WO2018219565A1

WO2018219565A1 - Clutch device with wear compensation, in particular for a motor vehicle

Info

Publication number: WO2018219565A1
Application number: PCT/EP2018/060917
Authority: WO
Inventors: Aurélien JAFFRES
Original assignee: Valeo Embrayages
Priority date: 2017-05-29
Filing date: 2018-04-27
Publication date: 2018-12-06
Also published as: FR3066794A1; FR3066794B1; KR20200014839A

Abstract

The invention relates to a clutch device (1) with wear compensation, in particular for a motor vehicle, comprising at least one reaction plate (4), first and second clutch discs (5a, b), first and second pressure plates (3a, 3b) actuated by a first and a second diaphragm spring (9a, 9b), respectively, a fixed cover (6), first means for detecting and compensating for wear mounted between the first diaphragm spring (9a) and the fixed cover (6), and second means for detecting and compensating for wear mounted between the second diaphragm spring (9b) and the second pressure plate (3b).

Description

Clutch device with catch-up of wear, in particular for a motor vehicle

The present invention relates to a clutch device to take up wear, especially for a motor vehicle.

A clutch device conventionally comprises a reaction plate, a movable pressure plate and a friction disk mounted between said reaction and pressure plates. The movement of the pressure plate is controlled by a diaphragm, itself controlled by a clutch abutment.

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

The use of the clutch device causes wear of the friction disc liners and the counter-materials of the associated pressure and reaction plates. This results in a variation of the position of the pressure plate relative to the associated diaphragm and / or with respect to the reaction plate, generating a variation of the friction disk clamping force and a modification of the licking point and the stroke of the clutch stop. It is recalled that the licking point is the position from which a torque can be transmitted through the clutch device.

A wear-catching clutch device is known from document FR 2 780 1 19. This device comprises a cover inside which is mounted a pressure plate intended to bear on a friction disk, a diaphragm inserted between them. between the cover and the pressure plate, for actuating the pressure plate between a fully engaged position in which said pressure plate is pushed against the friction disk, and a fully disengaged position wherein said pressure plate is spaced apart from the friction disc by biasing means of the pressure plate.

Means for catching the wear of the friction disk are interposed between the diaphragm and the pressure plate, and comprise at least one retrofit member movable in a determined range and having a ramp cooperating with a counter-ramp turned on the side of the diaphragm. pressure plate, so as to adjust the distance between the diaphragm and the pressure plate and compensate the wear of the friction disc according to the angular position of the ramp relative to the counter-ramp.

The device further comprises means for detecting wear, able to authorize the displacement of the movable catch member in case of wear of the friction disc and able to prevent such displacement when this wear is not sufficient. , said detection means comprising at least one movable detection member, in a determined range, with respect to the catch member and having a ramp cooperating with a counter ramp turned on the side of the pressure plate.

The device finally comprises a pressing member constraining the ramps of said movable members against the associated counter ramps, the pressing member being adapted to cooperate with a fixed stop, for example the cover, so as to release said movable members when wear friction disc is detected.

The movable catch member is biased by means of a spring, so as to catch the clearance between the latter and the pressing member, when said movable catch member is released by the pressure member and the diaphragm . Furthermore, the mobile detection member is biased by another spring so as to make up the clearance between the latter and the pressing member, when said movable detection member is released by the pressing member and the diaphragm.

In operation, the assembly is subjected, alternately, to successive phases of clutch and disengagement. In the clutching phase, the diaphragm presses on the pressure plate, via the play-catching member. In the declutching phase, the pressure plate is returned to its disengaged position by means of return means generally taking the form of elastically deformable tongues.

When the friction disk is not worn and that the counter-materials of the pressure and reaction plates are not worn, the pressing member constantly maintains the detection member and / or the retraction member prestressing: said organs are immobilized.

In case of wear, the pressure member bears on the stop and a play is created between the pressing member and the detection member. As the latter is constrained by a spring, it is moved to fill the game above. In the engaged position, the force applied by the diaphragm on the catch member prevents the displacement of the latter, by pressing and friction on the pressure plate. Then, when the diaphragm is moved to its disengaged position, the return tongues of the pressure plate tend to press the pressure plate against the play catch member, and the play catch member against the diaphragm. The force exerted by the return tongues is relatively small so as to allow, despite the friction in play, a displacement of the play catch member, under the effect of the stress applied by the corresponding spring. This movement makes it possible to make up the clearance between the pressing member and the catching member. This compensates for the wear of the friction plate as well as the wear of the counter-materials of the associated pressure and reaction plates.

Such an operation requires in particular the use of biasing means of the pressure plate exerting relatively low forces, to allow movement of the catch member despite the friction in play. This is detrimental to operation because such return means can transmit axial vibrations and generate pumping phenomena of the pressure plate. In order to remedy this drawback, the patent application FR 3,009,592, in the name of the Applicant, proposes a clutch device with wear catch-up, in particular for a motor vehicle, comprising a pressure plate designed to bear on a friction disc of the clutch device, a diaphragm for actuating the pressure plate between a fully engaged position in which said pressure plate is pushed against the friction disk, and a fully disengaged position in which said plate of pressure is pressure is removed from the friction disk by means of return means of the pressure plate. The clutch device comprises a wear-catching mechanism comprising:

- means of catching the wear of the friction disc being interposed between the diaphragm and the pressure plate, said wear compensating means comprising at least one movable catch member in a given range and having a ramp co-operating with a against-ramp turned on the side of the pressure plate, so as to adjust the distance between the diaphragm and the pressure plate and compensate the wear of the friction disc according to the position of the ramp relative to the counter-ramp,

- wear detection means capable of allowing the displacement of said movable catch member in case of wear of the friction disc and able to prevent such movement when this wear is not sufficient, said detection means comprising at least one less a movable detection member, in a given range, with respect to the mobile retraction member and having a ramp cooperating with a counter ramp turned on the side of the pressure plate,

- At least one pressing member forcing at least the ramp of the detection member against the associated counter ramp, the pressing member being adapted to cooperate with a fixed stop to release said movable members when a disk wear friction is detected, the mobile retraction member being urged so as to move when said movable retraction member is released by the diaphragm,

the mobile detection member being biased so as to move and catch, at least in part, the clearance between the latter and the pressing member, when said movable detection member is released by the pressing member and by the diaphragm.

In addition, the diaphragm may release the detection member and prevent the retraction member from moving in the fully engaged position, and the diaphragm may release the retraction member and prevent the displacement of the detecting member, position completely disengaged, the diaphragm always bearing on at least one of said members between its fully engaged positions and fully disengaged.

In this way, the biasing means of the pressure plate can exert a major force, this force being taken up by the mobile retraction member and then by the diaphragm, or by the movable detection member and then by the diaphragm, depending on the position of the diaphragm. Indeed, during their movements, said movable members are not subjected to the force exerted by the biasing means of the pressure plate and it is therefore possible to easily solicit their displacement, in case of wear.

As indicated above, the fact of having biasing means of the pressure plate exerting a large force, such as for example spring tongues having a high stiffness, allows to limit the transmission of axial vibrations and to avoid the pumping phenomena of the pressure plate.

The movable detection member and the movable catch member are biased by elastic members, for example traction springs.

In particular, at least one first circumferentially extending traction spring is mounted between the sensing member and the pressure plate, or between the sensing member and a lid rotatably coupled to the pressure plate. Second circumferentially extending traction springs are mounted between the sensing member and the catch member. These second springs provide the motorization function of the catch member with respect to the sensing member.

The counter-ramp of the pressure plate cooperating with the detection member and the counter-ramp cooperating with the catch member are identical.

The patent application FR 3,009,592 also applies such wear-compensating means to a double clutch.

It is recalled that a double clutch allows in particular to alternately couple the motor shaft of the vehicle with two coaxial input shafts of a gearbox, which can be of the robotic type.

Thus, a dual clutch allows to change gears while maintaining the transmission of a torque engine to the vehicle wheels. Indeed, the two clutches are respectively associated with even and odd gear ratios. During a gearshift, a first clutch is disengaged while the second clutch is engaged, so that the engine torque is progressively transferred from the first to the second clutch.

Each clutch comprises a mechanism comprising a diaphragm for cooperating with a pressure plate integral in rotation with the cover and the motor shaft. Each diaphragm is movable by means of a corresponding clutch abutment, between a rest position and an active position. Depending on the type of clutch, the active position of the diaphragm corresponds to a coupling or decoupling of the shafts of the engine and the gearbox and the rest position of the diaphragm corresponds to a decoupling or a coupling of these shafts. These are respectively a normally open clutch and a normally closed clutch. For safety reasons, at least one of the clutches is of the normally open type.

The clutch stop is controlled by an actuator controlled by an electronic computer to exert a predetermined force on the diaphragm and move it over a given distance.

The pressure plate of each clutch, biased by the corresponding diaphragm, is intended to clamp a friction disc on a corresponding reaction plate. A reaction plate may be provided for each clutch. Alternatively, a single reaction plate common to both clutches, mounted between the two friction discs, is used.

Each friction disk is rotatably connected to an input shaft of the gearbox and each reaction plate is for example integral in rotation with a flywheel connected to the motor shaft. Thus, the clamping of a friction disk between the corresponding pressure and reaction plates allows the transmission of a torque between the drive shaft and the associated gearbox shaft.

As before, the use of the clutches causes wear of the friction linings of the friction discs as well as the counter-materials of the pressure and associated reaction plates. This results in a variation of the position of each pressure plate with respect to the associated diaphragm and / or the reaction plate, generating a variation of the friction disk clamping force and a modification of the licking point and the stroke at the clutch stop. In this case, the licking point is the position from which a portion of the engine torque is transmitted to the gearbox shaft when closing the clutch.

In general, such wear is more present at the friction disc and the pressure and reaction plates belonging to the first clutch, that is to say the clutch associated with odd speeds reports. Thus, when the double clutch comprises only one wear compensating mechanism according to the invention, it preferably forms a part of the first clutch. Of course, the double clutch according to the invention may comprise both wear compensating mechanisms equipping the first clutch and a mechanism fitted to the second clutch.

The patent application FR 3,009,592 discloses in particular the use of a first wear-compensating mechanism fitted to the first clutch and a second wear-compensating mechanism fitted to the second clutch.

In this patent application is described a double clutch comprising a reaction plate intended to be coupled in rotation to a driving shaft, a first and a second friction disk, intended to be coupled respectively to a first and a second driven shaft, a first and second pressure plates, respectively actuated by a first and a second diaphragm so as to clamp or release the first and second friction disc on the reaction plate, the first pressure plate being fixedly connected to a movable cover; translation with respect to the reaction plate, and being actuated by pressing the first diaphragm on the movable cover, first detection means and catch-up of the wear of the first friction disc being interposed between the first diaphragm and the movable cover, second means for detecting and catching the wear of the second friction disc, being interposed between the second diaphragm me and the second pressure plate.

In operation, the support of each diaphragm is able to switch from the catch member to the detection member, and vice versa, between the clutch and disengage phases. It has been found that a defect of positioning of the sensing member with respect to the catch member causes a significant axial positioning defect at the radially inner periphery of the diaphragm, ie at the the support of the clutch stop. In order to take into account such a positioning defect and in order to be able to operate the above-mentioned tilting, it is necessary to provide an over-run the clutch abutment, which has a particular negative impact on the axial size and the operation of the device.

The invention aims to remedy, in whole or in part, the problems mentioned above.

For this purpose, it proposes a clutch device with wear catch-up, in particular for a motor vehicle, comprising:

a reaction plate intended to be coupled in rotation to a driving shaft, around an axis of rotation,

a friction disk, to be coupled to a driven shaft, a pressure plate actuated by a diaphragm so as to clamp or release the friction disk on the reaction plate,

- a lid,

means for detecting and compensating for wear, able to compensate for the wear of the friction disk, the means for detecting and compensating for wear being mounted between the diaphragm and the cover or between the diaphragm and the pressure plate; and comprising:

wear compensating means comprising at least one movable catch member in a determined range and having a ramp cooperating with a counter ramp connected to the lid or the pressure plate, so as to adjust the distance between the diaphragm and the cover or between the diaphragm and the pressure plate and compensate the corresponding wear as a function of the position of the ramp relative to the counter-ramp,

wear detecting means adapted to allow said retraction member to move in case of wear and able to prevent such displacement when this wear is not sufficient, said detecting means comprising at least one movable detection member , in a determined range, with respect to the catching member and having a ramp cooperating with a counterbeam integral with the lid or the pressure plate, the detection member and the catch member comprising stop means capable of limiting the relative movement of the detection member relative to the catch member,

characterized in that the abutment means comprise a movable or adjustable abutment portion with respect to the sensing element or with respect to the adjuster, the displacement of the movable abutment portion to adjust the displacement according to the axis of rotation of one end of the catch member adapted to serve to support the diaphragm relative to an end of the detecting member adapted to serve to support the diaphragm.

The displacement or adjustment of the movable stop portion makes it possible to adjust the stroke or the displacement allowed by the abutment means between the catching member and the detection member. It is possible to precisely adjust the axial position of the detection member with respect to the catch member and, as a result, the axial position of the radially inner periphery of the diaphragm when the diaphragm swings from the catch member to the detection member, so as to avoid any significant over-travel of the clutch abutment.

The movable abutment portion may be housed, at least in part, in a notch or recess of the retraction member or the detecting member. Said notch may lead to an end of said member which is opposite an end serving to support the diaphragm.

The movable abutment portion may comprise a threaded portion, engaged in a threaded portion of the sensing member or the catch member.

The movable abutment portion may comprise a screw whose threaded portion is engaged in a threaded portion secured to the sensing member or the catch member and whose head is adapted to bear on an abutment surface complementary to the catch-up member or the detection member, respectively. The movable abutment portion may be adapted to be immobilized in position by means of a locking member.

The movable abutment portion may comprise an axis engaged in an oblong hole of the detecting member or the catch member.

The axis is for example formed by the rod of a screw, the latter also forming the locking member. In this case, the tightening of the screw may allow the locking of the movable stop portion.

The movable abutment portion may comprise a cam adapted to pivot relative to the sensing member or relative to the catch member.

The rotation of the cam makes it possible to vary the distance and thus the allowed travel or the authorized movement between the cam and the opposite member, that is to say the detection member or the catch member.

The device may comprise at least one pressing member constraining at least the ramp of the detection member against the associated counter ramp, the pressing member being adapted to cooperate with a fixed stop so as to release the detection member when a wear is detected, the catch member being urged to move when said catch member is released by the diaphragm, the sensing member being biased to move and catch, at least in part, the clearance between the latter and the pressing member, when said detecting member is released by the pressing member and the diaphragm.

The diaphragm may release the detection member and prevent the retraction member from moving, in fully engaged position, the diaphragm releasing the retraction member and preventing the displacement of the detecting member, in the fully disengaged position, the diaphragm always bearing on at least one of said members between its fully engaged positions and fully disengaged. The detection member may comprise an end adapted to serve to support the diaphragm and an end comprising at least one ramp, cooperating with the counter ramp associated with the cover.

The catch member may comprise an end adapted to serve to support the diaphragm and an end comprising at least one ramp, cooperating with the counter ramp associated with the cover.

The device may comprise a stop member connected to the pressure member, the stop member being designed to move the pressure member away from the sensing member and / or the catch member in case of wear.

The pressing member may comprise at least one resilient tongue whose one end is adapted to bear on the movable detection member and / or on the corresponding mobile retraction member.

The angle of the ramps of the catch member and the detection member, and / or the angle of the associated counter ramp, is between 2 and 20 °.

The invention may also relate to a method of adjusting a wear-catching clutch device, in particular for a motor vehicle, comprising:

a friction disk, intended to be coupled to a driven shaft,

a pressure plate actuated by a diaphragm so as to clamp or release the friction disk on the reaction plate,

- a lid,

wear compensating means comprising at least one movable catch member in a determined range and having a ramp cooperating with a counter ramp connected to the cover or the pressure plate, so as to adjust the distance between the diaphragm and the cover or between the diaphragm and the pressure plate and compensate the corresponding wear depending on the position of the ramp relative to the counter-ramp,

wear detecting means adapted to allow said retraction member to move in case of wear and able to prevent such displacement when this wear is not sufficient, said detecting means comprising at least one movable detection member , in a determined range, with respect to the catching member and having a ramp cooperating with a counterbeam integral with the lid or the pressure plate,

the detection member and the catch member comprising stop means capable of limiting the relative movement of the detection member relative to the catch member,

characterized in that the method comprises the steps of:

measuring the position of the sensing member with respect to the catching member, in an axial direction, generally perpendicular to the displacement of the sensing member with respect to the wear compensating member;

- Adjust the stop means, so as to adjust the authorized movement of the detection member relative to the catch member.

Such an adjustment can be achieved by moving a moving abutment portion or by machining, by adding material or by deformation of material, for example.

Advantageously, this method makes it possible to adjust the displacement along the axis of rotation of an end of the retrofit member adapted to serve to support the diaphragm with respect to an end of the detecting member adapted to be used for the support of the diaphragm. The invention may relate in particular to a simple clutch, of normally closed type and pulled or pushed type.

In such a case, the lid may be integral with the reaction plate.

The invention can also be applied to a hybrid architecture, the clutch can then be of normally open type.

Alternatively, the invention may relate to a double clutch. In such a case, the double clutch can comprise:

at least one reaction plate intended to be coupled in rotation to a driving shaft, around an axis of rotation,

first and second friction discs bearing friction linings, for coupling respectively to a first and a second driven shaft,

a first and a second pressure plate actuated respectively by a first and a second diaphragm so as to clamp or release the first and second friction disc on the reaction plate, the first pressure plate being fixedly connected to a movable cover in translation relative to the reaction plate, and being actuated by pressing the first diaphragm on the movable lid,

a fixed cover fixed to the reaction plate and housing the second pressure plate, the second friction disc and / or the second diaphragm,

first detection and wear-catching means adapted to compensate for the wear of the first friction disk, the first detection and wear-catching means being mounted between the first diaphragm and the fixed cover,

second detection and wear-compensating means adapted to compensate for the wear of the second friction disc, the second wear-detecting and compensating means being mounted between the second diaphragm and the second pressure plate, the first wear detecting and compensating means and the second wear detection and retrieval means each comprising:

wear compensating means interposed between the first diaphragm and the fixed cover, or respectively between the second diaphragm and the second pressure plate, said wear compensating means comprising at least one movable catch member in a determined range and having a ramp cooperating with a counter ramp turned on the side of the fixed cover or the second pressure plate, so as to adjust the distance between the first diaphragm and the fixed cover, or respectively between the second diaphragm and the second pressure plate and compensate for the corresponding wear as a function of the position of the ramp relative to the counter-ramp,

wear detecting means capable of permitting the displacement of said movable compensating member in case of wear and capable of preventing such displacement when this wear is not sufficient, said detecting means comprising at least one detection member mobile, in a given range, relative to the movable catch member and having a ramp cooperating with a counter-ramp turned to the side of the fixed cover or the second pressure plate.

The first wear detecting and compensating means and / or the second wear detecting and compensating means may be equipped with abutment means of the abovementioned type, that is to say having a movable abutment portion or adjustable relative to the sensing member or relative to the catch member, the displacement of the movable stop portion for adjusting the relative displacement allowed by the stop means.

The mobile catch-up member and the detection member of the first wear detection and correction means may be located radially on the outside or radially inside the mobile catch-up member and on the body. detection of the second means of detecting and compensating for wear, so as to reduce axial size.

The device may comprise an abutment member connected to the pressure member, the abutment member being designed to move the pressure member away from the sensing member and / or the compensating member in case of wear, stop member being connected to the pressing member in an area between the sensing member and the catch member, or offset radially inwardly or outwardly of these members, preferably half-way between the sensing element and the catching member.

In this way, it limits the tilting effect of the pressure member, such a tilting having an influence on the positions of the actual bearing areas of the pressing member on the sensing member and / or on the member catching up. The aforementioned characteristic thus makes it possible to control the position of said movable members so as to guarantee the proper functioning of the corresponding wear detecting and compensating means.

The pressing member may interact with the fixed cover or the movable cover through an additional piece.

The stop member may comprise an end bearing against the fixed cover or the movable cover, and an end connected to the pressing member.

The clutch device according to the invention may also include one or more of the following features:

the pressure plate is biased towards its disengaged position, opposite the reaction plate, by first elastic return means, such as, for example, elastic return tongues mounted between the pressure plate and the reaction plate,

said elastic tongues rotate the reaction plate with the pressure plate,

the counter ramps are formed on the radial part of the corresponding cover, the detection member is located radially outside the corresponding wear compensating member,

the detection member and the catching member comprise at least one zone in which they are radially spaced from one another,

the sensing element and the catching member have, in front view, a generally circular shape with at least one zone provided with bulges in which said members are locally spaced apart from one another in the radial direction, the pressing member pressing on the corresponding ends of the movable members at said zone,

- The pressing member exerts a pressure force distributed between the sensing member and the catch member and the axial component of this force along the axis X can be applied to an application radius located between the sensing member and the catch-up member.

- The end of the stop member which is connected to the pressure member is housed in said area provided with bulges.

More specifically, the dual clutch may include one or more of the following features:

the first clutch and / or the second clutch are of the normally open type,

the double clutch comprises a single reaction plate serving to support the first friction disc and the second friction disc,

the first diaphragm is in the form of an elastic annular sheet and is pivotally mounted around support zones of the movable cover,

the second diaphragm is in the form of an elastic annular sheet whose radially outer periphery is pivotally mounted relative to the fixed cover,

an elastic member keeps the radially outer periphery of the second diaphragm resting on the fixed lid, the fixed cover comprises radial flanges for fixing on the reaction plate, connected to an annular part surrounding, at least in part, the second pressure plate, the second friction disc and / or the second diaphragm, said part annular of the fixed cover being extended by an annular portion extending radially inwards,

the counter-ramp is formed on the radial part of the fixed lid,

the movable cover has a radially outer portion extending from the first pressure plate and partly surrounding the fixed cover, extended by a portion extending radially inwards and serving to support the first diaphragm,

a first elastic member, such as for example a circumferentially extending tension spring, is mounted between the detection member, on the one hand, and the fixed cover or the second pressure plate, on the other hand,

a second elastic member, such as for example a pin-shaped spring, is mounted between each detection member and the corresponding catch member,

the first elastic member exerts a tangential or circumferential force greater than the tangential or circumferential force exerted by the second elastic member,

the length of the first elastic member is important, so as to be able to urge the displacement of the detection member over a wide angular range, for example between 30 ° and 120 °,

- The pressing member is fixed to the fixed cover at a first end, and is adapted to bear, at a second end, on the sensing member and the corresponding wear compensating member, for example on the first movable detection and retraction members, so as to force the ramps to bear against the counter-ramp, the stop member comprises a first end fixed, for example by riveting, radially between the detection member and the corresponding wear compensating member, preferably radially at mid-distance between said movable members, and a second cylindrical end forming an enlarged head of larger dimension than the rest of the stud and defining a shoulder,

the enlarged head of the abutment stud is able to bear against a radial surface of the movable lid or the fixed lid,

the enlarged head of the abutment stud is intended to rest on the corresponding radial surface when the displacement of the corresponding pressure plate is important, that is to say when there is wear of the friction disc liners; and or counter-materials of the pressure plate and the associated reaction plate.

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 non-limiting example with reference to the accompanying drawings in which:

FIG. 1 is a perspective view with partial cutaway of a double clutch according to one embodiment of the invention;

FIGS. 2 and 3 are exploded views, in perspective, of the double clutch,

FIG. 4 is a view in axial section of the clutch device,

- Figures 5 to 8 are schematic views illustrating the operation of the first clutch, in the absence of wear, the movable stop portion not being shown,

FIGS. 9 to 16 are diagrammatic views illustrating the operation of the first clutch, in case of wear, the movable stop portion being not shown,

FIGS. 17 to 19 are diagrams illustrating various embodiments of the mobile or adjustable stop means, - Figure 20 is a schematic view illustrating the sensing member, the catch member and the movable or adjustable stop member.

A dual wear-compensating clutch 1 according to one embodiment of the invention is shown in FIGS. 1 to 4. This is intended to couple a motor with a first and a second input shaft of a box of speeds (not shown). The axis of the double clutch is referenced X. The double clutch 1 comprises first and second clutches 2a, 2b (also called clutch mechanisms) for passing reports of different parities.

The first clutch 2a comprises a first pressure plate 3a and a reaction plate 4 between which a first friction disc 5a extends. The first pressure plate 3a is rotatably coupled to the reaction plate 4 and is translatable relative thereto, between an engaged position and a disengaged position, in which it squeezes the first friction disk 5a on the platen. reaction 4, or respectively releases the first friction disc 5a.

The reaction plate 4 is fixed on a cover 6 called fixed cover, itself intended to be coupled to the motor shaft. The first friction disc 5a is intended to be coupled to the first input shaft of the gearbox. Thus, in the engaged position of the first clutch 2a, the motor shaft is coupled to the first input shaft of the gearbox.

The first pressure plate 3a is fixed on a cover 7 movable in translation relative to the reaction plate 4 and the fixed cover 6, and extending forwardly. First elastic return tongues 8a are mounted between the first pressure plate 3a and the reaction plate 4.

The first clutch 2a further comprises a first diaphragm 9a in the form of an elastic annular sheet, and is pivotally mounted around bearing zones 10 of the movable cover 7. The control of the first clutch 2a is conventionally done by means of a first clutch abutment (not shown) cooperating with the radially inner periphery of the first diaphragm 9a. The first diaphragm 9a forms a lever transmitting the force applied by the first control stop to the first pressure plate 3a, via the movable cover 7.

In order to allow effective clamping of the first friction disc 5a, the first diaphragm 9a is preloaded at rest. Without this pre-charge, the first diaphragm 9a would, at rest, in a state of elasticity requiring a start of travel of the first relatively large control stop to apply an effective clamping force on the first friction disc 5a. When the first clutch abutment is actuated, it balances the pre-charge of the first diaphragm 9a before starting the tightening of the first friction disc 5a. The pre-charge of the first diaphragm 9a makes it possible to reduce the approach run of the first clutch abutment in order to clamp the first friction disc 5a, and to always have a minimum pre-load force, for example on the ball bearing of the first clutch abutment and on the ball bearing which supports the double clutch 1. This increases the service life of said bearings and limits the vibrations of the double clutch 1.

The first clutch 2a is of the normally open type. The rest position of the first diaphragm 9a therefore corresponds to a disengaged state of the first clutch 2a. The first diaphragm 9a preferably has a portion of the Belleville washer type for returning the first diaphragm 9a to its rest position.

In the rest position of the first diaphragm 9a, that is to say when the first stop does not exert or little effort on the first diaphragm 9a, the first diaphragm 9a therefore does not exert (or little) stress on the first pressure plate 3a. The first pressure plate 3a is separated from the reaction plate 4 by means of the resilient tongues 8a, so as to release the first friction disc 5a.

The second clutch 2b has a second pressure plate 3b, and a second friction disk 5b extending radially between the reaction plate 4 and the second pressure plate 3b. The second friction disc 5b is interposed axially between the reaction plate 4 and the second pressure plate 3b. The same reaction plate 4 is thus used for the two clutches 2a, 2b, each friction disc 5a, 5b being disposed on the side of one of the two axial bearing surfaces of the reaction plate 4. Second elastic tongues of recall 8b are mounted between the second pressure plate 3b and the reaction plate 4.

The second pressure plate 3b is rotatably coupled to the reaction plate 4 and is translatable relative thereto, between an engaged position and a disengaged position, in which it squeezes the second friction disk 5b on the platen. reaction 4, or respectively releases the second friction disc 5b.

The second friction disc 5b is coupled to the second input shaft of the gearbox. Thus, in the engaged position of the second clutch 2b, the motor shaft is coupled to the second input shaft of the gearbox.

The second clutch 2b further comprises a second diaphragm 9b in the form of an elastic annular sheet whose radially outer periphery is pivotally mounted relative to the fixed cover. An elastic member 1 1 (Figure 3) maintains the radially outer periphery of the second diaphragm bearing 12 on the fixed cover 6 (Figure 4).

The control of the second clutch 2b is conventionally done by means of a second clutch abutment (not shown) cooperating with the radially inner periphery of the second diaphragm 9b, via a force transmission member (not shown). ). The second diaphragm 9b forms a lever transmitting the force applied by the second clutch abutment to the second pressure plate 3b, to allow effective clamping of the second friction disc 5b.

The second clutch 2b is also of the normally open type. In the rest position of the second diaphragm 9b, that is to say when the second control stopper exerts little or no effort on the second diaphragm 9b, the second diaphragm 9b does not exert (or little) stress on the second pressure plate 3b. The second pressure plate 3b is spaced from the reaction plate 4 via the elastic tongues 8b, so as to release the second friction disk 3b.

The fixed cover 6 comprises, from the rear to the front, radial flanges 6a for fixing on the reaction plate 4, connected to an annular portion 6b surrounding, at least in part, the second pressure plate 3b, the second friction disc 5b and / or the second diaphragm 9b. Said annular portion 6b is extended by an annular portion 6c extending radially inwards.

Furthermore, the movable cover 7 has a radially outer portion 7a extending forwardly from the first pressure plate 3a and partially surrounding the fixed cover 6, extended at the front by a radially extending portion 7b. inside and serving to support the first diaphragm 9a.

In order to compensate for the wear of the first friction disk 5a, the first pressure plate 3a and / or the reaction plate 4, the first clutch 2a is equipped with first detection and wear compensating means.

The first catch and wear detecting means equipping the first clutch 2a are interposed axially between the fixed cover 6 and the first diaphragm 9a, more precisely interposed axially between the radial portion 6c of the fixed cover 6 and the first diaphragm 9a. The first catch-up and wear-detection means comprise a first mobile catch-up member 13a in the form of a ring comprising an end 13'a (see FIG. 5 in particular) against which the first diaphragm 9a is able to come in abutment, and an end comprising at least one ramp 14a (see in particular FIG 5) extending circumferentially, cooperating with an associated ramp against 15a formed directly on the radial portion 6c of the fixed cover 6. Of course, the counter-ramp 15a can be formed by an independent piece and fixed on the fixed lid 6.

The first catch-up and wear detection means also comprise a first mobile detection member 16a in the form of a ring having an end 16'a (see FIG. 5 in particular) against which the first diaphragm 9a is adapted to come to bear, and an end comprising at least one ramp 17a (see in particular FIG 5) extending circumferentially, cooperating with the counter-ramp 15a of the radial portion 6c of the fixed cover 6.

By way of example, the angle α (FIG. 20) of the ramps 14a, 17a of said movable members 13a, 16a and of the counter ramp 15a of the fixed cover 6 is between 2 and 20 °.

The two movable members 13a, 16a are concentric and separated from each other, the first detection member 16a being located radially outside the first wear-compensating member 13a. Alternatively, the respective positions of said movable members 13a, 16a can be reversed. Note however that the possibility of inversion of the movable members 13a, 16a is related to the internal architecture of the mechanism.

As is best seen in Figure 6 in particular, the detection member 16a comprises a tab 26a which extends radially inward radially through a notch 27a formed in the wear compensating member 13a. The tab 26a is inserted along the X axis between the mobile retraction member 13a and the counter-ramp 15a of the fixed cover 6.

Centering means, such as for example studs, ensure the proper positioning of the movable members 13a, 16a.

A first elastic member 18a, such as for example a circumferentially extending tension spring, is mounted between the first detection member 16a and the fixed cover 6.

A second elastic member 19a, such as for example a pin-shaped spring, is mounted between the first detection member 16a and the first catch member 13a.

The length of the first spring 18a is important, so as to be able to bias the displacement of the first detection member 16a over a wide angular range (for example between 30 ° and 120 °).

The first clutch 2a also comprises at least one first pressing member 20a in the form of an elastic tongue exerting an axial force. Said tongue 20a is fixed to the fixed cover 6, at a first end, and is able to bear, at a second end, on the first detection member 16a and possibly on the first wear compensating member 13a, so that to constrain them in bearing on the radial part 6c of the fixed cover 6.

An abutment stud 21a is fixed on the second end of said tongue 20a. The abutment stud 21a has in particular a first end 22a (FIG. 4) fixed, for example by riveting, radially between the first detecting member 16a and the first wear compensating member 13a, preferably radially at mid-distance. between said movable members 13a, 16a, and a second cylindrical end 23a forming an enlarged head of larger dimension than the rest of the pad 21a and defining a shoulder. The stud 21 has passed through a hole in the movable cover 7 and is able to bear against a radial bottom surface formed by a countersink 24 formed in the mobile cover 7. In particular, the enlarged head 23a of the stop stud 21a is intended to rest on the bottom surface of the counterbore 24 when the displacement of the first pressure plate 3a is important, that is to say when there is a wear of the linings of the first friction disc 5a and / or counter-materials of the first pressure plate 3a and the reaction plate 4.

The operation of the first detection and wear-compensating means will now be described with reference to FIGS. 5 to 16.

As is diagrammatically illustrated in FIGS. 5 to 8, the first catch-up and wear-detection means are inoperative when the linings of the first friction disc 5a are not or little worn out and the counter-materials of the first pressure plate 3a and the associated reaction plate 4 are not worn, for example when the cumulative axial wear is less than 0.05 mm.

As illustrated in FIG. 5, in the fully engaged position and in the absence of wear, the first diaphragm 9a bears on the first catch member 13a, so as to push the first pressure plate 3a against the elastic tongues. 8a. The first pressure plate 3a and the corresponding reaction plate 4 (axially fixed) then grip the first friction disc 5a carrying the linings. In this position, the head 23a of the abutment stud 21 is flush with the bottom surface of the countersink 24 of the movable lid 7.

In addition, in this position, the tab 26a bears on a first edge 32a of the notch 27a of the catch member 13a, as can be seen in FIG. 6.

Furthermore, as shown in FIG. 7, in the fully disengaged position and in the absence of wear, the first diaphragm 9a bears on the first detection member 16a, a gap being created between the first diaphragm 9a and the first diaphragm 9a. corresponding end of the first catch member 13a. In the fully disengaged position and in the absence of wear, the first edge 32a of the notch 27a of the catch member 13a bears on the lug 26a, as can be seen in FIG. 8.

It can thus be seen that, in the absence of detection of wear, the second zone of the elastic tongue 20a and / or the first diaphragm 9a maintains the first detection member 16a and the first catch member 13a resting on the lid fixed 6, regardless of the operating phase of the first clutch 2a (clutch / clutch). In this case, the resistive torque generated by the friction between said members 13a, 16a and the fixed cover 6 is greater than the torque exerted by the springs 18a, 19a. Said members 13a, 16a are thus immobilized in rotation relative to the fixed cover 6, whatever the operating phase of the first clutch 2a.

FIGS. 9 to 16 illustrate the case where the linings of the first friction disc 5a (or else the counter-materials of the first pressure plate 3a and of the reaction plate 4) present a wear, which must be compensated for in order to avoid a malfunction of the first clutch 2a.

In this case, as illustrated in FIG. 9, the head 23a of the abutment stud 21a abuts on the bottom surface of the countersink 24 of the movable lid 7, in a fully engaged position, so that the second zone of the tongue elastic strip 20a is detached from the corresponding secondary end of the first detection member 16a. A game j1 is formed between said secondary end of the first detection member 16a and the second zone of the tongue 20a.

Thus, in particular, there may be an axial clearance between the first pressing member 20a and the corresponding secondary end of the first wear-catching member 13a, even though the first pressing member 20a bears on the end corresponding secondary of the first sensing member 16b. It is possible in some cases that the end 16'a of the first detection member 16a and the secondary end of the first detection member 16a are combined. Similarly, it is possible that the end 13'a of the first catch member 13a and the secondary end of the first catch member 13a are merged.

The first detection member 16a, which is no longer subjected to an axial force, is rotated by the first elastic members 18a, so as to at least partially fill the clearance j1 (Figure 1 1). During this rotation, the second elastic member 19a is constrained. The direction of rotation of the detection member 16a with respect to the catch member 13a is represented by an arrow R1 in FIG. 12.

For example, the rotation of the first detecting member 16a is stopped when the corresponding secondary end of the first detecting member 16a rests on the second zone of the tongue 20a or when the lug 26a bears on the edge 33a ( opposite the edge 32a) of the notch 27a of the catch member 13a, as illustrated in FIG. 12.

It will be noted that during this phase, the first catch member 13a is held in abutment on the fixed cover 6 by the first diaphragm 9a. It is immobilized in rotation relative to the fixed cover 6.

During the next disengaging phase, the first diaphragm 9a transfers its support from the first catch member 13a to the first detection member 16a. This moment is also called tipping point. Figures 13 to 16 are views illustrating the positions of these elements during such a transfer. During such disengagement, the first pressure plate 3a is spaced from the reaction plate 4 by means of the corresponding return tongues 8a, so as to release the first friction disk 5a.

As illustrated in FIGS. 13 and 14, when the first diaphragm 9a is in the fully disengaged position, it completely releases the first catch member 13a. In this position, the first detection member 16a is held fixed in rotation by pressing on the first diaphragm 9a and on the fixed cover 6. Furthermore, the head 23a of the stopper 21a is spaced from the bottom surface of the counterbore 24 of the movable cover 7 and the second zone of the movable tab 20a is spaced apart by a clearance j2 with respect to the corresponding secondary end of the first catch member 13a.

The first catch member 13a, constrained by the second elastic member 19a, is rotated as shown in Figures 15 and 16, so as to fill all or part of the game J2 between said first catch member 13a and the tongue 20a. The direction of rotation of the catch member 13a with respect to the detection member 16a is represented by an arrow R2 in FIG.

For example, the rotation of the first catch member 13a is stopped when the corresponding secondary end of the first catch member 13a comes to bear again on the second zone of the tongue 20a or when the edge 32a of the notch 27a of the catch member 13a bears on lug 26a, as illustrated in FIG.

The pivoting of the first catch member 13a and the first sensing member 16a relative to the fixed cover 6 allows, via the ramps 14a, 17a and against the ramp 15a, to increase the axial distance between the fixed cover 6 and the bearing area of the first diaphragm 9a on said members 13a, 16a, which makes it possible to progressively compensate for the wear of the linings of the first friction disc 5a and / or the wear of the counter-materials of the first pressure plate 3a and reaction plate 4.

Such a structure makes it possible to maintain the initial position of the stop.

According to the invention, a movable or adjustable abutment portion 34 is mounted on the tab 26a, the position of said abutment portion 34 being adjustable or adjusted as needed, so as to adjust precisely the position, along the X axis, of the end 13'a of the catch member 13a with respect to the end 16'a of the detection member 16a. In this way, it is possible to precisely adjust the position along the X axis of the radially inner periphery of the first diaphragm 9a, and thus also the position of the corresponding clutch abutment, in particular at the moment of tilting of the first diaphragm 9a of the catch member 13a to the detection member 16a, or vice versa.

The movable abutment portion 34 may be formed by a screw, as shown in Figure 17. The screw 34 comprises a head 35 intended to abut against the corresponding edge of the notch 27a of the catch member 13a. The screw 34 further comprises a threaded portion 36 engaged in a tapping of the tab 26a. The rotation of the screw 34 thus makes it possible to adjust the position of the head 35.

According to another embodiment illustrated in Figure 18, the movable abutment portion is formed by a shim 34 having two branches 37 located on either side of the tab 26a. Said tab 26a further comprises an oblong hole 38. A screw 39 is engaged in the branches 37 and in the oblong hole 38. The wedge 34 further comprises a head 40, intended to bear on the corresponding edge of the notch 27a of the catch member 13a. The position of the head 40 relative to the tab 26a can thus be adjusted by moving the shim 34 and by moving the screw 39 in the slot 38. Once the correct position is set, the shim 34 can be immobilized in position on the lug 26a, by tightening the screw 39, the branches 37 then pinching the tab 26a.

According to another embodiment illustrated in Figure 19, the movable abutment portion is a cam 34 adapted to pivot on the tab 26a, about an axis formed for example by a pin 41 engaged in the tab 26a. The pivoting of the cam 34 makes it possible to vary the distance between the axis of the pin 41 and the outer surface of the cam, intended to bear against the corresponding edge of the notch 27a of the catching 13a. As before, the cam 34 can be immobilized in rotation once the correct position has been set.

To make such an adjustment, the distance along the X axis between the ends 13'a and 16'a can be measured and then the movable stop portion 34 can be moved in the circumferential direction by a distance a, in order to adjust the desired distance (Figure 20).

It will be noted that, because of the presence of the ramps 14a, 17a and against the ramp 15a, there is a reduction effect between the displacement a of the movable member and the displacement b of the end 13'a relative at the end 16'a, along the X axis. For example, for an angle a of the ramps 14a, 17a and the counter ramp 15a of the order of 5.5 °, a displacement a of the stop generates a displacement b which is equal to one-tenth of the displacement a. It is therefore understood that it is possible to finely adjust the displacement b, that is to say the position of the end 13'a with respect to the end 16'a, so as to control in particular the axial position the radially inner periphery of the diaphragm 9a and the corresponding clutch abutment.

In order to compensate for the wear of the second friction disk 5b, the second pressure plate 3b and / or the reaction plate 4, the second clutch 2b is equipped with second means of catching up and detecting wear.

The second catch-up and wear detection means equipping the second clutch 2b are interposed axially between the second diaphragm 9b and the second pressure plate 3b.

The second catch-up and wear detection means comprise a second mobile catch-up member 13b in the form of a ring having one end against which the second diaphragm 9b is able to bear, and an end comprising at least a ramp 14b extending circumferentially, cooperating with an associated counterbeam 15b formed directly on the second pressure plate 3b. The second catch-up and wear detection means also comprise a second mobile detection member 16b in the form of a ring having one end against which the second diaphragm 9b is able to come into abutment, and an end comprising minus a ramp 17b extending circumferentially cooperating with the counter-ramp 15b of the second pressure plate 3b.

By way of example, the angle of the ramps 14b, 17b of said movable members 13b, 16b and of the counter-ramp 15b of the second pressure plate 3b is between 2 and 20 °.

The two movable members 13b, 16b are concentric and separated from each other for example by centering and spacing pins. In the embodiment shown in the figures, the second mobile detection member 16b is located radially outside the second corresponding mobile retraction member 13b. Alternatively, the respective positions of said movable members 13b, 16b can be reversed, depending on the architecture of the device 1.

A first circumferentially extending first tension spring 18b is mounted between the second sensing member 16b and the second pressure plate 3b.

A second spring, such as for example a pin-shaped spring 19b, is mounted between the second detection member 16b and the second catch member 13b.

The length of the first spring 18b is important, so as to be able to bias the displacement of the second detection member 16b over a wide angular range (for example between 30 ° and 120 °).

The second clutch 2b also comprises at least one second pressing member 20b in the form of an elastic tongue exerting an axial force. Said tongue 20b is fixed to the pressure plate 3b at a first end and bears, at a second end, on the corresponding secondary end of the second detection 16b and possibly on the second wear compensating member 13b, so as to constrain bearing on the second pressure plate 3b. Thus, in particular, there may be an axial clearance between the second pressing member 20b and the corresponding secondary end of the second wear-catching member 13b, even though the second pressing member 20b bears on the end corresponding secondary of the second sensing member 16b.

An abutment stud 21b is fixed on the second end of said tongue 20b. The stop stud 21b has a cylindrical end 23b forming an enlarged head of larger dimension than the rest of the pad 21b and defining a shoulder.

The second catch-up and wear detection means may also comprise a movable stop portion 34 that can be moved and can be adjusted or adjusted as needed to accurately adjust the position, along the X axis, of the end 13'b of the catch member 13b with respect to the end 16'b of the detection member 16b. In this way, it is possible to precisely adjust the position along the X axis of the radially inner periphery of the second diaphragm 9b.

It should be noted that the invention is also applicable to clutches of normally closed type. The invention is also applicable to clutches of normally open type, for hybrid applications in particular.

Claims

1. Clutch device (1) with wear-compensating, in particular for a motor vehicle, comprising:

a reaction plate (4) intended to be coupled in rotation to a driving shaft, around an axis of rotation (X),

a friction disc (5a) intended to be coupled to a driven shaft,

a pressure plate (3a) actuated by a diaphragm (9a) so as to clamp or release the friction disc (5a) on the reaction plate (4),

a cover (6),

means for detecting and compensating for wear, able to make up for the wear of the friction disc (5a), the means for detecting and compensating for wear being mounted between the diaphragm (9a) and the cover (6) or between the diaphragm (9b) and the pressure plate (3b) and comprising:

wear compensating means comprising at least one catching member (13a) movable in a determined range and comprising a ramp (14a) cooperating with a counter ramp (15a) integral with the cover (6) or the pressure plate ( 3b), so as to adjust the distance between the diaphragm (9a) and the cover (6) or between the diaphragm (9a) and the pressure plate (3a) and compensate for the corresponding wear as a function of the position of the ramp (14a) with respect to the counter ramp (15a),

wear detection means adapted to allow the displacement of said catch member (13a) in case of wear and able to prevent such displacement when this wear is not sufficient, said detection means comprising at least one member detecting device (16a), in a determined range, with respect to the catching member (13a) and comprising a ramp (17a) co-operating with a against-ramp (15a) secured to the lid (6) or the pressure plate (3a),

the sensing member (16a) and the catching member (13a) having stop means (34) adapted to limit the relative displacement of the catch member (13a) relative to the sensing member (16a). ), characterized in that the abutment means comprise an abutment portion (34) movable or adjustable relative to the detecting member (16a) or relative to the adjuster (13a), the displacement of the part movable stop (34) for adjusting the displacement along the axis of rotation (X) of an end (13'a) of the catch member (13a) adapted to serve to support the diaphragm (9a ) relative to an end (1 6'a) of the detection member (16a) adapted to serve to support the diaphragm (9a).

2. Device according to claim 1, characterized in that the movable abutment portion (34) comprises a threaded portion (36), engaged in a threaded portion of the detecting member (16a) or the catch member ( 13a).

3. Device according to claim 2, characterized in that the movable stop portion (34) comprises a screw whose threaded portion (36) is engaged in a threaded portion (26a) integral with the detection member (16a) or of the retraction member (13a) and whose head (35) is able to bear on an abutment surface complementary to the retraction member (13a) or the detecting member (16a) respectively.

4. Device according to claim 1 or 2, characterized in that the movable stop portion (34) is adapted to be immobilized in position by means of a locking member (39).

5. Device according to claim 4, characterized in that the movable abutment portion (34) comprises an axis (39) engaged in an oblong hole (38) of the detection member (16a) or the catch-up member. (13a).

6. Device according to one of claims 1 to 4, characterized in that the movable stop portion (34) comprises a cam adapted to pivot relative to the detection member (16a) or relative to the body of catching up (13a).

7. Device (1) according to one of claims 1 to 6, characterized in that it comprises at least one pressing member (20a) for constraining at least the ramp (17a) of the detection member (16a) against the associated counterbeam (15a), the pressing member (20a) being adapted to cooperate with a fixed stop (7b) so as to release the detection member (16a) when wear is detected,

the catching member (13a) being urged to move when said catch member (13a) is released by the diaphragm (9a),

the sensing member (16a) being biased to move and catch, at least in part, the play (j1) between the latter and the pressing member (20a), when said sensing member (16a) is released by the pressing member (20a) and the diaphragm (9a).

8. Device (1) according to one of claims 1 to 7, characterized in that the diaphragm (9a) releases the sensing member (16a) and prevents the displacement of the catch member (13a) in position fully engaged, and in that the diaphragm (9a) releases the retraction member (13a) and prevents the displacement of the detecting member (16a), in the fully disengaged position, the diaphragm (9a) always bearing on at least one of said members (13a, 16a) between its fully engaged positions and fully disengaged.

9. Device (1) according to one of claims 1 to 8, characterized in that the catching member (13a) comprises an end (13'a) adapted to serve to support the diaphragm (9a) and a end comprising at least one ramp (14a), cooperating with the counter-ramp (15a) associated with the cover (6) or the pressure plate (3a).