FR3067423A1 - CLUTCH MECHANISM FOR A MOTOR VEHICLE - Google Patents

Abstract

The invention relates to a clutch mechanism (1) comprising a cover (2), a pressure plate (14), and a diaphragm (25) mounted axially between the radial portion (3) of the cover (2) and the pressure plate. (14), the diaphragm (25) bearing on the pressure plate (14) and on the lid (2), characterized in that it comprises an annular ring (37) bearing axially on the diaphragm (25) at opposite the lid (2) and means for axially holding the rod (37) bearing on the diaphragm (25), said holding means being fixed relative to the lid (2) and being located radially inside the periphery radially external (31) of the diaphragm (25).

Description

Clutch mechanism for a motor vehicle

The present invention relates to a clutch mechanism for a motor vehicle, intended to equip a clutch device.

A clutch device conventionally comprises a reaction plate intended to be coupled in rotation to a crankshaft of a vehicle engine, a friction disc intended to be coupled to an input shaft of a gearbox, and a pressure plate. The movement of the pressure plate is controlled by a diaphragm, itself controlled by a clutch bearing.

The pressure plate is thus movable between a clutch position in which the friction disc is clamped between said pressure and reaction plates, and a declutch position in which the friction disc is released.

Damping means are generally mounted between the friction disc and the input shaft of the gearbox, the damping means acting against the rotation of the friction disc relative to the shaft. gearbox input.

In the case of a hybrid motor vehicle, a thermal energy source (thermal engine) is used with an electrical energy source (electric motor). We speak of a rechargeable hybrid vehicle when a hybrid vehicle, combining these two energies, can be recharged on an electrical network, which allows for greater autonomy compared to a conventional hybrid vehicle. A rechargeable hybrid vehicle can be of the PHEV type (acronym for Plugin-Hybrid Electric Vehicle, in English). In this configuration, the electric motor and the heat engine act together to drive the vehicle. The use of electric mode depends on the configuration of the vehicle. For such a vehicle, the use of the electric mode is more frequent than the use of the thermal mode. As a result, the clutch connecting the engine to the gearbox is, for the most part, in the disengaged or open position. In such a case, a clutch of the normally open type will preferably be used, so that the diaphragm is actuated only to close the clutch, that is to say to engage the clutch.

At low vehicle speed, it is possible to drive the vehicle using the electric motor only or, when a significant torque is to be supplied, using the internal combustion engine only or using the electric motor and of the heat engine.

In operation, the electric motor can be used to start or restart the engine. For this, the clutch device is closed so as to transmit a torque from the electric motor to the heat engine. When the first explosions of the heat engine take place, it is then possible to open the clutch again, the speed of the heat engine gradually increasing until reaching a synchronization speed of, for example, between 3000 and 7000 rpm . Once the synchronization speed has been reached, the electric motor and the heat engine can again be coupled together so as to act in concert and thus provide significant torque.

In order to improve user comfort and reduce the vehicle's energy consumption, it may be preferable to quickly reach synchronization speed after starting or restarting the engine.

For this, one solution is to reduce the inertia of the device by reducing, for example, its radial dimensions.

More generally, the invention applies to other types of motorization, in particular a motorization using a heat engine only, for which it is sought to reduce the radial size of the device or of the mechanism. clutch.

The invention aims to respond to these technical problems.

To this end, it offers a clutch mechanism comprising a cover, a pressure plate, and a diaphragm mounted axially between the radial part of the cover and the pressure plate, the diaphragm resting on the pressure plate and on the cover. , characterized in that it comprises an annular rod bearing axially on the diaphragm opposite the cover and means for axially holding the rod bearing on the diaphragm, said holding means being fixed relative to the cover and being located radially inside the radially outer periphery of the diaphragm.

The holding means make it possible to effectively maintain the diaphragm on the cover, by means of the annular ring. Such a structure makes it possible to limit the radial size and the inertia of the mechanism. Indeed, the annular ring and the holding means are located radially inside the radially external periphery of the diaphragm, the holding means then being able to pass through the diaphragm.

The support area of the diaphragm on the cover can be located radially on the outside with respect to the support area of the diaphragm on the pressure plate.

Such a structure is of the normally open type. In other words, the pressure plate is pushed back in the direction of the cover, axially opposite the reaction plate and the friction disc, in the rest position, that is to say when no effort is required. is applied by the clutch stop on the diaphragm.

The annular ring and the retaining means may be located axially opposite or near the areas of support of the diaphragm on the cover.

The diaphragm is articulated around said support zones in operation. Such positioning makes it possible to limit the friction between the diaphragm, on the one hand, and the annular ring or the holding means, on the other hand. This improves the operation of the mechanism while avoiding premature wear thereof.

The diaphragm may include petals on its radially external periphery, delimited by notches opening at the radially external periphery of the diaphragm, the holding means passing axially through at least one of said notches.

Each notch may have a general T-shape and has a radially extending part opening out at the radially external periphery of the diaphragm, and a part extending perpendicular to said radial part, the holding means being housed at least in the radial part of the corresponding notch.

Such petals are known in particular from patent application FR2984434 in the name of the Applicant.

The holding means may comprise at least one rivet comprising an axial part having a first end fixed to the cover and a second end forming an enlarged head, the rod bearing axially on said head.

The rod can bear on the radially internal part of the enlarged head and on the axial part of the rivet.

The rod can include U-shaped or Omega-shaped fixing zones, connected by zones in the shape of a circular arc, each fixing zone being supported on the enlarged head of the corresponding rivet.

The arcuate zones can extend in a first radial plane, the U or Omega zones can extend in a second radial plane, the first and second radial planes being axially offset one with respect to the other.

Each fixing zone can be located at least partially radially outside the cylindrical part of the rivet.

Each fixing zone may be able to come radially outwardly pressing on the cover.

Each fixing zone can be inserted radially between the cylindrical part of the rivet and the cover.

The holding means may include at least one holding tab extending from the cover.

The retaining tab can be formed integrally with the cover.

The holding tab can be obtained by folding an area of the cover.

The rod can be centered by axial retaining rivets or by retaining tabs.

The retaining lug may comprise a first part extending axially and passing axially through the diaphragm and a second part extending radially from the first part, the rod being axially supported on the second part.

The second part can extend radially outward from the first part.

The pressure plate may comprise at least one support surface extending radially, the holding means being able to bear axially on said support surface in a disengaged position.

The holding means and the support surface thus make it possible to limit the lifting of the pressure plate during operation.

The cover may include an annular portion extending radially and an annular portion extending axially from the radially outer periphery of the annular portion.

The radial part of the cover may include at least one annular arched zone.

The arched area may have a frustoconical shape.

The arched area increases the stiffness of the cover.

The radial part of the cover can comprise at least two annular arched zones.

A first arched area can be located in the radially inner periphery of a radial part of the cover, a second arched area can be located in a radially central region of the radial part. This increases the stiffness of the cover, in controlled areas of the cover, in particular in areas intended to undergo high mechanical stresses.

The holding means are at least three in number, for example six in number.

The holding means are regularly distributed over the circumference.

The invention also relates to a clutch device for a motor vehicle, comprising a reaction plate intended to be coupled in rotation to a crankshaft, a friction disc intended to be coupled to an input shaft of a gearbox. , and a clutch mechanism of the aforementioned type, the pressure plate being actuated by the diaphragm so as to tighten or release the friction disc on the reaction plate.

Damping means can be mounted between the friction disc and the input shaft of the gearbox, the damping means acting against the rotation of the friction disc relative to the shaft. gearbox input.

Of course, as already indicated above, the invention is not limited to vehicles with hybrid motorization.

The clutch device is for example a double clutch.

The invention will be better understood and other details, characteristics and advantages of the invention will appear on reading the following description given by way of nonlimiting example with reference to the appended drawings in which:

- Figures 1 to 7 show a clutch mechanism according to a first embodiment, in particular:

- Figure 1 is an exploded perspective view of the clutch mechanism,

- Figure 2 is an exploded side view of the clutch mechanism,

- Figure 3 is a perspective view of the clutch mechanism,

- Figure 4 is an axial sectional view of the clutch mechanism,

FIG. 5 is a detailed view of FIG. 4,

FIG. 6 is a detailed view of FIG. 4,

FIG. 7 is a perspective view of the diaphragm,

- Figures 8 to 11 show a clutch mechanism according to a second embodiment, in particular:

FIG. 8 is an exploded perspective view of the clutch mechanism,

FIG. 9 is a perspective figure of the annular rod,

FIG. 10 is a view in axial section of the mechanism,

FIG. 11 is a detailed view of FIG. 10,

- Figures 12 to 14 show a clutch mechanism according to a first embodiment, in particular:

FIG. 12 is an exploded perspective view of the clutch mechanism,

FIG. 13 is a view in axial section of the mechanism,

- Figure 14 is a detail view of Figure 13.

Figures 1 to 7 show a clutch mechanism 1 for a motor vehicle, according to a first embodiment of the invention.

The mechanism 1 comprises a cover 2 comprising an annular part 3 of axis X extending radially and a cylindrical part 4 extending axially from the radially external periphery of the radial part 3.

The radial part 3 comprises a first camber 5 or annular frustoconical portion, located at the level of the radially internal periphery 6 of the radial part 3, and a second camber 7 or frustoconical annular portion, located at the level of a radially median zone 8 of the radial part 3.

The radial part 3 of the cover has holes 9 of circular section, regularly distributed over the circumference. The holes 9 are for example six in number and are situated at the level of the radially external periphery of the radial periphery.

The radial part 3 further comprises projecting support zones 10, directed towards the internal volume of the cover 2, as is known per se. The support zones 10 are for example obtained by stamping.

The cylindrical part 4 has axially extending openings 11. An annular rim 12 extends radially from the axial end of the cylindrical part 4 which is opposite to the radial part 3. The annular rim 12 comprises in particular fixing holes 13 intended for fixing the cover 2 on a reaction plate , for example by screwing or riveting.

The mechanism 1 also comprises an annular pressure plate 14, mounted in the cover 2. The pressure plate 14 has a first radial face 15, oriented towards the cover 2, and a second radial face 16 opposite the first face. The second face 16 is intended to come to bear on a friction disc.

The pressure plate 14 has tabs 17 extending radially from the radially outer periphery of the pressure plate. Tabs 18 make it possible to couple the pressure plate 14 in rotation, on the one hand, and the reaction plate and the cover 2, on the other hand. Said tongues 18 are elastically deformable and allow the pressure plate 14 to be returned to a rest position which is here a disengaged position.

Each tongue 18 thus has a first end fixed to a lug 17 of the pressure plate 14, for example by means of rivets 19, and a second end fixed to the rim of the cover 2 and / or to the reaction plate, for example by through rivets 20.

An annular support zone 21 projecting from the first face 16 of the pressure plate 14 is formed at the radially internal periphery 22 of the pressure plate. Radial grooves 23, regularly distributed around the circumference, are formed in the support area.

Countersinks 24 of circular section, for example six in number, are formed in the first face 15 of the pressure plate 14.

The clutch mechanism 1 further comprises a diaphragm 25, mounted in the cover 2 and interposed axially between the radial part 3 of the cover and the pressure plate 14.

The diaphragm 25 comprises an annular part 26, elastically deformable in the manner of a Belleville washer and of the fingers 27 extending radially inwards, from the annular part 26. The radially internal end 28 of the fingers 27 is intended to the support of a clutch bearing. Slots 29 extend radially between the fingers 27 of the diaphragm 25, each slot 29 having a base 30 or an enlarged radially outer end.

The radially outer periphery 31 of the annular part comprises notches 32 in the general shape of a T, distributed over the circumference. Each notch has a first branch oriented radially 33 and opening out at the radially outer periphery 31 of the diaphragm 25, and a second branch 34 perpendicular to the first branch 33. Said openings 32 delimit petals 35 located at the outer periphery of the diaphragm 31.

The diaphragm 25 is supported on the support areas 10 of the cover 2, on the one hand, and on the support area of the pressure plate 36 on the other hand. As can be seen more clearly in FIGS. 4 to 6, the support zones 10 of the diaphragm 25 on the cover 2 are located radially outside the support zones 36 of the diaphragm 25 on the pressure plate 14.

The diaphragm 25 is held in abutment on the bearing areas of the cover 10, by means of an annular ring 37 and rivets 38. The annular ring 37 is entirely annular and of circular shape. Each rivet 38 is engaged in the holes 9 of the cover 2 and fixed to said cover 2. Each rivet 38 further comprises an enlarged head 39 serving for the axial support of the annular ring 37.

The support zone 40 of the diaphragm on the annular ring 37 is located axially opposite the support 10 of the diaphragm 25 on the cover

2. The rod 37 is supported on the diaphragm 25, at the level of the petals 35.

Each rivet 38 has an axial or cylindrical part 41 having a first end 42 fixed to the cover 2 and engaged in one of the holes 9, and a second end forming an enlarged head 39, the rod 37 bearing axially on said head 39, in particular on the radially internal part 43 of the enlarged head 39 and on the axial part 41 of the rivet 38.

The diaphragm 25 is thus kept in abutment on the support zones 10 of the cover 2, by means of the rod 37 and the rivets 38.

In operation, when the diaphragm 25 is actuated by the clutch stop, the diaphragm 25 rocks around the support zones 10 of the cover 2 and causes the axial displacement of the pressure plate

14. In the embodiment illustrated in Figures 1 to 7, the clutch mechanism 1 is of the normally open type. Thus, in the rest position, the pressure plate 14 is returned to the disengaged position by the elastic tabs 18, in the direction of the radial part 3 of the cover 2, and the diaphragm 25 is also returned to its disengaged position. When actuated by the clutch stop, the diaphragm 25 pushes the pressure plate 14 opposite the radial part 3 of the cover 2, in the direction of the reaction plate, so as to clamp the friction disc between the reaction plate and pressure plate 14.

During such an actuation, the fingers 27 of the diaphragm 25 can penetrate, at least partially, in the grooves 23 of the pressure plate 14.

Furthermore, in the disengaged or rest position, the heads 39 of the rivets 38 can bear on the bottom surfaces of the countersinks 24, so as to limit movement of the pressure plate 14 during disengagement.

In addition, before mounting the clutch mechanism 1 on the gearbox, the diaphragm 25 is not subjected to the action of the clutch stop so that the latter is in a so-called storage position or transport, which is located beyond its disengaged position. In the storage position, the diaphragm 25 bears on the radially internal periphery 6 of the radial part 3 of the cover 2, which makes it possible to precisely control its position within the mechanism 1.

During the mounting of the clutch mechanism 1, the diaphragm 25 is prestressed and is released from its support on the cover 2.

FIGS. 8 to 11 illustrate a second embodiment of the invention, which differs from that described with reference to FIGS. 1 to 7, in that the rod 37A comprises fixing zones 44 in the form of a U or Omega, connected by zones in the shape of an arc of a circle 45, each fixing zone 44 being supported on the enlarged head 39 of the corresponding rivet 38.

The arcuate zones 45 extend in a first radial plane, the U or Omega 44 zones extending in a second radial plane, the first and second radial planes being axially offset relative to the other.

Each fixing zone 44 is located at least partially radially outside the cylindrical part 41 of the rivet 38, each fixing zone 44 being inserted radially between the cylindrical part of the rivet 38 and the cover 2, so as to be held radially the annular ring 37A. In particular, the radially external support 46 of each attachment zone 44 of the rod 37A is produced on a shoulder 47 extending axially formed in the radial part 3 and / or in the axial part 4 of the cover 2.

Figures 12 to 14 illustrates a third embodiment of the invention, which differs from that set out with reference to Figures 1 to 7 and 8 to 11, in that the rod 37, 37A is held axially using lugs 48 and not rivets 38.

Each tab 48 extends from the radial part 3 of the cover and comes integrally with said cover 2. Each tab 48 has a first part 49 extending axially and passing axially through the corresponding T-shaped notch 32 of the diaphragm 25, between the petals 35, and a second part 50 extending radially outward from the first part. The rod 37 is axially supported on the second part 50.

The retaining tab 48 can be obtained by folding an area of the cover 2. Thus, during the mounting of the mechanism 1, the diaphragm 25 and the rod 37 are mounted in the cover 2 then the tabs 48 are folded so as to maintain in position the rod 37 resting on the diaphragm 25.

In each of the abovementioned embodiments, the structure of the mechanism 1 makes it possible to reduce the radial size of said mechanism 1, in a little complex and inexpensive manner.

Claims (15)

1. Clutch mechanism (1) comprising a cover (2), a pressure plate (14), and a diaphragm (25) mounted axially between the radial part (3) of the cover (2) and the pressure plate ( 14), the diaphragm (25) bearing on the pressure plate (14) and on the cover (2), characterized in that it comprises an annular ring (37, 37A) bearing axially on the diaphragm (25) opposite the cover (2) and the axial retaining means of the rod (37, 37A) bearing on the diaphragm (25), said retaining means being fixed relative to the cover (2) and being located radially at the inside the radially outer periphery (31) of the diaphragm (25). 2. Mechanism (1) according to claim 1, characterized in that the support area (10) of the diaphragm (25) on the cover (2) is located radially outside with respect to the support area ( 36) of the diaphragm (25) on the pressure plate (14). 3. Mechanism according to claim 1 or 2, characterized in that the annular ring (37, 37A) and the holding means are located axially opposite or near the bearing zones (10) of the diaphragm (25) on the cover (2). 4. Mechanism (1) according to any one of the preceding claims, characterized in that the diaphragm (25) comprises petals (35) on its radially external periphery (31), delimited by notches opening at the level of the radially periphery external (31) of the diaphragm (25), the holding means passing axially through at least one of said notches. 5. Mechanism (1) according to claim 4, characterized in that each notch has a general T shape (32) and has a portion extending radially opening at the radially outer periphery (31) of the diaphragm (25) , and a part extending perpendicular to said radial part, the holding means being housed at least in the radial part of the corresponding notch. 6. Mechanism (1) according to one of claims 1 to 5, characterized in that the holding means comprise at least one rivet 5 (38) comprising an axial part having a first end (42) fixed to the cover (2) and a second end forming an enlarged head (39), the rod (37, 37A) bearing axially on said head (39). 7. Mechanism (1) according to claim 6, characterized in that the rod (37) bears on the radially internal part of the enlarged head 10 (39) and on the axial part (41) of the rivet (38). 8. Mechanism (1) according to claim 6, characterized in that the rod (37A) comprises fixing zones (44) in the form of a U or Omega, connected by zones (45) in the form of an arc of circle, each fixing zone (44) bearing on the enlarged head (39) of the rivet (38) 15 correspondent. 9. Mechanism (1) according to claim 8, characterized in that each fixing zone (44) is located at least partly radially outside the cylindrical part (41) of the rivet (38). 10. Mechanism according to claim 9, characterized in that each fixing zone (44) is able to come radially outwardly against the cover (2). 11. Mechanism (1) according to one of claims 1 to 5, characterized in that the holding means comprise at least one holding tab (48) extending from the cover (2). 25 12. Mechanism (1) according to claim 11, characterized in that the retaining lug (48) comprises a first part (49) extending axially and passing axially through the diaphragm (25) and a second part (50) s' extending radially from the first part (49), the ring (37) being axially supported on the second part (49). 13. Mechanism (1) according to claim 12, characterized in that the second part (50) extends radially outward from the first part (49). 14. Mechanism (1) according to one of claims 1 to 13, 5 characterized in that the pressure plate (14) comprises at least one bearing surface extending radially, the holding means being capable of bearing axially on said bearing surface in a disengaged position. 15. Clutch device for a motor vehicle, comprising a reaction plate intended to be coupled in rotation to a crankshaft, a friction disc intended to be coupled to an input shaft of a gearbox, and a clutch mechanism (1) according to one of claims 1 to 14, the pressure plate being actuated by the diaphragm (25) so as to tighten or release the friction disc on the 15 reaction plate.