FR3029249A1 - FRICTION CLUTCH - Google Patents

Abstract

The invention relates to a friction clutch (10) comprising a reaction plate (20) movable in the axial direction, a pressure plate (18) movable in the axial direction with respect to the reaction plate for the friction clutch. a clutch disk (24) between the reaction plate and the pressure plate and a clearance adjuster disposed laterally to the reaction plate for clearance compensation of a critical gap due to wear between the plate pressure device and the reaction plate, wherein the clearance compensating device (33) comprises a circumferentially rotatable ramp ring (34) provided with a plurality of axially projecting ramps (36) and a spindle system. acting on the ramp ring (34) for the rotation of the latter.

Description

The invention relates to a friction clutch for coupling a transmission shaft of a motor vehicle engine 5 with at least one input shaft of a motor vehicle gearbox. It is known to provide the friction clutches with a slack adjuster for compensating for wear formed on the friction linings. This is an unfavorable evolution of the clamping force of an actuating system requesting a reaction plate of the friction clutch to move the pressure plate, e.g. ex. a spring diaphragm, which is detected as a result of wear, a backlash being performed as a function of the clamping force. Alternatively, critical spacing between the clutch housing and the clutch disk friction wear system may be detected ("captured") and corrected for the clutch housing. critical spacing. Compensation means such as ramp systems or threads disposed between the reaction plate and the actuation system 25 can then be rotated as a correction. The object of the present invention is to provide a friction clutch with a slack adjuster where the slack adjuster is provided with a new slack adjuster. This problem is solved by the friction clutch according to the invention. invention. According to the invention, a friction clutch is provided for coupling a transmission shaft of a motor vehicle engine with at least one input shaft of a motor vehicle gearbox, comprising a an axially movable reaction plate, a pressure plate movable in the axial direction with respect to the reaction plate for frictionally clamping a clutch disc between the reaction plate and the pressure plate and a pressure device; backlash resting against the reaction plate for compensating play of a critical gap due to wear between the pressure plate and the reaction plate, wherein the clearance adjuster comprises a rotary ramp ring in the circumferential direction, provided with a plurality of projecting ramps in the axial direction, and a spindle system acting on the ramp ring for the rotation of the ramp ring, where the spindle system co mporte a force accumulator element for the temporary accumulation of a prestressing force generated by a closing of the friction clutch in case of wear of the clutch disc and released at the next opening of the friction clutch for the rotation of the ramp ring. As set forth above, the backlash device for compensation of a critical wear gap between a pressure plate and a reaction plate of a friction clutch of a motor vehicle is known. In the known clutch, the slack adjuster is disposed laterally to the pressure plate, e.g. ex. between the pressure plate and the diaphragm spring or between the diaphragm spring and the clutch cover. The invention allows a backlash device is not disposed laterally to the pressure plate, but laterally to the reaction plate, in particular in a flywheel system disposed against the reaction plate. The flywheel system can p. ex. be realized as a single-mass or dual-mass flywheel system. The slack adjuster is provided with a ramp ring and a spindle system acting on the ramp ring for rotation of the ramp ring. This spindle system has a force accumulator element for the temporary accumulation of a prestressing force. In case of wear of the clutch disk, the prestressing force is generated by closing the friction clutch and accumulated in the force accumulator element. This prestressing force will be released at the next opening of the friction clutch. Under the action of this prestressing force, the ramp ring is rotated according to a corresponding angular value to catch the play of the friction clutch. The spindle system may advantageously comprise a spindle connected by positive engagement to the ramp ring, against which a force accumulator element is arranged, so that the prestressing force can be generated in the force accumulator element by means of a movement movement. translation of the spindle. For example, the force accumulator element can be made as a pressure spring. For a definite wear of the clutch disc, the spindle can be rotated due to the closing of the friction clutch by the pressure plate. As in the closed state of the friction clutch, the ramp ring is tightened under the effect of the clamping force of the pressure plate, the ramp ring can not be moved in this state. In this case, the rotation of the spindle can be converted into translation movement by the positive engagement connection, made in particular by the toothing between the spindle and the ramp ring. This translation of the spindle makes it possible to compress the pressure spring disposed on the spindle. A prestressing force can thus be accumulated in the pressure spring. If the friction clutch is disengaged again, the bushing will no longer be blocked by the clamping force. Therefore, the prestressing force accumulated in the pressure spring will be released. Under the action of this prestressing force, the pin can be pushed back by the pressure spring. The toothing between the spindle and the ramp ring allows the ramp ring to be rotated by a corresponding angular value by the spindle to catch the friction clutch play. The spindle system may in particular comprise a drive spring operable by the pressure plate to detect the critical spacing due to wear between the pressure plate and the reaction plate, the spindle being drivable in rotation by the spring drive. The pin can p. ex. have a pinion connected to the pin and secured in rotation therewith. For rotation of the pinion of the pin, the drive spring may have a ratchet drive gear on the contour of the pinion. In case of defined wear of the clutch disk, the drive spring is actuated due to the displacement of the pressure plate to the reaction plate by the pressure plate. The pinion of the spindle is thus rotated by the driving pawl of the drive spring. The spindle system may preferentially comprise a helical wheel for the connection by positive engagement with the ramp ring, the helical wheel being fixed on the spindle integrally in rotation. The connection by positive engagement between the ramp ring and the helical wheel can in particular be achieved by meshing. The helical wheel may have a plurality of helical threads for meshing with the ramp ring. The spindle and the helical wheel can be made in one piece. In this case, the helical threads can be formed directly on the spindle. It will also be possible to form the helical wheel separately from the spindle. The attachment of the helical wheel on the spindle may in particular be performed by screwing or welding.

The ramp ring may in particular have a plurality of contact teeth for connection by positive engagement with the helical wheel. As previously stated, the connection by positive engagement between the ramp ring and the helical wheel may in particular be carried out by meshing. The shapes of the contact teeth and the helical thread may advantageously be complementary. The meshing of the helical threads of the helical wheel and the contact teeth of the ramp ring will convert a rotational movement of the helical wheel into a translational movement. An advantageous embodiment of the invention further provides a flywheel system disposed on the reaction plate, the play retrofit device can be integrated in the flywheel system. The flywheel system can p. ex. have an inertia disk and several friction discs, the ramp ring can be disposed between the inertia disk and a friction disc or between two friction discs. A friction disc can p. ex. be made as reaction plate of the friction clutch. The flywheel system may preferably be provided with an inertia disk, the ramp ring being able to be disposed between the inertia disk and the reaction plate. The reaction plate can p. ex. be arranged on the inertia disk so as to be displaceable in the axial direction by means of a spring element.

The spring element can p. ex. include several leaf springs. The inertia disk may in particular have several counter-ramps protruding in the axial direction to form a stop for the ramps of the ramp ring. It is also possible to have the counter-ramps on the reaction plate. The counter ramps may in particular be formed substantially identically to each other and be regularly distributed in the circumferential direction. The number of counter-ramps can advantageously correspond to that of the ramps of the ramp ring. Counter-ramps can advantageously be formed directly on the inertia disk. In the case where the counter-ramps are arranged on the reaction plate, the counter-ramps can also be formed directly on the reaction plate. The invention will be described hereinafter with reference to the accompanying drawings, based on preferred exemplary embodiments, the exposed features being able to represent respective aspects of the invention, whether taken singly or in combination. The drawings represent: FIG. 1: a schematic sectional view of a friction clutch according to a first embodiment of the invention, FIG. 2: a diagrammatic elevational view of the play-catching device of the friction clutch of FIG. 1, Fig. 3: a schematic sectional view of a friction clutch according to a second embodiment of the invention, FIG. 4: a schematic sectional view of the friction clutch of FIG. 3 in a closed situation, the friction clutch being in a normal state of service, FIG. 5: a schematic sectional view of the friction clutch of FIG. 3 in partial opening condition, the friction clutch being in a normal operating state, FIG. 6: a schematic sectional view of the friction clutch of FIG. 3 in the open position, the friction clutch being in a normal operating state, FIG. 7: a schematic sectional view of the friction clutch of FIG. 3 in the closed position, the friction clutch being in a state of wear, and FIG. 8: a schematic sectional view of the friction clutch of FIG. 3 in the open situation, the friction clutch being in a state of wear. Fig. 1 is a schematic sectional view of a friction clutch 10 according to a first embodiment of the invention. The friction clutch 10 includes a clutch cover 14 and a pressure plate 18 axially movable by means of a diaphragm spring 16, and which can be moved by the diaphragm spring 16 to a reaction plate 20 to clamp a clutch disk 24 provided with friction linings 22 between the pressure plate 18 and the reaction plate 20 for closing the friction clutch 35. This friction clutch 10 is further provided with a steering wheel system The flywheel system 12 comprises a starter ring 26 and an inertia disk 28 to which a cover 30 is connected. In order to compensate for a critical spacing due to wear between the plate of 18 and the reaction plate 20, the flywheel system 12 is provided with a play-catching device 32 arranged in the cover 30. The play-catching device 32 comprises a rotatable ramp ring 34 in the circumferential direction it, said ramp ring 34 being provided with several ramps 36 protruding axially. In this embodiment, the ramp ring 34 is disposed between the inertia disk 28 and the reaction plate 20. The inertia disk 28 has several counter-ramps 38 protruding axially. For the rotation of the ramp ring 34 relative to the inertia disk 28, the clearance adjuster 32 is provided with a spindle system 40 engaged with the ramp ring 34. The spindle system 40 includes a pin 42, a helical wheel 44 fixedly fixed in rotation on the pin 42 and a pinion 46 integrally connected in rotation with the pin 42. The pinion 46 has a plurality of teeth 47 distributed over the circumference of the pinion 46. The pinion 46 can be driven by rotation by a driving pawl 48 geared in the teeth 47 of the pinion 46. As shown in FIG. 1, the drive pawl 48 is attached to a drive spring 50. The drive spring 50 can be actuated by an actuating member 52 attached to the drive spring 50 of the pressure plate 18. As shown in FIG. spring of FIG. 2, a force accumulator element 56 formed as a compression spring 54 is disposed on the spindle 42. In this exemplary embodiment, the pressure spring 54 is disposed between the spindle 42 and a support 58, fixing 58 being fixed on the inertia disk 28 for fixing the spindle system 40. As is also apparent from FIG. 2, the ramp ring 34 has a plurality of contact teeth 60 for a positive engagement connection with the helical wheel 44. The helical wheel 44 is therefore provided with a plurality of helical threads 62 for a positive engagement connection with the ramp ring 34 The meshing of the helical thread 62 between the contact teeth 60 of the ramp ring 34 positively connects the helical wheel 44 of the spindle system 40 with the ramp ring 34.

In case of defined wear of the clutch disc 24, the actuating element 52 fixed against the drive spring 50 is pushed downwards by the friction clutch 10 being closed by the pressure plate. 18. The pinion 46 is therefore rotated by the drive pawl 48 of the drive spring 50. The helical wheel 44 and the pin 42 therefore rotate as well. As in the closed state of the friction clutch 10, the ramp ring 34 is locked under the effect of the clamping force of the pressure plate 18, the ramp ring 34 can not be moved in this state. The rotational movement of the spindle 42 or the helical wheel 44 is converted into translation movement by the toothing between the helical threads 62 and the contact teeth 60 of the ramp ring 34. This translation movement of the spindle 42 compresses the compression spring 54 disposed between the pin 42 and the fixing support 58. A prestressing force is thus generated and accumulated in the pressure spring 54.

When the friction clutch 10 is disengaged, the ramp ring 34 is no longer locked by the clamping force, but only by the clamping force of the drive spring 50, the clamping force of the drive spring 50 being less than the prestressing force in the compression spring 54. The prestressing force accumulated in the compression spring 54 is released by disengaging the friction clutch 10. Under the effect of this prestressing force, the spindle 42 and the helical wheel 44 are pushed by the pressure spring 54 in the direction of removal relative to the mounting bracket 58. The contact teeth 60 of the ramp ring 34 are thus pushed by the helical thread 62 of the wheel helical 44, which rotates the ramp ring 34 to a corresponding angular value to catch the play of the friction clutch 10. FIG. 3 is a diagrammatic sectional view of a friction clutch 10 according to a second embodiment of the invention. The difference between the friction clutch 10 of FIG. 1 and the friction clutch of FIG. 3 lies in the design of the drive spring 50 and the actuating element 52. In this exemplary embodiment, the actuating element 52 is not fixed on the drive spring 50, but on the pressure plate 18. As shown in FIG. 3, the clearance adjuster 32 includes a stroke limiting member 64 for limiting the stroke of the drive spring 50. This stroke limiting member 64 is fixed against the flywheel system cover 30. As is also apparent from FIG. 3, the reaction plate 20 is disposed on the inertia disk 28 axially displaceable by a spring element 66. The spring element 66 may in particular comprise a plurality of leaf springs. Figs. 4 to 6 show an operating sequence of the friction clutch 10 of FIG. 3 in a normal state of service. Fig. 4 shows the friction clutch 10 in a closed position. In this situation, the drive spring 50 is only slightly pushed down by the actuating element 52 of the pressure plate 18. As shown in FIG. 4, the driving pawl 48 of the drive spring 50 is between two teeth 47 of the pinion 46; yet no force is exerted by the drive pawl 48 on the teeth 47 of the pinion 46. The pinion 46 is therefore not rotated by the drive spring 50. FIG. 5 shows the friction clutch 10 in partial opening situation. In the phase between the closure situation and the partial opening situation, the pressure plate 18 moves upwards. The drive spring 50 is therefore no longer constrained by the actuating element 52. The drive spring 50 thus expands upwards. No contact is shown between drive pawl 48 and teeth 47 of pinion 46. FIG. 6 shows the friction clutch 10 in partial opening position. In the phase between the partial opening situation and the opening situation, the pressure plate 18 continues to move upwards. A further expansion of the drive spring 50 is limited by the travel limiter member 64. FIGS. 7 to 8 illustrate a backlash process of the friction clutch 10 of FIG. 3. FIG. 7 shows a situation of closure of the friction clutch 10 in a state of wear. In this situation, the actuating element 52 is pushed down by the pressure plate 18. The driving pawl 48 therefore forces a tooth 47 of the pinion 46. The pinion 46 is thus rotated by the ratchet drive 48 of the drive spring 50. The helical wheel 44 and the spindle 42 which are integrally rotatably connected to the pinion 46 also rotate. As the ramp ring 34 is in the closed state of the friction clutch 10 locked under the effect of the clamping force of the pressure plate 18, the ramp ring 34 can not be moved in this state. The rotational movement of the spindle 42 or the helical wheel 44 is converted into translational movement due to the meshing of the helical threads 62 with the contact teeth 60 of the ramp ring 34. This translatory movement of the spindle 42 the pressure spring 54 disposed between the pin 42 and the fixing support 58 is compressed. A prestressing force is thus generated and accumulated in the pressure spring 54. FIG. 8 shows an opening situation of the friction clutch 10 in the state of wear. In this situation, the ramp ring 34 is no longer blocked by the clamping force. The disengagement of the friction clutch 10 frees the prestressing force accumulated in the compression spring 54. Under the action of this prestressing force, the pin 42 and the helical wheel 44 are pushed back by the pressure spring 54 into the direction away from the mounting bracket 58. The contact teeth 60 of the ramp ring 34 are thus pushed by the helical thread 62 of the helical wheel 44, which rotates the ramp ring 34 by a value of corresponding angle to make up the play of the friction clutch 10.

List of reference numbers 10 Friction clutch 12 Flywheel system 14 Clutch cover 16 Diaphragm spring 18 Pressure plate 20 Reaction plate 22 Friction pad 24 Clutch disk 26 Starter ring 28 Inertia disk 30 Flywheel system cover 32 Playback device 34 Ramp ring 36 Ramp 38 Counterbeam 40 Spindle system 42 Spindle 44 Helical wheel 46 Pinion 47 Sprocket teeth 48 Drive ratchet 50 Drive spring 52 Operating element 54 Pressure spring 56 Force accumulator element 58 Mounting bracket 60 Ramp ring contact teeth 62 Helical thread 64 Stroke limiting element 66 Spring element

Claims (9)

REVENDICATIONS1. Friction clutch for coupling a transmission shaft of a motor vehicle engine with at least one input shaft of a motor vehicle gearbox, comprising a reaction plate (20) movable in the direction axial, a pressure plate (18) movable in the axial direction relative to the reaction plate (20) for frictionally clamping a clutch plate (24) between the reaction plate (20) and the platen pressure (18) and a clearance adjuster (32) abutting against the reaction plate (20) to compensate for a critical clearance due to wear between the pressure plate (18) and the reaction plate (20), wherein the clearance adjuster (32) comprises a circumferentially rotatable ramp ring (34) provided with a plurality of axially projecting ramps (36) and a spindle system ( 40) acting on the ramp ring (34) for the rotation of the ring at ramp (34), wherein the spindle system (40) has a force accumulator element (56) for the temporary accumulation of a prestressing force generated by a friction clutch (10) closure in case of clutch disk wear (24) and released at the next opening of the friction clutch (10) for rotation of the ramp ring (34). 2. Friction clutch according to claim 1, characterized in that the spindle system (40) has a pin (42) connected by positive engagement to the ramp ring (34) against which a force accumulator element ( 56), so that the prestressing force can be generated in the force accumulator element (56) by translational movement of the spindle (42). Friction clutch according to claim 2, characterized in that the spindle system (40) comprises a drive spring (50) operable by the pressure plate (18) to detect the critical spacing due to wear. between the pressure plate (18) and the reaction plate (20), the pin (42) being rotatable by the drive spring (50). Friction clutch according to claim 2 or 3, characterized in that the spindle system (40) has a helical wheel (44) for positive engagement connection with the ramp ring (34), the helical wheel ( 44) being secured to the spindle (42) in rotationally integral manner. 20 A friction clutch according to claim 4, characterized in that the ramp ring (34) has a plurality of contact teeth (60) for positive engagement with the helical wheel (44). Friction clutch according to one of Claims 1 to 5, characterized in that an inertia flywheel system (12) arranged on the reaction plate (20) is provided for the damping of rotational vibrations. , the play catch device (32) being integrated with the flywheel system (12). Friction clutch according to Claim 6, characterized in that the flywheel system (12) is provided with an inertia disc (28), the ramp ring (34) being arranged between the disc inertia (28) and the reaction plate (20). 8. friction clutch according to claim 6 or 7, characterized in that the inertia disk (28) has a plurality of counter-ramps (38) projecting in the axial direction to form a stop for the ramps (36) of the ring with ramp (34). 9. Friction clutch according to claim 8, characterized in that the counter-ramps (38) are formed directly on the inertia disk (28).