Clutch-actuating device and methods of determining clutch parameters

• US 6,896,112 B2
• Filed: 12/10/2003
• Issued: 05/24/2005
• Est. Priority Date: 06/13/2001
• Status: Expired due to Fees

• Current Assignee: LuK Lamellen und Kupplungsbau Beteiligungs KG
• Original Assignee: LuK Lamellen und Kupplungsbau Beteiligungs KG
• Inventors: Brandt, Martin, Deimel, Andreas, Pfeiffer, Andreas, Berger, Reinhard, Zimmermann, Martin, Stork, Holger, Jager, Thomas, Rammhofer, Thomas, Hirt, Gunter
• Primary Examiner(s): Lorence, Richard M.
• Application Number:
  US10/733,175
• Publication Number:
  US 20040188218A1
• Time in Patent Office: 531 Days
• Field of Search: 192/52.4, 192/90, 477174-176, 477/180, 701/67, 701/68
• US Class Current: 192/52.4
• CPC Class Codes: F16D 2500/1024 combined with hydraulic actuation
• CPC Class Codes: F16D 2500/3022 Current
• CPC Class Codes: F16D 2500/3024 Pressure
• CPC Class Codes: F16D 2500/3026 Stroke
• CPC Class Codes: F16D 2500/3028 Voltage
• CPC Class Codes: F16D 2500/30401 On-off signal indicating the engage or disengaged position of the clutch
• CPC Class Codes: F16D 48/066 Control of fluid pressure, e.g. using an accumulator F16D48/062, F16D48/068 take precedence

Abstract

A clutch-actuating device for a clutch in a motor vehicle power train has an actuator motor driving an actuating member and a transfer mechanism which transmits the movement of the actuating member to a clutch release element that is movable against an opposing force of a clutch spring to displace the clutch from a closed position to an open position. The transfer mechanism has a first movement range in which the movement of the actuating member in the opening direction of the clutch does not displace the clutch from its closed position, and a second movement range in which the movement of the actuating member causes a displacement of the clutch. The transfer mechanism has an interval of loose play, which is used up within the first range.

Claims

1. A clutch-actuating device for a clutch in a motor vehicle power train, wherein the power train includes an engine, a clutch, a transmission, and a control unit;

said clutch actuating device comprising an actuator motor driving an actuating member, and further comprising a transfer mechanism operable to transmit a movement of the actuating member to a clutch release element that is movable against an opposing force of a clutch spring to displace the clutch from a closed position to an open position, wherein the transfer mechanism has a first movement range in which said movement of the actuating member in an opening direction of the clutch does not displace the clutch from its closed position, and a second movement range in which the movement of the actuating member causes a displacement of the clutch, wherein the transfer mechanism has an interval of loose play, and wherein said loose play is used up within the first range, the device further including a compensation spring mechanism which introduces a first force/displacement characteristic into the movement of the actuating member within the first range, wherein the displacement of the clutch in the second range follows a clutch displacement characteristic, and wherein in said second range said clutch characteristic is superimposed on said first force/displacement characteristic.

2. A method of determining the closed position of the clutch that is equipped with the clutch-actuating device of claim 1, comprising the steps of:

moving the actuating member through a transition from the first to the second range while simultaneously monitoring a parameter that exhibits a predetermined characteristic change during said transition,

detecting said predetermined characteristic change and equating a position where said characteristic change and occurred to the closed position of the clutch.

3. The method of claim 2, wherein the step of moving the actuating member comprises an underlying monotonic movement with a superimposed oscillatory movement, and wherein said oscillatory movement has a small amplitude in comparison to a total displacement range of the actuating member.

4. The method of claim 2, wherein the transfer mechanism contains a hydraulic circuit with a snifting bore, and wherein the method is performed in conjunction with a snifting cycle.

5. The method of claim 4, wherein the parameter being monitored comprises a hydraulic pressure downstream of the snifting bore.

6. The method of claim 2, wherein the parameter being monitored comprises at least one operating parameter of the actuator motor.

7. The method of claim 2, wherein the clutch has a gripping point, and wherein said determination of the closed position is performed immediately after initializing the control unit, prior to starting the engine, and prior to a first opening of the clutch that is followed by a closing of the clutch as far as the gripping point.

8. The method of claim 4, wherein said determination of the closed position is performed while the engine is running and a vehicle brake is applied, and wherein—

if the transmission is not already in a neutral position—

the transmission is set into the neutral position for a short time by interval by a transmission actuator.

9. A method of determining an actuating force of the clutch that is equipped with the clutch-actuating device of claim 1, wherein said first range and said second range have different force-displacement characteristics, the method comprising the steps of:

moving the actuating member through at least part of the first range;

determining a first value of an operating parameter of the actuator motor, said first value being representative of a known force generated by the actuator motor to move the actuating member within the first range;

moving the actuating member through at least part of the second range;

determining a second value of said operating parameter of the actuator motor, said second value being representative of a force generated by the actuator motor to move the actuating member within the second range; and

determining the actuating force based on said known force and on said first and second values of the operating parameter.

10. A method of determining a temperature of the actuator motor in the clutch-actuating device of claim 1, wherein said actuator motor is an electric motor and wherein said first range and said second range have different force-displacement characteristics, the method comprising the steps of:

moving the actuating member through at least part of the first range;

determining at least one temperature-dependent operating parameter value of the actuator motor, said temperature-dependent operating parameter value being dependent on said temperature of the actuator motor;

comparing the at least one temperature-dependent operating parameter value to a stored table of parameter values as a function of temperature values, and

determining the temperature of the actuator motor from said stored table by finding a match between the at least one temperature-dependent operating parameter value and one of the parameter values in said stored table.