JP2008240951A - Clutch control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make compatible resistance against engine stall and clutch synchronization failure suppression. <P>SOLUTION: The clutch control device 50 controls torque transmission between an engine 10 and a transmission 30 by adjusting stroke of an actuator 23 for a clutch for conducting clutch stroke and by changing an engaging state of a clutch disk 21a and a flywheel 10a. The clutch control device 50 strokes the actuator 23 for the clutch to move the clutch stroke closer to a boundary point of perfect engagement and half clutch according to a detection signal of an engine water temperature sensor 17 and an engine rotation number sensor 16 when the friction clutch 21 is perfectly engaging. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a clutch control device that drives and controls an actuator to change the engagement state between a clutch disk and a wheel, and more particularly, to a clutch control device that improves engine stall resistance.

  Conventionally, an automated manual transmission system (hereinafter referred to as “automatic manual transmission system”) that attaches an actuator to an existing manual transmission and automatically performs a series of gear shifting operations (clutch engagement / disengagement, gear shift, selection) according to the driver's will or vehicle condition. AMT ") is known. In this system, for example, in clutch control, the clutch actuator is driven and controlled to control the transmission torque (clutch torque) between the flywheel and the clutch disk. By controlling the clutch torque by this actuator, a suitable clutch operation according to the vehicle state is realized. In such clutch control, the clutch torque is controlled by controlling the pressure-bonding load of the clutch disk to the flywheel by an actuator. Further, a clutch control device is disclosed that controls the actuator by correcting the engagement amount when the clutch engagement amount becomes inappropriate (see Patent Document 1).

  In a vehicle equipped with an AMT, when the engine speed and the input speed of the transmission are synchronized, the clutch actuator moves the clutch (flywheel and clutch disk) to the complete engagement point. This complete engagement point is equivalent to a state where a foot is released from the clutch pedal in a vehicle equipped with a normal manual transmission, and there is a distance to a position where the clutch is disengaged (hereinafter referred to as a standby point). When trying to stop the vehicle, torque is generated in the direction of stopping the engine (negative side), and engine stall (hereinafter referred to as engine stall) may occur due to clutch disengagement delay. Therefore, in the conventional AMT, in order to prepare for the engine stall while ensuring the fully engaged state, the clutch is moved in the disengagement direction in advance on the condition that the accelerator is off, and the distance to the standby point is shortened. ing.

  On the other hand, if the clutch is moved in the disengagement direction, depending on the amount of movement, if the output of the drive source (engine, etc.) suddenly changes, the clutch pressing force will be insufficient, and the engine speed and the input speed will be synchronized. There was a case where behavior such as collapse, shock and sliding occurred. For this reason, the engine water temperature is as low as possible within the conceivable range, the engine speed is as large as possible within the conceivable range, and the amount of movement that does not cause synchronization breakdown even in a fuel cut state (worst condition) is a fixed value. It was set and controlled based on the fixed value.

JP-A-9-112589

  However, the engine stall resistance and the clutch synchronization loss are in a trade-off relationship with a preset movement amount. In the conventional clutch control device, since the movement amount is a fixed value in anticipation of the worst condition, it has not been possible to achieve both of them. In other words, there was a problem with the engine stall resistance.

  The main object of the present invention is to achieve both engine stall resistance and suppression of clutch synchronization failure.

  In one aspect of the present invention, a clutch having a flywheel that rotates integrally with an output shaft of a drive source, a clutch disk that faces the flywheel and rotates integrally with an input shaft of a transmission, and the clutch disk An actuator that displaces the clutch stroke, adjust the stroke of the actuator to cause the clutch stroke, and change the engagement state between the clutch disk and the wheel to change between the drive source and the transmission. In the clutch control device for controlling torque transmission, when the clutch is fully engaged, the clutch stroke is brought close to the boundary point between the full engagement and the half clutch according to one or both of the engine water temperature and the engine speed. The actuator is stroked as described above.

  In the clutch control device according to the present invention, when the clutch is fully engaged and the fuel is cut, the clutch stroke is set to a fully engaged or half-engaged state according to one or both of the engine water temperature and the engine speed. The actuator is preferably stroked so as to approach the clutch boundary point.

  In the clutch control device of the present invention, it is preferable to monitor whether or not the fuel cut is performed based on a signal for controlling a fuel injection state of the engine.

  In the clutch control device of the present invention, it is preferable to monitor whether or not the fuel cut is performed based on a measured value or an estimated value of engine output torque.

  In the clutch control device of the present invention, it is preferable to predict the fuel cut based on predetermined information before the fuel cut.

  In the clutch control device of the present invention, when the engine output torque becomes smaller than a set value when the actuator is stroked so as to approach the boundary point, the negative torque generated on the output shaft of the engine is reduced. It is preferable to control.

  According to the present invention, the amount of movement of the clutch that is guaranteed not to cause the synchronization loss of the clutch is not a fixed value. By making it variable in the disengagement direction in advance, the clutch disengagement time can be shortened, and both stall resistance and suppression of synchronization loss can be achieved. Further, since the negative torque itself generated on the output shaft of the engine is suppressed to be small, the worst condition can be expected to be small, and a larger amount of movement of the clutch can be expected than the conventional device.

(Embodiment 1)
The clutch control device according to the first embodiment will be described with reference to the drawings. FIG. 1 is a block diagram schematically showing a configuration of a vehicle control system applied to a clutch control device according to Embodiment 1 of the present invention. FIG. 2 is a block diagram schematically showing the configuration of the clutch control device (ECU) and its peripheral part according to Embodiment 1 of the present invention.

  In this vehicle control system, an automatic clutch 20 is assembled to a flywheel 10a that rotates integrally with an output shaft (crankshaft) of an engine (internal combustion engine) 10 serving as a drive source, and an automatic transmission is provided via the automatic clutch 20. 30 is connected.

  The engine 10 is connected to an ignition ignition switch 11. In addition, the engine 10 is provided with an injector actuator 12 that adjusts the fuel injection amount from the injector (including fuel cut). Further, the engine 10 is provided with an igniter actuator 13 for adjusting the ignition timing. The engine 10 is provided with an engine speed sensor 16 that detects the engine speed Ne. Further, the engine 10 is provided with an engine water temperature sensor 17 for detecting the engine water temperature Tw.

  The automatic clutch 20 includes a mechanical (dry single plate type) friction clutch 21, a clutch lever 22, and a clutch actuator 23. The clutch actuator 23 is an actuator for operating rotation transmission by the friction clutch 21 via the clutch lever 22.

  The friction clutch 21 includes a clutch disk 21 a that is disposed to face the flywheel 10 a and rotates integrally with the input shaft 31 of the automatic transmission 30. The friction clutch 21 is displaced by the clutch actuator 23 to make a clutch stroke, and the pressure-bonding load of the clutch disk 21a to the flywheel 10a changes, so that the flywheel 10a and the clutch disk 21a are separated (the output shaft of the engine 10 and the automatic The rotation transmission (torque transmission) between the input shafts 31 of the transmission 30, that is, the clutch torque is changed.

  The clutch actuator 23 includes a DC electric motor 24 as a drive source, and the clutch 24 is moved by moving the rod 25 forward or backward by moving the motor 24 forward or backward. As a result, the release bearing 27 is pushed through the clutch lever 22, and the diaphragm spring 28 that is elastically contacted with the release bearing 27 is deformed to generate a pressure-bonding load on the pressure plate 29. The pressure plate 29 is supported by a cover 21b of the friction clutch 21 that rotates integrally with the flywheel 10a. The clutch actuator 23 moves the clutch lever 22 via the rod 25, thereby changing the pressure-bonding load of the clutch disc 21 a to the flywheel 10 a via the pressure plate 29 and operating the rotation transmission by the friction clutch 21.

  Specifically, when the rod 25 is moved (advanced) forward and the clutch lever 22 is pushed to the right side in FIG. 1 by the rod 25, the pressure-bonding load of the clutch disc 21a to the flywheel 10a is reduced. Yes. Conversely, when the rod 25 is moved backward (retracted) and the clutch lever 22 is returned, the pressure load of the clutch disc 21a against the flywheel 10a increases.

  Here, the relationship between the movement position of the rod 25 (stroke of the clutch actuator 23) and the rotation transmission (clutch torque) due to the displacement (clutch stroke) of the clutch disk 21a of the friction clutch 21 will be described. When the rod 25 is moved (advanced) forward, finally, there is almost no crimping load of the clutch disc 21a to the flywheel 10a. At this time, the flywheel 10a and the clutch disc 21a are disconnected, and the rotation transmission between the flywheel 10a and the clutch disc 21a is lost. The state where the rotation transmission is lost is referred to as a clutch non-engagement state. The position of the rod 25 at this time is called a standby point. The amount of movement corresponding to the position of the rod 25 is referred to as a clutch stroke as a control amount.

  When the rod 25 is moved backward (retracted) from the standby point, the pressure-bonding load of the clutch disc 21a to the flywheel 10a increases according to the amount of movement. At this time, rotation transmission between the flywheel 10a and the clutch disk 21a is performed with a difference in the number of rotations (slip amount) according to the pressure load. In particular, the flywheel 10a and the clutch disk 21a rotate synchronously when there is almost no difference in the rotational speed (slip amount) due to an increase in the pressure-bonding load due to such movement (retraction) of the rod 25. This state of synchronous rotation is referred to as a fully engaged state of the clutch. The position of the rod 25 at this time is referred to as a boundary point between complete engagement and half-clutch, and a point where a predetermined amount of clutch stroke is performed from this boundary point to the complete engagement side is referred to as a complete engagement point. Therefore, the amount of slip between the flywheel 10a and the clutch disk 21a is controlled by the clutch actuator 23 by controlling the amount of movement (clutch stroke) of the rod 25 from the standby point to the moving position at the time of synchronization (completely engaged point). Is controlled. Hereinafter, a state in which the movement amount (clutch stroke) of the rod 25 is in the range from the standby point to the complete engagement point and the flywheel 10a and the clutch disk 21a slip is referred to as a half-clutch state. The half-clutch state including the complete engagement state is particularly referred to as a clutch engagement state.

  FIG. 3 is a graph showing a basic relationship of the clutch torque with respect to the movement amount (clutch stroke) of the rod 25. In the figure, the zero point of the clutch stroke corresponds to the standby point. The positive side of the zero point (standby point) corresponds to the amount of movement to the complete engagement point side. The clutch torque is a torque that can be transmitted from the flywheel 10a side to the clutch disc 21a. Therefore, the clutch torque also increases due to the shift toward the engagement side of the clutch as the clutch stroke increases. The vehicle obtains, for example, smooth startability and accurate acceleration by controlling the clutch torque according to the state.

  The automatic clutch 20 is provided with a stroke sensor 26 that detects a clutch stroke St, which is a movement position of the rod 25 of the clutch actuator 23. This clutch stroke St is used for determining the state of rotation transmission by the friction clutch 21 and the like.

  The automatic transmission 30 is, for example, a parallel shaft gear type transmission having five forward speeds and one reverse speed, and includes an input shaft 31 and an output shaft 32 and a plurality of transmission gear trains. The input shaft 31 of the automatic transmission 30 is connected to the clutch disk 21a of the friction clutch 21 so that power can be transmitted, and the output shaft 32 is connected to an axle (not shown) so as to be able to transmit power. The input shaft 31 is provided with a rotation speed sensor 33 for detecting the rotation speed (input shaft rotation speed Ni). The automatic transmission 30 also includes a shift actuator 41 for operating switching of a gear train (shift stage) capable of transmitting the power. The automatic transmission 30 is switched to a required shift stage by driving the shift actuator 41.

  The vehicle control system of FIG. 1 includes an electronic control unit (ECU) 50. Referring to FIG. 2, the ECU 50 includes a detection unit 51 that performs various controls, a calculation unit 52, and a control unit 53. The detection unit 51 detects vehicle states (vehicle speed, engine water temperature, engine speed, input speed, engine torque, accelerator opening, clutch stroke, fuel injection state, etc.) based on detection signals from various sensors and control signals from various actuators. To detect. The computing unit 52 computes numerical information necessary for clutch control with reference to a predetermined characteristic map, database, and the like based on information relating to the vehicle state. The control unit 53 controls the control amount of the clutch actuator 23 based on the detected (calculated) engine water temperature, engine speed, and fuel injection state.

  The ECU 50 is configured around a well-known microcomputer (CPU), and includes a ROM storing various programs, a characteristic map, a learning value (complete engagement point, standby point), a readable / writable RAM such as various data, and a backup. An EEPROM or the like that can hold data without a power source is provided. The ECU 50 includes various sensors such as an ignition switch 11, an engine speed sensor 16, an engine water temperature sensor 17, a stroke sensor 26, a speed sensor 33, an accelerator opening sensor 42, an injector actuator 12, an igniter actuator 13, and a clutch. Actuators such as the actuator 23 for shifting and the actuator 41 for shifting are connected. The ECU 50 receives detection signals from various sensors, and thereby detects the vehicle state (ignition switch 11 on / off state, engine speed Ne, engine water temperature Tw, clutch stroke St, input shaft speed Ni, engine torque, accelerator opening. Ap, clutch stroke, fuel injection state, etc.) are detected. Then, the ECU 50 drives the injector actuator 12, the igniter actuator 13, the clutch actuator 23, and the speed change actuator 41 based on the vehicle state.

  Specifically, the ECU 50 drives the injector actuator 12 to adjust the fuel injection amount of the injector or perform fuel cut according to the vehicle state. Further, the ECU 50 adjusts the ignition timing of the engine 10 by driving the igniter actuator 13 according to the vehicle state. Further, the ECU 50 drives the clutch actuator 23 to adjust the rotation transmission by the friction clutch 21 according to the vehicle state. Further, the ECU 50 drives the gear shift actuator 41 in accordance with the vehicle state to switch the gear train (speed stage) capable of transmitting power in the automatic transmission 30.

  The accelerator opening sensor 42 detects the accelerator opening Ap of the accelerator pedal.

  Next, the control aspect of the clutch control apparatus of Embodiment 1 is demonstrated using drawing. FIG. 4 is a flowchart schematically showing a control mode of the clutch control device according to the first embodiment of the present invention. FIG. 5 is a flowchart schematically showing a calculation mode of the target clutch torque when the clutch control device according to the first embodiment of the present invention is completely engaged. FIG. 6 is a graph schematically showing an example of the relationship between the engine water temperature, the engine speed, and the engine output torque that are the basis of control in the clutch control device according to the first embodiment of the present invention.

  First, the ECU 50 performs clutch control (normal control) (step A1).

  Next, during the clutch control, the ECU 50 determines whether or not the friction clutch 21 is completely engaged (locked up) based on detection signals from various sensors (step A2). If not completely engaged (NO in step A2), the process proceeds to step A4.

  When fully engaged (YES in step A2), the ECU 50 calculates a target clutch torque suitable for complete engagement corresponding to the vehicle state based on detection signals from various sensors (step A3), and then step A7. Proceed to

  Here, the calculation of the target clutch torque suitable for complete engagement is performed according to the flowchart of FIG.

  That is, when the engagement is complete (YES in step A2), the ECU 50 determines whether or not the accelerator is OFF based on the detection signal of the accelerator opening sensor 42 (step B1). If the accelerator is not OFF (NO in step B1), the process proceeds to step B5.

  When the accelerator is OFF (YES in step B1), the ECU 50 determines whether or not the fuel is cut based on the control signal of the injector actuator 12 (signal for controlling the fuel injection state of the engine) ( Step B2). Here, the fuel cut is determined based on the control signal of the injector actuator 12. However, the fuel cut may be determined based on the engine output torque or the estimated value, and may be determined before the fuel cut. It is preferable to predict and determine the fuel cut based on the information. Further, the prediction of fuel cut can be determined using information on an electric load such as an air conditioner or a head ride, and a change with time may be taken into consideration. When the fuel cut is not performed (NO in step B2), the process proceeds to step B4.

  When the fuel is cut (YES in step B2), the ECU 50 determines that the full engagement, the accelerator is OFF, and the accelerator based on the map and the calculation formula according to the detection signals of the engine speed sensor 16 and the engine water temperature sensor 17. A target clutch torque suitable for the fuel cut (at the worst condition) is calculated (step B3), and then the process proceeds to step A7. The target clutch torque here is set so that the clutch is on the fully engaged side of the boundary point between the fully engaged and half-clutch where the synchronization does not break. As shown in FIG. 6, the engine output torque increases as the engine water temperature increases. In addition, the engine output torque is variable based on the characteristic that the engine output torque decreases as the engine speed increases.

  When the fuel cut is not performed (NO in step B2), the ECU 50 determines that the complete engagement, the accelerator is OFF, and the accelerator based on the map and the calculation formula according to the detection signals of the engine speed sensor 16 and the engine water temperature sensor 17. A target clutch torque suitable for non-fuel cut is calculated (step B4), and then the process proceeds to step A7. The target clutch torque here is also set so that the clutch is on the fully engaged side of the boundary point between the fully engaged and half-clutch where the synchronization does not break. As shown in FIG. 6, the engine output torque increases as the engine water temperature increases. In addition, the engine output torque is variable based on the characteristic that the engine output torque decreases as the engine speed increases.

  If the accelerator is not OFF (NO in step B1), the ECU 50 calculates a target clutch torque suitable for complete engagement corresponding to the vehicle state based on the detection signals of various sensors (step B5), and then step Proceed to A7.

  If not completely engaged (NO in step A2), the ECU 50 determines whether or not the clutch control is under start control performed at the start (step A4). If the start control is not being performed (NO in step A4), the process proceeds to step A6.

  When starting control is being performed (YES in step A4), the ECU 50 calculates a target clutch torque suitable for starting in response to the vehicle state based on detection signals from various sensors (step A5), and then proceeds to step A7. .

  When the start control is not being performed (NO in step A4), the ECU 50 calculates a target clutch torque suitable for shifting according to the vehicle state based on the detection signals of various sensors (step A6), and then proceeds to step A7.

  After step A3, step A5, and step A6, the ECU 50 calculates the target clutch stroke based on the calculation formula and the map according to the calculated target clutch torque (step A7).

  Finally, the ECU 50 feedback-controls the clutch actuator 23 based on the calculated target clutch stroke and the detection signal of the stroke sensor 26 (step A8).

  When controlling the clutch actuator based on the target clutch torque suitable for the worst condition in Step B3, if the engine output torque becomes smaller than the set value, the negative torque generated on the output shaft of the engine 10 is reduced. Make it smaller. For example, it is preferable to control the ECU 50 so that fuel is blown even when the accelerator is OFF, and the negative torque is kept small.

  Further, when calculating the target clutch torque suitable for the worst condition in step B3, if the engine output torque increases to the negative side, for example, at the time of engine low water temperature, fuel cut is prohibited and generated on the output shaft of the engine 10. The ECU 50 is preferably controlled so as to suppress the negative torque.

According to the first embodiment, the amount of movement of the clutch that is guaranteed not to cause the synchronization loss of the clutch is not a fixed value, and the clutch is set on the fully engaged side of the boundary point between the fully engaged and half clutch according to the conditions. By making the variable in the disengagement direction in advance, the clutch disengagement time for avoiding the engine stall can be shortened. The first embodiment can be shortened by about 30% to 80% compared to the conventional apparatus. The reason why the movement amount (stroke amount) of the clutch can be shortened is as follows. The negative torque generated in the output shaft of the engine 10 has the following relationship with the conditions 1 to 3 Condition 1: Larger as the engine water temperature is lower (larger on the negative side)
Condition 2: Larger as the engine speed is higher (larger on the negative side)
Condition 3: When the engine is in a fuel cut state, it is larger (larger on the negative side)
Since the stroke amount of the clutch is changed according to these conditions, the worst condition itself does not change, but the time that is not the worst condition is overwhelmingly much, and a larger stroke amount can be expected than the conventional device, and It is possible to achieve both stallability and suppression of loss of synchronization. In other words, the frequency of incompatibility is overwhelmingly reduced.

  Further, since the negative torque itself generated on the output shaft of the engine 10 is suppressed to be small, the worst condition can be expected to be small, and a larger stroke amount of the clutch can be expected than the conventional device.

It is the block diagram which showed typically the structure of the vehicle control system applied to the clutch control apparatus which concerns on Embodiment 1 of this invention. It is the block diagram which showed typically the structure of the clutch control apparatus (ECU) which concerns on Embodiment 1 of this invention, and its peripheral part. It is a graph which shows the basic relationship of the clutch torque with respect to the moving amount (clutch stroke) of the rod of the vehicle control system applied to the clutch control apparatus which concerns on Embodiment 1 of this invention. It is the flowchart which showed typically the control aspect of the clutch control apparatus which concerns on Embodiment 1 of this invention. It is the flowchart which showed typically the calculation aspect of the target clutch torque at the time of complete engagement of the clutch control apparatus which concerns on Embodiment 1 of this invention. It is the graph which showed typically an example of the relationship of the engine water temperature used as the basis of control in the clutch control apparatus which concerns on Embodiment 1 of this invention, an engine speed, and an engine output torque.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Engine 10a Flywheel 11 Ignition switch 12 Injector actuator 13 Igniter actuator 16 Engine speed sensor 17 Engine water temperature sensor 20 Automatic clutch 21 Friction clutch 21a Clutch disk 21b Cover 22 Clutch lever 23 Clutch actuator 24 DC electric motor 25 Rod 26 Stroke sensor 27 Release bearing 28 Diaphragm spring 29 Pressure plate 30 Automatic transmission 31 Input shaft 32 Output shaft 33 Rotational speed sensor 41 Shifting actuator 42 Accelerator opening sensor 50 ECU (clutch control device)
51 Detection Unit 52 Calculation Unit 53 Control Unit

Claims (6)

A flywheel that rotates integrally with the output shaft of the drive source; a clutch that has a clutch disk that faces the flywheel and rotates integrally with the input shaft of the transmission; and an actuator that displaces the clutch disk and causes a clutch stroke. A clutch control that adjusts the stroke of the actuator to cause a clutch stroke, and changes the engagement state between the clutch disc and the flywheel to control torque transmission between the drive source and the transmission. In the device
When the clutch is fully engaged, the actuator is stroked so as to bring the clutch stroke closer to the boundary point between the full engagement and the half clutch according to one or both of the engine water temperature and the engine speed. A clutch control device.   When the clutch is fully engaged and the fuel is cut, the clutch stroke is brought close to the boundary point between the full engagement and the half clutch according to one or both of the engine water temperature and the engine speed. The clutch control device according to claim 1, wherein the actuator is caused to stroke.   The clutch control device according to claim 2, wherein the fuel cut is monitored based on a signal for controlling a fuel injection state of the engine.   The clutch control device according to claim 2, wherein the fuel cut is monitored based on a measured value or an estimated value of engine output torque.   The clutch control device according to claim 2, wherein the fuel cut is predicted based on predetermined information before the fuel cut.   2. When the actuator is stroked to approach the boundary point, when the engine output torque becomes smaller than a set value, the negative torque generated on the output shaft of the engine is controlled to be reduced. The clutch control device according to any one of 1 to 5.

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