WO2013020734A1

WO2013020734A1 - Speed-synchronized closing of a clutch

Info

Publication number: WO2013020734A1
Application number: PCT/EP2012/060662
Authority: WO
Inventors: Alexander Roesch
Original assignee: Robert Bosch Gmbh
Priority date: 2011-08-05
Filing date: 2012-06-06
Publication date: 2013-02-14
Also published as: DE102011080522A1

Abstract

The invention relates to a system (1) for speed-synchronized closing of a first clutch (3). The system (1) has a first clutch (3), an internal combustion engine (13), a first electrical motor (15) and a regulating unit (17). The first clutch (3) is connected to the internal combustion engine (13) on a first clutch side (5) and to the first electrical motor (15) on a second clutch side (7). The regulating unit (17) is designed to detect a coupling start (19) of the first clutch side (5) with the second clutch side (7) and to determine a speed (N₁) of the internal combustion engine (13) and a speed (N₂) of the first electrical motor (15) upon coupling start (19). The regulating unit (17) is further designed to adapt the speed (N₁) of the internal combustion engine (13) and the speed (N₂) of the first electrical motor (15) to each other after the coupling start (19).

Description

description

Speed-synchronized closing of a clutch prior art

Couplings are often used in many industries and in particular in the automotive industry. They are used to transmit torque between shafts. In motor vehicles couplings z. B.

disposed between an internal combustion engine and a transmission, which converts the force provided by the internal combustion engine into a movement of the wheels. In hybrid vehicles couplings z. B. used to switch between an electrical operation and a combustion operation.

In general, friction clutches are generally used in motor vehicles. However, these can be quite complex in construction and relatively expensive. In addition, there is always one for this type of clutch

Torque limitation. Alternative, cheaper types of couplings such as Clutches and jaw clutches are currently not used in comfort-determining areas, as these when closing or connecting the coupling halves due to a speed difference audible and possibly

noticeable torque change takes place.

Disclosure of the invention

There may therefore be a need for an improved possible noise and jerk-free way to close a cost-effective coupling during the movement of the opposite coupling halves. This object can be achieved by the subject matter of the present invention according to the independent claims. Advantageous embodiments of the present invention are described in the dependent claims. The following are features, details and possible benefits of one

Device according to embodiments of the invention discussed in detail.

According to a first aspect of the invention, a system for speed-locked closure of a first clutch is presented. The system comprises a first clutch, an internal combustion engine, a first electric motor and a control unit. The first clutch has a first clutch side and a second clutch side. The first clutch side is with the

Combustion engine and the second clutch side connected to the first electric motor. The control unit is executed, a

Clutch start of the first clutch side with the second clutch side to detect and at Einkupplungsbeginn a speed of

Determine internal combustion engine and a speed of the first electric motor. Furthermore, the control unit is designed to match the speed of the internal combustion engine and the rotational speed of the first electric motor to each other after the start of coupling.

In other words, the idea of the invention is based on controlling the speed difference of the two coupling halves to about zero, after the corresponding elements are in the correct position. That z. B. in a dog clutch after a claw on the first side of the clutch a

Recess on the other side of the clutch is located. In this way, a "tooth on tooth" is avoided at the start of coupling by at least a slight difference in rotational speed of the two coupling halves After "the teeth have found the gaps", the speed difference is reduced to zero, so that when the two coupling halves are touched in a positive manner a shock resp a jerk is avoided. This is made possible by a fast control technology and in particular a very fast control of the first electric motor by the control unit. The regulation of the electric motor can take place, for example, in the millisecond range. Thanks to the system according to the invention can for connecting a

Internal combustion engine with an electric motor z. B. in hybrid vehicles technically simpler and less expensive couplings such. B.

Jaw clutches or one-way clutches are used without any loss in ride comfort are expected.

The system according to the invention can be used in pure coupling applications e.g. be used in the commercial vehicle sector or work machine area. Furthermore, the system according to the invention can be used in the motor vehicle sector, in particular in hybrid vehicles. The use in a transmission is possible to switch gears without synchronization rings (friction clutches).

The first clutch may e.g. be mechanically, electromagnetically, hydraulically or pneumatically switchable. Furthermore, the coupling can be designed as a self-switching or externally switched coupling. In this case, the coupling can preferably be made non-positively or positively. For example, The clutch can be designed as a freewheel clutch, dog clutch or gear coupling. The first clutch can be arranged on a drive train which connects an internal combustion engine with a transmission.

The internal combustion engine may, for. B. be a gasoline or diesel engine. The first electric motor may be an electric machine, the z. B. is designed as a permanently excited three-phase synchronous machine. The first electric motor may be responsible for an electrical drive torque at the transmission input. Optionally, the first electric motor may be the main momentum carrier throughout the powertrain.

The control unit, also referred to as control electronics, can be connected bidirectionally with the first clutch, the first internal combustion engine and the first electric motor. The control unit can also be realized by a distributed system of several units communicating with each other. That is, the control unit may, for. B. receive signals such as position or speed signals from the individual elements and a

Send control signal to the respective elements. In this case, for example, on the drive train, in particular on the first clutch Position sensors such. B. Hall sensors, displacement sensors or time sensors may be provided.

The first clutch has a first clutch side and a second one

Clutch side up. The first coupling side and the second coupling side may, for. B. symmetrical. If appropriate, the first coupling side can be connected to the internal combustion engine via a second coupling. The second coupling side can, for. B. permanently connected to the first electric motor.

The control unit is designed to detect an engagement start of the first clutch side with the second clutch side. Of the

Einkupplungsbeginn can z. B. be the time or the process state, in which the first coupling side a predetermined distance to the second

Has coupling side. In this case, the control unit can the

Detecting the start of coupling by means of displacement sensors, for example on the first and on the second coupling side. Furthermore, the

Control unit detect the Einkupplungsbeginn on position sensors such as Hall sensors. In addition, the

Einkupplungsbeginn be detected by means of time sensors characterized in that a predetermined time interval is measured after actuation of the first clutch. In particular, with claw and toothed clutches can as

Einkupplungsbeginn be set the time at which the teeth and recesses of the opposite coupling sides are opposite, so that the coupling sides can be moved towards each other.

Once an engagement start has been determined by the control unit, the control unit determines a rotational speed of the internal combustion engine and a rotational speed of the first electric motor. In this way, the speed of the first clutch side and the second clutch side can be determined automatically and from this the speed difference can be calculated. For this purpose, speed sensors may be arranged on the internal combustion engine and on the first electric motor. Alternatively or additionally, the rotational speed can be determined with the aid of the position sensors of the individual phases of the first electric motor on the first electric motor. On the internal combustion engine can be a speed with the help of

Crankshaft sensor or indirectly by determining a firing angle and the Injection quantity can be determined. The speeds of the internal combustion engine and the first electric motor can be continuous or in certain

Time intervals are determined. After the start of coupling the control unit is designed, the

Speed of the internal combustion engine and the speed of the first electric motor to match each other such that at Einkupplungsende the difference in rotational speeds is about zero. The speeds can be z. B. thereby

be equalized that the speed of the first electric motor is reduced and optionally the speed of the engine is increased or vice versa. Preferably, the rotational speed of the first electric motor is adapted to the rotational speed of the internal combustion engine. In this way, a full synchronization of the two sides of the clutch can be achieved and clawing the teeth or claws each other can be avoided in claw and tooth clutches. However, synchronization will not take place until the teeth or jaws and opposite gaps in the coupling sides have been found to avoid a "tooth on tooth" on the coupling sides, which can be controlled quickly and accurately, preferably by the speed of rotation As a result, the closing of the clutch is much more comfortable.

In the case of an overrunning clutch, however, the synchronization proceeds somewhat differently from the claw and tooth clutches according to the same principle as described above. To make a one-way clutch comfortable, i. Without a "jerk" to bring into a positive fit, the speeds of the two freewheel halves in the

Range, so shortly before and after the speed equality slowly pass, for example in the form of a parabola or similar geometric function. Only after the positive engagement of the two coupling halves is the torque of the newly connected element (e.g., the internal combustion engine or the electric machine) raised to a desired value.

According to an embodiment of the invention, the rotational speed of the internal combustion engine and the rotational speed of the first electric motor are adjusted in response to a distance of the first clutch side from the second clutch side to each other. Ie, z. As in a dog clutch, the difference in rotational speeds is reduced in dependence on a positive connection distance. Different In other words, the closer the first clutch side and the second clutch side come, the more the difference between the rotational speed of the engine and the rotational speed of the first electric motor is reduced. When form fit both sides of the clutch with each other, the speeds of the engine and the first electric motor are about the same. In this case, the speed difference may be inversely proportional to the form-fitting distance of the coupling halves. Alternatively, the reduction of the speed difference may be followed by another algebraic function such as a parabola. According to a further embodiment of the invention is the

Control unit executed at Einkupplungsbeginn the speed of the

Internal combustion engine and the speed of the electric motor to regulate different values. In other words, the control unit directly controls the rotational speeds of the internal combustion engine and of the first electric motor

Clutch start so that the speed difference is not zero, but at least a small delta speed is present. This will

ensuring that the coupling halves are not tooth to tooth and can be brought together. In this way, a safe insertion of the first coupling half is ensured in the second coupling half.

According to a further embodiment, the control unit is designed to detect a Einkupplungsende and to regulate the Einkupplungsende the speed of the engine and / or the speed of the electric motor to a predetermined target value.

The Einkupplungsende can z. B. be the time at which the

Coupling halves are in positive engagement, ie, when the distance between the first and the second coupling half is zero. The coupling end can be detected, for example, via a time, position or displacement sensor. After the end of the engagement process, ie after the clutch end, in particular the torque of the first electric motor can be regulated to a predefinable desired value. The predefinable setpoint value can be specified, for example, by the control unit or indirectly by a user. According to a further embodiment of the invention, the system further comprises a second electric motor which is connectable to the internal combustion engine. The control unit is executed, the second

To control electric motor such that the second electric motor controls the speed of the engine.

According to a further exemplary embodiment of the invention, the system has a second clutch which is arranged between the internal combustion engine and the second electric motor such that the internal combustion engine can be driven, regulated and / or started by the second electric motor when the second clutch is closed.

The second electric motor may, for. B. be made slightly smaller than the first electric motor and represent a permanently excited three-phase synchronous machine. The second electric motor may be responsible for the start of the internal combustion engine and be arranged on the drive train. For example, the second electric motor is arranged between the first coupling side and the internal combustion engine. The second clutch may be designed in analogy to the first clutch and be similarly controlled by the control unit. For example, the second clutch is a freewheel or dog clutch. The second clutch may be configured to decouple the engine from the second electric motor. The use of the second electric motor, especially when starting the engine, the load of the first electric motor or the

Control unit, which is connected to the first electric motor, reduce. By the first clutch, for example, the first and the second electric motor can be interconnected. The second electric motor can actively regulate the rotational speed of the internal combustion engine, for example, by driving it and holding it at a constant rotational speed, which without the second electric motor is somewhat

can be irregular. Thus, the rotational speed curve of the internal combustion engine is "smoothed" by the second electric motor and thus enables a comfortable engagement procedure. According to one embodiment of the invention, the first clutch is designed as an overrunning clutch. The overrunning clutch can be designed to switch automatically, ie without additional actuators, at a speed difference of the two coupling halves. The use of one-way clutches between an internal combustion engine and a first electric motor can be advantageous, in particular in hybrid vehicles, since they are more cost-effective compared to clutches generally used.

According to one embodiment of the invention, the first clutch is designed as a dog clutch. The claws of the claw coupling can be chamfered. The second clutch may also be designed as a claw or one-way clutch. In this case, the first and the second clutch can be designed as the same or different types of coupling.

According to a second aspect of the invention, the use of the above system in a hybrid vehicle is presented. The hybrid vehicle is, for example, a motor vehicle with an internal combustion engine and a first electric motor.

According to a second aspect of the invention, a method for speed-locked closure of a first clutch is presented. The method comprises the following steps: arranging a first clutch between an internal combustion engine and a first electric motor; Connecting a first coupling side with the internal combustion engine and a second

Coupling side with the first electric motor; Providing a control unit operatively connected to the first electric motor, the internal combustion engine and the first clutch; Detecting a Elnkupplungsbeginns the first clutch side with the second clutch side through the

Control unit; Determining a speed of the internal combustion engine and a rotational speed of the first electric motor at Einkupplungsbeginn by the

Control unit; Adjusting the speed of the internal combustion engine and the speed of the first electric motor to each other after the start of coupling by the control unit.

Other features and advantages of the present invention will become

Expert from the following description of exemplary Embodiments, which should not be construed as limiting the invention, with reference to the accompanying drawings.

Fig. 1 shows a schematic structure of the system according to a first

Embodiment of the invention

Fig. 2 shows a section of the first coupling according to a

Embodiment of the invention

Fig. 3 shows the control of the difference of the rotational speeds of the first

Electric motor and the internal combustion engine in response to a

Form-fitting distance

Fig. 4 shows a schematic structure of the system according to a second embodiment of the invention

All figures are merely schematic representations of devices according to the invention or of their components according to embodiments of the invention. In particular, distances and size relationships are not shown to scale in the figures. In the various figures, corresponding elements are provided with the same reference numbers.

In Fig. 1, an embodiment of the system 1 for speed-synchronized closing of a first clutch 3 is shown. The first clutch 3 is arranged on a drive train 9. On the first

Coupling side 5, the first clutch 3 is connected to an internal combustion engine 13. On the second clutch side 7, the first clutch 3 is connected to a first electric motor 15 and a transmission 11. A

Control unit 17, also referred to as power electronics, is on

Combustion engine side and on the electric motor side of the first clutch 3 redundantly connected to the individual elements of the drive train 9. That is, the control unit 17 can determine both a rotational speed Ni of the internal combustion engine 13 and a rotational speed N _{2 of} the first electric motor. Furthermore, the control unit 17 can detect a start of coupling of the first coupling side 5 with the second coupling side 7. This can be done for example via way or position sensors on the first clutch 3. Further, the control unit 17 can control the rotational speed Ni of the engine 13 and the rotational speed N _{2 of} the first electric motor 15. In particular, the

Control unit 17, the rotational speeds Ni, N ₂ equal to each other. In Fig. 1, the first clutch 3 is exemplified as a dog clutch. The first clutch 3 is in an open state, and the claws of the first clutch side 5 are opposite to the claws of the second clutch side 7. At the same rotational speeds Ni, N ₂ on both clutch sides 5, 7 would be a

Close the first clutch 3 not possible. Therefore is at

Einkupplungsbeginn a certain difference between the speeds Ni, N ₂ on the two sides of the first clutch 3 necessary. This can be done by the

Control unit 17 can be adjusted.

In the event that the first clutch 3 is designed as an overrunning clutch, this can be designed self-switching. Is the speed N _{2 of} the first

Electric motor 15 is greater than the rotational speed Ni of the internal combustion engine 13, the overrunning clutch freewheeling. Is the speed N _{2 of} the first

Electric motor 15 is smaller than the rotational speed Ni of the internal combustion engine 13, go the clutch sides 5, 7 of the one-way clutch a positive engagement, and the clutch is closed.

In Fig. 2 is a section of the first clutch 3, which is designed as a claw clutch with chamfered claws shown. 2, the claws of the first coupling side 5 are opposite recesses of the second coupling side 7, so that a closing of the coupling is possible. This is going through

different speeds Ni, N ₂ on the two coupling sides 5, 7 achieved. At Einkupplungsbeginn the first clutch side 5 and the second clutch side 7 are at a certain distance X from each other. This distance is also referred to as positive locking distance X. The control unit 17 can detect, for example, a start of coupling as soon as the

Forming distance X falls below a threshold X ₀ . In Fig. 3, the control of the difference of the rotational speeds Ni, N _{2 of} the first

Electric motor 15 and the internal combustion engine 13 as a function of the form-fitting distance X shown. The form-fitting distance X is plotted in millimeters on the abscissa. On the ordinate, the difference Δ (Ni, N ₂ ) of the rotational speeds Ni, N _{2 of} the first electric motor 15 and the internal combustion engine 13 is plotted. The difference between the speeds is shown in revolutions per minute. At a positive connection distance X> X ₀ , the first clutch 3 is open. Approximately at a difference of the rotational speeds Ni, N ₂ of 30 to 50 revolutions per minute, the engagement process is initiated and a start of coupling 19 detected by the control unit 17. The smaller the positive connection distance X becomes, the smaller the difference Δ (Ni, N ₂ ) becomes. At a form-fitting distance of X = 0, that is, when the first clutch 3 is closed, the speed difference is also zero.

After the first clutch 3 is now closed, detects the

Control unit 17 a Einkupplungsende 21 and controls, for example, the speed N _{2 of} the first electric motor 15 to a predetermined setpoint.

Thanks to this approach and the structure of the system 1 is a

Popping noise and a jerking when closing the first clutch 3 avoided.

This is achieved by the fact that the precise speed control of the first electric motor 15 with the first engagement of the coupling halves reduces the difference in rotational speeds such that the difference Δ (Ni, N ₂ ) of the rotational speeds Ni, N _{2 is} zero when the two coupling sides are positively contacted.

In Fig. 4, the application of the system 1 using the example of a hybrid vehicle, which is designed for example as a parallel or as a serial hybrid is shown. In addition to the elements shown in FIG. 1, the system 1 has a second electric motor 23, which is arranged in the drive train 9 and can be connected to the internal combustion engine 13 via a second clutch 25. The gear 11 is connected to the wheels 29 of the vehicle. Furthermore, in the exemplary embodiment illustrated in FIG. 4, the control unit 17 has a first control element 33 for the first electric motor 15 and a separate second control element 35 for the second electric motor 23. The power electronics of the two electric motors is thus designed separately, and the electric motors 15, 23 can be controlled independently of each other. Further, in the control unit 17, a DC-DC converter 31 and a charger 37 for charging a battery 27 z. B. in a generator operation of the first electric motor 15 is provided. For example, in the event that the first clutch 3 is opened, the first electric motor 15 provide for startup of the hybrid vehicle and the second electric motor 23 with the second clutch 25 closed provide the

Start internal combustion engine 13. Alternatively, the first clutch 3 may be closed and the second clutch 25 may be opened so that when starting both

Electric motors 15, 23 are used. In this case, the rotational speed Ni of the internal combustion engine 13 can be quickly adjusted by an accurate speed determination of the second electric motor 23 to the rotational speed N _{2 of} the first electric motor 15. The second electric motor 23 can significantly accelerate the matching of the rotational speeds Ni, N ₂ . At speed synchronism of the first electric motor 15 and the second electric motor 23 and des

Internal combustion engine 13, the first clutch 3 can be closed without jerking and noiseless.

In hybrid operation, both the first and second electric motors 15, 23 may function as motors. Alternatively, one of the

Electric motors 15, 23 act as a generator. Furthermore, both can

Electric motors 15, 23 act as a generator. The electric motor 23 can additionally be used as an engine starting device. In electric operation of the vehicle, both the first and second electric motors may be used to drive the vehicle. The electric motor 23 and the second clutch 25 can be omitted with the additional use of a separate starting device for the internal combustion engine 13.

In conclusion, it should be noted that terms such as "comprising" or the like are not intended to exclude that other elements or steps may be envisioned.Furthermore, it should be understood that "a" or "an" does not exclude a multitude It should further be noted that the reference signs in the claims should not be construed as limiting the scope of the claims.

Claims

claims

System (1) for the speed-synchronized closing of a first clutch

(3) having the system

a first clutch (3);

an internal combustion engine (13);

a first electric motor (15);

a control unit (17);

wherein the first clutch (3) has a first coupling side (5) connected to the

Internal combustion engine (13) is connected and a second coupling side (7) which is connected to the first electric motor (15) has;

wherein the control unit (17) is executed, a Einkupplungsbeginn

(19) to detect the first coupling side (5) with the second coupling side (7);

wherein the control unit (17) is designed to determine a speed (Ni) of the internal combustion engine (13) and a rotational speed (N ₂ ) of the first electric motor (15) at the start of coupling (19);

wherein the control unit (17) is designed according to

Einkupplungsbeginn (19) the speed (Ni) of the internal combustion engine (13) and the speed (N ₂ ) of the first electric motor (15) to each other

equalize.

System (1) according to claim 1,

wherein the rotation speed (Ni) of the internal combustion engine (13) and the rotation speed (N ₂ ) of the first electric motor (15) are made equal to each other depending on a distance of the first coupling side (5) from the second coupling side (7).

System (1) according to one of claims 1 and 2,

wherein the control unit (17) is designed to control the rotational speed (Ni) of the internal combustion engine (13) and the rotational speed (N ₂ ) of the first electric motor (15) to different values at the start of coupling (19). System (1) according to one of claims 1 to 3,

wherein the control unit (17) is adapted to detect a Einkupplungsende (21);

wherein the control unit (17) is designed to control after the Einkupplungsende (21) the speed (Ni) of the internal combustion engine (13) and / or the rotational speed (N ₂ ) of the first electric motor (15) to a predetermined target value.

The system (1) according to any one of claims 1 to 4, further comprising a second electric motor (23) connectable to the internal combustion engine (13);

wherein the control unit (17) is designed to control the second electric motor (23) in such a way that it controls the rotational speed (N-i) of the

Internal combustion engine (13) controls.

The system (1) of claim 5, further comprising

a second clutch (25);

wherein the second clutch (25) between the internal combustion engine (13) and the second electric motor (23) is arranged such that the

Internal combustion engine (13) in the closed second clutch (25) by the second electric motor (23) can be driven, regulated and / or startable.

System (1) according to one of claims 1 to 6,

wherein the first clutch (3) is designed as an overrunning clutch.

System (1) according to one of claims 1 to 6,

wherein the first clutch (3) is designed as a dog clutch.

Use of the system (1) according to one of claims 1 to 8 in a hybrid vehicle.

A method of speed synchronized closing a first clutch (3), the method comprising the following steps

Arranging a first clutch (3) between an internal combustion engine (13) and a first electric motor (15); Connecting a first coupling side (5) to the internal combustion engine (13) and a second coupling side (7) to the first electric motor (15); Providing a control unit (17) which is operatively connected to the first electric motor (15), the internal combustion engine (13) and the first clutch (3);

Detecting a start of engagement (19) of the first clutch side (5) with the second clutch side (7) by the control unit (17);

Determining a speed (Ni) of the internal combustion engine (13) and a rotational speed (N ₂ ) of the first electric motor (15) at the start of coupling (19) by the control unit (17);

Aligning the rotational speed (Ni) of the internal combustion engine (13) and the rotational speed (N ₂ ) of the first electric motor (15) after the coupling start (19) to each other by the control unit (17).