FR2764655A1 - Standard clutch mechanism for motor vehicles - Google Patents

Abstract

The mechanism contains a reaction plate (2), a cover (3) with a bottom piece (4) for fixing the clutch mechanism (1) onto the reaction plate (2), and a diaphragm reaction plate (5,6) for clutching and de-clutching the mechanism. There is a pressure plate (7) with a rear face (70) containing a projecting annular rim (8) divided into reaction sectors (80,81) and tongues (9) axially elastic for joining in rotation the cover (3) to the pressure plate (7). Each of the elastic tongues (9) extensions in the form of fixing pieces (19), are fixed by moulding onto or hooked onto at least one of the reaction sectors (80,81).

Description

 The present invention relates to a clutch mechanism for a clutch comprising a reaction plate, in particular for a motor vehicle, comprising a cover with a bottom for fixing the clutch mechanism to the reaction plate of the clutch, engagement means. with axial action bearing on the bottom of the cover, declutching means associated with the clutch means to counteract at will the action of the latter, a pressure plate with a dorsal face provided, in axial projection directed towards the bottom of the cover, an annular bead divided into a support sector for support of the engagement means urging the pressure plate in the direction opposite to the bottom of the cover, axially elastic and circumferentially acting tabs intervening between the cover and the pressure plate to link in rotation the pressure plate to the cover while allowing axial movement of the pressure plate relative to the cover key. Usually the pressure plate, made of moldable material, has radially projecting tabs at its outer periphery for fixing the tongues.

 As a result, the pressure plate does not have an annular shape.

 In order to remedy this drawback, one can then consider using a solution of the type described in document GB-A-2 176 549.

 In the latter, the tongues are fixed, on the one hand, by riveting to a ring interposed between the diaphragm and the pressure plate and, on the other hand, by means of pins supported on the pressure plate.

 To do this, the ring is fixed with lugs to the cover and the pressure plate has blind holes for mounting the pins.

 At the locations of the holes, the pressure plate is locally reduced in thickness, a lesser thickness of material existing between the bottom of the holes and the front face of the pressure plate, forming a friction face for a friction disc intended to be tightened. between the pressure and reaction plates under the action of the engaging means most often consisting of a diaphragm.

 This local reduction in thickness can be annoying from the thermal point of view, the tray plate, following heating in service not behaving in the same way at these locations.

 The object of the present invention is to overcome this drawback in a simple and economical manner, while having a pressure plate of annular shape.

 According to the invention a clutch mechanism of the above-mentioned type, is characterized in that the elastic tongues each form the extension of a fixing part fixed by overmolding or stapling on at least one support sector.

 Thus the pressure plate can be of annular shape and is devoid of holes for members for fixing the tongues, which simplifies the manufacture of said plate. Furthermore, the fastening of the fixing piece to the support sector or sectors is easy to carry out since the fixing piece is in one piece with its associated tongue and therefore has the same thickness as the latter, it that is to say a small thickness.

 This stapling is quick and can be done with simple shaped tools. Overmolding is easy to carry out because the pressure plate is made of moldable material. The pressure plate has a uniform thickness and behaves better when it is heated. It can rotate at a higher rotational speed thanks to its annular shape.

 Thanks to the invention, the number of parts is reduced since the fixing members are eliminated. There are therefore fewer parts to store for the manufacture of the clutch mechanism. In addition, the support sectors are used to carry out the fixing and this in an economical manner.

 The fixing is robust because the support sectors are large.

 Advantageously, the fixing piece comprises at least one coupling lug extending between a first support sector and a second consecutive support sector. This coupling tab is extended at one of its ends by the tongue concerned and at the other of its ends by at least one fixing sector engaged with at least one of the first and second support sectors. The fixing sector also belongs to the fixing part.

 Thus in a first embodiment, the attachment sectors can extend radially below the support sectors and the tongues radially above the support sectors.

 The tongues in a second embodiment extend radially below the support sectors as well as the fixing sectors.

 The coupling lugs are inclined in the axial direction, towards the bottom of the cover, to allow an axial displacement of the pressure plate and fix the tabs to the cover. These coupling lugs make it possible to link the fixing part to the pressure plate in rotation.

 In the first embodiment, the cover has a radial rim at its outer periphery for fixing the tabs.

 In the second embodiment, the tongues are fixed to small columns integral with the cover and forming a secondary tilting support for a diaphragm belonging to the engagement means.

 As a variant, the columns are simple columns alternating with the columns forming the secondary support.

 Advantageously, the tongues belong to a single and same piece in the form of a fixing washer in one piece with the coupling lugs and the tongues.

 In all cases, the fixing piece at the same thickness as the tabs, so that the tabs can easily be superimposed to transmit the required torque.

 In another embodiment, the fixing piece comprises at least one mortise in which a bearing sector forming a tenon engages for fixing by stapling the fixing piece to the pressure plate. This is achieved by threading mortises on the posts.

 Advantageously, the fixing part is fixed by snap-fastening on the support sectors.

 In one embodiment, the support sectors each have a groove (or groove) in which the fastening part engages by snap-fastening, which is thus wedged axially on the pressure plate. As a variant, only part of the support sectors each have a groove.

 This is easy to achieve, the grooves having come from molding or turning with the pressure plate.

 Advantageously, the fixing piece is attached to the dorsal face of the pressure plate for good ventilation.

 The solution according to the invention is therefore compact axially.

Other advantages will emerge in the light of the description which follows with reference to the appended drawings in which:
- Figure 1 is a partial half-sectional view of a clutch equipped with the clutch mechanism according to the invention;
- Figure 2 is a front view of the tab pressure plate assembly according to arrow 2 in Figure 1;
- Figure 3 is a partial view showing the attachment of the mechanism of Figure 1 on the clutch reaction plate;
- Figure 4 is a partial view showing the mounting of one of the fixing parts
- Figures 5 and 6 are views similar to Figures 1 and 2 of the clutch mechanism alone for a second embodiment;
- Figure 7 is a partial view similar to Figure 2 for a third embodiment.

 The clutch mechanism 1, illustrated in FIGS. 1 to 4, forms a unitary assembly belonging to a clutch of a motor vehicle comprising a reaction plate 2.

 The clutch mechanism 1 comprises a cover 3 with a bottom 4 for fixing the clutch mechanism 1 to the reaction plate 2 of the clutch, clutch means 5 with axial action resting on the bottom 4 of the cover, declutching means 6 associated with declutching means 5 to counteract at will the action of these, a pressure plate 7 with a dorsal face 70 provided, in axial projection, directed towards the bottom 4 of the cover 3, with an annular bead 8 divided into support sectors 80.81 ... for support of the engagement means 5 urging the pressure plate 7 in the direction opposite to the bottom 4 of the cover 3, tongues 9 axially elastic and with circumferential action intervening between the cover 3 and the pressure plate 7 for rotationally linking the pressure plate 7 to the cover 3 while allowing axial movement of the pressure plate 7 relative to the cover 8.

 The support sectors 80, 81 ... therefore have an annular shape with here lateral edges inclined in the same direction, each with respect to a radial direction.

The internal periphery 96 of each sector 80, 81 ... is therefore circumferentially in the form of an arc of a circle. Axially this periphery 96 is inclined for reasons of demolding.

 According to the invention the pressure plate 7 has an annular shape and is made of moldable material, here cast iron, in an aluminum-based variant.

 In these Figures 1 to 4, the cover 3 is plate-shaped and has at its outer periphery, a radial flange 35,36 for fixing the cover 3 on the reaction plate 2 of the clutch which, as we as is known, in a motor vehicle application, is locked in rotation on the crankshaft of the motor vehicle engine.

 The engagement means 5 urge the pressure plate 7 in the direction opposite to the bottom 4 of the cover 3, that is to say towards the reaction plate 2, for tightening the friction disc 10 of the clutch between the pressure plates 7 and reaction 2.

 This friction disc 10 has at its outer periphery friction linings II secured to a support 12 rigidly or resiliently coupled to a hub (not visible) internally grooved for rotationally connecting the friction disc 10 with in this case the input shaft of the gearbox.

 The pressure plate 7 therefore has a front face 71 forming a friction face for one of the friction linings 11, optionally split, while the reaction plate 2 has a friction face for the other friction lining 11 dorsally, knowing that the friction linings II are arranged for attachment on either side of the support 12.

 The engaging means 5 and declutching means 6 here belong to the same annular piece of frustoconical shape in the free state.

 This part 5,6 is called a diaphragm and has a continuous peripheral part 5, in the form of a Belleville washer, extended radially inwards by a central part 6 fragmented into radial fingers by slots.

 These slots are blind and open at their external periphery each in an enlarged orifice 61 located at the internal periphery of the Belleville washer 5.

Internally, these slots open into the central opening of the diaphragm 5,6.

 The Belleville washer 5 has a planar shape when the clutch mechanism is attached to the reaction plate 2.

 This Belleville washer forms the engaging means 5 while the declutching means are constituted by the central part 6 more precisely the radial fingers thereof.

 The external periphery of the Belleville washer 5 is supported on the bead 8 of the pressure plate 7.

 This bead 8 forms a boss projecting axially in the direction of the bottom 4 of the cover 3. The top 180 of the bead 8 and therefore of the sectors 80.81 ... has a pointed shape for local contact with the Belleville washer 5 of the diaphragm 5.6 .

 The clutch is therefore normally engaged - friction linings 11 clamped between the plates 2 and 7 - and to disengage the latter, it is necessary to act on the internal end of the fingers of the diaphragm 5,6, here by pushing, with the using a non-visible clutch release bearing to counteract the load exerted by the Belleville washer 5 on the pressure plate 7.

 During this maneuver the pressure plate 7 is allowed to move axially in the direction of the bottom 4 of the cover 3 under the restoring force exerted by the resilient tongues 9 axially transmitting the engine torque to the pressure plate 7 linked in rotation to the cover 3 via the tabs 9.

 To do this, the diaphragm 5,6 is pivotally mounted on the bottom 4 of the cover 3 using assembly means 30. These assembly means 30 here comprise tabs 32 of axial orientation issued by cutting and folding of the bottom 4 has a hole centrally and generally in transverse orientation. The legs 32 each pass through an enlarged orifice 61 and are folded radially outwards at their free end to form a wedging elbow for a ring ring 34 mounted at its internal periphery on the legs 132 and having at its external periphery a rounded edge for forming a secondary support 33 for the internal periphery of the Belleville washer 5 opposite a primary support 31 formed directly by stamping in the bottom 4.

 In the engaged clutch state, the diaphragm 5,6 is supported on the primary support 31 and is supported on the secondary support 33 when disengaging the clutch.

 The diaphragm 5,6 is therefore tiltably interposed between the supports 31,33 located radially below the bead 8 in contact with the external periphery of the Belleville washer 5.

 Here the cover 3 is attached by screws 37 (FIG. 3) to the reaction plate, more specifically the radial fixing flange 35, 36, which has alternating fixing pads 35, perforated for the passage of the fixing screws 37, of which the head rests on said pad 35, and coupling pads 36 offset axially relative to the fixing pads 35 and this in the direction of the bottom 4 of the cover 3.

 It is on these coupling areas 36, that are fixed, radially beyond the bead 8, the elastic tongues 9 at their free end relative to their other end secured, according to the invention, to a fixing piece 90.

 Fixing members 38, here rivets as a variant of screws, bolts or the like, fix the free ends of the tongues to the coupling areas 36 here extending radially above the diaphragm 5,6 and the bead 8.

 Any other means of fixing the cover to the reaction plate can be envisaged. For example, reference will be made to FIG. 3 of document WO 95/13481 showing a fixing by crimping of the cover 3 to the reaction plate 2.

 We see in this document that the elastic tabs are fixed at their free end to the pressure plate with the aid of fixing members.

 The present invention makes it possible to eliminate such organs.

 More precisely, according to the invention, the axially elastic tongues 9 each form the extension of a fixing piece 19, fixed by overmolding or stapling on at least one support sector 80, 81 ... belonging to the bead 8.

 Here the tongues 9 are of tangential orientation. Of course as a variant, they can be inclined as in FIG. 3 of the aforementioned document WO 95/13481.

 In FIGS. 1 to 6, the tongues 9 all belong to one and the same fixing part 19 comprising a fixing washer 90 and coupling lugs 92.

 The tongues 9 are in one piece with the washer 90 of the same thickness as the tongues.

 The washer 90 extends generally radially below the support sectors 80, 81 distributed regularly circumferentially for the formation of the fractionated annular bead 8.

 A passage 91 therefore exists between two consecutive support sectors. This passage 91 is inclined circumferentially because it is delimited by two inclined lateral edges of two support sectors 80, 81 ... consecutive.

 The tongues 9 form the extension of coupling legs 92 extending between a first support sector 80 and a second support sector 81 consecutive. The legs 92 are therefore inclined circumferentially because they each pass through a passage 91.

 The legs 92 are connected to the washer 90.

 The tabs 92 are inclined axially so that the washer 90 is offset axially with respect to the tongues which are in the plane of the coupling pads 36.

 The washer 90 is attached to the dorsal face 70 of the pressure plate 1.

The support sectors 80,81 - and therefore the bead 8, forming a boss here split, extend in axial projection relative to the dorsal face 70. A groove or groove 93 is formed at the internal periphery of each sector d '' support 80.81. This groove 93 (FIG. 3) is delimited by the dorsal face 70 of the pressure plate 9, by a flank 94 parallel to said face 70, generally of transverse orientation, and by a bottom 95 generally of axial orientation connecting the flank 94 at face 70.

 The groove 93 is therefore blind by being open radially inward.

During assembly, push on the washer 90 using a tool according to the arrow
F in Figure 4.

 The washer 90 tilts in contact with the internal periphery 96 of each sector inclined axially until it penetrates into the groove 93 where it straightens.

 This is allowed because the washer 90 is thin. The fixing washer 90 therefore extends generally below the support sectors 80, 81.

 Here several fastening parts 19 and therefore several washers 90 and tongues 9 are superimposed to transmit the required torque from the cover 3 to the pressure plate 7.

 The number of tabs 9 and washers 90 depends on the applications, knowing that each washer 90 engages with a sector 80.81 ..

 The fastening of the washers 90 and therefore of the fastening parts 19 is therefore by stapling consisting here of a snap-fitting produced in favor of the support sectors 80, 81.

 The legs 92 have a shape complementary to the passages 91 and engage in a complementary manner between two support sectors 80, 81, so that the washer 90 is linked in rotation by cooperation of shapes with the pressure plate 7 thanks to the legs 92.

 Thanks to the grooves 93, the washer 90 is wedged axially in both directions on the pressure plate 7 while being trapped between the sidewall 94 and the dorsal face 70.

 It will be appreciated that the assembly is simple and rapid, the tool pushing the washer 90 in the direction of the dorsal face 70.

 In FIG. 2, the tongues 9 extend radially above the bead 8 (and therefore sectors 80, 81, etc.). The coupling lugs 92 extend radially above the washer 90 and partly radially above the bead 8.

 Of course we can reverse the structures. As visible in FIGS. 5 and 6, the tongues 9 and the tabs 192 for coupling the tongues 9 to the washer 90 extend radially below the washer 90 and the bead 8.

 The free ends of the tongues 192 are fixed by riveting to posts 132 replacing the lugs 32 of FIG. 1.

 The columns 132 therefore each pass axially through an enlarged orifice 61 of the diaphragm and have a profiled head 134 having a bead 133 for forming the secondary support 133 opposite the primary support 31, which may alternatively consist of a rod.

 As in FIG. 2, each washer 90 is snap-fitted into a groove 93.

 The columns 132 have a pin 135 directed axially towards the pressure plate 7 (towards the dorsal face 70 thereof).

 These pins 195 each pass through a hole 98 which each tab 9 has at its free end.

 Then we crush the pins 135 to achieve riveting.

 The legs 192 are inclined axially towards the bottom 4 of the cover 3 from the washer 90.

 In FIG. 1, the legs 91 are inclined axially towards the bottom 4 in the direction of the coupling pads 36.

 Each tab 9 of FIG. 1 also has at its free end a hole 98 for the passage of the rivet 38.

 In FIGS. 5 and 6, to avoid any rotation of the washer 90, it is possible to provide tabs 292 visible in dotted lines in FIG. 6 and each engaged in a passage 91 provided between two consecutive support sectors.

 The tabs 292 engage in a complementary manner between two consecutive support sectors 80,81 to produce a connection in rotation of the washer 80.

 As a variant, the washer 90 may include tabs with holes for the passage of a support sector forming a tenon. The holes form mortises.

 The washer 90 is therefore fixed by threading it onto the bearing sectors concerned.

 Stapling is thus carried out so that the grooves 93, produced by molding or by turning, are not compulsory.

 Of course, as a variant, each washer 90 can be divided into annular fixing sectors each carrying a tongue, so that several fixing parts 19 are provided.

 The grooves made in each sector, instead of extending circumferentially as in FIGS. 1 to 6, can affect the inclined lateral edges of the sectors 80, 81 of pointed shape (FIGS. 1 and 5) for local contact with the diaphragm 5, 6.

 Thus in FIG. 7, two grooves 193 are provided in the lateral edges facing two consecutive sectors 80,81.

 Each tab 92 of FIG. 1 is snap-fitted in the grooves 193 facing each other.

 Each tab 92 is connected to a fixing sector engaged with at least one of the sectors 80, 81, here with the two sectors.

 Each tab 92 is therefore extended by a fixing sector 190 extending radially below the support sectors 80, 81.

 The tongues 9 therefore belong to fixing pieces 19 each comprising an annular fixing sector 190 connected by a coupling tab 92 to a tongue 9.

 It will be appreciated that, in all cases, the fixing pieces 19 have a small thickness. Preferably, these parts are treated in the same way as the elastic tongue 9. The parts 19 and the tongues 9 are here made of metal.

 The treatment of the elastic tongues 9 gives them the desired elasticity.

 For this purpose the tongues are heat treated. They undergo for example a quenching operation, followed by a tempering operation. It is therefore the entire fixing part which undergoes these operations so that the stapling of the fixing parts is facilitated.

 These metal parts 19 are harder than the pressure plate. The pressure plate is homogeneous because it has no mounting hole for the members for fixing the tabs.

 Of course, the present invention is not limited to the embodiments described. In particular the fixing part, with its tabs, can be fixed on the crown of FIG. 4 of the aforementioned document GB-A-2 176 549.

 The lateral edges of the support sectors 80,81 ... may not be inclined relative to a radial direction.

 The clutch can be of the pulled type, that is to say that the diaphragm, in this case, bears on the outer periphery of its Belleville washer on the cover and on the inner periphery of its Belleville washer on the bead of the pressure plate as visible in Figure I of GB-A-2 176 549 cited above.

 It will be appreciated that the embodiments illustrated in the figures lead to axially compact solutions.

 As a variant, it is possible to mount at least one Belleville assistance washer with the diaphragm. This Belleville washer is supported at its outer periphery on the diaphragm by being interposed between the latter and the bead 8.

 At its internal periphery, this Belleville washer rests on a shoulder of the pressure plate implanted radially below the bead as visible for example in the addition N "86.983 figure 1. This is possible by having tabs fixed as in figures 1 and 7.

 As regards the embodiment of FIGS. 5 and 6, it would then be necessary to make passages for the legs 192 in the boss of the pressure plate carrying the aforementioned shoulder of the Belleville assistance washer.

 On the other hand, the solutions of document GB-A-2 176 549 do not allow the implantation of such an assistance washer because of the presence of the ring for fixing the tongues.

 As a variant, instead of being fixed to the balusters 132 of FIG. 5, the tongues 9 can be fixed to balusters without secondary support and alternating circumferentially with the balusters 132. These balusters pass through the orifices 61 of the diaphragm 5,6 to be fixed by riveting to the bottom 4 of the cover 3.

 The washer 90 can be crenellated and have legs projecting radially for mounting in a groove 93 formed in a support sector 80, 81 out of two, or one out of three, etc. depending on the applications.

 Thus only part of the support sectors can have a groove.

 The declutching means can bear indirectly on the bead. For example one or more Belleville washers can be mounted between the bottom 4 of the cover 3 and a false diaphragm resting on the bead. By false diaphragm is meant here a diaphragm whose external peripheral part is devoid of elasticity for example by means of radial slots opening outwards.

 It will be noted in FIGS. 1 to 7 that the bottom 95 of the grooves 93 extend radially below the circumference of the vertices 180 for reasons of resistance and due to the asymmetry of the support sectors; the vertices 180 being closer to the outer periphery of said sectors.

 As a variant with other forms of support sectors, the grooves may affect the external periphery of the support sectors, so that the washer 90 or the fixing sector 190 may extend generally radially above the support sectors. support.

 As a variant, it is possible to produce an overmolding replacing the grooves 93,193.

 Thus, the material of the support sectors 80, 81 may partially cover the fixing washer 90 or the fixing sector 190.

 As a variant, the tongues 9 can be fixed by overmolding on the legs 92, 192, for example being made of plastic.

 The tongues are in all cases integral with the fastening parts 19 with hitching legs 92,192.

Claims (16)

 1- Clutch mechanism for a clutch comprising a reaction plate (2), in particular for a motor vehicle, comprising a cover (3) with a bottom (4) for fixing the clutch mechanism (1) on the reaction plate ( 2) of the clutch, engagement means (5) with axial action bearing on the bottom of the cover, declutching means (6) associated with the engagement means (5) to counteract at will the action of these, a pressure plate (7) with a dorsal face (70) provided, in axial projection, directed towards the bottom (4) of the cover (3), with an annular bead (8) divided into support sectors (80,81 ...) for support of the engagement means (5) urging the pressure plate in the direction opposite to the bottom (4) of the cover (3), axially elastic tongues (9) with circumferential action intervening between the cover (3) and the pressure plate (7) for rotationally linking the pressure plate (7) to the cover (3) while allowing a axial movement of the pressure plate (7) relative to the cover (3), characterized in that said elastic tabs (9) each form an extension of a fixing piece (19) fixed by overmolding or stapling on at least one sector support (80.81).  2- Mechanism according to claim 1, characterized in that the fixing part (19) comprises at least one coupling lug (92,192) extended at one of its ends by an elastic tongue (9) and at the other from its ends by at least one fixing sector (90,190).  3- Mechanism according to claim 2, characterized in that the fixing sector (90,190) is engaged with at least one of the support sectors (80,81).  4- Mechanism according to claim 2 or 3, characterized in that the fixing sector (90,190) extends generally radially below the support sectors (80,81).  5- Mechanism according to any one of claims 2 to 4, characterized in that the elastic tongues (9) extend radially above the support sectors (80,81).  6- Mechanism according to claim 5, characterized in that the coupling lug (92) extends between two support sectors (80,81).  7- Mechanism according to claim 6, characterized in that the coupling lugs (92) engage in a complementary manner between two support sectors (80,81) for rotational connection of the fixing piece (90,190) with the pressure plate (7).  8- Mechanism according to any one of claims 5 to 7, characterized in that the elastic tongues (9) are fixed to a coupling range (36) belonging to a radial fixing flange (35,36) that has the cover at its outer periphery.  9- Mechanism according to any one of claims 2 to 4, characterized in that the elastic tongues (9) and the coupling tabs (9) extend radially below the support sectors (80,81).  10- Mechanism according to claim 9, characterized in that the tongues are each fixed to a column (132) fixed to the cover (3).  11 - Mechanism according to claim 10, characterized in that the columns (132) serve as tilting support to a diaphragm (5,6) constituting the engagement means (5) and disengagements (6) of the clutch.  12- Mechanism according to any one of claims 2 to 11, characterized in that the coupling lugs (92,192) are inclined axially in the direction of the bottom (4) of the cover (3).  13- Mechanism according to any one of claims 2 to 12, characterized in that the fixing part (19) is fixed by snap-fastening on at least one support sector (80,81) thanks to a groove ( 93,193) presented by said support sector (80,81).  14- Mechanism according to claim 13, characterized in that the groove (93) extends to the inner periphery (96) of the support sector (80,81).  15- Mechanism according to claim 13, characterized in that the groove (193) affects the lateral edge of the support sector (80,81).  16- Mechanism according to any one of claims 2 to 15, characterized in that the elastic tongues (9) are connected by coupling lugs (92,192) to a fixing washer (90) forming the fixing sectors.