CN108146422B

CN108146422B - Clutch control method and device and automobile

Info

Publication number: CN108146422B
Application number: CN201611109436.XA
Authority: CN
Inventors: 孙俊; 张岩; 林双武; 赵允喜; 侯海潇
Original assignee: SAIC Motor Corp Ltd
Current assignee: SAIC Motor Corp Ltd
Priority date: 2016-12-02
Filing date: 2016-12-02
Publication date: 2020-04-28
Anticipated expiration: 2036-12-02
Also published as: CN108146422A

Abstract

A control method and device of a clutch and an automobile are provided, wherein the method comprises the following steps: when the clutch is closed, performing accumulation calculation on a heat value generated by the clutch; and if the heat value obtained by the accumulation calculation is larger than or equal to a preset heat threshold value, controlling the output torque upper limit value of the power source to be reduced on the basis of the current output torque upper limit value. The scheme of the invention can realize continuous energy supply for the vehicle when the clutch is not seriously failed due to the slipping overheat, can reduce the probability of serious abrasion of the clutch and provides buffer time for safe operation of a user.

Description

Clutch control method and device and automobile

Technical Field

The invention relates to the field of control of a transmission system of an automobile, in particular to a method and a device for controlling a clutch and the automobile.

Background

With the development of the automobile industry, the power performance of automobiles is gradually improved, and higher requirements are put forward on the output torque and the torque response speed of a power source.

Clutches are important components of automotive drive trains for transmitting or interrupting torque output from a power source to a transmission. Specifically, the power source may include an engine or an electric motor, and when the power source is in contact with the clutch, the torque delivered by the clutch may gradually approach the output torque of the power source through the friction-slipping action between the driving part and the driven part of the clutch, and the rotation speed of the input shaft of the clutch may correspondingly gradually approach the rotation speed of the output shaft of the power source, so as to smoothly accelerate or decelerate the vehicle.

Further, when a torque difference and a rotational speed difference between a power source and a clutch of an automobile are large, the clutch may slip. Specifically, for example, when the automobile is suddenly driven by a large torque by engaging a clutch, or when a frequent gear shift occurs, or when the automobile is suddenly braked, the wheels suddenly and rapidly reduce the speed, and the transmission system connected to the power source still maintains the original rotation speed due to the rotational inertia, so that an inertia torque far greater than the torque of the power source is often generated in the transmission system, and in this case, parts of the transmission system are easily damaged. Because the clutch transmits torque by means of the friction force of the contact surface between the main turntable and the auxiliary turntable, when the load in a transmission system exceeds the torque which can be transmitted by the friction force of the clutch plates, the torque difference and the rotating speed difference between a power source and the clutch are generated, the main part and the auxiliary part of the clutch generate heat due to slipping, the torque transmission capability of the clutch is reduced, and the wear failure of the clutch plates is also caused.

In an existing automatic Transmission, such as an automatic-mechanical Transmission (AMT) or a Dual Clutch Transmission (DCT), a position sensor or a pressure sensor is often used to ensure the torque Transmission capability of the Clutch, and a thermal threshold is established for the amount of heat accumulated when the Clutch slips and is overheated, so as to provide a basis for controlling the slip problem of the Clutch, for example, the thermal threshold is established by simulation using a mature thermal model. Wherein the torque transmission capacity is used to indicate the maximum input torque that the clutch can normally transmit.

In an electrically driven gearbox, due to the fact that power switching between power sources is increased, the intervention of a motor exists, the torque response is faster, the torque is larger than that of a common traditional automobile, and the requirement on the torque transmission capacity of a clutch is higher. Therefore, the diagnosis of the clutch slip of the electrically driven gearbox is very important, and whether the clutch fails or not influences the function realization of the whole vehicle and the power output.

In the prior art, when the heat accumulated on the clutch exceeds a heat threshold, the clutch is normally directly opened, thereby cutting off the torque output from the power source to the transmission. However, such a solution would result in a sudden unpowered output of the vehicle, which could easily cause a hazard if it were on an unsafe road.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a control method and device of a clutch and an automobile, which can realize continuous energy supply for the automobile when the clutch is in non-serious failure due to slipping overheating, reduce the probability of serious abrasion of the clutch and provide buffer time for safe operation of a user.

To solve the above technical problem, an embodiment of the present invention provides a method for controlling a clutch, where the clutch is coupled to a power source, and the method includes: when the clutch is closed, performing accumulation calculation on a heat value generated by the clutch; and if the heat value obtained by the accumulation calculation is larger than or equal to a preset heat threshold value, controlling the output torque upper limit value of the power source to be reduced on the basis of the current output torque upper limit value.

Optionally, the performing an accumulation calculation on the calorific value generated by the clutch includes: calculating the rotating speed difference value of a driving disc and a driven disc of the clutch; calculating a torque difference value of the driving disc and the driven disc of the clutch; and when the rotating speed difference value is greater than or equal to a preset rotating speed difference threshold value and the torque difference value is greater than or equal to a preset torque difference threshold value, accumulating and calculating the heat value generated by the clutch.

Optionally, the method for controlling the clutch further includes: the count of the number of accumulated computations is increased once every time the output torque upper limit value of the power source is controlled to decrease on the basis of the current output torque upper limit value.

Optionally, the method for controlling the clutch further includes: and after the upper limit value of the output torque of the power source is controlled to be reduced on the basis of the current upper limit value of the output torque each time, clearing the heat value obtained by the accumulation calculation.

Optionally, the method for controlling the clutch further includes: disconnecting the clutch or turning on a limp home mode when the count of the cumulative count number reaches a preset value.

Optionally, the method for controlling the clutch further includes: after the output torque upper limit value of the power source is reduced every time, if the output torque of the power source is reduced to be less than or equal to the output torque upper limit value and the duration of the heat value obtained by the accumulation calculation being less than the preset heat threshold value reaches a preset time length, the count of the times of the accumulation calculation is reduced once until the count is reduced to zero.

In order to solve the above technical problem, an embodiment of the present invention further provides a control device for a clutch, where the clutch is coupled to a power source, the control device including: the heat accumulation calculation module is suitable for performing accumulation calculation on the heat value generated by the clutch when the clutch is closed; and the torque control module is suitable for controlling the upper limit value of the output torque of the power source to be reduced on the basis of the current upper limit value of the output torque when the heat value obtained by accumulation calculation is greater than or equal to a preset heat threshold value.

Optionally, the accumulation calculating module includes: the first calculation submodule is suitable for calculating the rotating speed difference value of a driving disc and a driven disc of the clutch; a second calculation submodule adapted to calculate a torque difference value of the driving disk and the driven disk of the clutch; and the first heat accumulation calculation submodule is suitable for performing accumulation calculation on the heat value generated by the clutch when the rotating speed difference value is greater than or equal to a preset rotating speed difference threshold value and the torque difference value is greater than or equal to a preset torque difference threshold value.

Optionally, the control device of the clutch further includes: and the first counting module is suitable for controlling the output torque upper limit value of the power source to be reduced on the basis of the current output torque upper limit value every time, and the count of the accumulated counting times is increased once.

Optionally, the control device of the clutch further includes: and the zero clearing module is suitable for clearing the heat value obtained by the accumulation calculation after the output torque upper limit value of the power source is controlled to be reduced on the basis of the current output torque upper limit value every time.

Optionally, the control device of the clutch further includes: a clutch control module adapted to disconnect the clutch or initiate a limp home mode when the count of accumulated counts reaches a preset value.

Optionally, the control device of the clutch further includes: and the second counting module is suitable for reducing the output torque upper limit value of the power source every time, and if the output torque of the power source is reduced to be less than or equal to the output torque upper limit value and the duration of the heat value smaller than the preset heat threshold value obtained by the accumulation calculation reaches the preset time length, the count of the times of the accumulation calculation is reduced once until the count is reduced to zero.

In order to solve the technical problem, an embodiment of the present invention further provides an automobile, where the automobile includes the control device of the clutch.

Compared with the prior art, the technical scheme of the embodiment of the invention has the following beneficial effects:

according to the embodiment of the invention, when the clutch is closed, the heat value generated by the clutch is accumulated and calculated; and if the heat value obtained by the accumulation calculation is larger than or equal to a preset heat threshold value, controlling the output torque upper limit value of the power source to be reduced on the basis of the current output torque upper limit value. By adopting the embodiment of the invention, when the clutch is not seriously failed due to the slipping overheat, the vehicle can be continuously powered, the probability of serious abrasion of the clutch can be reduced, and the buffering time is provided for safe operation of a user.

Further, by adopting the embodiment of the invention, when the torque transmission capability of the clutch is reduced along with the increase of the times of heat accumulation overrun of the clutch, namely the maximum input torque capable of being normally transmitted is reduced, the upper limit value of the output torque of the power source is reduced in stages, so that the problem of clutch slip is avoided to a greater extent, the wear frequency of the clutch is reduced, and the clutch is effectively protected.

Further, after the output torque of the power source is reduced for multiple times, when the heat obtained by accumulation calculation still exceeds the limit, the embodiment of the invention can be adopted to disconnect the clutch or start the limp mode to avoid the clutch from being overheated and worn, thereby protecting the clutch, other parts of a transmission system and other systems of the whole vehicle.

Further, when a smaller power source is adopted to output torque, and the heat does not exceed the limit within a certain time, namely the heating condition of the clutch is improved.

Drawings

FIG. 1 is a flow chart of a method of controlling a clutch in an embodiment of the present invention;

FIG. 2 is a flow chart of another method of controlling a clutch in an embodiment of the present invention;

FIG. 3 is a flow chart of a method of controlling a further clutch in an embodiment of the present invention;

FIG. 4 is a schematic structural diagram of a control device of a clutch according to an embodiment of the present invention;

fig. 5 is a schematic structural diagram of an accumulation calculating module in a control device of a clutch according to an embodiment of the present invention.

Detailed Description

As described above, when a torque difference and a rotation speed difference between a power source of an automobile and a clutch are large, the clutch slips, and once a slip problem occurs in a clutch plate, heat is easily generated and accumulated in the clutch, thereby causing wear of the clutch. This problem is exacerbated by the faster torque response in automatic clutches.

However, in the prior art, when the heat accumulated on the clutch exceeds the heat threshold value, the adopted technical scheme is generally to directly disconnect the clutch, so as to cut off the torque output from the power source to the transmission, which leads to the sudden unpowered output of the vehicle and is easy to cause danger if the vehicle is in an unsafe road section.

The inventors of the present invention have studied to find that the key to the above problem is that when the amount of heat accumulated in the clutch exceeds a heat threshold, and a slip problem occurs, the torque transmission capability of the clutch will decrease, but it does not indicate that the clutch will fail immediately once the torque transmission capability decreases.

According to the embodiment of the invention, when the clutch is closed, the heat value generated by the clutch is accumulated and calculated; and if the heat value obtained by the accumulation calculation is larger than or equal to a preset heat threshold value, controlling the output torque upper limit value of the power source to be reduced on the basis of the current output torque upper limit value. By adopting the embodiment of the invention, when the clutch is not seriously failed due to the overheat caused by slipping, the vehicle can be continuously powered, and the probability of serious abrasion of the clutch is reduced by reducing the upper limit value of the output torque of the power source, thereby providing buffer time for safe operation of a user.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.

Referring to fig. 1, fig. 1 is a flowchart of a method for controlling a clutch according to an embodiment of the present invention. The control method of the clutch may include steps S101 to S102.

Step S101: and when the clutch is closed, performing accumulation calculation on the calorific value generated by the clutch.

Step S102: and if the heat value obtained by the accumulation calculation is larger than or equal to a preset heat threshold value, controlling the output torque upper limit value of the power source to be reduced on the basis of the current output torque upper limit value.

In a specific implementation of step S101, the power source powers the vehicle via the clutch after the clutch is closed. The clutch may be used in an automatic transmission, such as an automatic mechanical transmission or a dual clutch automatic transmission, among others. The power source can comprise an engine and a motor, and both a traditional automobile and a new energy automobile can adopt the embodiment of the invention.

Further, an Electronic Control Unit (ECU) of the vehicle may issue a command to open or close the clutch, and the clutch opening or closing signal may be acquired in the form of a vehicle body CAN signal through a vehicle Controller Area Network (CAN).

In a specific implementation, the step of performing an accumulation calculation on the calorific value generated by the clutch may comprise the steps of: calculating the rotating speed difference value of a driving disc and a driven disc of the clutch; calculating a torque difference value of the driving disc and the driven disc of the clutch; and when the rotating speed difference value is greater than or equal to a preset rotating speed difference threshold value and the torque difference value is greater than or equal to a preset torque difference value, accumulating and calculating the heat value generated by the clutch.

In the cumulative calculation of the amount of heat generated by the clutch, the amount of heat generated by the clutch in the normal range should not be accumulated. Specifically, the difference in rotational speed between the driving and driven discs of the clutch is typically small, and the difference in torque transmitted across the clutch and requested by the power source is also small, with the heat generated by the clutch and the rate of heat increase being within acceptable normal ranges. Therefore, in the embodiment of the present invention, the rotation speed difference value and the torque difference value between the driving disk and the driven disk of the clutch are detected, and when it is detected that the rotation speed difference value is greater than or equal to the preset rotation speed difference threshold value and the torque difference value is greater than or equal to the preset torque difference threshold value, the heat value generated by the clutch is accumulated, and otherwise, the heat value is not accumulated.

Further, the rotating speeds of the driving disk and the driven disk of the clutch can be obtained according to the rotating speed of the power source and the rotating speed of the gearbox, and the torque of the driving disk and the driven disk of the clutch can be obtained according to the torque of the power source and the torque of the gearbox.

Wherein the rotational speed and the torque of the power source may be measured in real time by a controller corresponding to the power source. Specifically, for a conventional automobile, the controller for the power source may include an engine controller; for a hybrid vehicle, the controller for the power source may include an engine controller and a motor controller; for a pure electric vehicle, the controller of the power source may include a motor controller.

The rotational speed and torque of the gearbox can be measured in real time by a gearbox Control Unit (TCU).

The preset rotation speed difference threshold value and the preset torque difference threshold value can be calibrated by performing a torque transmission capability test of the slipping and heating of the clutch according to the actual vehicle type and the model of the gearbox. Further, the torque transmission capability test of the slip heating of the clutch can adopt the existing conventional test setup, and the invention is not limited to this. Further, the amount of heat generated by the clutch may be accumulated using conventional heat calculation formulas, such as calculating the amount of heat generated by the clutch from the torque applied to the clutch and the differential speed across the clutch.

In the specific implementation of step S102, if the heat value obtained by the accumulation calculation is greater than or equal to a preset heat threshold, the output torque upper limit value of the power source is controlled to be decreased on the basis of the current output torque upper limit value.

The limit value of the preset heat threshold value is related to the yield limit of the material of the clutch, and is determined according to the test result. Specifically, after the allowable range of the heat productivity of the clutch and the bearable heat increase rate can be reasonably calibrated through a bench test of the torque transmission capacity of the clutch after slipping and heating at different rotating speeds of the clutch and the material characteristics of the clutch, the limit value of the preset heat threshold value is obtained through a method of real vehicle calibration and the bench test according to calibration software. Further, the preset heat threshold should be lower than the limit value of the preset heat threshold.

It should be noted that a higher predetermined heat threshold value means that the output torque upper limit value of the power source is reduced after the clutch accumulates a higher amount of heat. If the preset heat threshold is set too high, the problem that the clutch is subjected to slipping abrasion but the upper limit value of the output torque of the power source is not controlled may occur, so that the embodiment of the invention cannot achieve the effect of preventing excessive heat accumulation of the clutch. If the preset heat threshold value is set too low, the output torque upper limit value of the power source is possibly controlled to be reduced under the state that the heat is normally accumulated by the clutch, so that the output power is insufficient, and the driving control experience is influenced.

Further, when the heat value is greater than or equal to a preset heat threshold value, the output torque upper limit value of the power source is controlled to be reduced on the basis of the current output torque upper limit value so as to reduce the output torque of the vehicle, and therefore heat accumulation generated on the clutch is relieved. The current output torque upper limit value is the output torque upper limit value adopted by the power source in the process of accumulating the heat value to the preset heat threshold value.

Wherein, the limit value of the torque upper limit value is determined according to the test result. Specifically, after the allowable range of the heat productivity of the clutch and the bearable heat increase rate can be reasonably calibrated through the bench test of the torque transmission capacity of the clutch after the clutch slips and generates heat under different rotating speeds and the material characteristics of the clutch, the limit values of the upper limit values of the torque after different slipping times are obtained through the method of real-vehicle calibration and the bench test according to calibration software, namely, the limit values are reduced along with the increase of the count of the accumulated calculating times. Further, the set value of the torque upper limit value should be lower than the limit value of the torque upper limit value.

By adopting the embodiment of the invention, when the heat value accumulated and calculated by the clutch exceeds the limit, the closed state of the clutch is kept to realize the purpose of continuously supplying energy to the vehicle, and the probability of the clutch abrasion is reduced by reducing the upper limit value of the output torque of the power source, thereby providing buffer time for the safe operation of a user.

Referring to fig. 2, fig. 2 is a flowchart of another clutch control method in an embodiment of the invention. The another clutch control method may include steps S201 to S210.

Step S201: the clutch is closed.

Step S202: and calculating the rotating speed difference and the torque difference.

Step S203: judging whether the rotating speed difference is greater than or equal to a threshold value and the torque difference is greater than or equal to the threshold value, and if so, executing the step S204; otherwise, the process may return to step S202 to continue execution.

Step S204: and accumulating to calculate the heat value.

Regarding the execution of steps S201 to S204, please refer to the description of steps S101 to S102 in fig. 1 for execution, which is not described herein again.

Step S205: judging whether the heat value of the accumulated calculation is greater than or equal to a preset heat threshold value, and if so, executing step S206; otherwise, the process may return to step S204 to continue execution.

Step S206: the count is incremented once.

In a specific implementation, the count of the number of accumulated computations is increased once every time the output torque upper limit value of the power source is controlled to decrease on the basis of the current output torque upper limit value.

Preferably, different output torque upper limit values may be set corresponding to the counts corresponding to different cumulative count numbers, the higher the count of the cumulative count number, the lower the output torque upper limit value is set. And when the count is increased, controlling the output torque upper limit value of the power source to be converted into the output torque upper limit value corresponding to the increased count. On the contrary, when the count is decreased, the output torque upper limit value of the power source is controlled to be changed to the output torque upper limit value corresponding to the decreased count. It is understood that, as the output torque upper limit value changes, the output torque of the power source will be adjusted accordingly to be lower than the output torque upper limit value after the transition. By adopting the embodiment of the invention, when the torque transmission capability of the clutch is reduced along with the increase of the times of heat accumulation overrun of the clutch, namely the maximum input torque capable of being normally transmitted is reduced, the upper limit value of the output torque of the power source is reduced in stages, so that the problem of clutch slip is avoided to a greater extent, the wear frequency of the clutch is reduced, and the clutch is effectively protected.

Step S207: judging whether the count reaches a preset value, and if so, executing step S208; otherwise, step S209 may be performed.

Step S208: disconnect clutch or open limp home mode.

In a specific implementation, when the count of the accumulated counting times is more and reaches a preset value, the clutch failure can be judged, and the occurrence of the clutch slip fault is confirmed. To protect the clutch, and other components of the transmission system, from damage, the clutch is controlled to be disengaged or to engage a Limp Home Mode (LHM).

Specifically, the effective use range of the clutch can be obtained through a bench test, the material characteristics of the clutch and a torque transmission capacity test after the clutch slips, and the failure condition of the clutch can be judged. For example, by using a bench test, the torque transmission capability is continuously reduced after the clutch is slipped for a plurality of times according to the torque transmission capability of the clutch, and the clutch can be regarded as being out of work after the torque transmission capability is reduced to a certain extent. The number of times of slip permission can be determined by using the torque at which it is determined that the clutch is failed and the difference between the start value of the output torque upper limit value and the output torque upper limit values before and after the transition.

It is understood that the preset value that can be set can be a positive integer.

Further, the settable preset value may have a corresponding relationship with a difference of the output torque upper limit values before and after the transition. Specifically, in other condition determination, when the difference between the converted output torque upper limit value and the current output torque upper limit value is smaller corresponding to the count increased by one, that is, the torque transmission capability of the clutch is divided more finely, a higher preset value may be set. When the difference between the converted output torque upper limit value and the current output torque upper limit value is larger corresponding to the count plus one, that is, the output torque of the power source is reduced to a greater extent for each adjustment, a lower preset value may be set.

Further, if the preset value is too high, it means that the number of times of lowering the upper limit value of the output torque is more, which is not favorable for protecting the clutch, other components of the transmission system and other systems of the whole vehicle. On the contrary, if the preset value is too low, the embodiment of the invention cannot provide the due effect of buffering time for the user to perform safe operation. As a non-limiting example, the preset value may be selected from 2 times to 4 times.

And the limp-home mode is started, so that the power output time can be prolonged and the driving safety of a user is enhanced compared with the clutch disconnection. The limp home mode is to control the Transmission to enter a protection state through an automatic Transmission Control Unit (TCU) when the vehicle is out of order and may cause damage to internal components of the automatic Transmission or potential safety hazards related to the automatic Transmission.

By adopting the embodiment of the invention, when a smaller power source output torque upper limit value is adopted and the heat obtained by one or more times of accumulation calculation still exceeds the limit, the clutch can be disconnected or the limp mode can be started to avoid the overheating wear of the clutch, thereby protecting the clutch.

Step S209: controlling the output torque upper limit value of the power source to decrease on the basis of the current output torque upper limit value.

Regarding the execution of step S209, please refer to the description of step S102 in fig. 1 for execution, and the description thereof is omitted here.

Step S210: and (5) clearing the heat value.

In specific implementation, after the output torque upper limit value of the power source is controlled to be reduced on the basis of the current output torque upper limit value each time, the heat value obtained by the accumulation calculation is cleared. To ensure more accuracy in recalculating the amount of heat accumulated on the clutch.

For more details on the control method of the other clutch shown in fig. 2, please refer to the related description of the control method of the clutch shown in fig. 1, and will not be described herein again.

By adopting the embodiment of the invention, the failure condition of the clutch can be reflected in a multi-level manner, and the output torque is reduced by reducing the upper limit value of the output torque of the power source in a layered manner, so that the clutch, other parts of a transmission system and other systems of the whole vehicle can be better protected.

Fig. 3 is a flowchart of a control method of a clutch according to another embodiment of the present invention. As shown in fig. 3, still another clutch control method may include steps S301 to S317.

Step S301: the clutch is closed.

Step S302: and calculating the rotating speed difference and the torque difference.

Regarding the execution of steps S301 to S302, please refer to the description of steps S201 to S202 in fig. 2 for execution, which is not described herein again.

Step S303: the timing is started.

Step S304: judging whether the rotating speed difference is greater than or equal to a threshold value or not, and the torque difference is greater than or equal to the threshold value, and if so, executing the step S306; otherwise, step S305 may be performed.

Step S305: and clearing the accumulated heat.

In specific implementation, after the timing is started, the heat value obtained by the accumulation calculation is valid only when the rotating speed difference value between the driving disc and the driven disc of the clutch is greater than or equal to a preset rotating speed difference threshold value and the torque difference value between the driving disc and the driven disc of the clutch is greater than or equal to a preset torque difference threshold value. Otherwise, the heat value obtained by accumulating and calculating on the clutch needs to be cleared. To ensure that timing is only initiated when the speed difference is greater than or equal to the preset speed difference threshold and the torque difference is greater than or equal to the preset torque difference threshold.

Step S306: and accumulating to calculate the heat value.

Step S307: judging whether the heat value of the accumulated calculation is greater than or equal to a preset heat threshold value, and if so, executing the step S308; otherwise, step S314 may be performed.

Step S308: the count is incremented once.

Step S309: judging whether the count of the accumulated counting times reaches a preset value, and if so, executing step S310; otherwise, step S311 may be performed.

Step S310: disconnect clutch or open limp home mode.

Step S311: controlling the output torque upper limit value of the power source to decrease on the basis of the current output torque upper limit value.

Step S312: and clearing the accumulated heat.

Regarding the execution of steps S306 to S312, please refer to the description of steps S204 to S210 in fig. 2 for execution, which is not described herein again.

Step S313: and (6) timing and clearing.

In specific implementation, after the output torque upper limit value of the power source is controlled to be reduced on the basis of the current output torque upper limit value, the time is cleared, and the step S301 is returned to continue to be executed, so that the rotating speed difference value and the torque difference value are recalculated under the condition that the clutch is closed.

Step S314: judging whether the timed duration reaches a preset duration, and if so, executing the step S315; otherwise, the process may return to step S307 to continue the execution.

Step S315: the count is decremented once until it is reduced to zero.

In specific implementation, when the heat value obtained by the accumulation calculation is smaller than a preset heat threshold value and the duration is long, it can be judged that the heat generated on the clutch is dissipated, the clutch is difficult to slip or even fail, and the service life of the clutch can be prolonged by reducing the count once, so that a longer buffer time is provided for a user to perform safe operation.

It can be understood that the preset time period cannot be set to be too short, and if the preset time period is too short, the accumulated count number is reduced if the heat easily generated on the clutch is not dissipated, so that the effect of reducing the probability of the clutch being worn by the embodiment of the invention is reduced. On the contrary, the preset duration cannot be set to be too long, and if the preset duration is too long, the count of the accumulated counting times is easy to be increased and not reduced, so that the clutch is judged to be invalid quickly after the preset value is reached, and the effect of providing buffer time for the safe operation of a user is reduced.

Further, through a bench test, clutch material characteristics and a torque transmission capacity test after the clutch slips, how long the clutch reduces torque is measured, and the accumulated heat of the last slipping of the clutch can be dissipated to a limit value which does not affect transmission of new torque, so that reasonable preset time is set.

In another embodiment, the step of initiating timing is initiated at a different point in time. Specifically, the upper limit value of the output torque is reduced after the count is increased, timing is not performed until the output torque of the power source is reduced to be less than or equal to the upper limit value of the reduced output torque, and the count of the number of times of the accumulation calculation is reduced once until the count is reduced to zero when the duration of the heat value obtained by the accumulation calculation being less than the preset heat threshold reaches the preset duration.

Specifically, after each slipping count, the output torque of the power source is counted after being reduced to a new output torque upper limit value, and if the accumulated heat in the preset time period does not reach the threshold value, the heat generated on the clutch can be judged to be dissipated, the clutch cannot slip or even lose efficacy, the service time of the clutch can be prolonged by a mode of counting once, and therefore longer buffer time is provided for safe operation of a user.

Step S316: the output torque upper limit value of the power source is controlled to be increased on the basis of the current output torque upper limit value.

In specific implementation, when the count of the accumulated number of times is decreased, the output torque upper limit value of the power source may be controlled to be increased on the basis of the current output torque upper limit value according to the decreased count, so as to provide a larger output torque and enhance the driving experience of the user.

Preferably, different output torque upper limit values may be set corresponding to the counts corresponding to different cumulative count numbers, the lower the count of the cumulative count number, the higher the output torque upper limit value is set. And when the count is reduced, controlling the output torque upper limit value of the power source to be converted into the output torque upper limit value corresponding to the reduced count. And conversely, when the count is increased, controlling the output torque upper limit value of the power source to be converted into the output torque upper limit value corresponding to the increased count. It is understood that, as the output torque upper limit value changes, the output torque of the power source will be adjusted accordingly to be lower than the output torque upper limit value after the transition.

By adopting the embodiment of the invention, when the torque is output by adopting a smaller power source and the heat obtained by re-accumulation calculation is not exceeded any more within a certain time, the heating condition of the clutch is improved, the energy supply time can be prolonged, and more buffer time is provided for the safe operation of a user.

Step S317: and (6) timing and clearing.

In specific implementation, after the output torque upper limit value of the power source is controlled to be increased on the basis of the current output torque upper limit value, the time is cleared, and the step S301 is returned to continue to be executed, so that the rotating speed difference value and the torque difference value are recalculated under the condition that the clutch is closed.

For more details on the control method of the another clutch shown in fig. 3, reference is made to the description above related to the control method of the clutch shown in fig. 1 and the control method of the another clutch shown in fig. 2, and details thereof are not repeated here.

By adopting the embodiment of the invention, the situation that the clutch slips occasionally and cannot transmit torque can be avoided, and the vehicle can be driven according to the actual torque transmission capacity of the clutch before the clutch is judged to be in real failure. The embodiment of the invention can avoid the problem that the clutch cannot work due to the fact that the clutch is disconnected or the clutch is started in a limp mode when the clutch can transmit low torque, and can also avoid the problem that the clutch cannot be driven due to the fact that the power source outputs high torque to enable the clutch to continuously slip when the clutch cannot transmit high torque due to the slip problem.

Referring to fig. 4, fig. 4 is a schematic structural diagram of a control device of a clutch according to an embodiment of the present invention. The control of the clutches may include a heat accumulation calculation module 41, a torque control module 42, a first count module 43, a zeroing module 44, a clutch control module 45, and a second count module 46.

Wherein the heat quantity accumulation calculation module 41 is adapted to perform an accumulation calculation on the heat quantity value generated by the clutch when the clutch is closed. The torque control module 42 is adapted to control the output torque upper limit value of the power source to decrease on the basis of the current output torque upper limit value when the heat value obtained by the accumulation calculation is greater than or equal to a preset heat value threshold value. The first counting module 43 is adapted to increase the count of the cumulative count number once each time the output torque upper limit value of the power source is controlled to decrease on the basis of the current output torque upper limit value. The zero clearing module 44 is adapted to zero the heat value obtained by the accumulation calculation each time the output torque upper limit value of the power source is controlled to decrease based on the current output torque upper limit value. The clutch control module 45 is adapted to disconnect the clutch when the count of the cumulative number of calculations reaches a preset value. The second counting module 46 is adapted to, after reducing the output torque upper limit value of the power source each time, reduce the count of the number of times of the accumulation calculation once until the count is reduced to zero if the output torque of the power source is reduced to be less than or equal to the output torque upper limit value and the duration of the heat value obtained by the accumulation calculation being less than the preset heat threshold value reaches a preset duration.

Fig. 5 is a schematic structural diagram of the accumulation calculating module 41 in the control device of the clutch according to the embodiment of the present invention. The cumulative calculation module 41 may include a first calculation submodule 411, a second calculation submodule 412, and a first heat cumulative calculation submodule 413. Wherein the first calculating submodule 411 is adapted to calculate a difference between the rotation speeds of the driving disk and the driven disk of the clutch. The second calculation submodule 412 is adapted to calculating a difference in torque between the driving discs and the driven discs of the clutch. The first heat accumulation calculation submodule 413 is adapted to perform accumulation calculation on the heat value generated by the clutch when the rotation speed difference value is greater than or equal to a preset rotation speed difference threshold value and the torque difference value is greater than or equal to a preset torque difference threshold value.

For more details of the control device of the clutch, refer to the above description of the control method of the clutch, and are not repeated herein.

The embodiment of the invention also provides an automobile which comprises the control device of the clutch, and the automobile can execute the control method of the clutch.

Those skilled in the art will appreciate that all or part of the steps in the methods of the above embodiments may be implemented by hardware related to instructions of a program, which may be stored in a computer-readable storage medium, and the storage medium may include: ROM, RAM, magnetic or optical disks, and the like.

Although the present invention is disclosed above, the present invention is not limited thereto. Various changes and modifications may be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A method of controlling a clutch coupled to a power source, the method comprising:

when the clutch is closed, performing accumulation calculation on a heat value generated by the clutch;

if the heat value obtained by the accumulation calculation is larger than or equal to a preset heat threshold value, controlling the output torque upper limit value of the power source to be reduced on the basis of the current output torque upper limit value;

further comprising: when the output torque upper limit value of the power source is controlled to be reduced on the basis of the current output torque upper limit value, the count of the accumulated counting times is increased once;

further comprising:

after the output torque upper limit value of the power source is reduced every time, if the output torque of the power source is reduced to be less than or equal to the output torque upper limit value and the duration of the heat value obtained by the accumulation calculation being less than the preset heat threshold value reaches a preset time length, the count of the times of the accumulation calculation is reduced once until the count is reduced to zero.

2. The method of claim 1, wherein said accumulating the amount of heat generated by said clutch comprises:

calculating the rotating speed difference value of a driving disc and a driven disc of the clutch;

calculating a torque difference value of the driving disc and the driven disc of the clutch;

and when the rotating speed difference value is greater than or equal to a preset rotating speed difference threshold value and the torque difference value is greater than or equal to a preset torque difference threshold value, accumulating and calculating the heat value generated by the clutch.

3. The control method of a clutch according to claim 1, characterized by further comprising: and after the upper limit value of the output torque of the power source is controlled to be reduced on the basis of the current upper limit value of the output torque each time, clearing the heat value obtained by the accumulation calculation.

4. The control method of a clutch according to claim 1, characterized by further comprising:

disconnecting the clutch or turning on a limp home mode when the count of the cumulative count number reaches a preset value.

5. A control device for a clutch, the clutch being coupled to a power source, the device comprising:

the heat accumulation calculation module is suitable for performing accumulation calculation on the heat value generated by the clutch when the clutch is closed;

the torque control module is suitable for controlling the upper limit value of the output torque of the power source to be reduced on the basis of the current upper limit value of the output torque when the heat value obtained by accumulation calculation is larger than or equal to a preset heat threshold value;

further comprising:

after the output torque upper limit value of the power source is reduced every time, if the output torque of the power source is reduced to be less than or equal to the output torque upper limit value and the duration of the heat value obtained by the accumulation calculation, which is less than the preset heat threshold value, reaches a preset time length, the count of the times of the accumulation calculation is reduced once until the count is reduced to zero;

further comprising:

and the second counting module is suitable for reducing the output torque upper limit value of the power source every time, and if the output torque of the power source is reduced to be less than or equal to the output torque upper limit value and the duration of the heat value smaller than the preset heat threshold value obtained by the accumulation calculation reaches the preset time length, the count of the times of the accumulation calculation is reduced once until the count is reduced to zero.

6. The control device of a clutch according to claim 5, wherein the accumulation calculation module includes:

the first calculation submodule is suitable for calculating the rotating speed difference value of a driving disc and a driven disc of the clutch;

a second calculation submodule adapted to calculate a torque difference value of the driving disk and the driven disk of the clutch;

and the first heat accumulation calculation submodule is suitable for performing accumulation calculation on the heat value generated by the clutch when the rotating speed difference value is greater than or equal to a preset rotating speed difference threshold value and the torque difference value is greater than or equal to a preset torque difference threshold value.

7. The control device of a clutch according to claim 5, characterized by further comprising:

and the zero clearing module is suitable for clearing the heat value obtained by the accumulation calculation after the output torque upper limit value of the power source is controlled to be reduced on the basis of the current output torque upper limit value every time.

8. The control device of a clutch according to claim 5, characterized by further comprising:

a clutch control module adapted to disconnect the clutch or initiate a limp home mode when the count of accumulated counts reaches a preset value.

9. An automobile, characterized by comprising a control device of a clutch according to any one of claims 5 to 8.