JP2005048894A - Clutch control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable smooth start while suppressing wear of clutch facing. <P>SOLUTION: In clutch connection control at the time of vehicle start, as a result of clutch slow connection control after a half clutch state is realized (S6), when clutch connection operation is retarded (S7) and when the retard time reaches time limit set in accordance with an accelerator opening or fuel supply amount, which is closely correlated to transmitted torque (S8), an alarm is outputted to inform an operator of progress of wear of clutch facing (S9). In addition, along with the alarm output, slow clutch connection is forcibly performed by predetermined strokes (S10). Then, since the clutch stroke is changed, the time limit limiting the retard time of the clutch connection operation is reset (S11), and a timer measuring the retard time is reset (S12). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a technique that enables a smooth start while suppressing wear of a clutch facing in clutch connection control when starting a vehicle.

  2. Description of the Related Art In recent years, mechanical automatic transmissions that perform automatic transmission according to a running state by electronically controlling a clutch and a gear type transmission have been put into practical use. In the mechanical automatic transmission, since the fluid clutch (torque converter) is not interposed in the driving force transmission system from the engine to the driving wheels, the driving force transmission efficiency is high and the fuel consumption can be improved. In addition, since there is no slip feeling peculiar to the fluid clutch, drivability is improved. On the other hand, if the clutch is suddenly connected when the vehicle starts, the speed difference between the engine rotational speed and the input shaft rotational speed of the gear type transmission is large, which may cause a large shock or engine stall. For this reason, half-clutch control of the clutch is indispensable as clutch control when the vehicle starts.

By the way, when the vehicle is started, if the accelerator pedal is not depressed, the half-clutch state may be maintained for a long time, and the wear of the clutch facing may progress. For this reason, as disclosed in Patent Document 1, a technique for requesting further depression of the accelerator pedal by issuing an alarm when the half-clutch state is maintained for a predetermined time has been proposed. In addition, in order to suppress the progress of wear of the clutch facing, a technique for issuing a warning and forcibly connecting the clutch has been developed.
Japanese Patent Laid-Open No. 11-247898

  However, the conventional clutch control has the following problems because the predetermined time until the alarm is issued is a constant value regardless of the magnitude of torque transmitted by the clutch. That is, if the predetermined time is set short to give priority to the protection of the clutch, when the transmission torque is small, the half-clutch state is forcibly terminated in a short time, so that a smooth start cannot be made. On the other hand, if the predetermined time is set long to give priority to smooth start, when the transmission torque is large, the half-clutch state is maintained more than necessary, and the suppression of wear of the clutch facing becomes insufficient.

  Therefore, in view of the above-described conventional problems, the present invention performs clutch control that enables smooth start while suppressing wear of the clutch facing by performing clutch connection control according to the transmission torque. An object is to provide an apparatus.

  For this reason, in the invention according to claim 1, when the vehicle starts, the clutch connecting means for connecting the clutch from the disconnected state to the connected state through the half-clutch state, and during the clutch connecting operation by the clutch connecting means, A stagnation determining means for determining whether or not the connection operation is stagnation; a stagnation time measuring means for measuring the stagnation time when the stagnation determination means determines that the clutch connection operation is stagnation; Based on a parameter having a correlation, a time limit setting means for setting a time limit for limiting the stagnation time of the clutch connection operation, and a stagnation time measured by the stagnation time measurement means is set by the time limit setting means. Forcibly connecting means for forcibly loosely connecting the clutch when the time limit is reached.

  The invention according to claim 2 is characterized in that the forcible connection means forcibly loosely connects the clutch by a predetermined stroke.

  According to a third aspect of the invention, there is provided an alarm generating means for issuing an alarm when the stagnation time reaches a time limit.

  According to a fourth aspect of the present invention, the time limit setting means sets the time limit shorter as the transmission torque increases.

  The invention according to claim 5 is characterized in that the parameter correlated with the transmission torque is an accelerator opening or a fuel supply amount.

  According to a sixth aspect of the present invention, the stagnation determining means determines whether or not the clutch connection operation is stagnation based on a rate of change of the clutch stroke.

  According to the first aspect of the present invention, the time limit for limiting the stagnation time of the clutch connection operation is appropriately set based on the parameter correlated with the transmission torque during the clutch connection operation at the time of starting the vehicle. In addition, during the clutch engagement operation, a stagnation time during which the engagement operation is stagnation is measured. When the stagnation time reaches the time limit, the clutch is forcibly loosely connected. For this reason, if the time limit is set to a time when there is no possibility that the wear of the clutch facing proceeds, smooth start can be performed while suppressing the wear of the clutch facing. At this time, the time limit for limiting the stagnation time of the clutch connection operation is set according to the transmission torque that has a close correlation with the degree of wear of the clutch facing, so that the clutch load in the half-clutch state is properly maintained. You can also.

  According to the second aspect of the present invention, when the stagnation time of the clutch connection operation reaches the time limit, the clutch is forcibly loosely connected by a predetermined stroke, so that the connection operation can be performed in a short time. And the occurrence of shock can be suppressed.

  According to the third aspect of the present invention, when the stagnation time of the clutch connection operation reaches the time limit, an alarm is issued, so that the driver can recognize that the accelerator pedal has not been depressed sufficiently when starting. . Then, by further depressing the accelerator pedal, the stagnation of the clutch connection operation can be prevented.

  According to the fourth aspect of the present invention, the time limit is shortened as the transmission torque increases, so that wear of the clutch facing is fast, that is, it is possible to effectively suppress the progress of wear of the clutch facing in a high load state. it can.

  According to the invention described in claim 5, since the time limit for limiting the stagnation time of the clutch connection operation is set based on the accelerator opening or the fuel supply amount, a signal used for vehicle control can be utilized. It is not necessary to provide a simple sensor, and an increase in cost for implementing the present invention can be suppressed.

  According to the sixth aspect of the invention, since it is determined whether or not the clutch connection operation is stagnant based on the stroke change rate of the clutch, the control structure is not complicated, and the processing of the in-vehicle control unit is performed. An increase in load can be suppressed.

  Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 shows a vehicle configuration provided with a clutch control device according to the present invention.

  A gear-type transmission (hereinafter referred to as “transmission”) 14 is attached to the engine 10 via a clutch 12. The engine 10 includes a fuel injection pump 18 whose fuel injection amount (fuel supply amount) is controlled by an engine control unit 16 incorporating a microcomputer, and an engine rotation speed sensor 20 that detects the engine rotation speed Ne. It is attached. The clutch 12 is connected with an output shaft of a clutch booster 22 as a clutch driving actuator, and a clutch stroke sensor 24 for detecting the stroke L is attached.

  On the other hand, an actuator 30 is attached to the transmission 14 for switching the gear stage with a working fluid via an electromagnetic valve 28 that is controlled to open and close by a transmission control unit 26 incorporating a microcomputer. Further, the transmission 14 includes a position sensor 32 that detects a gear position, a vehicle speed sensor 34 that detects a vehicle speed V from the rotation speed of its output shaft, and a counter rotation speed sensor 36 that detects a rotation speed Nc of the counter shaft. , Is attached.

  In the driver's cab, an accelerator opening sensor 40 that detects the accelerator opening θ through an operation amount of the accelerator pedal 38, a brake switch 44 that detects that the brake pedal 42 is depressed, and a shift instruction of the transmission 14 Is provided, and a display monitor 48 that displays the shift state of the transmission 14 is provided. The display monitor 48 may be incorporated with a notification device such as a buzzer for notifying the end of a shift or the occurrence of an abnormality.

  And the signal of the accelerator opening sensor 40 is input into the engine control unit 16, and the fuel injection pump 18 is controlled according to the accelerator opening θ. On the other hand, the signals of the engine speed sensor 20, clutch stroke sensor 24, position sensor 32, vehicle speed sensor 34, counter speed sensor 36, brake switch 44 and shift lever 46 are input to the transmission control unit 26, and the engine control unit. The clutch booster 22, the electromagnetic valve 28, and the display monitor 48 are controlled to perform automatic shift control or manual shift control while communicating with each other. Since the transmission control unit 26 controls the connection / disconnection of the clutch 12, it also functions as a clutch control device.

  Here, the clutch control unit 26 having various functions as a clutch control device and various sensors realize clutch connection means, stagnation determination means, stagnation time measurement means, time limit setting means, forced connection means, and alarm generation means, respectively. Is done.

  Next, clutch connection control of the clutch control device at the time of vehicle start will be described with reference to the flowcharts shown in FIGS. Such clutch connection control is executed, for example, when it is determined based on signals from the position sensor 32, the vehicle speed sensor 34, and the brake switch 44 that the vehicle is in a standby state.

  In step 1 (abbreviated as “S1” in the figure, the same applies hereinafter), it is determined based on a signal from the accelerator opening sensor 40 whether the accelerator opening θ is equal to or greater than a predetermined value. That is, after entering the vehicle start standby state, it is determined whether or not the accelerator pedal 38 is actually depressed to start the vehicle. If the accelerator opening θ is equal to or greater than the predetermined value, the process proceeds to step 2 (Yes), and if the accelerator opening θ is less than the predetermined value, the process waits (No).

  In step 2, the clutch booster 22 is controlled and the clutch 12 is suddenly connected.

  In step 3, based on the signal from the clutch stroke sensor 24, it is determined whether or not the clutch stroke L has become a predetermined value or less. Here, the predetermined value is a value for determining whether or not the clutch 12 is in the half-clutch state, and is set to an appropriate value according to the characteristics of the clutch 12. If the clutch stroke L becomes equal to or smaller than the predetermined value, the process proceeds to step 4 (Yes), and if the clutch stroke L is larger than the predetermined value, the process returns to step 2 (No). In other words, the clutch 12 is shifted from the engaged / disengaged state to the half-clutch state in a short time by the processing of Step 2 and Step 3.

  In step 4, a time limit for limiting the stagnation time is set in order to prevent the clutch connection operation from stagnation for a long time in the half-clutch state. That is, since the degree of wear of the clutch facing in the clutch 12 has a close correlation with the transmission torque, there is a characteristic that varies depending on, for example, the accelerator opening θ or the fuel injection amount Tp. For this reason, the permissible time (time limit) during which wear of the clutch facing in the half-clutch state is not promoted gradually decreases nonlinearly as the accelerator opening θ increases, as shown in the map of FIG. Therefore, the map shown in FIG. 4 is referred to using the accelerator opening θ detected by the accelerator opening sensor 40 as a parameter, and the time limit is uniquely set. Here, instead of the accelerator opening θ, the fuel injection amount Tp controlled by the engine control unit 16 may be used. Note that the processing in step 4 corresponds to time limit setting means.

  In step 5, a timer is started to start measuring the stagnation time of the clutch engagement operation.

  In step 6, a subroutine (see FIG. 5) for loosely connecting the clutch 12 according to the operating state is called in order to further connect the clutch 12 from the half-clutch state.

  In step 7, it is determined whether or not the clutch engagement operation is stagnant (meaning that the clutch stroke L does not change) even though the clutch loose connection control is performed based on the signal from the clutch stroke sensor 24. Determined. That is, based on the change rate ΔL of the clutch stroke L, it is determined whether or not the clutch connection operation is stagnant. If the clutch connection operation is stagnated, the process proceeds to Step 8 (Yes), and if the clutch connection operation is not stagnated, the process proceeds to Step 11 (No). In addition, the process of step 7 corresponds to a stagnation determination means.

  In step 8, it is determined by referring to the timer whether or not the clutch engagement operation is stagnant for the time limit. If the clutch connection operation is stagnant for the time limit, the process proceeds to step 9 to execute processing for suppressing wear of the clutch facing (Yes). On the other hand, if the clutch engagement operation has not stagnated for a predetermined time, the routine proceeds to step 13 (No).

  In step 9, the notification device of the display monitor 48 is activated for a predetermined time to notify that there is a possibility that the wear of the clutch facing may progress. In addition, the process of step 9 corresponds to an alarm generation means.

  In step 10, the clutch booster 22 is controlled to forcibly loosely connect the clutch 12 by a predetermined stroke. In addition, the process of step 10 corresponds to a forced connection means.

  In step 11, the time limit for limiting the stagnation time of the clutch engagement operation is reset by the same processing as in step 4. Note that the processing in step 11 corresponds to time limit setting means.

  In step 12, the timer is reset, i.e. restarted. Note that a series of processing in step 5, step 8 and step 12 corresponds to the stagnation time measuring means.

  In step 13, based on the signals from the engine speed sensor 20 and the counter speed sensor 36, it is determined whether or not the engine speed Ne and the counter speed Nc substantially match. If the engine rotation speed Ne and the counter rotation speed Nc substantially match, the process proceeds to step 14 (Yes), and if the engine rotation speed Ne and the counter rotation speed Nc do not approximately match, the process returns to step 6 ( No).

  In step 14, the clutch booster 22 is controlled and the clutch 12 is completely connected. A series of processes in Step 2, Step 3, Step 6 (the entire subroutine shown in FIG. 5), Step 13 and Step 14 correspond to the clutch connecting means.

  FIG. 5 shows the processing contents of a subroutine for performing clutch loose connection control.

  In step 21, the engine speed Ne is read from the engine speed sensor 20.

  In step 22, the engine rotational acceleration α is calculated based on the rate of change of the engine rotational speed Ne.

  In step 23, it is determined whether the engine rotational speed Ne is low and the engine rotational acceleration α is small or negative. If such a condition is satisfied, the processing in this subroutine is terminated (Yes), and if this condition is not satisfied, the process proceeds to Step 24 (No). Here, when the engine rotational speed Ne is low and the engine rotational acceleration α is small or negative, the transmission torque is extremely small, so that the clutch connection operation is stagnated from the viewpoint of preventing the occurrence of engine stall.

  In step 24, it is determined whether or not “the engine rotational speed Ne is high and the engine rotational acceleration α is small” or “the engine rotational speed Ne is low and the engine rotational acceleration α is large”. If such a condition is satisfied, the process proceeds to Step 25 (Yes), and if this condition is not satisfied, the process proceeds to Step 26 (No).

  In step 25, the clutch booster 22 is controlled, and the clutch 12 is slowly connected or the amount of connection is reduced.

  In step 26, the clutch booster 22 is controlled so that the clutch 12 is connected faster or the connection amount is slightly increased.

  According to the clutch connection control described above, when the vehicle starts, the clutch 12 is suddenly connected from the disengaged state to the half-clutch state. The clutch 12 is loosely connected based on the engine rotational speed Ne and the engine rotational acceleration α until the engine rotational speed Ne and the counter rotational speed Nc substantially coincide with each other after the half-clutch state is reached. At this time, if the engine rotational speed Ne is low and the engine rotational acceleration α is small or negative, the clutch stroke L at that time is maintained, that is, the clutch engagement operation is stagnated. Even if the clutch loose connection control is performed, if the clutch connection operation is stagnated for a time limit set in accordance with the accelerator opening θ that has a close correlation with the transmission torque, wear of the clutch facing proceeds. The notification device of the display monitor 48 is activated for a predetermined time in order to notify the user of this. Further, in accordance with the operation of the notification device, the clutch 12 is forcibly loosely connected by a predetermined stroke so as to enable smooth start while suppressing the progress of wear of the clutch facing.

  Therefore, when the notification device is activated when the clutch connection operation is stagnated for a limited time, the driver recognizes that the accelerator pedal 38 is not sufficiently depressed when starting, and further depressing the accelerator pedal 38 causes the stagnation of the clutch connection operation. Can be prevented. In addition, since the clutch 12 is forcibly loosely connected by a predetermined stroke along with the operation of the notification device, the connection operation of the clutch 12 is not performed at a stretch in a short time, and the occurrence of shock is suppressed and the clutch Smooth start can be performed while suppressing the acceleration of wearing of the facing. At this time, the time limit for limiting the stagnation time of the clutch connection operation is appropriately set according to the transmission torque that has a close correlation with the degree of wear of the clutch facing. Therefore, the load of the clutch 12 in the half-clutch state is appropriately set. Can be held.

Vehicle configuration diagram including a clutch control device according to the present invention Main routine flowchart showing clutch connection control Main routine flowchart showing clutch connection control Explanatory drawing of the map in which the correlation between torque and time limit is set Subroutine flowchart showing clutch loose connection control

Explanation of symbols

12 Clutch 16 Engine control unit 20 Engine speed sensor 22 Clutch booster 24 Clutch stroke sensor 26 Transmission control unit 36 Counter speed sensor 40 Accelerator opening sensor 48 Display monitor

Claims (6)

Clutch connecting means for connecting the clutch from a disconnected state to a connected state via a half-clutch state when the vehicle starts,
A stagnation determining means for determining whether or not the connection operation is stagnant during the clutch connection operation by the clutch connection means;
A stagnation time measuring means for measuring the stagnation time when it is determined by the stagnation determining means that the clutch connection operation is stagnant;
Time limit setting means for setting a time limit for limiting the stagnation time of the clutch connection operation based on a parameter correlated with the transmission torque;
Forcibly connecting means for forcibly and slowly engaging the clutch when the stagnation time measured by the stagnation time measuring means reaches the time limit set by the time limit setting means;
A clutch control device comprising:   The clutch control device according to claim 1, wherein the forcible connection means forcibly and gently connects the clutch by a predetermined stroke.   The clutch control device according to claim 1, further comprising alarm generation means for issuing an alarm when the stagnation time reaches a time limit.   4. The clutch control device according to claim 1, wherein the time limit setting unit sets the time limit to be shorter as transmission torque increases. 5.   The clutch control device according to any one of claims 1 to 4, wherein the parameter correlated with the transmission torque is an accelerator opening or a fuel supply amount.   The said stagnation determination means determines whether the clutch connection operation is stagnation based on the rate of change of the stroke of the clutch. Clutch control device.

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