter.

5. The multi-cylinder internal combustion engine of claim 4, wherein:
the interposer means comprises independent opposed levers pivotally mounted intermediate their ends on support plate means, the opposed levers are swingable in a plane normal to the axis of the stud and have end portions constructed and arranged to semi-encompass the stud upon the end portions being moved toward each other into abutting relation to the stud, and the lever end portions when semi-encompassing the stud are effective to block movement of the load transfer means axially of the stud.

6. The multi-cylinder internal combustion engine of claim 5, wherein:
the control rods are mounted on the support plate and coupled to the independent opposed levers, and the combined actuation and interconnection link is operable to shift the control rods in synchronized opposite directions of movement to pivot the independent opposed levers toward each other.

7. The multi-cylinder internal combustion engine of claim 6, wherein the biasing means comprises compression spring means externally encompassing each load transfer means tubular member and reacting against the support plate means to urge the tubular member axially of the fulcrum supporting means stud on which it is mounted out of the plane of movement of the opposed levers.

8. The multi-cylinder internal combustion engine of claim 3, wherein:
the interposer member comprises opposed levers pivotally mounted on support plate means positioned above the rocker arms, each fulcrum supporting means comprises an elon-gated stud having its longitudinal axis extending in a generally vertical direction relative to the engine surface on which each fulcrum supporting means is mounted, each stud at its end away from the engine surface projects through the support plate means, the opposed levers are swingable on the support plate means in a plane normal to the axis of the? related stud and have end portions constructed and arranged to partially surround the latter, and the lever end portions when encompassing the studs block movement of the coacting load transfer means tubular members axially of the support plate means.

9. The multi-cylinder internal combustion engine of claim 8, wherein:
the control rods are mounted on the support plate and coupled to the independent opposed levers, and the combined actuation and interconnection link is operable to shift the control rods in synchronized opposite directions of movement to pivot the independent opposed levers toward each other.

10. The multi-cylinder-internal combustion engine of claim 9, wherein the biasing means comprises compression spring means externally encompassing each load transfer means tubular member and reacting against the support plate means to urge the tubular member axially of the fulcrum supporting means stud on which it is mounted away from the plane of movement of the opposed levers.