FR3038949A1 - DOUBLE CLUTCH, IN PARTICULAR FOR MOTOR VEHICLE - Google Patents

Abstract

The invention relates to a double clutch (1), particularly for a motor vehicle, comprising at least one reaction plate (3) designed to be coupled in rotation to a driving shaft, a first and a second friction disk (4, 27). , respectively for coupling to first and second driven shafts, first and second pressure plates (2, 26) respectively actuated by a first and a second diaphragm (22, 32) so as to clamp or release the first and second friction discs (4, 27) on the reaction plate (3), respectively during clutching and disengaging phases, the first pressure plate (2) being fixedly connected to a movable cover in translation by relative to the reaction plate (3), and being actuated by pressing the first diaphragm (22) on the movable lid, a cover (5) fixed with respect to the reaction plate (3).

Description

The present invention relates to a double clutch, in particular for a motor vehicle.

A double clutch enables the motor shaft of the vehicle to be coupled alternately with two coaxial input shafts of a gearbox, which may 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 with the rotation of 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.

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 integral in rotation with the motor shaft. Thus, the clamping of a friction disc between the corresponding pressure and reaction plates allows the transmission of a torque between the motor shaft and the associated shaft of the gearbox.

Patent FR 3 000 152, in the name of the Applicant, discloses a double clutch comprising a central reaction plate, attached to a cover, hereinafter referred to as a fixed cover. Furthermore, the pressure plate associated with the first clutch is attached to a movable cover, the associated diaphragm moving said pressure plate through the movable cover.

In this document, the two clutches are of the normally open type, that is to say are open in the absence of action exerted by the clutch abutment on the corresponding diaphragms.

In a double clutch having such a structure, it is important to control the position of the pressure plates relative to the fixed cover, so as to avoid any interference or contact between them, in particular in case of wear of the friction disc linings. associated with the first clutch.

The axial position of the pressure trays is currently dependent on the dimensional tolerances of manufacture and assembly of the parts in the concerned dimension chain, namely the clutch abutment, the diaphragm, the movable cover, the pressure plates, the disks of friction and the reaction plateau. The axial position of the pressure plates is also dependent on the wear of the friction liners, the pressure plates and the reaction plate. The elements inducing a great uncertainty in terms of positioning are in particular the clutch abutment and the diaphragm of the first clutch.

It is therefore difficult to know and accurately limit the position of the pressure plates relative to the reaction plate, because of the large number of uncertainties from the side chain.

Moreover, it will be noted that the limitation of the displacement of one of the pressure plates also makes it possible to limit the deflection of the associated diaphragm. Axially limiting the travel of the clutch actuator. The space available for the travel of the actuator must indeed be limited when it is desired to reduce the size of the transmission. The invention aims in particular to provide a simple, effective and economical solution to these problems. For this purpose, it proposes a double clutch, in particular for a motor vehicle, comprising - at least one 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 first and second driven shafts; 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 discs on the reaction plate, respectively when clutch and disengage phases, the first pressure plate being fixedly connected to a cover movable in translation relative to the reaction plate, and being actuated by pressing the first diaphragm on the movable lid, - a fixed cover relative to the plate reaction device, characterized in that: - the first pressure plate and the reaction plate comprise stop means capable of limiting the e axial displacement of the first pressure plate and the movable lid relative to the reaction plate and the fixed cover during the clutch phase, and / or - the second pressure plate and the reaction plate comprise suitable abutment means to limit the axial displacement of the second pressure plate relative to the reaction plate during the clutch phase.

The abutment means preferably form a direct axial support, that is to say without intermediate element, of the first pressure plate on the reaction plate.

In this way, in the engaged position, the position of the first pressure plate and / or the second pressure plate can be limited with respect to the reaction plate in case of wear of the friction linings, by means of the abutment means. . It is then easier to determine precisely the positions of said pressure plates, so as to reduce their movement to a minimum. This avoids any risk of interference in case of significant wear of the lining of the first friction disc and / or the second friction disc.

In addition, the first pressure plate and / or the second pressure plate may comprise an annular friction portion intended to support the corresponding friction disc in the engaged position, at least one stop lug extending radially towards the outside from the friction portion of the first pressure plate and / or the second pressure plate, said abutment lug having an abutment surface adapted to bear on an abutment surface complementary to the reaction plate.

The stop lug extending radially outwardly from the friction portion of the first pressure plate and / or the second pressure plate may have at least one bearing boss extending axially towards the reaction plate.

The reaction plate may comprise an annular friction portion intended to support the first friction disc and / or the second friction disc in the engaged position, at least one stop tab extending radially outwardly from the portion friction of the reaction plate, said abutment lug of the reaction plate having the complementary abutment surface.

The stop tab extending radially outwardly from the friction portion of the reaction plate may comprise at least one bearing boss extending axially towards the first pressure plate and / or the second reaction plate.

Furthermore, the first pressure plate, the second pressure plate and / or the reaction plate may comprise fixing lugs for fixing the mobile cover to the first pressure plate, the fixing of elastic tongues connecting the first plate of the pressure plate. pressure and / or the second pressure plate and the reaction plate, and / or the attachment of the reaction plate to the fixed cover.

In this case, at least one stop lug of the reaction plate may be merged with at least one lug of the reaction plate, said lug comprising an abutment zone forming said complementary abutment surface and a second attachment zone to which the fixed cover and / or at least one resilient tongue is fixed.

This limits the number of legs of the reaction plate.

The stop tabs of the first pressure plate and / or the second pressure plate can be distinct from the brackets of the corresponding pressure plate.

The stop tabs can be angularly distributed around the axis of rotation X.

The dual clutch may comprise a single reaction plate, arranged axially between the first and second friction discs.

Of course, the double clutch may comprise two separate reaction plates, each reaction plate being associated with one of the pressure plates.

In addition, the fixed cover may have a general bell shape, the second pressure plate, the second friction disc and the second diaphragm being housed, at least in part, in the fixed cover.

Preferably, each clutch is of the normally open type. The invention will be better understood and other details, features and advantages of the invention will become apparent on reading the following description given by way of non-limiting example with reference to the accompanying drawings, in which: FIG. 1 is a view in perspective, from the front, the double clutch according to one embodiment of the invention, - Figure 2 is a perspective view, from the rear, of the double clutch, - Figure 3 is a side view of the double clutch, - Figures 4 and 5 are half-views in axial section of the double clutch, - Figure 6 is an exploded view, in perspective and from the front, of the reaction plate and pressure plates, - the Figure 7 is an exploded view, in perspective and from the rear, of the reaction plate and the pressure plates.

Figures 1 to 7 show a double clutch 1, in particular for a motor vehicle, according to one embodiment of the invention. The dual clutch is for coupling a motor with first and second input shafts of a gearbox. The double clutch 1 comprises first and second gearshift clutches of different ratios. The clutch 1 rotates about the axis of rotation X.

The first clutch comprises a first pressure plate 2 and a reaction plate 3 between which a first friction disc 4 extends. The first pressure plate 2 is rotatably coupled to the reaction plate 3 and is movable in translation relative to to it, between an engaged position and a disengaged position, in which it clamps the first friction disc 4 on the reaction plate 3, or respectively releases the first friction disc 4.

The reaction plate 3 is fixed on a cover 5, called fixed cover, coupled to the motor shaft.

More particularly, as is best seen in Figures 6 and 7, and the reaction plate 3 comprises an annular portion having two opposed radial friction faces 6, 7, respectively facing forwards and backwards and intended respectively to the support of the corresponding friction discs. Tabs 8 extend from the radially outer periphery of the annular portion. In particular, the reaction plate 3 comprises tabs 8 for mounting the reaction plate 3 on the cover 5 and the mounting of resilient tongues 10, 11 (Figures 1 to 5), by means of rivets. For this, said tabs 8 comprise a zone (FIGS. 6, 7) comprising holes 12 for the passage of the corresponding rivets. Said tabs 8 further comprise radial abutment or bearing surfaces 13 facing rearward, in a different zone.

In addition, tabs 9 extend from the radially outer periphery of the annular portion, said tabs 9 having radial abutment or bearing surfaces 14 facing forward.

The first friction disc 4 is coupled to the first input shaft of the gearbox, the reaction plate 3 and the first pressure plate 2 being rotatably coupled to the drive shaft. Thus, in the engaged position of the first clutch, the motor shaft is coupled to the first input shaft of the gearbox.

The first pressure plate 2 comprises an annular portion comprising a radial friction surface 15 facing forward, intended to support the first friction disk 4. Tabs 16 extend radially outwardly from the annular portion , said tabs 16 for fixing the resilient tongues 10 and a movable cover 18, by means of rivets. Said tongues 10 make it possible to couple in rotation the reaction plate 3 and the first pressure plate 2, while allowing the first pressure plate 2 to move axially relative to the reaction plate 3. Said tongues 10 form elastic return means tending to return the first pressure plate 2 in its disengaged position.

Furthermore, tabs 17 extend radially outwardly from the annular portion of the first pressure plate 2, said tabs 17 having radial abutment surfaces 19 facing forward, able to bear on the surfaces of radial stops 13 of the lugs 8 of the reaction plate 3, in the engaged position of the first clutch.

Optionally, the abutment lugs 17 comprise a bearing boss extending axially towards the reaction plate 3.

The first pressure plate 2 is fixed on the movable lid 18, which can thus be moved axially relative to the reaction plate 3 and the fixed lid 5. The mobile lid 18 comprises a portion 20 extend axially towards the before, extended by an annular portion 21 extend radially inwardly.

A first diaphragm 22 is pivotally mounted on the fixed cover 5, by means of rivets 23 ensuring the centering of said diaphragm 22 while allowing it to tilt. The first diaphragm 22 is in the form of an elastic annular sheet bearing on an area 24 of the fixed cover 5, the first diaphragm 22 tilting around this bearing zone 24 (Figure 5).

The control of the first clutch is conventionally done by means of a first clutch abutment (not shown) cooperating with the radially inner periphery of the first diaphragm 22. The first diaphragm 22 forms a lever transmitting the force applied by the first abutment. clutch to the first pressure plate 2, via the movable cover 18.

In order to allow effective clamping of the first friction disc 4, the first diaphragm 22 is pre-loaded at rest. When the first clutch abutment is actuated, it balances the pre-charge of the first diaphragm 22 before starting the tightening of the first friction disc 4.

The first clutch is of the normally open type. The rest position of the first diaphragm therefore corresponds to a disengaged state of the first clutch. The first diaphragm 22 preferably has a portion of the Belleville washer type for returning the first diaphragm to its rest position.

In the rest position of the first diaphragm 22, that is to say when the first abutment exerts a zero or low force on the first diaphragm 22, the first diaphragm 22 thus exerts a zero or low force on the first pressure plate 2 The first pressure plate 2 is separated from the reaction plate 3 by means of the elastic tongues 10, so as to release the first friction disc 4.

During the clutching phase, the first pressure plate 2 is brought closer to the reaction plate 3. If the wear of the friction linings 4 'of the first friction disk 4 is too great, the abutment surfaces 19 of the first plate pressure then come to bear on the corresponding abutment surfaces 13 of the reaction plate 3, so as to limit the approach of the first pressure plate 2 and the reaction plate 3, thus avoiding any risk of interference. Such abutment means also make it possible to accurately control the maximum wear of the linings 4 'of the first friction disc 4.

The second clutch comprises a second pressure plate 26, and a second friction disc 27 extending radially between the reaction plate 3 and the second pressure plate 26. The same reaction plate 3 is thus used for the two clutches, each friction disc 4, 27 being disposed on the side of one of the two radial bearing surfaces 6, 7 of the reaction plate 3. The second pressure plate 26 is rotatably coupled to the reaction plate 3 and is movable in translation thereof, between an engaged position and a disengaged position, in which it closes the second friction disc 27 on the reaction plate 3, respectively releases the second friction disc 27.

The second friction disc 27 is coupled to the second input shaft of the gearbox. Thus, in the engaged position of the second clutch, the motor shaft is coupled to the second input shaft of the gearbox.

The second pressure plate 26 has an annular portion comprising a rearwardly facing radial friction surface 28 for supporting the second friction disk 27. Tabs 29 extend radially outwardly from the annular portion , said tabs 29 for fixing the resilient tongues 11, by means of rivets. Said tongues 11 make it possible to couple in rotation the reaction plate 3 and the second pressure plate 26, while permitting the axial displacement of the second pressure plate 26 with respect to the reaction plate 3. Said tongues 11 form elastic return means tending to return the second pressure plate 26 in its disengaged position.

Furthermore, lugs 30 extend radially outwardly from the annular portion of the second pressure plate 26, said lugs 30 having radial abutment surfaces 31 facing rearwardly, able to bear on the surfaces of the radial stops 14 of the lugs 9 of the reaction plate 3, in the engaged position of the second clutch.

Optionally, the stop tabs 30 comprise a bearing boss extending axially towards the reaction plate 3.

Furthermore, optionally, the lugs 8 may also include at least one bearing boss extending axially towards the first pressure plate 2 and / or the second pressure plate 26.

A second diaphragm 32 is pivotally mounted on the fixed cover 5, by means of rivets ensuring the centering of said diaphragm 32 while allowing it to tilt. The second diaphragm 32 is, as before, in the form of an elastic annular plate bearing on the fixed lid 5 at a bearing zone 33, the second diaphragm 32 thus pivoting around this bearing zone 33 (Figures 4 and 5).

The control of the second clutch is conventionally done by means of a second clutch abutment (not shown) cooperating with the radially inner periphery of the second diaphragm 32, via a force transmission member. The second diaphragm 32 forms a lever transmitting the force applied by the second clutch abutment to the second pressure plate 26, to allow effective clamping of the second friction disc 27.

A support washer 34, fixed on the fixed cover 5 by means of rivets, comes to press and hold in position the radially outer periphery of the second diaphragm 32 against the bearing zone 33.

The second clutch is also of the normally open type. In the rest position of the second diaphragm 32, that is to say when the second clutch abutment exerts a zero or low force on the second diaphragm 32, the second diaphragm 32 exerts a zero or low force on the second plate of pressure 26. The second pressure plate 26 is separated from the reaction plate 3 by means of the elastic tongues 11, so as to release the second friction disk 27. The second diaphragm 32, the second pressure plate 26 and the second friction disc 27 are housed in the fixed cover 5. The fixed cover 5 comprises, from the rear to the front, radial flanges 35 for attachment to the reaction plate 3, connected to an annular portion 36 surrounding the aforementioned elements of the second clutch, itself extended by an annular portion 37 extending radially inwards and carrying the bearing zones 24, 33 of the diaphragms 22, 32

During the clutching phase, the second pressure plate 26 is brought closer to the reaction plate 3. If the friction lining 27 'of the second friction disk 27 is too large, the abutment surfaces 31 of the second plate pressure 26 then bear against the corresponding abutment surfaces 14 of the reaction plate 3, so as to limit the approach of the second pressure plate 26 and the reaction plate 3. Such abutment means make it possible in particular to control with precision the maximum wear of the liners 27 'of the second friction disc 27.

Claims (11)

1. Double clutch (1), especially for a motor vehicle, comprising - at least one reaction plate (3) intended to be coupled in rotation to a driving shaft, - first and second friction discs (4, 27), for coupling to first and second driven shafts respectively, first and second pressure plates (2, 26) respectively actuated by a first and a second diaphragm (22, 32) so as to clamp or release the first and second friction discs (4, 27) on the reaction plate (3), respectively during clutching and disengaging phases, the first pressure plate (2) being fixedly connected to a movable cover (18) in translation with respect to the reaction plate (3), and being actuated by pressing the first diaphragm (22) on the movable cover (18), - a cover (5) fixed with respect to the reaction plate (3), characterized in what: - the first pressure plate (2) and the reaction plate ion (3) comprise stop means (13, 19) able to limit the axial displacement of the first pressure plate (2) and the movable cover (18) with respect to the reaction plate (3) and the fixed cover (5). ) during the clutching phase, and / or - the second pressure plate (26) and the reaction plate (3) comprise stop means (14, 31) able to limit the axial displacement of the second pressure plate (26) relative to the reaction plate (3) during the clutch phase. 2. Double clutch (1) according to claim 1, characterized in that the abutment means (13, 19) form a direct axial support of the corresponding pressure plate (2, 26) on the reaction plate (3). 3. Double clutch (1) according to claim 1 or 2, characterized in that the first pressure plate (2) and / or the second pressure plate (26) comprise an annular friction portion intended to support the disk. corresponding friction (4, 27) in the engaged position, at least one stop lug (17, 30) extending radially outwardly from the friction portion of the first pressure plate (2) and / or the second plate pressure device (26), said abutment lug (17, 30) having an abutment surface (19, 31) adapted to bear on a complementary abutment surface (13, 14) of the reaction plate (3). 4. Double clutch (1) according to claim 3, characterized in that the stop lug (17, 30) extending radially outwardly from the friction portion of the first pressure plate (2) and / or the second pressure plate (26) has at least one bearing boss extending axially towards the reaction plate (3). 5. Double clutch (1) according to one of claims 3 or 4, characterized in that the reaction plate (3) comprises an annular friction portion intended to support the first friction disc (4) and / or of the second friction disc (27) in the engaged position, at least one abutment lug (8, 9) extending radially outwardly from the friction portion of the reaction plate (3), said abutment lug (8). 9) of the reaction plate (3) having the complementary abutment surface (13, 14). 6. Double clutch (1) according to claim 5, characterized in that the stop lug (8, 9) extending radially outwardly from the friction portion of the reaction plate (3) comprises at least one boss bearing axially extending towards the first pressure plate (2) and / or the second reaction plate (26). Double clutch (1) according to one of Claims 1 to 6, characterized in that the first pressure plate (2), the second pressure plate (26) and / or the reaction plate (3) comprise fastening tabs (8, 16, 29) for: - fixing the movable cover (18) on the first pressure plate (2), and / or - fixing elastic tongues (10, 11) connecting the first plate of pressure (2) and / or the second pressure plate (26), on the one hand, and the reaction plate (3), on the other hand, and / or - the attachment of the reaction plate (3) to the lid fixed (5). 8. Double clutch (1) according to claims 5 to 7, characterized in that at least one abutment lug (8, 9) of the reaction plate (3) coincides with at least one bracket (8) of the reaction plate (3), said tab (8) having an abutment zone forming said complementary abutment surface (13) and a second attachment zone to which the fixed cover (5) or at least one resilient tongue (10) is fixed. , 11). 9. Double clutch (1) according to claims 3 and 7, characterized in that the stop tabs (17, 30) of the first pressure plate (2) and / or the second pressure plate (26) are separate legs securing (16, 29) the corresponding pressure plate (2, 26). 10. Double clutch (1) according to one of claims 1 to 9, characterized in that it comprises a single reaction plate (3) disposed axially between the first and second friction discs (4, 27)). 11. Double clutch (1) according to one of claims 1 to 10, characterized in that the fixed cover (5) has a generally bell-shaped, the second pressure plate (26), the second friction disk (27). ) and the second diaphragm (32) being housed, at least in part, in the fixed cover (5).