GB2319579A

GB2319579A - Clutch control which increases clutch torque when an anti-slip regulation is activated

Info

Publication number: GB2319579A
Application number: GB9722810A
Authority: GB
Inventors: Michael Salecker; Martin Zimmermann
Original assignee: LuK Getriebe Systeme GmbH
Current assignee: LuK Getriebe Systeme GmbH
Priority date: 1996-11-05
Filing date: 1997-10-30
Publication date: 1998-05-27
Anticipated expiration: 2017-10-30
Also published as: JPH10148222A; DE19747925A1; JP3953603B2; GB9722810D0; FR2755409B1; FR2755409A1; GB2319579B; BR9705414A; DE19747925B4

Abstract

A motor vehicle comprises a control unit 50, for controlling an automatic operation of clutch 3, which is in signal connection with at least one anti-slip regulation electronic unit 100, eg ABS electronics. This unit 100 issues a control signal 102, when it is activated in a slip situation, to the control unit 50 which increases clutch torque, when the engine speed is within a predefinable speed, from an actual controlled value to a maximum value. When the anti-slip regulation is activated, the speed of response of the control unit 50 is equal to or greater than the response speed without the presence of the control signal 102, hence the torque or an engagement position of the clutch 3 is not substantially changed. The control unit 50 controls an electric motor 19 coupled to an actuator 15 that supplies pressurized fluid via master cylinder 30 to slave cylinder 18 which acts on the clutch 3 by a disengagement bearing 12 and a fork 12.

Description

MOTOR VEHICLE The invention relates to a motor vehicle with a device for the automatic operation of an assembly such as for example a gearbox and/or a torque transfer system, such as clutch, in the drive train of a motor vehicle with at least one control unit for controlling the automatic operation of the clutch, which is in signal connection with at least one anti-slip regulating electronics unit, with at least one actor controllable by the at least one control unit.

Furthermore the invention relates to a method relating to same.

Anti-slip regulating systems are generally known. They are for example described by DE Magazine Article Auto & Technik, vol. 1, 1992, pps. 104 to 112. These systems act quickly in the case of a wheel slip situation on the engine moment by means of a throttle valve control or cn the brake force of individual wheels by means of anti blocking systems. The drive power of the slipping wheels is thereby reduced and the slip broken down.

Motor vehicles of this kind are known or example from DE 43 16 421 and EP 0 259 634. The EP 0 259 634 discloses a deliberate control of a clutch for disengaging the clutch when an anti-slip regulation is active. The DE 43 16 421 discloses that in the case of an active anti-slip regulation the clutch remains in its position or is engaged or disengaged at a reduced speed compared to the otherwise usual operating speed. The aforementioned procedure and methods of the devices in the case of active anti-slip regulation have the disadvantage that on the one hand the drive connection between the engine and drive train is opened and thus where applicable drive torque no longer exists and thereby where applicable the vehicle can enter into a safety-critical situation if a power demand is desired by the driver despite active anti-slip regulation.

Furthermore it can be disadvantageous if the clutch is held in its actual position when an anti-slip regulation is activated or if the clutch is closed more slowly than without the presence of an activity of an anti-slip regulation. This has the drawback that an increased slip is built up in the area of the clutch or this is deliberately broken down at a slower rate. This produces where applicable an increased wear and/or an increased energy input for example in the area of the friction faces of the clutch. Furthermore there is the drawback that with an operating situation with an active anti slip regulation and a control or regulation of the clutch in a clutch position between the fully engaged position and the fully disengaged position, cf DE 195 04847, the two regulations or controls (anti slip regulation and clutch position regulation or control) have a detrimental effect on each other and results in vibrations in the regulation and control behaviour.

The object of the invention is to provide a device with an automated assembly, such as for example a clutch and/or a gearbox for a motor vehicle with at least one anti-slip regulation which with an advantageous safety behaviour nevertheless causes the lowest possible strain (thermal and mechanical strain) on the assembly such as the clutch.

Furthermore it is the object of the invention to provide a device which at least reduces the disadvantages of the prior art. Furthermore the object is to design the control behaviour of the automated clutch and the control unit belonging to same so that mutual detrimental effects of the relevant regulations or controls are reduced or prevented.

According to the invention this is reached in that with an automated operation of a clutch with the presence of a control signal of the anti-slip regulation indicating an activity the control unit controls by means of the actor the torque transferable by the clutch from the value of the transferable torque actually controlled substantially to a maximum value of the transferable torque..

With a mctor vehicle with a device for the automated operation of a clutch in the drive train with a drive assembly, a gearbox and a clutch, such as for example a friction clutch, with at least one control unit for controlling the automated operation which is in signal connection with sensors and where applicable other electronics units, such as an engine electronics, an ABS electronics and/or an anti-slip regulating electronics unit, wherein the anti slip regulating electronics issues a control signal in the case of activity in a slip situation, with an actor controllable by the at least one control unit for operating the clutch, this can likewise be achieved if with an automated operation of the clutch, with a presence of a control signal of the anti-slip remllation, which shows that the anti-slip regulation is active, the control unit controls the clutch from the actual engagement position into a substantially fully engaged engagement position.

It is advantageous if in addition to the automated operation of the clutch an automated operation of the gearbox likewise takes place by means of an actor and a control unit controlling the actor. An automated operation can hereby be a fully automatic gear change process or a shift and/or selection process desired on the part of the driver and controlled by at least one actor.

It can likewise be expedient if the control of the increase of the torque transferable by the clutch or the operation of the clutch for adjusting a clutch position to the engagement position by means of the control unit and the actor with the presence of a control signal of the anti-slip regulation indicating an activity, takes place at a speed which is equal to or greater than the speed which can be controlled with a control without the presence of a control signal of the anti-slip regulation or would be controlled by the control unit.

It is particularly expedient if a control of the increase of the torque transferable by the clutch with the presence of a control signal of the anti slip regulation indicating an activity, takes place at a speed which is equal to or greater than the speed which with a control can be controlled without the presence of a control signal of the anti slip regulation even if without the presence of such a control signal the transferable torque or the engagement position of the clutch would not be substantially changed.

It can furthermore be advantageous if a control of the transferable torque or of the engagement position of the torque transfer system with the presence of a control signal of the anti-slip regulation indicating an activity, takes place at a speed which is equal to or greater than the speed which is controllable with a control without the presence of a control signal or anti-slip regulation (ASR) even if without the presence of such a control signal the transferable torque or the engagement position of the torque transfer system would not be substantially changed.

It can likewise be advantageous if a control of the increase of the torque transferable torque by the clutch with the presence of a control signal of the anti-slip regulation indicating an activity, takes place with a predefinable speed which is equal to or greater than the speed which can be controlled with a control without the presence of a control signal of the anti-slip regulation even if without the presence of such a control signal the transferable torque or the engagement position of the clutch in the actual operating area would not be substantially changed.

Furthermore it is expedient if the control unit controls the torque transferable by the torque transfer system during an activity of an anti-slip regulation to a maximum value or controls the clutch engaged, at least for as long as there is no control signal deviating therefrom, by way of example in the case of a shift process.

It is likewise expedient if the control unit with the presence of an activity of the anti slip regulation generates a control signal for engaging the clutch only in the case of an engine speed n t > a predefinable speed.

This predefinable speed (engine speed) can be for example a speed limit in the area of 1200 1/mien to 2000 1/min.

It can thereby likewise be advantageous if the control unit with the presence of an activity of the anti slip regulation generates a control signal for engaging the clutch in the case of an engine speed nwe > idling speed plus a predefinable value (nmt > idling speed + WERT). This value of WERT can be for example in the range from 200 1/min to 1000 1/min.

Furthermore it can be advantageous according to the invention if the control unit generates a control signal for engaging the clutch only with a control signal generated and/or transferred by the anti slip regulation and with the presence of the control signal of the control unit the actor is controlled and the clutch engaged.

It is expedient if the control unit only generates a control signal for engaging the clutch in the case of a control signal generated and/or transferred by the anti slip regulation and in the presence of an engine speed greater than a predefinable engine speed (n > WERT ~ n) and with the presence o the control signal of the control unit the actor is controlled and the clutch engaged.

Furthermore it is advantageous if the control unit after a presence of a control signal which signals the activity of an anti-slip regulation and/or with the presence of a signal which signals an end of an activity of an anti-slip regulation controls the transferable torque of the clutch to a value adapted to the actual operating position. The actual operating position is thereby determined based on at least some of the signals, such as the engine speed, gear input speed, gear output speed, the gear engaged in the gearbox, the accelerator pedal operation, the vehicle speed, the engine moment and other signals of the vehicle.

It is likewise expedient if the transferable torque controlled to a value adapted to the operating position assumes a value substantially in a range between a minimum value and a maximum value.

It is advantageous if the minimum value is substantially zero and the maximum value is substantially the maximum adjustable value.

According to a further inventive idea it is particularly advantageous with a method for controlling a torque transferable by a clutch of a motor vehicle by means of a device for the automated operation of a clutch, with a control unit for controlling the automated operation of the clutch which is in signal connection with an anti-slip regulating electronics which issues a control signal when it is active in a slip situation, with an actor controllable by the control unit for adjusting the torque transferable by the clutch and controlled by the control unit if the control unit in the case of an automated operation of the clutch carries out the following steps: - Evaluation whether the control unit has a control signal indicating an activity of the anti slip regulation; - with the presence of this signal the control of the torque transferable by the clutch by means of the actor from the value of the transferable torque actually controlled to a maximum value of the transferable torque.

According to a further idea according to the invention it can be expedient if a method for controlling an assembly is used which operates or controls a device mentioned above.

The invention will now be explained in further detail with reference to the drawings in which: Figure 1 is a diagrammatic illustration of a vehicle with a device according to the invention and Figure 2 is a diagram.

Figure 3 is a block circuit diagram.

Figure 1 shows a motor vehicle 1 with drive assembly 2 such as for example an internal combustion engine and/or hybrid drive assembly andor electric motor, with a torque transfer system 3 such as a clutch and a gearbox 4 wherein a drive axle 5 is mounted on the output side of the gearbox and drives by means of a differential 6 two drive shafts 7a and 7b which in turn drive the driven wheels 8a and 8b.

The torque transfer system 3 is shown as a friction clutch on a flywheel 9 with pressure plate 10, clutch disc 11, disengagement bearing 12 and disengagement ork 13 wherein the disengagement fork is force-biased by an actor 15 with a master cylinder 16 of a pressurised medium pipe 17, such as hydraulic pipe, and a slave cylinder 18. The actor 15 is shown as an actor operated by pressurised medium and having an electric motor 19 which operates through a gearbox (not shown) the master cylinder piston 20 so that the torque transfer system such as clutch can be engaged and disengaged through the pressurised medium pipe 17 and the slave cylinder 18. Furthermore the actor housing comprises the control unit 50 with electronics for operating and controlling the actor 15, that is both the power electronics and also control electronics. The actor is provided with a snifting bore 21 which is connected to a reservoir 22 for the pressurised medium. The control unit is thus integrated in the actor 15 wherein it can however also be installed in a separate housing. The control unit 50 likewise controls the actor 60 for the automated operation of the gearbox.

The actor 60 contains for example electric motors and gearbox for operating shift elements of the gearbox 4 inside same. The gears thereby convert the rotational movement of the electric motor output shaft into operating movement. A gear detection sensor 31 is mounted on the gearbox 4 of the vehicle or on the actor 60 to detect at least the gear position actually engaged and feed same to the control unit 50.

The gearbox can be operated manually by means of a shift lever or automatically by means of an actor controllable by the control unit.

The motor vehicle 1 with an automated gearbox 4 has an operating element 30 on which is mounted at least one shift intent sensor or gear selection sensor 32 which detects a shift intent of the driver or a gear operation on the part of the driver and sends this information to the control unit. Furthermore the vehicle is equipped with at least one speed sensor 33 which detects the speed of the gear output shaft and wheel speeds respectively. Furthermore there is a throttle valve sensor 34 to detect the throttle valve position and a speed sensor 35 to detect the engine speed.

The gear detection sensor 31 detects the position of shift elements inside the gearbox or the gear engaged in the gearbox 4 so that by means of the signal at least the engaged gear is registered by the control unit 50.

Furthermore when using an analog sensor the mc-rement of the shift elements inside the gearbox can be detected so that early detection cf the next gear engaged can be carried out.

Furthermore the control unit 50 can also consist of two or more individual control units which can also oe mounted in different housings.

The actor 15 is ed from a battery 40 wherein the at least one actor 15, 50 has a permanent current connection.

Furthermore the device has a generally multi-stepped ignition switch 41 which is operated as a rule by the ignition key whereby the lead 42 to the starter of the internal combustion engine 2 is switched on. A signal is sent through the lead 43 to the electronics unit of the actor 15 after which the actor 15 is activated when the ignition is switched on. The device has a sensor or switch 44 which is for example a brake pedal switch which is likewise connected through the lead 45 to the control unit and at the same time the brake -light 47 fcr example is switched through the lead 46. If now when the ignition is not switched on, that is with an opened switch 41 the brake is operated then the switch 44 closes and the control unit of the actor 15 is activated through the connection 45 so that when the shift lever is operated before te ignition is switched on a reaction of the torque transfer system can take place and the clutch can be disengaged at the right time.

The illustrated embodiment is not restricted only to a device operated by pressurised medium, but devices which have a purely mechanical force transfer for disengaging the torque transfer system can also be expedient n some cases.

Such devices operate a disengagement member or disengagement bearing directly or through a rod linkage or through a flexible connection.

The control unit 50 of the automated torque transfer system and/or automated gearbox is in signal connection with a control unit 100 of an anti-slip regulation through a signal connection 102. Furthermore the control unit 50 can be in signal connection with a control unit 101 of an antiblocking system ABS and/or with a control unit of a traction control. The control units are in connection with sensors and/or other electronics units through the signal connections 143, 14 and/or 105.

If for example the control unit 100 of the anti-slip regulation controls a deliberate brake operation and/or an engine moment engagement, then the control unit 100 sends to the control unit 50 a signal indicating an activity. The control unit 50 in turn generates with the presence of this signal and with the presence of a suitable engine speed a control signal which shows that the anti-slip regulation is active.

With the presence of this signal the control unit controls the torque transferable by the torque transfer system or the engagement position of the torque transfer system according to the features described above.

Figure 2 shows a diagram in which a transferable clutch mordent 201 and a signal 202 are recorded as a function of tie t. The signal 202 shows whether an anti-slip regulation is regarded by the control unit 50 as active, such as with an activity of the anti-slip regulation ASR and with the presence of a sufficiently high engine speed.

In the time area between to and t1 the ASR system is not active and the transferable clutch moment 201 is controlled in the manner of moment matching a value between a moment from zero and a maximum moment depending on requirements and existing engine moment. At time point t1 the ASR control is activated and the transferable clutch moment is increased to the maximum value which is reached at tmax-wert. Between tN and t2 the ASR system is active and the transferacle cluthc moment is controlled to the maximum value. At title point t2 the anti-slip regulation is activated and the transferable clutch moment 201 is reduced to a value belonging to the operating situation.

The speed at which the clutch is closed between t and tmax-wert is determined from a maximum value between the actual speed vwtu.ll and a predefinable speed vvorgabe . If vaktue@ vaktuell is above vVOw, then the clutch is closed with Vaktuoii until vaktuell is less than vvorgabe and then the clutch operation is followed up at the speed vvO- The curve 202 shows a signal ASR~Activ signalling an activity of the anti-slip regulation. This signal ASR~Activ 202 is without the presence of an ASR-activity equal to nil and with the presence of an ASR-activity substantially unequal to nil or equal to a predefinable value such as equal to one.

The present invention relates further to the prior application DE 195 04 847 whose contents belong exoressly to the disclosure of the present application.

The device according to the invention has the advantage that the slip occurring for example on the wheel does not or only slightly appear on the clutch and the control units of the anti-slip regulation and the clutch and/or gearbox operation do not have a considerable detrimental effect on each other.

Figure 3 shows a block circuit diagram 300 according to the invention for controlling the torque transferable by the clutch. In block 301 the control process is started for example in a sub-program of the control program. This start can be controlled by an event such as by a signal which is produced by the control unit which is produced for example with G comparison of wheel speeds if the wheel speeds have a predefinable slip, a predefinable differential speed from each other. The process can however also be called up repeatedly in the time cycle of the main program. This can take place for example every 10 to 100 ms.

In block 302 the actual operating situation of the vehicle is determined from at least some of the vehicle data such as engine speed, engine moment, gear input speed, gear output speed, vehicle speed, accelerator pedal position, gear transnission ratio brake operation etc. From this data or signals which are detected by sensors or determined by other electronics units and sent to the control unit the torque transferable by the clutch is determined in block 303.

In block 304 the torque transferable by the clutch is set or regulated by means of a control signal from the actor, In block 305 the signal sent by the anti slip regulating electronics is detected which indicates an activity of the anti slip regulating system or indicates no activity of this system. In block 306 this signal is evaluated and it is asked whether there is activity of the anti slip regulating system. If this is not the case then it continues at block 304. Similarly it could be further continued at block 302 or 303. If there is activity then in block 307 it is asked whether the engine speed is less than a boundary value of the engine speed. If this is the case then it is continued at block 304. It could likewise be further continued at 302 or 303. If there is a speed which is greater than the boundary limit then in block 308 the torque transferable by the clutch is raised to the maximum value with a speed which is at least the normal operating speed. A maximum operating speed can likewise be selected.

In block 309 it is asked whether there is a slip situation and/or whether the anti slip regulation is furthermore active. If this is the case then it continues at block 308 and the clutch is furthermore engaged or held engaged otherwise it continues at block 302 and the torque transferable by the clutch and which is normal in the actual operating situation is controlled. If this is the case for example with a control process with moment matching in an operating situation in which only a part of the maximum transferable torque exists as engine moment then the clutch can again be partially opened so that according to the method of moment matching only a torque transferable by the clutch such as clutch moment is set which lies in a tolerance band about the actual engine moment.

The patent claims filed with the application are proposed wordings without prejudice for achieving wider patent protection. The applicant retains the right to claim further features disclosed up until now only in the description and/or drawings.

References used in the sub-claims refer to the further design of the subject of the main claim through the features of each sub-claim; they are not to be understood as dispensing with obtaining an independent subject protection for the features of the sub-claims referred to.

The subjects of these sub-claims however also form independent inventions which have a configuration independent of the subjects of the preceding sub-claims.

The invention is not restricted to the embodiment of the description. Rather numerous modifications and alterations are possible within the framework of the invention, more particularly those variations, elements and combinations and/or materials which are inventive for example through combination or modification of individual features or elements or method steps contained in the drawings and described in connection with those in the general description and embodiments and claims and lead through combinable features to a new subject or to new method steps or sequence of method steps where they relate to manufacturing, testing and work processes.

Claims

1. Motor vehicle with a device for the automatic operation of an assembly, such as for example a gearbox and/cr a torque transfer system, in the drive train, with at least one control unit for controlling the automatic operation of the clutch, which is in signal connection with at least one anti-slip regulating electronics unit, which issues a control signal when it is active in a slip situation, with at least one actor controllable by the at least one control unit for adjusting the torque transferable by the clutch, characterised in that with an automatic operation of a clutch with the presence of a control signal of the antislip regulation indicating activity, the control unit controls by means of the actor the torque transferable by the clutch from the value of the transferable torque actually controlled to a maximum value of the transferable torque.

2. Motor vehicle with a device for the automatic operation of a clutch in the drive train, with a drive assembly, a gearbox and a clutch, such as a friction clutch, with at least one control unit for controlling the automatic operation which is in signal connection with sensors and where applicable with other electronics units, such as engine electronics, ABS electronics and/or anti-slip regulating electronics, wherein the anti slip regulating electronics issues a control signal in the event of actIvity in a slip situation with at least one actor controllable by the control unit for operating the clutch, characterised in that with an automatic operation of the clutch with the presence of a control signal of the anti-slip regulation which indicates that the anti-slip regulation is active, the control unit controls the torque transfer system from the actual engagement position into a substantially fully engaged engagement position.

3. Motor vehicle more particularly according to one of claims r or 2, characterised in that in addition to the automatic operation of the clutch an automatic operation of the gearbox is controllable by means of an actor and a control unit controlling the actor.

4. Motor vehicle more particularly according to one of the preceding claims characterised in that a control of the increase of the torque transferable by the clutch by means of the control unit and the actor with the presence of a control signal of the anti-slip regulation indicating activity, takes place at a speed which is equal to or greater than the speed which is controllable when controlling without the presence of a control signal of the anti-slip regulation.

5. Motcr vehicle more particularly according to one of the preceding claims, characterised in that a control of the increase of the torque transferable by the clutch with the presence of a control signal of anti-slip regulation indicating activity, takes place at a speed which is equal to or greater than the speed which can be controlled during a control without the presence of a control signal of the anti-slip regulation even if without the presence of such a signal the transferable torque or the engagement position of the clutch would not be substantially changed.

6. Motor vehicle more particularly according to one of the preceding claims, characterised in that a control of the increase of the torque transferable by the clutch with the presence of a control signal of the anti-slip regulation indicating activity, takes place at a speed which is equal to or greater than the speed which can be controlled during a control without the presence of a control signal of the anti-slip regulation even if without the presence of such a signal the transferable torque or the engagement position of the clutch in the actual operating area would not be substantially changed.

7. Motor vehicle more particularly according to one of the preceding claims, characterised in that the control unit controls the torque transferable by the torque transfer system during an activity of an anti-slip regulation to a maximum value or sets the clutch engaged, at least as long as no control signal deviating therefrom exists for example in the case of a shift process.

8. Motor vehicle more particularly according to one of the preceding claims, characterised in that the control unit with the presence of an activity of the anti slip regulation generates a control signal for engaging the clutch only at an engine speed nmt > predefinable speed.

9. Motor vehicle more particularly according to one of the preceding claims, characterised in that the control unit with the presence of an activity of the anti slip regulation generates a control signal for engaging the clutch at an engine speed nKt > idling speed plus a predefinable value.

10. Motor vehicle more particularly according to one of the preceding claims, characterised in that the control unit only generates a control signal for engaging the clutch in the event of a control signal which has been generated and/or transferred by the anti-slip regulation.

11. Motor vehicle more particularly according to one of the preceding claims, characterised in that the control unit only generates a control signal for engaging the clutch in the event of a control signal generated and/or transferred by the anti-slip regulation and with the presence of an engine speed nmt > a predefinable engine speed.

12. Motor vehicle more particularly according to one of the preceding claims characterised in that the control unit according to the presence of a control signal which signals the activity of an anti-slip regulation and/or with the presence of a signal which signals an ending of an activity of an anti-slip regulation, controls the transferable torque of the clutch to a value adapted to the actual operating position.

13. Motor vehicle more particularly according to claim 12, characterised in that the transferable torque controlled to a value adapted to the operating position assumes a value substantially in a range between a minimum value and a maximum value.

14. Motor vehicle more particularly according to claim 12, characterised in that the minimum value is substantially zero and the maximum value is substantially the maximum value which can be set.

15. Motor vehicle with a device for the automatic operation of an assembly such as a clutch characterised by its special configuration and method of operation according to the present application documents.

16. Method for controlling a torque transferable by a clutch of a motor vehicle by means of a device for the automated operation of a clutch, with a control unit for controlling the automated operation of the clutch which is in signal connection with an anti-slip regulating electronics which issues a control signal when it is active in a slip situation, with an actor controllable by the control unit for adjusting the torque transferable by the clutch and controlled by the control unit, characterised in that the control unit in the case of an automated operation of the clutch carries out the following steps: - Evaluation whether the control unit has a control signal indicating an activity of the anti slip regulation; - with the presence of this signal the control of the torque transferable by the clutch by means of the actor from the value of the transferable torque actually controlled to a maximum value of the transferable torque.

17. Motor vehicle substantially as herein described with reference to the accompanying drawings.

18. Method substantially as herein described with reference to the accompanying drawings.