JP2005048893A - Clutch control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To release a brake with appropriate timing by outputting a service brake release signal to a vehicle start auxiliary device in accordance with a state of clutch connection. <P>SOLUTION: In clutch connection control at the time of vehicle start, although clutch slow connection control is performed after a half clutch state is realized (S4), when clutch connection operation is retarded continuously for a second predetermined time (S5), an alarm for informing the possibility of progress of clutch facing wear is outputted (S9), and slow connection of a clutch is forcibly performed by predetermined strokes (S10). When the clutch connection operation is not retarded continuously for the second predetermined time but is retarded continuously for a first predetermined time which is shorter than the second one (S6), since it seems to be apparent that predetermined torque is transmitted by the clutch, a brake release signal is outputted to the vehicle start auxiliary device (S11). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a technique for outputting a brake release signal at an appropriate timing to a vehicle start assist device in clutch connection control at the time of vehicle start.

  Large commercial vehicles are often equipped with a vehicle start assist device for the purpose of eliminating the need to operate the brake pedal when starting the vehicle and reducing the labor of the driver. The vehicle start assist device operates the service brake until the clutch is connected even if the foot is released from the brake pedal. In the vehicle start assist device, as disclosed in Patent Document 1, when the operation amount of the clutch pedal, that is, the clutch stroke becomes a predetermined value, the driver's intention to start, the service brake is set. Canceled.

In recent years, a mechanical automatic transmission that performs automatic transmission according to a running state by electronically controlling a clutch and a gear type transmission has 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. On the other hand, if the clutch is suddenly connected when the vehicle starts, the speed difference between the input rotational speed and the output rotational speed is large, which may cause a large shock or engine stall. For this reason, half-clutch control is indispensable as clutch connection control when the vehicle starts.
JP 2003-72532 A

  By the way, since the clutch facing has a characteristic of gradually wearing out, the clutch stroke and the clutch connection position are not always constant. For this reason, in the vehicle start assist device, when the service brake is released according to the clutch stroke, the service brake is not necessarily released at an appropriate timing. In particular, when starting on a slope, if the service brake is released too early, the vehicle may move backward. In order to solve such a problem, it may be possible to provide a function for adjusting the release point of the service brake. However, even with such a function, the service brake cannot be released at an appropriate timing.

  Therefore, in view of the conventional problems as described above, the present invention outputs a service brake release signal to the vehicle start assist device in accordance with the engagement state of the clutch so that the brake can be released at an appropriate timing. An object of the present invention is to provide a clutch control device.

  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, First stagnation determining means for determining whether or not the connection operation has been continuously stagnated for a first predetermined time, and the clutch connection operation has been stagnated continuously for a first predetermined time by the first stagnation determining means. And a release signal output means for outputting a brake release signal to the vehicle start assist device.

  According to a second aspect of the present invention, a gradient detection unit that detects a gradient of a road surface on which the vehicle is located, and a first time setting that sets the first predetermined time based on the gradient detected by the gradient detection unit Means.

  According to a third aspect of the present invention, the second stagnation determining means for determining whether or not the connection operation has been continuously stagnated for a second predetermined time during the clutch connection operation by the clutch connecting means, and the second Forcibly connecting means for forcibly loosely connecting the clutch by a predetermined stroke when it is determined by the stagnation determining means that the clutch connection operation has been continuously stagnated for a second predetermined time. To do.

  According to a fourth aspect of the present invention, a gradient detecting means for detecting a gradient of a road surface on which the vehicle is located, and a second time setting for setting the second predetermined time based on the gradient detected by the gradient detecting means. Means.

  According to a fifth aspect of the present invention, there is provided an alarm means for issuing an alarm when it is determined by the second stagnation determining means that the clutch engagement operation has been continuously stagnation for a second predetermined time. .

  The invention according to claim 6 is characterized in that the second predetermined time is set longer than the first predetermined time.

  According to the first aspect of the present invention, if the connecting operation is continuously stagnated during the first predetermined time during the clutch connecting operation at the time of starting the vehicle, a brake release signal is output to the vehicle starting assist device. That is, if the clutch engagement operation is continuously stagnated for the first predetermined time, it is considered that a predetermined torque is clearly transmitted by the clutch. Therefore, the brake is released according to the engagement state of the clutch regardless of the clutch stroke, and can be released at an appropriate timing even when the clutch facing is worn.

  According to the second aspect of the present invention, the first predetermined time is set according to the road surface gradient, so that the brake is not released too early, and the reverse of the vehicle due to insufficient torque is prevented particularly when starting on a slope. be able to.

  According to the third aspect of the present invention, when the clutch engagement operation is continuously stopped for the second predetermined time, the clutch is forcibly loosely connected by a predetermined stroke. For this reason, if the second predetermined time is a time when there is no possibility that the wear of the clutch facing proceeds, the half-clutch state is not maintained more than necessary, and the wear of the clutch facing can be suppressed. In addition, since the connection operation is not performed at once in a short time, the occurrence of shock can be suppressed.

  According to the invention described in claim 4, since the second predetermined time is set according to the road surface gradient, the clutch engagement operation does not proceed with insufficient torque, and engine stall can be prevented.

  According to the fifth aspect of the present invention, when the clutch engagement operation is continuously stagnated for the second predetermined time, an alarm is issued, so that the driver recognizes that the accelerator pedal has not been depressed sufficiently at the start. Can do. Then, by further depressing the accelerator pedal, the stagnation of the clutch connection operation is prevented, and the vehicle can be started quickly.

  According to the invention described in claim 6, since the second predetermined time is set longer than the first predetermined time, the clutch engagement operation proceeds after the brake is released, and an excessive load acts on the clutch. Can be prevented.

  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 solenoid valve 28, and the display monitor 48 are controlled while communicating with each other, and a service brake release signal is output to the vehicle start assist device 50. Since the transmission control unit 26 controls the connection / disconnection of the clutch 12, it also functions as a clutch control device.

  Here, the transmission control unit 26 having various functions as a clutch control device and various sensors enable clutch connection means, first stagnation determination means, second stagnation determination means, release signal output means, and first time setting. Means, second time setting means, and forced connection means are realized. Further, the transmission control unit 26 and the display monitor 48 implement alarm means.

  Next, a first embodiment of processing contents in the clutch control device will be described with reference to the flowchart shown in FIG. Note that such control is executed when the vehicle is on standby.

  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 disengaged state to the half-clutch state in a short time by the processing of step 2 and step 3.

  In step 4, a subroutine (see FIG. 3) is called to loosely connect the clutch 12 according to the operating state in order to further connect the clutch 12 from the half-clutch state.

  In step 5, the state in which the clutch connection operation is stagnant (hereinafter referred to as “stuck state”) despite the fact that the clutch loose connection control is performed based on the signal from the clutch stroke sensor 24 is the second predetermined time. It is determined whether it is continuous. Here, the second predetermined time is set to a time during which wear of the clutch facing may progress as a result of maintaining the half-clutch state for a long time. If the stagnation state continues for the second predetermined time, the process proceeds to step 9 (Yes), and 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. Is done. In step 10, the clutch booster 22 is controlled to forcibly loosely connect the clutch 12 by a predetermined stroke. On the other hand, if the stagnation state does not continue for the second predetermined time, the process proceeds to Step 6 (No). Note that the processing of Step 5, Step 9 and Step 10 corresponds to second stagnation determination means, warning means and forced connection means, respectively.

  In step 6, based on the signal from the clutch stroke sensor 24, it is determined whether or not the stagnant state continues for the first predetermined time despite the clutch loose connection control being performed. Here, the first predetermined time is shorter than the second predetermined time, and it is clear that the predetermined torque is transmitted to the drive wheels as a result of the half-clutch state being maintained for a long time. Set to time. If the stagnation state continues for the first predetermined time, the process proceeds to step 11 (Yes), and a service brake release signal is output to the vehicle start assist device 50. On the other hand, if the stagnation state does not continue for the first predetermined time, the process proceeds to Step 7 (No). Note that the processes in step 6 and step 11 correspond to the first stagnation determination means and the release signal output means, respectively.

  In step 7, 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 8 (Yes), and if the engine rotation speed Ne and the counter rotation speed Nc do not approximately match, the process returns to step 4 ( No).

  In step 8, the clutch booster 22 is controlled and the clutch 12 is completely connected. A series of processes in Step 2, Step 3, Step 4 (the entire subroutine shown in FIG. 3), Step 7 and Step 8 correspond to the clutch connection means.

  FIG. 3 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 half-clutch state does not proceed and the clutch engagement operation is stagnated.

  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 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. In order to notify that there is a possibility that the wear of the clutch facing may progress if the clutch engagement operation is continuously stagnated for the second predetermined time despite the clutch loose connection control being performed. The notification device is activated for a predetermined time. 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.

  Accordingly, when the notification device is activated when the clutch engagement operation is continuously stagnated for the second predetermined time, the driver recognizes that the accelerator pedal 38 is not sufficiently depressed when starting, and further depresses this. 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.

  On the other hand, if the clutch engagement operation is not continuously stagnated for the second predetermined time, but if it is stagnated continuously for the first predetermined time shorter than that, a predetermined torque is transmitted to the drive wheels. Therefore, a service brake release signal is output to the vehicle start assist device 50. For this reason, the service brake is released according to the engagement state of the clutch irrespective of the clutch stroke, and can be released at an appropriate timing even when the clutch facing is worn.

  FIG. 4 shows a flowchart of the second embodiment of the processing contents in the clutch control device. In the second embodiment, a gradient sensor (gradient detection means) that detects the gradient of the road surface on which the vehicle is located is provided, and the signal is input to the transmission control unit 26. In addition, since the processing contents in the second embodiment are the same as those in the first embodiment, only different processes are described in order to eliminate redundant explanation.

  In step 12, which is executed after step 4, the road surface gradient is detected based on the signal from the gradient sensor.

  In step 13, the map shown in FIG. 5 is referred to and first and second predetermined times corresponding to the gradient are set. Here, in the map, considering that the torque required for vehicle start increases as the gradient increases, the first and second predetermined times gradually increase from the predetermined gradient as the gradient increases. Is set. Thereafter, the processing from step 5 onward is executed. Note that the processing of step 12 and step 13 corresponds to first time setting means and second time setting means.

  In this way, if the first predetermined time is set according to the road surface gradient, the brake is not released too early, and the vehicle can be prevented from reversing due to insufficient torque especially when starting on a slope. . Further, if the second predetermined time is set according to the road surface gradient, the clutch engagement operation does not proceed with insufficient torque, and engine stall can be prevented. Then, as shown in FIG. 5, if the second predetermined time is set longer than the first predetermined time, the clutch engagement operation proceeds after the service brake is released, and an excessive load is applied to the clutch 12. Can be prevented.

Vehicle configuration diagram including a clutch control device according to the present invention The flowchart which shows 1st Embodiment of the processing content in a clutch control apparatus. Subroutine flowchart showing clutch loose connection control The flowchart which shows 2nd Embodiment of the processing content in a clutch control apparatus. Explanatory drawing of the map which sets the 1st and 2nd predetermined time

Explanation of symbols

DESCRIPTION OF SYMBOLS 12 Clutch 20 Engine rotational speed sensor 22 Clutch booster 24 Clutch stroke sensor 26 Transmission control unit 36 Counter rotational speed sensor 48 Display monitor 50 Vehicle start assist device

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,
First stagnation determination means for determining whether or not the connection operation has been continuously stagnated for a first predetermined time during the clutch connection operation by the clutch connection means;
A release signal output means for outputting a brake release signal to the vehicle start assist device when it is determined by the first stagnation determination means that the clutch engagement operation is continuously stopped for a first predetermined time;
A clutch control device comprising: Slope detecting means for detecting the slope of the road surface on which the vehicle is located;
First time setting means for setting the first predetermined time based on the gradient detected by the gradient detection means;
The clutch control device according to claim 1, further comprising: A second stagnation determination means for determining whether or not the connection operation has been continuously stagnated for a second predetermined time during the clutch connection operation by the clutch connection means;
Forcibly connecting means for forcibly and loosely engaging the clutch by a predetermined stroke when the second stagnation determining means determines that the clutch connection operation has been continuously stagnated for a second predetermined time;
The clutch control device according to claim 1 or 2, further comprising: Slope detecting means for detecting the slope of the road surface on which the vehicle is located;
Second time setting means for setting the second predetermined time based on the gradient detected by the gradient detection means;
The clutch control device according to claim 3, further comprising:   5. The alarm unit according to claim 3, further comprising an alarm unit that issues an alarm when it is determined by the second stagnation determination unit that the clutch engagement operation has been continuously stagnation for a second predetermined time. The clutch control device described.   The clutch control device according to claim 3, wherein the second predetermined time is set longer than the first predetermined time.

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