Actuating installation for pneumatic clutch actuation with overload protection and/or incorrect-operation protection

• US 6,234,290 B1
• Filed: 08/06/1999
• Issued: 05/22/2001
• Est. Priority Date: 08/06/1998
• Status: Expired due to Fees

• Current Assignee: Mannesmann Sachs AG (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: Mannesmann Sachs AG (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Otto, Thomas, Stürmer, Winfried, Liebler, Jürgen, Pankoke, Jörg, Hirschmann, Frank, Lindner, Joachim, Ester, Barbara, Drexl, Hans-Jürgen
• Primary Examiner(s): Lorence, Richard M.
• Application Number:
  US09/369,825
• Time in Patent Office: 655 Days
• Field of Search: 192/85.R, 192/85.CA, 192/914.A, 192/99.S, 192/114.R
• US Class Current: 192/85.51
• CPC Class Codes: B60K 23/02 for main transmission clutches
• CPC Class Codes: B60T 7/06 Disposition of pedal
• CPC Class Codes: F16D 2048/0203 with an accumulator; Details thereof
• CPC Class Codes: F16D 2048/0212 Details of pistons for master or slave cylinders especially adapted for fluid control for other details of pistons in master or slave cylinders F16D2025/081 or F16D25/082
• CPC Class Codes: F16D 2048/0215 for damping of pulsations within the fluid system
• CPC Class Codes: F16D 2048/0221 Valves for clutch control systems; Details thereof
• CPC Class Codes: F16D 2300/22 Vibration damping
• CPC Class Codes: F16D 25/083 Actuators therefor F16D25/085 - F16D25/087 take precedence
• CPC Class Codes: F16D 25/14 Fluid pressure control
• CPC Class Codes: F16D 48/02 Control by fluid pressure

Abstract

An actuating installation for a friction clutch arranged in the drive line between a drive unit and a transmission. The installation having an actuating arrangement for the actuation of the friction clutch and a clutch-pedal arrangement, which is connected to the actuating arrangement and has a clutch pedal, which, in a first operating state, is actuable according to a force-travel characteristic of a first type. The actuating installation has a signaling and/or protection device, which is in operative connection with or is operatively integrated in the clutch-pedal arrangement, so that, after the response of the signaling and/or protection device to a second operating state, the clutch pedal can be actuated only according to a force/travel characteristic of a second type, which differs significantly from the force/travel characteristic of the first type in order thus to indicate the second operating state.

Claims

1. An actuating installation for a friction clutch arranged in a drive line of a motor vehicle between a drive unit and a transmission, comprising:

actuating means for actuating the friction clutch;

a clutch-pedal arrangement connected to the actuating means and having a clutch pedal operatively connected to the actuating means for actuating the friction clutch via the actuating means, the clutch pedal, in at least one first operating state of at least one of the actuating installation, the friction clutch and the motor vehicle, being actuable according to a force/travel characteristic of a first type; and

a signaling and protection device one of in operative connection with and operatively integrated in the clutch-pedal arrangement so as to be responsive to at least one second operating state of at least one of the actuating installation, the friction clutch and the motor vehicle so that the clutch pedal, in a response state of the device, can be actuated only according to a force/travel characteristic of a second type, which, in order to indicate the second operating state, differs significantly from a force/travel characteristic of the first type.

2. An actuating installation as defined in claim 1, wherein the device is configured to receive at least one of an electric, mechanical, hydraulic, pneumatic and optical signal which directly or indirectly indicates whether a first or a second operating state is present.

3. An actuating installation as defined in claim 2, wherein the respective signal is represented by one of a voltage, a current, a pressure, a force, a volume, a travel, an angle and a light intensity.

4. An actuating installation as defined in claim 2, wherein the signal represents a primary variable which one of determines the operating state and corresponds to an actuating state of one of the actuating means and the clutch-pedal arrangement.

5. An actuating installation as defined in claim 4, and further comprising a hydraulic system that connects the clutch-pedal arrangement to the actuating means, and a pneumatic system assigned to the actuating means, the primary variable being one of an actuating force, a hydraulic pressure in the hydraulic system connecting the clutch-pedal arrangement to the actuating arrangement, a pneumatic pressure in the pneumatic system assigned to the actuating arrangement, an actuating-travel difference, an actuating velocity and a hydraulic-medium volumetric flow (volume per unit of time) in the hydraulic system.

6. An actuating installation as defined in claim 5, wherein the device is operatively configured to respond to at least one of a clutch-pedal force exceeding a limit value;

a hydraulic pressure exceeding a limit value in the hydraulic system connecting the clutch-pedal arrangement to the actuating arrangement;

an incorrect or exceptional state of at least one of the actuating installation, the friction clutch and the motor vehicle;

a pneumatic pressure undershooting a limit value in the pneumatic system assigned to the actuating installation;

an actuating velocity, exceeding a limit value, of the clutch pedal;

a hydraulic-medium volumetric flow (volume per unit of time) exceeding a limit value in the hydraulic system connecting the clutch-pedal arrangement to the actuating means; and

a difference exceeding a limit value between clutch-pedal-side actuating travel and clutch-side actuating travel.

7. An actuating installation as defined in claim 4, wherein the device, in the response state, is operative to prevent a secondary variable from rising above a critical threshold, the secondary variable occurring in the actuating installation and being dependent on the actuating state of the clutch-pedal arrangement.

8. An actuating installation as defined in claim 5, wherein the device is operative to smooth peaks of a secondary or tertiary variable occurring in the actuating installation and dependent on the actuating state of the clutch-pedal arrangement.

9. An actuating installation as defined in claim 8, wherein at least one of the secondary variable and the tertiary variable is one of an actuating force, a hydraulic pressure in the hydraulic system connecting the clutch-pedal arrangement to the actuating arrangement, an actuating-travel difference, an actuating velocity and a hydraulic-medium volumetric flow (volume per unit of time) in the hydraulic system.

10. An actuating installation as defined in claim 8, wherein the device is operative to act on the secondary or tertiary variable so as to at least one of limit a rise in said variable and smooth said variable by virtue of at least one of the following measures:

a) i) an actuating force stored in an energy storage arrangement;

ii) the actuating force is absorbed by an abutment arrangement;

b) actuating travel is absorbed by an idle-travel arrangement;

c) an actuating velocity is decelerated by a braking device;

d) i) a hydraulic connection is interrupted by a hydraulic interrupt device;

ii) the hydraulic connection is choked by a hydraulic choke device;

e) i) hydraulic medium is stored intermediately by a hydraulic pressure accumulator arrangement; and

ii) the hydraulic medium is at least one of discharged by a hydraulic discharge device into a pressureless or pressure-reduced region of the hydraulic system and stored intermediately by a hydraulic-medium intermediate-accumulator arrangement while reducing the hydraulic pressure prevailing in the hydraulic system.

11. An actuating installation as defined in claim 10, wherein a plurality of measures mentioned under a) to e) are used at least one of simultaneously and successively according to a preset program of travel measures in order to provide a certain force/travel characteristic.

12. An actuating installation as defined in claim 11, wherein, during a course of a clutch-pedal actuation, after the response of the device, the force/travel characteristic is first significantly determined by at least one of measure a) i) and measure e) i) and is then significantly determined by at least one of measure b), measure e) ii), measure a) ii), and measure d) i).

13. An actuating installation as defined in claim 1, wherein a force/travel characteristic of the second type differs from a force/travel characteristic of the first type due to the fact that, according to the force/travel characteristic of the second type, the clutch pedal one of can be actuated against substantially reduced counterforces or even without substantial counterforces at least over a substantial part of its actuating stroke, and can be actuated with actuating forces to be expected from a vehicle driver at most only over a markedly restricted section of the actuating stroke possible according to the force/travel characteristic of the first type or against substantially larger counterforces.

14. An actuating installation as defined in claim 1, wherein the device includes a blocking device by means of which the clutch pedal can be blocked.

15. The actuating installation as defined in claim 14, wherein the blocking device comprises at least one engagement element assigned to the clutch-pedal arrangement for blocking of an actuating movement of the clutch pedal by producing one of a positive-locking and a frictional engagement between the engagement element, moving along during a clutch-pedal actuation, and an associated counterelement secured against an associated movement during the clutch-pedal actuation.

16. An actuating installation as defined in claim 15, wherein the engagement element and the counterelement can be brought into engagement with one another by at least one of mechanical, hydraulic, and electrical conversion of an actuating force exerted on the clutch pedal, and by means of a hydraulic slave-cylinder arrangement, if need be against the action of a preloading-spring arrangement, which preloads the engagement element and the counter-engagement element in a direction of a position without mutual engagement, or wherein the engagement element and the counterelement are preloaded by means of a preloading-spring arrangement in the direction of mutual engagement and can be disengaged from one another by means of a pneumatic-cylinder arrangement against the action of the preloading-spring arrangement.

17. An actuating installation as defined in claim 15, wherein the clutch-pedal arrangement comprises a plunger arrangement, which connects the clutch-pedal to a transmitter-element arrangement, has the engagement element, has a longitudinal axis and is displaceable at least approximately along the longitudinal axis in accordance with the actuating movement of the clutch pedal, the extension of the plunger arrangement being variable in at least one radial direction relative to the longitudinal axis as a function of the actuating force exerted on the plunger arrangement by the clutch pedal, and, if the extension exceeds a limit due to an actuating force exceeding a limit value, the engagement element, projecting beyond the limit, of the plunger arrangement can be brought into one of positive-locking and frictional engagement with the associated counterelement in order to block or brake the actuating movement.

18. An actuating installation as defined in claim 17, wherein the plunger arrangement comprises a first end element, having a clutch-pedal-side end, and a second end element, having a transmitter-element-side end and movable relative to thee first end element, a spring arrangement being effectively arranged between the end elements, the spring arrangement preloads the end elements relative to one another in order to spread the two ends apart, so that a relative movement, shortening a distance between the two ends, of the two end elements against a preloading force of the spring arrangement can be converted into an one of an extension and a swing-out movement of the engagement element, if need be serving as intermediate element, in a direction of the limit.

19. An actuating installation as defined in claim 18, wherein a shortening in the distance between the two ends which is necessary for producing the engagement between the engagement element and the counterelement is substantially less than a disengaging travel of the clutch pedal.

20. An actuating installation as defined in claim 15, and further comprising a transmitter arrangement having the engagement element and a transmitter which is motionally coupled to the clutch pedal and is displaceable along an axis of movement in accordance with the actuating movement of the clutch pedal so that an extension of the transmitter element is variable in at least one radial direction relative to the axis of movement as a function of an actuating force exerted on the transmitter element by the clutch pedal and so that, if the extension exceeds a limit due to an actuating force exceeding a limit value, the engagement element projecting beyond the limit, of the transmitter element can be brought into one of positive-locking and frictional engagement with the associated counterelement in order to block the actuating movement.

21. An actuating installation as define in claim 20, wherein the transmitter element comprises a first sectional element, motionally coupled to the clutch pedal, and a second sectional element, movable relative to the first sectional element, and a spring arrangement being effective between the sectional elements so as to preload the sectional elements relative to one another in order to spread the two sectional elements apart so that a relative movement of the two sectional elements toward one another against a preloading force of the spring arrangement can be converted into one of an extension and a swing-out movement of the engagement element in the direction of the limit.

22. An actuating installation as defined in claim 21, wherein the relative movement of the two sectional elements which is necessary for producing the engagement between engagement element and counterelement is substantially less than the disengaging travel of the clutch pedal.

23. An actuating installation as defined in claim 16, and further comprising a pedal anchor secured in the vehicle, the pedal anchor one of carries the engagement element and serves as the engagement element, the clutch pedal one of carrying the counterelement and serving as the counterelement.

24. An actuating installation as define in claim 23, wherein the clutch pedal can be locked in a positive manner on the pedal anchor in a preset position by the engagement element and the counterelement .

25. An actuating installation as defined in claim 24, wherein one of the engagement element and the counterelement is a sliding pin which engages in an opening of the other element of the engagement element and the counterelement in order to block the clutch pedal.

26. An actuating installation as defined in claim 1, wherein the device comprises at least one of a hydraulic interrupt and choke device, which serves as a blocking device for the clutch pedal and by means of which a hydraulic connection connecting a hydraulic master-cylinder arrangement of the clutch-pedal arrangement to the actuating means can be interrupted and choked.

27. An actuating installation as defined in claim 26, wherein the hydraulic interrupt and choke device comprises a barrier element which can be moved out of a through position without interrupting or choking the hydraulic connection into a barrier position and, in the barrier position, at least reduces a cross section of a hydraulic passage.

28. An actuating installation as defined in claim 27, wherein the barrier element can be put into the barrier position by at least one of mechanical, hydraulic and electrical conversion of an actuating force exerted on the clutch pedal, and by means of a hydraulic slave-cylinder arrangement against the action of a preloading-spring arrangement, which preloads the barrier element in a direction of the through position, the barrier element being movable into the barrier position by a preloading arrangement that preloads the barrier element in the direction of the barrier position and being movable into the through position from the barrier position by a pneumatic-cylinder arrangement against the action of the preloading-spring arrangement.

29. An actuating installation as defined in claim 28, wherein the hydraulic slave-cylinder arrangement is connected at a point of the hydraulic connection which lies between the hydraulic passage and the hydraulic master-cylinder arrangement.

30. An actuating installation as defined in claim 1, wherein the device has a freeing and idle-travel arrangement by means of which the clutch pedal can be freed and, in a response state, permits an actuating movement of the clutch pedal via idle travel, corresponding to at least a substantial part of normal clutch-pedal-actuating travel, without clutch actuation and without damaging components of the actuating installation.

31. An actuating installation as defined in claim 30, wherein the freeing and idle-travel arrangement comprises a first element, which moves during a clutch-pedal actuation, and a second element, which is motionally coupled to a transmitter element of a transmitter-element arrangement, the first element and the second element being motionally coupled and can be moved relative to one another for the freeing of the clutch pedal and for the provision of idle travel.

32. An actuating installation as defined in claim 31, wherein the first element is the clutch pedal.

33. An actuating installation as defined in claim 32, wherein the second element is one of a clutch-pedal plunger and a pivoted element pivotable with the clutch pedal about a common pivot.

34. An actuating installation as defined in claim 33, wherein the clutch-pedal plunger, at least in a certain area, is designed as a spring element that is preloaded in a direction of a maximum effective length of the plunger and, during shortening of an effective length of the plunger, starting from a maximum effective plunger length, is increasingly loaded.

35. An actuating installation as defined in claim 31, wherein the first element and the second element are integrated in a plunger arrangement connecting the clutch pedal to the transmitter element and permit shortening in length of the plunger arrangement in order to one of free the clutch pedal and provide idle travel.

36. An actuating installation as defined in claim 1, wherein the clutch-pedal arrangement comprises a plunger arrangement having a first plunger member and a second plunger member, said first and second plunger members, in order to shorten an effective length of the plunger arrangement, being movable relative to one another.

37. An actuating installation as defined in claim 36, wherein a spring arrangement is effective between the two plunger members so that the plunger members, at least in a relative-position region adjoining a relative position having maximum effective length of the plunger arrangement, one of can be preloaded relative to one another and are preloaded relative to one another in a direction of an increase in the effective length.

38. An actuating installation as defined in claim 36, wherein a pneumatic slave-cylinder arrangement is formed in the plunger arrangement for moving the two plunger members relative to one another for increasing the effective length and for securing the two plunger members in a given relative position.

39. An actuating installation as defined in claim 37, wherein the first element and the second element, for the motional coupling, can be locked on one another in a positive manner.

40. An actuating installation as defined in claim 37, and further comprising latching means for latching the first element and the second element together to create the motional coupling.

41. An actuating installation as defined in claim 40, wherein the latching means comprises at least one locking element which is movable between a locking position and an unlocking position and which can be put into the unlocking position by at least one of mechanical, hydraulic and electrical conversion of an actuating force exerted on the clutch pedal, and by means of a hydraulic slave-cylinder arrangement which preloads the locking element in the direction of the locking position, the locking element being preloaded by a preloading-spring arrangement in a direction of the unlocking position and can be put into the locking position by means of a pneumatic-cylinder arrangement against the action of the preloading-spring arrangement.

42. An actuating installation as defined in claim 40, wherein the latching means comprises at least one latching element which can be used by at least one of mechanical and hydraulic conversion of an actuating force exerted on the clutch pedal.

43. An actuating installation as defined in claim 42, wherein the latching element is formed one of by a spring element of the spring arrangement effective between the two plunger members and by a clutch-pedal-side end section of the clutch-pedal plunger so that, starting from a maximum effective length of the plunger arrangement, the effective length, at adequate counterforce exerted on the clutch-pedal plunger by the transmitter element, in the response state of the device, can first be shortened by clutch-pedal actuation under elastic deformation and correspondingly increasing loading of the spring element, in the course of which the spring element, after reaching a certain loading, unlatches and the clutch pedal is thereby freed, by permitting a further shortening in the effective length.

44. An actuating installation as defined in claim 1, wherein the device is arranged in a hydraulic system connecting a hydraulic master-cylinder arrangement of the clutch-pedal arrangement to the actuating means and comprises at least one of a hydraulic-medium accumulator and a discharge arrangement, which comprises at least one first hydraulic-medium intermediate accumulator essentially receiving the hydraulic pressure in the hydraulic system, serving as a hydraulic pressure accumulator and if need capable of being rendered active and inactive, and further comprises at least one second hydraulic-medium intermediate accumulator capable of being rendered active and inactive, significantly reducing the hydraulic pressure in the hydraulic system when specifically rendered active and serving as a hydraulic pressure-relief accumulator, and a hydraulic discharge valve for the specific discharge of hydraulic medium to a pressureless or pressure-reduced region of the hydraulic system.

45. An actuating installation as defined in claim 44, wherein the respective hydraulic-medium intermediate accumulator has a holding arrangement for a hydraulic piston, by means of which holding arrangement the intermediate accumulator can be held in the inactive state and which holding arrangement can be released for rendering the intermediate accumulator active, the respective hydraulic-medium intermediate accumulator can be rendered active and inactive by means of a hydraulic valve alternatively opening or closing a hydraulic connection.

46. An actuating installation as defined in claim 45, wherein the holding arrangement can be released at least one of electrically, mechanically, hydraulically and pneumatically;

the discharge valve and the hydraulic valve being at least one of an electrically operable, a hydraulically operable, a mechanically operable and a pneumatically operable valve.

47. An actuating installation as defined in claim 46, wherein the respective hydraulic-medium intermediate accumulator can be rendered active by at least one of mechanical, hydraulic and electrical conversion of an actuating force exerted on the clutch pedal, and by means of a hydraulic slave-cylinder arrangement, the respective hydraulic-medium intermediate accumulator can be rendered inactive pneumatically.

48. An actuating installation as defined in claim 44, wherein the hydraulic-medium intermediate accumulator of the hydraulic-medium accumulator arrangement can be switched over between a pressure-accumulator function and a pressure-relief-accumulator function, so that the hydraulic-medium intermediate accumulator, depending on the switching state, serves as one of a first and a second hydraulic-medium intermediate accumulator.

49. An actuating installation as defined in claim 48, wherein the discharge valve and the hydraulic valve can be actuated for opening the valve by at least one of mechanical, hydraulic and electrical conversion of an actuating force exerted on the clutch pedal, and by means of a hydraulic slave-cylinder arrangement, the valve having a valve-element arrangement, which is preloaded by means of a preloading-spring arrangement in the direction of a position opening the valve, and can be put into a position closing the valve by means of a pneumatic-cylinder arrangement against the action of the preloading-spring arrangement.

50. An actuating installation as defined in claim 49, wherein at least one of the discharge valve, the hydraulic valve and a second hydraulic-medium intermediate accumulator is integrated in a first hydraulic-medium intermediate accumulator so that one of the second hydraulic-medium intermediate accumulator is rendered active and the valve is opened when the first hydraulic-medium intermediate accumulator has received a preset hydraulic medium.

51. An actuating installation as defined in claim 50, wherein a holding arrangement is provided so that, after the second hydraulic-medium intermediate accumulator is rendered active or the valve is opened, the holding arrangement keeps the hydraulic-medium intermediate accumulator active or keeps the valve open.

52. An actuating installation as defined in claim 51, wherein the holding arrangement can be actuated at least one of manually, hydraulically, pneumatically, mechanically and electrically for rendering the second hydraulic-medium intermediate accumulator inactive or respectively for closing the valve.

53. An actuating installation as defined in claim 48, wherein the hydraulic-medium intermediate accumulator which can be switched over between a pressure-accumulator function and a pressure-relief-accumulator function has a separating element which subdivides a receiving space into a hydraulic sectional space and a pneumatic sectional space and is movable in the direction of an increase in size of the hydraulic sectional space while the pneumatic sectional space is reduced in size and in the direction of a decrease in the size of the hydraulic sectional space while the pneumatic sectional space is increased in size.

54. An actuating installation as defined in claim 53, wherein the separating element is a piston element, which is displaceably arranged in the receiving space and has a first end face defining the pneumatic sectional space and a second end face defining the hydraulic sectional space, the end faces have surface areas which are preferably adapted to one another, in order to set a response threshold for the pressure-accumulator function.

55. An actuating installation as defined in claim 54, wherein the respective hydraulic-medium intermediate accumulator is integrated in a hydraulic measuring-cylinder arrangement, which detects a position of a release-bearing arrangement of the actuating means and an engaging or actuating state of the friction clutch.

56. An actuating installation as defined in claim 1, wherein the actuating means comprises a positioning arrangement having a control valve, and a release-bearing arrangement serving to actuate the friction clutch, the positioning arrangement comprising a pressure-medium-power cylinder arrangement which acts on the release-bearing arrangement and which, via the control valve connected to a pressure-medium source, can be actuated as a function of a hydraulic or mechanical reference variable and an actual variable representing the position of the release-bearing arrangement so that the reference variable can be produced by means of the clutch-pedal arrangement and can be transmitted to the positioning arrangement by means of a mechanical or hydraulic transmission section.

57. An actuating installation as defined in claim 1, wherein there is no significant difference between the force/travel characteristic decisive in the first operating state and the force/travel characteristic decisive in the second operating state after the response of the device, the device signaling the second operating state in another manner.

58. An actuating installation as defined in claim 57, wherein the device signals the second operating state at least one of by means of an acoustic or optical signaling device, by placing or keeping the drive unit in a state which transmits no drive, and by significant change in a force/travel characteristic of another actuating element.

59. A signaling and protection device for an actuating installation for a friction clutch arranged in a drive line of a motor vehicle between a drive unit and a transmission, and connected to a clutch actuator and a clutch pedal arrangement, the device being one of in operative connection with and operatively integrated in the clutch-pedal arrangement so as to be responsive to at least one second operating state of at least one of the actuating installation,the friction clutch and the motor vehicle so that the clutch pedal, in a response state of the device, can be actuated only according to a force/travel characteristic of a second type, which, in order to indicate the second operating state, differs significantly from a force/travel characteristic of a first type, the force/travel characteristic of the clutch pedal not being significantly influenced or such influencing being possible at all on account of the specific design of the signaling and/or protection device.