Device for optional engaging and disengaging of a friction clutch for motor vehicles

1. A device for the optional disengaging and engaging, respectively, of a friction clutch for motor vehicles, with an actuating mechanism, the clutch having an engaging state and a disengaging direction and the actuating mechanism being operatively connected with the friction clutch via at least one actuating force transmission member for applying an actuating force, the actuating force transmission member being pre-stressed in the disengaging direction by means of a spring, and there being a sensor device for sensing a variable representative of at least one of the group consisting of the disengaging and engaging state, respectively, of the friction clutch and of the state of wear on the friction clutch with a sensor; wherein by means of the sensor the force of the spring for pre-stressing the actuating force transmission member can be sensed as the variable representative of at least one of the group consisting of the disengaging and engaging state, respectively, of the friction clutch and of the state of wear on the friction clutch; and wherein the sensor is arranged in series with the spring for pre-stressing the actuating force transmission member.

2. A device according to claim 1 , wherein the sensor is an electric pressure sensor.

3. A device according to claim 2 , wherein the electric pressure sensor has a piezoelectric element.

4. A device according to claim 1 , wherein the sensor is arranged on a side of the spring for pre-stressing the actuating force transmission member, which side faces away from the actuating force transmission member.

5. A device according to claim 1 , wherein the actuating mechanism is a slave cylinder of a hydraulic clutch control, which, for applying an actuating force, is operatively connected with the friction clutch via a release bearing as an actuating force transmission member, the release bearing being pre-stressed in the disengaging direction by a pre-load spring.

6. A device according to claim 5 , wherein the slave cylinder is in the form of a central disengaging device.

7. A device according to claim 6 , wherein the pre-load spring is formed as a compression spring, preferably a coil compression spring, and has one end which is supported at the release bearing and has another end which is supported at a housing of the central disengaging device, the sensor being arranged in a flux of force between the pre-load spring and the housing of the central disengaging device.

8. A device according to claim 7 , wherein a spring plate is provided at the housing-side end of the pre-load spring, via which spring plate the pre-load spring is supported at the housing of the central disengaging device, the sensor being arranged at the spring plate.

9. A device according to claim 8 , wherein the spring plate has a fixing section in which the sensor is received.

10. A device according to claim 9 , wherein an evaluation electronics circuit for the sensor is also received in the fixing section of the spring plate.

11. A device according to claim 8 , wherein the spring plate, with the aid of three bearing sections, abuts in statically determined fashion on a plane surface of the housing of the central disengaging device, the sensor having an actuating section which forms one of the three bearing sections.

12. A device according to claim 7 , wherein the pre-load spring is supported at three points on a plane surface of the housing of the central disengaging device, wherein an actuating section of the sensor placed on the housing-side end of the pre-load spring forms a bearing section, whilst two further bearing sections are formed by deflections of a last housing-side turn of the pre-load spring, which deflections extend in a direction towards the plane surface of the housing.

13. A device according to claim 7 , wherein the housing of the central disengaging device has a hole in which the sensor is arranged, a final section of the pre-load spring extending in a direction towards the hole, engages in the hole and abuts the sensor with an actuating effect.

14. A device for the optional disengaging and engaging, respectively, of a friction clutch for motor vehicles, with an actuating mechanism, the clutch having an engaging state and a disengaging direction and the actuating mechanism being operatively connected with the friction clutch via at least one actuating force transmission member for applying an actuating force, the actuating force transmission member being pre-stressed in the disengaging direction by means of a spring, and there being a sensor device for sensing a variable representative of at least one of the group consisting of the disengaging and engaging state, respectively, of the friction clutch and of the state of wear on the friction clutch with a sensor; wherein by means of the sensor the force of a spring arranged in parallel with the spring for pre-stressing the actuating force transmission member can be sensed as the variable representative of at least one of the group consisting of the disengaging and engaging state, respectively, of the friction clutch and of the state of wear on the friction clutch; and

wherein the sensor is arranged in series with the spring which is arranged in parallel with the spring for pre-stressing the actuating force transmission member.

15. A device according to claim 14 , wherein the sensor is an electric pressure sensor.

16. A device according to claim 15 , wherein the electric pressure sensor has a piezoelectric element.

17. A device according to claim 14 , wherein the sensor is arranged on a side of the spring arranged in parallel with the spring for pre-stressing the actuating force transmission member, which side faces away from the actuating force transmission member.

18. A device according to claim 14 , wherein the actuating mechanism is a slave cylinder of a hydraulic clutch control, which, for applying an actuating force, is operatively connected with the friction clutch via a release bearing as an actuating force transmission member, the release bearing being pre-stressed in the disengaging direction by a pre-load spring.

19. A device according to claim 18 , wherein the slave cylinder is in the form of a central disengaging device.

20. A device according to claim 14 , wherein the spring arranged in parallel to the spring for pre-stressing the actuating force transmission member is a tension spring.

21. A device for the optional disengaging and engaging, respectively, of a friction clutch for motor vehicles, with an actuating mechanism in the form of a central disengaging device as a slave cylinder of a hydraulic clutch control, the clutch having an engaging state and a disengaging direction and the central disengaging device being operatively connected with the friction clutch via at least one actuating force transmission member in the form of a release bearing for applying an actuating force, the release bearing being pre-stressed in the disengaging direction by means of a pre-load spring, and there being a sensor device for sensing a variable representative of at least one of the group consisting of the disengaging and engaging state, respectively, of the friction clutch and of the state of wear on the friction clutch with a sensor; wherein by means of the sensor the force of the pre-load spring can be sensed as the variable representative of at least one of the group consisting of the disengaging and engaging state, respectively, of the friction clutch and of the state of wear on the friction clutch;

wherein the pre-load spring is formed as a compression spring, preferably a coil compression spring, and has one end which is supported at the release bearing and has another end which is supported at a housing of the central disengaging device, the sensor being arranged in a flux of force between the pre-load spring and the housing of the central disengaging device; and

wherein a spring plate is provided at the housing-side end of the pre-load spring, via which spring plate the pre-load spring is supported at the housing of the central disengaging device, the sensor being arranged at the spring plate.

22. A device according to claim 21 , wherein the spring plate has a fixing section in which the sensor is received.

23. A device according to claim 22 , wherein an evaluation electronics circuit for the sensor is also received in the fixing section of the spring plate.

24. A device according to claim 21 , wherein the spring plate, with the aid of three bearing sections, abuts in statically determined fashion on a plane surface of the housing of the central disengaging device, the sensor having an actuating section which forms one of the three bearing sections.

25. A device according to claim 21 , wherein the sensor is an electric pressure sensor.

26. A device according to claim 25 , wherein the electric pressure sensor has a piezoelectric element.

27. A device for the optional disengaging and engaging, respectively, of a friction clutch for motor vehicles, with an actuating mechanism in the form of a central disengaging device as a slave cylinder of a hydraulic clutch control, the clutch having an engaging state and a disengaging direction and the central disengaging device being operatively connected with the friction clutch via at least one actuating force transmission member in the form of a release bearing for applying an actuating force, the release bearing being pre-stressed in the disengaging direction by means of a pre-load spring, and there being a sensor device for sensing a variable representative of at least one of the group consisting of the disengaging and engaging state, respectively, of the friction clutch and of the state of wear on the friction clutch with a sensor; wherein by means of the sensor the force of the pre-load spring can be sensed as the variable representative of at least one of the group consisting of the disengaging and engaging state, respectively, of the friction clutch and of the state of wear on the friction clutch;

wherein the pre-load spring is formed as a compression spring, preferably a coil compression spring, and has one end which is supported at the release bearing and has another end which is supported at a housing of the central disengaging device, the sensor being arranged in a flux of force between the pre-load spring and the housing of the central disengaging device; and

wherein the pre-load spring is supported at three points on a plane surface of the housing of the central disengaging device, wherein an actuating section of the sensor placed on the housing-side end of the pre-load spring forms a bearing section, whilst two further bearing sections are formed by deflections of a last housing-side turn of the pre-load spring, which deflections extend in a direction towards the plane surface of the housing.

28. A device according to claim 27 , wherein the sensor is an electric pressure sensor.

29. A device according to claim 28 , wherein the electric pressure sensor has a piezoelectric element.

30. A device for the optional disengaging and engaging, respectively, of a friction clutch for motor vehicles, with an actuating mechanism in the form of a central disengaging device as a slave cylinder of a hydraulic clutch control, the clutch having an engaging state and a disengaging direction and the central disengaging device being operatively connected with the friction clutch via at least one actuating force transmission member in the form of a release bearing for applying an actuating force, the release bearing being pre-stressed in the disengaging direction by means of a pre-load spring, and there being a sensor device for sensing a variable representative of at least one of the group consisting of the disengaging and engaging state, respectively, of the friction clutch and of the state of wear on the friction clutch with a sensor; wherein by means of the sensor the force of the pre-load spring can be sensed as the variable representative of at least one of the group consisting of the disengaging and engaging state, respectively, of the friction clutch and of the state of wear on the friction clutch;

wherein the pre-load spring is formed as a compression spring, preferably a coil compression spring, and has one end which is supported at the release bearing and has another end which is supported at a housing of the central disengaging device, the sensor being arranged in a flux of force between the pre-load spring and the housing of the central disengaging device; and

wherein the housing of the central disengaging device has a hole in which the sensor is arranged, a final section of the pre-load spring extending in a direction towards the hole, engages in the hole and abuts the sensor with an actuating effect.

31. A device according to claim 30 , in the sensor is an electric pressure sensor.

32. A device according to claim 31 , wherein the electric pressure sensor has a piezoelectric element.