DE102012221977A1 - Method for controlling hydraulic actuator system to operate clutch for transmission of torque of drive motor for interrupting powertrain, involves detecting slowing operation of accelerator to control drive motor such that opening is closed - Google Patents

Abstract

The method involves detecting that a transmitter piston (130) is in a position in which a connection opening (160) is released. A slowing operation of an accelerator (175) is detected for controlling a drive motor (110) such that the connection opening is closed. The connection opening is arranged between a supply container (150) and a master cylinder (125), where the container stores hydraulic fluid (155). The connection opening is opened or closed depending on the position of the piston in the master cylinder. The piston is moved with limited speed into a closed position of the opening. Independent claims are also included for the following: (1) a computer program product comprising a set of instructions for performing a method for controlling a hydraulic actuator system for a clutch for transmission torque of a drive motor (2) a hydraulic actuator system for a clutch.

Description

The invention relates to a technique for actuating a clutch. In particular, the invention relates to a technique for operating a clutch for interrupting a drive train connecting a drive motor of a motor vehicle with drive wheels.

A motor vehicle includes a drive train that transmits a torque provided by a drive motor to drive wheels. In the drive train usually a clutch and a transmission are arranged. To change a gear of the gearbox, the power flow is interrupted by means of the clutch. In this case, the clutch can be hydraulically actuated by a hydraulic fluid is displaced in a master cylinder by means of a master piston and passed into a slave cylinder, where a slave piston disengages the clutch, so that the power flow is interrupted.

In order to prevent the master piston from assuming an undefined position relative to the slave piston due to, for example, temperature influences on the hydraulic fluid, the volume of the hydraulic fluid in the area between the pistons can be calibrated while the slave piston is at a predetermined position. For this purpose, a follow-up container for receiving hydraulic fluid is provided, which is connected by means of a connection opening with the master cylinder. To perform the calibration, the master piston is moved so that the connection opening is released, so that hydraulic fluid can be exchanged between the follower tank and the master cylinder. The replacement process is also called sniffing and the position of the master piston a snoop position.

DE 197 44 051 A1 shows a motor vehicle with a hydraulically operated clutch for selective separation of power transmission in a drive train.

DE 197 19 614 A1 shows a motor vehicle with an automated power transmission system.

If the master piston is in the sniffer position, it must be moved slowly to close the connection opening in order to maintain the defined positions of the master piston and the slave piston relative to one another. If, on a driver's request, a gear change takes place before the sniffing process is completed, the disengagement of the clutch can therefore be delayed, so that a gear change by the driver can be perceived as unclean or hakelig. The invention has for its object to provide a method, a computer program product and an actuator system with which a gear change can be performed in an improved manner from a snooping out.

The invention solves these objects by means of a method, a computer program product and a hydraulic actuator system having the features of the independent claims. Subclaims give preferred embodiments again.

A hydraulic actuator system for a clutch for transmitting a torque provided by a drive motor comprises a master cylinder with a master piston, a supply reservoir for receiving hydraulic fluid and a connection opening between the supply reservoir and the master cylinder, the communication opening being opened in dependence on a position of the master piston in the master cylinder or closed is. A method of controlling the actuator system according to the present invention includes detecting steps that the master piston is in a position where the communication port is released, detecting a deceleration operation of an accelerator pedal for controlling the drive motor and the method of the master piston such that the communication port is closed is.

According to the invention can be determined early on the basis of the decreasing operation of the accelerator pedal that a driver intends to change a gear of a gearbox in the drive train and to operate the clutch. This makes it possible to close the connection opening early, so that the hydraulic actuator is operational when a signal for actuating the clutch is received. In a preferred embodiment, this signal can be removed from a clutch pedal, wherein the clutch pedal exerts no hydraulic effect on the actuator system. By the described method, a gear change, in particular a rapid gear change in dynamic driving, can be performed with improved precision.

In a preferred embodiment, it is determined that the operation of the accelerator pedal decreases at least at a predetermined speed. Experience has shown that an actuation of the clutch pedal is preceded by an approximately sudden relief of the accelerator pedal, so that it is possible in this way to distinguish between an anticipated gear change and a speed or acceleration reduction of the motor vehicle.

Preferably, the master piston, after the connection opening is closed, further moved in response to a position of the clutch pedal to hydraulic fluid from the Displacing master cylinder. Thereby, the clutch operation can be performed with a predetermined relationship between the positions of the master piston and the slave piston, so that for the driver an immediate feedback during the gear change can take place.

In a further preferred embodiment, the master piston is moved at a limited speed to the position in which the connection opening is closed. In particular, this speed may be a predetermined speed that is below a maximum speed of an actuator configured to change the position of the master piston. As soon as the connection opening is closed, the master piston can also be moved at a greater speed, in particular at the speed with which the clutch pedal is actuated by a user.

In a preferred embodiment, it is additionally detected that the drive motor has a rotational speed which is in the range of a switching threshold. Thus, a situation in which the rotational speed of the drive motor indicates that a gear change is unlikely to be considered in the earliest possible determination of the shift, so that incorrect provisions of an upcoming gear change can occur reduced.

In particular, the switching threshold may be in the upper range of a usable speed band of the drive motor. The limitation of the usable speed band of the drive motor is usually the reason why a manual transmission is used in the drive train. If the drive motor reaches a speed that is in the upper range of its usable speed range, it is likely that a change to the next higher gear is imminent.

In one embodiment, a signal is provided indicating that the determination of the accelerator pedal depression has resulted in a procedure of the master piston to complete the snooping operation. In particular, the signal can already be provided before the master piston has completely closed the connection opening. As a result, the specific gear change intention can be provided as a signal for a further component of the motor vehicle.

A computer program product according to the invention comprises program code means for carrying out the described method when the computer program product runs on a processing device or is stored on a computer-readable medium.

A hydraulic actuator system according to the invention for a clutch for transmitting a torque provided by a drive motor comprises a master cylinder with a master piston, a secondary reservoir for receiving hydraulic fluid and a connection opening between the secondary reservoir and the master cylinder, wherein the communication port opens in response to a position of the master piston in the master cylinder or closed. Further, the actuator system comprises a sensor for determining an operation of an accelerator pedal for controlling the drive motor and a control device for moving the master piston so that the connection opening is closed, if the master piston is in a position in which the connection opening is released, while an actuation of the accelerator pedal decreases.

The inventive hydraulic actuator system can be used for improved control of a clutch in the drive train of a motor vehicle. Thus, it may be possible to perform a gear change of a gearbox in the drive train gentler, which increases the life of the gearbox and a user can be harassed to a reduced degree.

The invention will now be described in more detail with reference to the attached figures, in which:

1 an actuator system;

2 a flowchart of a method for controlling an actuator system, and

3 exemplary courses on the actuator system of 1
represents.

1 shows an actuator system 100 on board a motor vehicle 105 , A drive motor 110 is with a powertrain 115 connected, which is a clutch 120 includes. The powertrain 115 usually leads to a manual transmission and this to drive wheels of the motor vehicle 105 However, both are not in 1 are shown. The actuator system 100 for actuating the clutch 120 includes a master cylinder 125 with a master piston 130 , a slave cylinder 135 with a slave piston 140 , a connection line 145 to the hydraulic connection of the master cylinder 125 with the slave cylinder 135 , a back-up tank 150 for receiving hydraulic fluid 155 , the overflow tank 150 by means of a connection opening 160 with the master cylinder 125 hydraulically connected, an actuator 165 for changing the position of the master piston 130 in the master cylinder 125 and a control device 170 for controlling the actuator 165 , In the illustrated, preferred embodiment includes the actor 165 an electric motor, by means of a spindle drive to the master piston 130 acts.

On board the motor vehicle 105 are also an accelerator pedal 175 , whose position by means of a first sensor 180 can be sampled, and a clutch pedal 185 , whose position by means of a second sensor 190 can be scanned arranged. The first sensor 180 and preferably also the second sensor 190 are with the control device 170 connected. In one embodiment, there is still a third sensor 195 provided, that of the processing device 170 a speed signal of the drive motor 110 provides.

In a mode considered here, the clutch pedal acts 185 not directly on the actuator system 100 instead, by means of the second sensor 190 a position of the clutch pedal 185 determined and by the processing device 170 evaluated. In a usual operation, the controller controls 170 the actor 165 depending on the position of the clutch pedal 185 on, the master piston 130 in the master cylinder 125 to proceed. Will the master piston 130 in the presentation of 1 Move to the right, so he displaces hydraulic fluid 155 from the master cylinder 125 through the connection line 145 in the direction of the slave cylinder 135 so that the slave piston 140 in the presentation of 1 pressed to the left to the clutch 120 disengage. The disengagement or opening of the clutch 120 is usually required to select or insert another gear in the manual transmission, not shown.

Is the clutch 120 not actuated, ie not disengaged, the master piston is located 130 in the illustrated position with respect to the connection opening 160 and becomes when operating the clutch 120 in the presentation of 1 move to the right. Different influences, such as heat, can cause the relative positions of the pistons 130 and 140 to change over time. To undo this change, the master piston can 130 be proceeded so that he the connection opening 160 releases so that hydraulic fluid 155 from the return tank 150 in the master cylinder 125 can be run or taken out of it. This is the hydraulic fluid 155 in the trailer tank 150 usually under an atmospheric pressure. This process is also called "sniffing". To stop the sniffing process without the relative positions of the pistons 130 . 140 To make inaccurate, the master piston must 130 be moved slower than a predetermined speed until the connection opening 160 is closed again. Subsequently, the master piston 130 be operated again at any speed to the clutch 120 disengage.

Will the clutch pedal 185 operated at a time to which the master piston 130 located in the sniffer position, in which the connection opening 160 is fully or partially open, so the master piston 130 initially not be moved at the required speed to a conventional operation of the clutch pedal 185 to follow.

The control device 170 is set to a decreasing operation of the accelerator pedal 175 , which is adapted to the drive motor 110 to control, detect and on a decreasing operation of the accelerator pedal 175 to close on an impending gear change. The master piston 130 can be moved in this case from the sniffer position out so that the connection opening 160 is closed, even if at this time the clutch pedal 185 not yet been pressed. A subsequent operation of the clutch pedal 185 can then immediately a proportional actuation of the master piston 130 cause.

2 shows a flowchart of a method 200 for controlling the actuator system 100 out 1 , The procedure 200 is in particular for running on the control device 170 set up.

In a first, optional step 205 it is determined if the drive motor 110 has a speed which is in the upper speed range. The speed may be based on the signal of the third sensor 195 be determined. The upper speed range is usually located in the region of the upper end of a usable speed range. Includes the usable speed band of the drive motor 110 For example, a range of 1100 to 4400 U / min, so the upper speed range, for example, at 3500 or 4000 rev / min begin. In the upper speed range is usually also a switching threshold, the exceeding of which can trigger an automatic gear change when an automated mode is implemented, in which a driver of the motor vehicle 105 does not specify the gear change. Is the drive motor 110 in the upper speed range or its speed has exceeded the switching threshold, so the method moves 200 with one step 210 otherwise it can go through again. Is the first step 205 not implemented, the procedure begins 200 with the step 210 ,

In step 210 it is determined whether the master piston 130 the connection opening 160 releases. If this is not the case, a conventional actuation of the master piston takes place 130 depending on the position of the clutch pedal 185 in the steps 240 and 245 as described in more detail below. Otherwise, in one step 215 determines how strong the gas pedal 175 is pressed. In a subsequent step 220 Then, a change or a gradient of the operation of the accelerator pedal is determined. The gradient is 0 if the operation of the accelerator pedal 175 does not change, positive if the accelerator pedal 175 is pushed further and negative if the operation of the accelerator pedal 175 subsides. In this case, the amount of the gradient describes the rate of change of the operation of the accelerator pedal 175 ,

In one step 225 it is checked whether the gradient is negative and its amount exceeds a predetermined threshold. In other words, in step 225 Check if the gas pedal 175 is released quickly enough. If this is not the case, the process branches 200 to the steps 240 and 245 ,

Otherwise, in one step 230 Optionally output a signal indicative of an impending gear change. This signal may be from another component on board the motor vehicle 105 be evaluated.

In one step 235 becomes the master piston 130 with a predetermined maximum speed so that the connection opening 160 is closed. The movement of the master piston 130 can also follow a predetermined trajectory, in which a position-dependent maximum speed is maintained. This will cause the pistons 130 and 140 spent with high accuracy in predetermined relative positions.

In a subsequent step 240 becomes an operation of the clutch pedal 185 certainly. Subsequently, in one step 245 the master piston 130 depending on the particular clutch actuation proceed to the clutch 120 according to the position of the clutch pedal 185 to press. The steps 240 and 245 can be performed until the operation of the clutch pedal 185 finished.

3 shows exemplary processes at the actuator system 100 out 1 , In the horizontal direction, a time is shown. A first course 305 shows an operation of the accelerator pedal 135 , where a high value is a heavily operated accelerator pedal 175 or a request to the internal combustion engine 110 corresponds to the delivery of a high performance. A second course 310 corresponds to a qualitative derivation of the first course 305 after the time, ie a gradient of the operation of the gas pedal 175 , A third course 315 shows an example of an actuation of the clutch pedal 185 , wherein a high value of a strong operation of the clutch pedal 185 equivalent.

Approximately until a time t1, the accelerator pedal 175 increasingly activated, usually the speed of the drive motor 110 increases. After that, the operation of the accelerator pedal drops 175 rapidly from and from a time t3 on the clutch pedal 185 operated, for example, in a transmission of the drive train 115 to insert a new gear.

At a time t2 to which the clutch pedal 185 not yet operated, falls below the second course 310 with the gradient of the operation of the accelerator pedal 175 a threshold 320 , This event can be used as an indication that a gear change, and thus an actuation of the actuator system 100 Imminent. Due to this event, the master piston 130 immediately proceed in such a way that the connection opening 160 between the return tank 150 and the master cylinder 125 is closed. Then takes place at time t3, the operation of the clutch pedal 185 Thus, the actuation can be immediate and precise in an actuation of the clutch 120 be implemented. Remains the operation of the clutch pedal 185 However, at time t3 off, it can be waited until the clutch pedal 185 is actuated or it can be initiated a new snooping, in which the connection opening 160 through the master piston 130 released at short notice.

The determination of the upcoming clutch operation can be done in the same way, if the accelerator pedal 175 is less strong. It is also not required that the operation of the accelerator pedal 175 was changed before the rapid actuation degradation in the range of the time t1 takes place.

LIST OF REFERENCE NUMBERS

100

 actuator system

105

 motor vehicle

110

 drive motor

115

 powertrain

120

 clutch

125

 Master cylinder

130

 master piston

135

 slave cylinder

140

 slave piston

145

 connecting line

150

 An expansion reservoir

155

 hydraulic fluid

160

 connecting opening

165

 actuator

170

 control device

175

 accelerator

180

 first sensor

185

 clutch pedal

190

 second sensor

195

 third sensor

200

 method

205

 Drive motor in the upper speed range?

210

 Connection opening released?

215

 Determine: operation of the accelerator pedal

220

 Determine: gradient of actuation

225

 Gradient negative and greater in magnitude than threshold?

230

 Output signal

235

 Move the master piston slowly to zero position

240

 Determine operation of the clutch pedal

245

 Move the master piston in accordance with the clutch actuation

305

 first course (operation accelerator pedal)

310

 second course (gradient of the operation of the gas pedal)

315

 third course (operation clutch pedal)

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 19744051 A1 [0004]
• DE 19719614 A1 [0005]

Claims (9)

Procedure ( 200 ) for controlling a hydraulic actuator system ( 100 ) for a clutch for transmitting one of a drive motor ( 110 ) provided torque, wherein the actuator system ( 100 ) a master cylinder ( 125 ) with a master piston ( 130 ), a back-up tank ( 150 ) for receiving hydraulic fluid ( 155 ) and a connection opening between the back-up tank ( 150 ) and the master cylinder ( 125 ) and the connection opening in dependence on a position of the master piston ( 130 ) in the master cylinder ( 125 ) is open or closed, comprising the following steps: - detecting ( 210 ), that the master piston ( 130 ) is in a position in which the connection opening ( 160 ) is released; - To capture ( 215 - 225 ) a decreasing operation of an accelerator pedal ( 175 ) for controlling the drive motor ( 110 ), and - method ( 200 ) of the master piston ( 130 ) so that the connection opening ( 160 ) closed is. Procedure ( 200 ) according to claim 1, wherein 225 ), the operation of the accelerator pedal ( 175 ) at least at a predetermined speed ( 320 ) subsides. Procedure ( 200 ) according to claim 1 or 2, wherein the master piston ( 130 ) then in dependence on a position of a clutch pedal ( 185 ) continue ( 245 ) is added to hydraulic fluid ( 155 ) from the master cylinder ( 125 ) to displace. Procedure ( 200 ) according to one of the preceding claims, wherein the master piston ( 130 ) with a limited speed to the position in which the connection opening is closed, proceed ( 235 ) becomes. Procedure ( 200 ) according to one of the preceding claims, wherein additionally detected ( 205 ), that the drive motor ( 110 ) has a speed which is in the range of a switching threshold. Procedure ( 200 ) according to claim 5, wherein the switching threshold in the upper region of a usable speed band of the drive motor ( 110 ) lies. Procedure ( 200 ) according to one of the preceding claims, wherein a signal is provided ( 230 ) indicating that determining ( 215 - 225 ) the decreasing operation of the accelerator pedal ( 175 ) to a procedure ( 200 ) of the master piston ( 130 ) has led. Computer program product with program code means for carrying out a method ( 200 ) according to one of the preceding claims, if the computer program product is stored on a processing device ( 170 ) or stored on a computer readable medium. Hydraulic actuator system ( 100 ) for a clutch ( 120 ) for transmitting one of a drive motor ( 110 ) provided torque, wherein the actuator system ( 100 ) comprises: a master cylinder ( 125 ) with a master piston ( 130 ); - a back-up tank ( 150 ) for receiving hydraulic fluid ( 155 ); A connection opening ( 160 ) between the back-up tank ( 150 ) and the master cylinder ( 125 ), wherein the connection opening ( 160 ) in dependence on a position of the master piston ( 130 ) in the master cylinder ( 125 ) is open or closed; A sensor ( 180 ) for determining an operation of an accelerator pedal ( 175 ) for controlling the drive motor ( 110 ), and a control device ( 170 ) on the procedure ( 200 ) of the master piston ( 130 ) so that the connection opening ( 160 ) is closed, if the master piston ( 130 ) is in a position in which the connection opening ( 160 ) is released while pressing the accelerator pedal ( 175 ) subsides.

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