FR2480377A1 - Diaphragm clutch for motor vehicle - uses jointing ring to clamp diaphragm onto cover plate and separate tabs to locate ring in radial and axial directions - Google Patents

Abstract

The diaphragm automobile clutch uses a cover plate (10) to locate the diaphragm (11) and the axially mobile pressure plate (14) in relation to the flywheel (17) and the friction plate (18). The diaphragm comprises radial fingers (13) cantilevering internally from an annular Belleville spring (12), being clipped to the cover plate by a jointing ring (31). Opposed undulations (25,32) in the plate and ring (31) grip the diaphragm whilst forming a ring fulcrum. Separate cantilever tabs (26,35) at intervals on an intermediate circle support ring (31) radially fix its axial position respectively. The tabs may cantilever from the plate or ring, and the tab (26) may pass through an opening (28) in the root of a finger (13).

Description

 The present invention relates generally to diaphragm clutch mechanisms, in particular for a motor vehicle, of the type comprising a first generally annular part, called a cover, a second generally annular part, called a diaphragm, which has a peripheral part forming a washer. Belleville and a central part fragmented into radial fingers, assembly means pivotally securing said diaphragm to said cover, and a third annular part, called pressure plate, which is integral in rotation with the cover while being axially movable relative to to it, and on which the diaphragm bears by its peripheral part forming a Belleville washer.

 By its cover, such a clutch mechanism is adapted to be attached to a plate, called a reaction plate or flywheel, secured to a first shaft, in general a driving shaft, with insertion, between this reaction plate and the plate. pressure, a friction disc integral in rotation with a second shaft, in general a driven shaft, while, around it, is disposed a part, called a clutch release bearing capable of acting on the radial fingers of the diaphragm, for release control of the clutch thus formed, which is normally engaged, the pressure plate normally pressing the friction disc against the reaction plate under the stress of the peripheral portion forming Belleville washer of the diaphragm.

 The present invention relates more particularly to those of these clutch mechanisms in which the assembly means pivotally securing the diaphragm to the cover comprise, on the one hand, a fourth annular part, called a crown ring, which is disposed on the other. side of the diaphragm with respect to the cover, and which, by transverse support shoulders, is axially supported on the cover, in a first direction, and on the other hand retaining tabs, flat and thin, which pass through by a axial part of the orifices made in the diaphragm in the vicinity of the root of the radial fingers thereof, and which axially couple the crown ring to the cover, in a second direction opposite to the previous one, so that said crown ring is in fitting relationship with the v neck, this crown ring being linked axially in both directions to the cover.

 Such a clutch mechanism is described in the French patent filed on June 25, 1979 under 1g 79 16226.

In this French patent, the transverse support shoulders provided for the fitting relationship between the crown ring and the cover are formed on the axial part of the retaining tabs, constituting a flange means thereon.

Although this arrangement may be satisfactory, it has disadvantages, which are as follows.

 First of all, it involves a significant manufacturing complication for the retaining tabs.

 In addition, it inevitably leads to transverse support shoulders having circumferentially only a relatively small extension, so that the support area offered to the ring ring these transverse support shoulders can be poorly defined and / or be difficult to control, to the detriment of the working conditions of this crown ring, in particular when, as is the case in the French patent mentioned above, these transverse support shoulders affect one and the other of the axial edges of the axial part of the retaining tabs, being equally distributed over one and the other of these axial edges.

The present invention generally relates to a provision for avoiding these drawbacks, and also having other advantages.

 More specifically, the present invention relates to a diaphragm clutch mechanism, in particular for a motor vehicle, of the type comprising a first generally annular part, called a cover, a second generally annular part, said diaphragm, which has a peripheral part forming a delleville washer and a central part fragmented into radial fingers, assembly means pivotally securing said diaphragm to said cover, and a third annular part, called pressure plate, which is integral in rotation with the cover while being axially movable relative to it, and to which the diaphragm bears by its peripheral part forming a Belleville washer, said assembly means comprising on the one hand a fourth annular part, called crown ring, which is disposed on the other side of the diaphragm with respect to the cover, and which, by transverse support shoulders, is axially supported on the cover key, in a first direction, and on the other hand retaining tabs, flat and thin, which pass through an axial part of the orifices formed in the diaphragm in the vicinity of the root of the radial fingers thereof, and which axially couple the crown ring with the cover, in a second direction opposite to the previous one, this clutch mechanism being characterized in that the said transverse support shoulders are formed on support lugs distinct from the retaining lugs.

 Thus, in achieving the desired fitting relationship between the crown ring and the cover, an advantageous separation is obtained between, on the one hand, the axial support of this ring crown on the cover, in a first direction , and, on the other hand, its axial retention, in the opposite direction.

 I1 results, in fact, in particular, a simpler configuration of the retaining tabs, and therefore, easier manufacturing conditions for them.

 It also follows that, each transverse support shoulder can individually have a greater circumferential extension, the support area of the crown ring is better defined and better controlled.

 However, the arrangement according to the invention makes it possible, moreover, to modulate, at the option of each particular application for example, the conditions for producing the retaining tabs and the supporting tabs used.

 Indeed, these can, if desired, be placed on the same circumference of the assembly, or, on the contrary, on different circumferences thereof.

 In addition, the support legs, which are flat and extend axially, can be relatively elongated circumferentially and relatively thin radially, or vice versa, regardless of the configuration of the axial part of the retaining legs, which can also be relatively elongated circumferentially and relatively thin radially, or vice versa.

The characteristics and advantages of the invention will become apparent from the description which follows, by way of example, with reference to the appended schematic drawings in which
Figure 1 is a partial elevational view, along arrow I of Figure 2, with a local cutaway, of a diaphragm clutch mechanism according to the invention
Figure 2 is an axial sectional view along the broken line II-II of Figure 1
Figure 3 shows, on a larger scale, the detail of Figure 2 identified by an insert III thereon
Figure 4 is a partial sectional view along line IV-IV of Figure 3 ;;
Figure 5 is, on the scale of Figure 3, another view in partial axial section of the clutch mechanism according to the invention, along the line V- V of Figure 1
Figure 6 is a partial sectional view corresponding along line VI-VI of Figure 5
Figures 7 and 8 are, on a different scale, views respectively similar to those of Figures 3 and 5, and relate to an alternative embodiment of the invention
Figure 9 is a view similar to that of Figure 8 and relates to another alternative embodiment of the invention
Figures 10 and 11, 12 and 13, and 14 and 15, are respectively views similar to those of Figures 7 and 8, and relate to other alternative embodiments of the invention
FIG. 16 is a partial view in circumferential section of the variant implementation-illustrated by FIGS. 14 and 15, along the line XVI-XVI of FIG. 14.

In accordance with the embodiments shown in these figures, the diaphragm clutch mechanism according to the invention generally comprises a first generally annular part 10, called the cover, a second generally annular part 11, called the diaphragm, which has a peripheral part 12 forming a Belleville washer and a central part fragmented into radial fingers 13, assembly means pivotally securing the diaphragm ll to the cover 10 and detailed below, and a third annular part 14, called the pressure plate , which is integral in rotation with the cover 10 while being axially movable relative to the latter, as specified below, and on which the diaphragm 11 bears by its peripheral part forming a Belleville washer 12.

 By areas 15 of a peripheral radial rim 16, the cover 10 is adapted to be attached to a plate 17, called the reaction plate or flywheel, which is shown diagrammatically in broken lines in FIG. 2, and which is integral with a first shaft, in practice a driving shaft, with insertion, between this reaction plate 17 and the pressure plate 14, of a friction disc 18, which is also shown diagrammatically in broken lines in FIG. 2, and which is integral in rotation of a second shaft, in practice a driven shaft.

For action of the diaphragm 11, the pressure plate 14 has, from place to place, axial bosses 20 on which bears the peripheral part forming a washer.
Belleville 12 of this diaphragm 11.

Peripherally, it has radially projecting, from place to place, tabs 21 between which and pads 22 of the peripheral rim 16 of the cover 10 extend, substantially tangentially to a circumference of the assembly, tongues 23 ensuring its joining in rotation to this cover 10 while allowing axial movement.

These arrangements are well known in themselves, and not being part of the present invention, they will not be described in detail here.

The cover 10 provides a first support, or primary support, to the diaphragm 11, and more precisely to the peripheral part forming a Belleville washer 12 thereof, at the internal periphery of this peripheral part, and, in the embodiment shown, for this purpose, it has an annular half-wave deformation forming a first support rod 25.

 The assembly means pivotally securing the diaphragm 11 to the cover 10 comprise, on the one hand a fourth annular part 31, called the crown ring, and on the other hand retaining lugs 26.

The crown ring 31, which is arranged on the other side of the diaphragm 11 relative to the cover 10, provides a second support, or secondary support, to said diaphragm 11.

 To this end, it has annularly, in line with the rod 25 of the cover 10, a half-wave deformation forming a second support rod 32, in contact with the peripheral part forming Belleville washer 12 of the diaphragm 11.

In the embodiment shown in Figures 1 to 6 the retaining tabs 26, which are six in number, come from a single piece of the cover 10, by appropriate folding and cutting, and, their line of root folding extending substantially tangentially relative to a circumference of the assembly, their axial part 27 is relatively thin radially and relatively elongated circumferentially.

Extending along substantially the same circumference
C of the assembly, of average radius R, FIG. 3, they pass through an axial part 27 the diaphragm 11 by means of orifices 28 formed therein in the vicinity of the root of the radial fingers 13 thereof.

They also pass through the ring 31, by means of orifices 36 provided for this purpose therein, and, beyond this ring 31, they form a wedging elbow 30; in the embodiment shown in FIGS. 1 to 6, this is defined, on the one hand by the axial part 27 of the retaining tabs 26, and on the other hand by a part 29 of these folded overall radially in the direction opposite to the axis of the assembly.

 As described in French patent N 79 16226 mentioned above, a fitting relationship is established between the crown ring 31 and the cover 10: the crown ring 31 axially bears, in a first direction, on the cover 10, by transverse support shoulders 34 and, in a second direction, opposite to the previous one, the retaining lugs 26, by their wedging elbow 30, axially align the ring ring 31 with the cover 10.

According to the invention, the transverse support shoulders 34 are formed on support lugs 35 distinct from the retaining lugs 26, but passing through them as orifices 28 in the diaphragm 11.

 In the embodiment shown in Figures 1 to 6, the transverse support shoulders 34 are formed at the end of the support legs 35, over the entire circumferential extension thereof, and these support legs 35 , which extend generally axially, are flat, being relatively elongated circumferentially, and relatively thin radially.

In practice, in this exemplary embodiment, the legs come from a single piece of the cover 10, by appropriate folding and cutting, like the retaining legs 26.

In the embodiment shown in Figures 1 to 6, there are three of them, and are regularly distributed circularly, alternately with the retaining tabs 26, two successive support tabs 35 circumferentially surrounding two retaining tabs 26 successive.

 Finally, in the embodiment shown in Figures 1 to 6, the support tabs 35 extend along substantially the same circumference C of the assembly as the axial part 27 of the retaining tabs 26, Figures 3 and 5 .

 During assembly of the assembly, which is done before folding of the part 29 of the retaining lugs 26 which form the end part, the diaphragm 11 is engaged by its orifices 28 both on the retaining lugs 26 and on the support legs 35, each then extending substantially all axially.

 After this fitting of the diaphragm 11, the crown ring 31 is in turn engaged on the retaining tabs 26, through its orifices 36.

But, at the end of such an engagement, it abuts on the transverse support shoulders 34 formed at their ends by the support legs 35, FIG. 6, no orifice being provided at the right of such legs in this crown.

 After folding of the part 29 of the retaining tabs 26, the crown ring 31 is therefore embedded between, on the one hand, the wedging elbow 30 which then jointly form the retaining tabs 26, and on the other hand the shoulders transverse support 34 of the support legs 35.

 In accordance with the variant embodiment illustrated by FIGS. 7 and 8, the support tabs according to the invention 35 are arranged along a substantially different circumference from that on which the axial part 27 of the retaining tabs 26 extends.

 In practice, and as shown, the mean radius R1 of the circumference C1 along which the support legs 35 are arranged is less than the mean radius R2 of the circumference C2 on which the axial part 27 of the legs extend. deduction 26.

The mounting conditions of the ring crown 31 are thereby reinforced, a lever arm existing between retaining tab 26 and support tab 35 when ring crown 31 tends to tilt around the wedging elbow 30 formed by these retaining tabs 26.

 In other words, the conditions being equal, this ring 31 then has, for a given thickness, better resistance to bending in line with the support it offers to the diaphragm 11, or, for a given bending in right of this support, it can advantageously have a lesser thickness.

In the foregoing, it has been assumed that, like the axial part 27 of the retaining lugs 26, the support lugs 35 according to the invention are relatively thin radially and relatively elongated circumferentially.

 Alternatively, Figure 9, their root fold line extending radially, these support legs 35 are relatively thin circumferentially, and relatively elongated radially.

 A similar arrangement can be adopted for the retaining tabs 26, or at least some of them.

 It is also possible to combine jointly retaining and / or support tabs, relatively thin radially and relatively circumferentially elongated, with tabs, support and / or retaining, relatively radially elongated and relatively thin circumferentially.

 In the foregoing, the retaining tabs 26 and the support tabs 35 are an integral part of the cover 10, having come in one piece with it.

It is not necessarily so.

 For example, FIGS. 10 to 16, they can, on the contrary, as an alternative, form an integral part of the crown ring 31, having come in a single piece with the latter, by appropriate cutting and folding.

 For example, and as shown, the retaining tabs 26 then pass through their axial part 27 the cover 10, by means of orifices 40 formed for this purpose therein.

Jointly, the support legs 35 are axially bearing against the cover 10 by the transverse shoulders 34 which they form at their ends.

In the exemplary embodiment shown in FIGS. 10 and 11, retaining lugs 26 and support lugs 35 result from a folding of the crown ring 31 carried out in the direction of the periphery of the assembly.

As a variant, FIGS. 12, 13, they result from a folding carried out in the direction of the axis of the assembly; in this case, the secondary support offered by the diaphragm 11 the crown ring 31 is discontinuous.

 In the embodiment shown in Figures 10 and 11, the retaining tabs 26, on the one hand, and the support tabs 35, on the other hand, are on circumferences C2, C1 of the assembly of mean radii R2, R1 different, the radius R1 being, as before, less than the radius R2.

 As a variant, FIGS. 12, 13, they are all on the same circumference C of the assembly, of average radius R.

 In the alternative embodiment illustrated by FIGS. 14 to 16, the retaining tabs 26 and the support tabs 35, which come from the ring ring 31, and which are relatively thin circumferentially and relatively elongated radially, are all, by their axial part, substantially on the same circumference of the assembly; but, the free end of the support legs 35 is truncated by a chamfer 42, so that, as before, the barycenter of the transverse support shoulder 34 which it forms in contact with the cover 10 is on a circumference C1 of the assembly, of average radius R1 smaller than the average radius R2 of the circumference C2 of the assembly on which the axial part 27 of the retaining tabs 26 is located.

 The present invention is not limited to the embodiments described and shown, but encompasses any variant embodiment and / or combination of their various elements.

 In particular, the retaining tabs 26 may be made up of parts that are independent of the cover 10 or of the ring crown 31, these parts simply bearing axially on this cover 10 or this ring ring 31, either individually or in groups, such as as described for example in the French patent filed March 27, 1975 under NO 75 09588 and published under NO 2 305 638, in particular with reference to Figure 13 of this patent.

 The number of retaining lugs and / or the number of support lugs can be different from those given by way of example, the section of these lugs can be any, and it is possible to associate with the lug retaining lugs support in different numbers and / or of different nature.

To couple the crown ring to the cover, it is not necessary that, as described, the retaining tabs form a wedging elbow, other provisions that can on the contrary be adopted for axial support of the crown ring on these legs retaining or axial support thereof on the cover.

In the case of a timing elbow, the configuration and / or the orientation thereof is arbitrary.

 Furthermore, the field of application of the invention is not limited to the case where, as described, the diaphragm clutch mechanism concerned by itself forms an isolated entity to be mounted overall as a whole on a plate reaction 17, but extends on the contrary as well in the case where this clutch mechanism is considered already mounted on such a reaction plate, the assembly constituting a diaphragm clutch, whatever the mounting method then adopted for the various components of this diaphragm clutch.

In addition, the field of application of the invention extends equally well to the case where, as described in the French patent NO 79 16226 mentioned above, a slight clearance is left at the diaphragm between its primary and secondary supports, that in case, the crown ring elastically applying this diaphragm against the cover in all circumstances, such a game never occurs.

 Finally, the invention also finds its application in the case of the reconditioning of a clutch mechanism, the retaining lugs of which usually comprise a wedging elbow; after elimination of the latter to gain access to the parts which it encloses, said retaining tabs, by their remaining axial part, can advantageously serve as support tabs, in cooperation with new retaining tabs put in place for this purpose .

Claims (13)

1. Diaphragm clutch mechanism, in particular for a motor vehicle, of the type comprising a first generally annular part, called a cover, a second generally annular part, called a diaphragm, which has a peripheral part forming a Belleville washer and a central part fragmented into radial fingers , assembly means pivotally securing said diaphragm to said cover, and a third annular piece, called pressure plate, which is integral in rotation with the cover while being axially movable relative thereto and on which the diaphragm bears by its peripheral part forming a Belleville washer, said assembly means comprising, on the one hand a fourth annular part, called a crown ring, which is arranged on the other side of the diaphragm relative to the cover, and which, by shoulders transverse support, is axially supported on the cover, in a first direction, and on the other hand retaining lugs , flat and thin, which pass through an axial part of the orifices made in the diaphragm in the vicinity of the root of the radial fingers thereof, and which axially couple the crown ring to the cover, in a second direction opposite to the previous one, characterized in that that said support shoulders are formed on support lugs separate from the retaining lugs.  2. Clutch mechanism according to claim 1, ca acted in that said support shoulders are formed at the end of said support legs.  3. Clutch mechanism according to any one of claims 1, 2, characterized in that the support legs are flat, and extend axially. 4. Clutch mechanism According to claim 3, characterized in that the support legs are relatively elongated circumferentially and relatively thin radially.  5. Clutch mechanism according to claim 3, characterized in that the support legs are relatively thin circumferentially and relatively elongated radially.  6. Clutch mechanism according to any one of claims 1 to 5, characterized in that the support legs come from a single piece of the cover.  7. Clutch mechanism according to any one of claims 1 to 5, characterized in that the support legs come from a single piece of the crown ring.  8. Clutch mechanism according to any one of claims 1 to 7, characterized in that the support legs are arranged along substantially the same circumference of the assembly as that on which extends the axial part of the legs. detention.  9. Clutch mechanism according to any one of claims 1 to 7, characterized in that the support tabs and the retaining tabs extend along different circumferences of the assembly.  10. Clutch mechanism according to claim 8, characterized in that the radius of the circumference along which the support legs are arranged is less than the radius of the circumference over which the axial part of the retaining legs extends.  11. Clutch mechanism according to any one of claims 1 to 7, characterized in that the barycenter of each of the transverse support shoulders formed by the support legs is located on a circumference of the assembly of lower radius to that of the circumference on which the axial part of the retaining tabs is located. 12. Clutch mechanism according to any one of claims 1 to 11, characterized in that the number of support tabs is different from that of the retaining tabs.  13. Clutch mechanism according to claim 12, characterized in that there are two successive support lugs circumferentially surrounding two successive retaining lugs.