ITRM930157A1 - DIAPHRAGM FOR ENGAGEMENT MODULE AND ITS ENGAGEMENT MODULE, IN PARTICULAR FOR VEHICLES. - Google Patents

Description

"DIAPHRAGM FOR ENGAGEMENT MODULE AND ITS ENGAGEMENT MODULE, IN PARTICULAR FOR MOTOR VEHICLES"

SUMMARY

The diaphragm includes a Belleville washer, and radial fingers (62) fragmented by slits (64). Openings (181, 182, 183) are provided for the passage of a screwing tool (20). The slots (64) include a slot shaped portion. At least one buttonhole (65)? locally widened to create a third opening (181) which allows the passage of a tool (20) for screwing in a fixing screw (2).

Application: graft module comprising such a diaphragm.

DESCRIPTION of the industrial invention entitled: "DIAPHRAGM FOR ENGAGEMENT MODULE AND ITS ENGAGEMENT MODULE, IN PARTICULAR FOR MOTOR VEHICLES"

DESCRIPTION

The present invention relates to diaphragms for coupling modules, in particular of motor vehicles, of the kind comprising a peripheral part, forming a Belleville washer, and a central part fragmented into radial fingers by means of slots, said central part being provided with openings for the passage of screwing tools for fastening screws of the coupling module to a drive shaft.

Such a diaphragm? described in documents DE-A-30 13 298 and FR-A-2 662 767 and poses problems. In fact the openings weaken the fingers of the diaphragm and for reasons of angular orientation of the graft module with respect to its driving shaft, one of the fixing screws? offset from the other screws. It is therefore necessary to provide a specific opening, called the third opening, at the level of the diaphragm.

The installation of this third opening must leave enough material at the level of the fingers so that? these do not break. In addition, all the openings make the fingers of the diaphragm pi? flexible. This flexibility? increased? harmful since, for the same disengagement stroke, the lever of the pressure plate, which usually comprises the engagement module also equipped with a clutch clutch, is reduced so that the rubbing seals of the engagement clutch cannot be released in a convenient way.

Furthermore ? It is important that the root zone of the diaphragm fingers does not have a circumferential length too large, so that? these can conveniently control the desired deformation of the Belleville washer of the diaphragm. It is important that the diaphragm offers a maximum support surface for the clutch release bearing, in order to reduce wear.

The present invention aims to reconcile all these needs.

According to the invention, a diaphragm of the type indicated above in which the slots of the diaphragm have a slot shape opening into the central opening of the diaphragm by means of a slit of reduced width,? characterized by the fact that a third opening? provided at the level of the slot of the slots which separate the fingers of the diaphragm two by two for the passage of a tool for tightening a fixing screw, said opening concerning only one of the two adjacent radial fingers concerned and being formed by said slot .

Thanks to this third opening,? made possible an angular orientation of the graft module with respect to its driving shaft and a maximum of material is preserved for the affected finger since? the third opening? formed through the buttonhole.

Advantageously this third opening? obtained on the internal perimeter of the affected side of the slot of the affected slot.

Thanks to all these arrangements, the root regions of the diaphragm fingers can be reduced and said fingers provide a large support surface for the clutch release thrust bearing. The other openings are, for some of them, also formed through the slots of the slits concerning the two concerned fingers of the diaphragm.

According to an important feature,? was looking for a provision that allows you to further reduce flexibility? of the fingers of the diaphragm.

Thus, a diaphragm of the type indicated above, in which its radial fingers are divided into two elementary radial fingers by means of a slot,? characterized by the fact that at least one of the buttonholes? locally enlarged to create a first opening that allows the passage of a tool for screwing a fixing screw.

So, the fingers of the diaphragm are enlarged, so that their resistance? good despite the openings, and that these are less flexible than those of the prior art.

Thanks to the buttonholes, the root area of the fingers of the diaphragm can? being reduced, while at their inner periphery said fingers offer a large support surface for the clutch release thrust bearing.

According to another characteristic, at least a second opening, for the passage of said screwing tool,? provided at the level of the slits which separate the fingers of the diaphragm two by two, said opening concerning the two adjacent fingers concerned of the diaphragm.

Furthermore, the slot associated with the third opening has a specific shape to impart good mechanical characteristics of rotation to said fingers.

Thanks to these three series of openings, an ideal solution is obtained to answer the problem posed, while having the possibility? to have a large number of openings.

According to another feature, said diaphragm which? integrated with an engagement module comprising at least one rubbing washer installed radially beneath the windows for housing elastic members with circumferential action and columns which connect two guide washers arranged on both sides of a disk. characterized by the fact that the columns are installed radially beyond the of the inner circumferential edge of the windows, and in that said engagement clutch passages are installed radially beneath the windows in the space cleared by the rubbing washer.

Preferably, the openings are installed at the lower corners of the windows.

Thanks to this arrangement,? It is possible to retain all the functions of the engagement clutch, while minimizing its resistance.

The mounting of the plug module with integrated fastening screws? cos? made possible, with good performance, both for the diaphragm and for the clutch engagement.

The following description illustrates the invention with reference to the attached drawings in which:

- figure 1? an elevation view with local removal showing an engagement module provided with a diaphragm according to the invention;

- figure 2? a sectional view along the line 2-2 of Figure 1;

- figure 3? a partial view along the arrow 3 of Figure 2 of the engagement clutch; - figure 4? an axial view of another set screw with in part its associated passage in the engagement clutch; And

- figure 5? a partial view of the diaphragm according to the invention.

In the illustrated figures, it is a question of assembling a flywheel 1 on the crankshaft 8 of an internal combustion engine by means of a plurality of elements. of fastening screws 2. Here, the flywheel 1 forms the reaction plate of an automotive clutch. It ? here unitary but well understood it can? be divided as described in document FR-A-2. 662. 767.

In this case the flywheel comprises a first mass of inertia fixed by means of the screws 2 to the crankshaft 8, a second mass of inertia comprising a plate which forms the reaction plate of the clutch.

The first mass has a central hub which allows the flywheel to be fixed on the crankshaft.

As is known, a clutch comprises at least, in axial succession, the flywheel 1 or reaction plate, a clutch 3, a pressure plate 4, a cover 5, a diaphragm 6.

All these elements being annular in shape. In figure 2 the flywheel 1? intended to be made integral with a driving shaft, here the crankshaft 8 of the internal combustion engine.

Engagement clutch fitted with rubbing seals 35? designed to be made integral in rotation with a driven shaft 7, here the input shaft of the gearbox, in a manner known per se, by means of a hub 31 with an internal grooved hole for this purpose, the end? shaft 7 being grooved in a complementary manner.

The lid 5? integral in rotation with the rotation plate 1 and? axially connected to this.

The diaphragm 6 rests on the cover 5 and urges the pressure plate 4 towards the reaction plate 1 for an axial tightening of the coupling clutch 3 between the two plates 1, 4. The diaphragm 6 has a frusto-conical shape in the free state and comprises a circularly continuous peripheral part that forms a Belleville washer 61 and a central part circularly fragmented into radial fingers 62 through slits 64.

The end? internal of the slits 64 opens into the internal perimeter of said central part, in a central opening common to all the fingers 62.

Its extremity? external opening into enlarged orifices 63, here globally rectangular in shape, obtained at the level of the internal periphery of the Belleville washer 61 (Figure 5). The slots 64 are globally shaped like a slot opening into the central aperture of the diaphragm through a slit of reduced width.

Here the diaphragm 6? mounted in a rotatable manner on the lid 5, in the form of a bottom plate, which has at its outer periphery a radial edge fragmented in fixing areas 55 and a bottom 56 centrally open.

The fastening areas 55 are used to fasten the cover 5 to the reaction plate 1 by means of screws 3, to axially and rotate the cover 5 to said plate 1.

In variant you can? proceed with a riveting, as described in document FR-A-2.526.104, or a crimping.

Here the assembly? realized as in document FR-A-2 .585 .424 (US-A-4.751.991), thanks to assembly means, which rotatably secure the diaphragm 6 to the cover 5 by axially applying said diaphragm 6 with a clamping load elastic constantly against a primary support 53 carried by the lid 5. Here this support consists of a drawing, in variant pu? be a split ring.

These assembly means comprise retaining brackets 51 formed in one piece from the bottom 56 of the lid 1 by folding. These brackets 51 have an axial part which crosses the diaphragm 6 through enlarged orifices 67 thereof, described below, and an end wing? bent radially in the opposite direction to the axis of the assembly and defining with said axial part a locking elbow.

A crown - elastic ring 54, here of truncated cone shape,? blocked in said elbow and d? shaped to obtain a secondary support for the diaphragm arranged in front of the primary support.

Alternatively, the assembly means can comprise columns and elastic rings, as in document FR-A-2.311.221.

Normally the graft? engaged, its engagement clutch 3 being clamped between the plates 1, 4. To disengage,? it is necessary to force by pushing in the direction of the arrow F (figure 2) on the extremity? of the diaphragm fingers by means of a clutch release thrust bearing schematized in 70, with consequent cancellation of the load exerted by the diaphragm 6 on the pressure plate 4, a release of the engagement clutch and disengagement of the clutch to change in particular the gears.

At the time of the disengagement operation, is produced cos? a lifting of the pressure plate by means of tabs 43 described hereinafter, the plate 4 being recalled by said tabs in the direction of the bottom 56 of the lid.

Here the diaphragm? sandwiched between said primary 53 and secondary 54 abutments at the inner periphery of its Belleville 61 washer and rests at the outer periphery of its Belleville 61 washer on a fractionated annular rib 41 of the pressure plate.

Well understood, the graft can? be of the drawn type as described for example in document FR-A-2.463.874.

The diaphragm then rests at the outer periphery of its Belleville washer on a support carried by the cover and at the inner periphery of its Belleville washer on the rib of the pressure plate.

In this case, the bearing, pulling on the end? of the diaphragm fingers, relieves the effort normally exerted by the diaphragm to disengage the clutch.

Well understood as described in the document FR-A-2.550.835, the lid can? be in one piece with the diaphragm.

The pressure plate 4? integral in rotation with the cover 5, and therefore with the plate or flywheel 1, being mounted axially movable with respect thereto by means of tangential elastic tabs 43, here three in number.

To do this, the plate 4 has at its external perimeter three tabs 42 on which the tabs are fixed by riveting, which are also fixed by riveting at their other end. to the cover, one of the fixing points being indicated at 57 in Figure 1.

Well understood, this link can? be of the tenon-mortise type, with radial projections of the pressure plate which penetrate into complementary grooves made in the shell of the lid.

Alternatively, this connection of the tenon-mortise type can? be made between the pressure plate and a peripheral annular edge of the reaction plate as disclosed in the aforementioned document FR-A-2 .550.835, the lid then being flat in shape.

As described in the document US-A-4.892.177, you can? provide for an arrangement with two pressure plates and an actuation crown.

The engagement clutch 3 here comprises two coaxial parts mounted movable relative to each other against elastic means with circumferential action 36 and rubbing means 39 with axial action.

Here the first part comprises two guide washers 33 connected to each other by columns 37 which also serve to fix a disk 34 flanked to one of the washers 33. This disk 34 carries on its outer perimeter, on each of its faces, rubbing seals 35 possibly split.

It is these rubbing seals 35 which are intended to be clamped between the plates 1, 4 for the transmission of torque from the drive shaft to the driven shaft.

The second part of the clutch 3 comprises a disc 32 axially interposed between the two guide washers 33. Here the clutch? of the type described in the document EP-A-0.382 .616 and the disk 32? mounted cos? movable in rotation, with a play defined by means of meshing with play, with respect to the hub 31. For this reason? will you do? referring to Figure 3 of the aforementioned document. Elastic means of low rigidity are also provided.

Well understood the disk 32 can? be integral with the hub 31 and the structures can be inverted, the disc 32 being movable with respect to the hub 31 and the guide washers integral with the hub 31, the disc 34 being integral with the disc 32.

The rubbing means 39 comprises two rubbing washers 131 of identical shape on either side of the disc 32, as well as on the other. elastic clamping means. These elastic means rest on one of the guide washers and on one of the washers 131 to urge the disk 32 in the direction of the other guide washer 33 and thus axially tighten the other washer 131 between said disk 32 and the other guide washer. concerned 33.

Also provided are annular bearings 132, of L-shaped section, inserted radially between the inner perimeter of the guide washer concerned and the hub 31. Such a bearing? visible in Figure 2 and comprises steady rests which enter corresponding openings of the guide washer for its rotation.

You will notice? that the rubbing washer 131? annular in shape and comprises three triangular protruding tips which each carry penetrating pins in a corresponding opening formed in the guide washer. These 131 washers come like that? made integral in rotation with the guide washers 33.

The washers 33 extend axially on both sides of the disc 32. The columns 37 extend here in correspondence with the outer perimeter of said washers and pass through the disc through oblong openings 38, which presents this in correspondence with its outer periphery.

The circumferentially acting elastic means 36 here consist of spiral springs mounted partly in windows of the disc 32 and partly in windows of the guide washers, said windows being arranged opposite and indicated at 135 in Figure 3.

Here the openings 38 alternate circumferentially with the windows 135 three in number, so? such as the springs 36 mounted without play in said windows. Of course, some of the springs 36, possibly in the form of blocks of elastomeric material, can be mounted with play in the windows of the disc 32 for deferred intervention.

The rubbing means 39 are therefore installed here radially below the windows 135 and the springs 36 as shown in Figure 3, while the posts 37 and their openings 38 are installed radially beyond the window. of the inner perimeter of the windows 135 (the inner circumferential edge of these).

For memory we will mention? that the flywheel 1 carries on its outer perimeter a starting ring 12 suitable for being operated by the vehicle starter, said flywheel 1 being shaped on its internal perimeter as a flange for assembly by mating with the crankshaft and by means of screws fixing 2, each having a head 21 and a threaded shank 22 which passes through an associated opening 11 obtained in the flywheel 1 to screw in the end? crankshaft 8 shaped for this purpose.

Flywheel 1? then tightened between the heads 21 of the screws 2 and the end? crankshaft free 8.

The fingers 62 of the diaphragm 6 are here divided into two elementary radial fingers each by means of a slot 65 as described in document FR-A-2.311.221. One of the buttonholes 66 has a special shape and will come? described below.

The lateral sides of the slots 65 are distant from each other. Buttonhole 65? elongated radially from one end? external closed at one end? internal located at a distance from the inner perimeter of the fingers 62 and from the central opening of the diaphragm 6.

The extremities the outer slots 65 are widened to form orifices 67, which are generally rectangular in shape and identical to the orifices 63 (Figure 5). The orifices 67 alternate circumferentially with the orifices 63.

In Figure 1, nine retaining or assembly brackets 51 are provided and the diaphragm comprises nine radial fingers 52.

The slots 64 have an identical shape to the slots 65 and differ from these in that the end? of their buttonhole? open by means of a slit that connects it radially to the central opening of the diaphragm. This crack? very small in width (figure 3).

The brackets 51 alternate circumferentially with the radial orientation brackets 52 delimiting the internal perimeter of the bottom 56 of the lid 5. The brackets 52 limit the inclination of the diaphragm when the lid 5 does not? mounted on the flywheel. The brackets 51 pass through the orifices 67 of the slots 65.

According to a characteristic of the invention, at least one of the slots 65? locally enlarged to create a first opening 183 which allows the passage of a tool for screwing in a fixing screw 2. This opening 183? here made on the internal periphery of slot 65.

According to a feature of the invention, a second opening 182? provided at the level of the slot of the slots 64 which separate the fingers 62 two by two for the passage of said screwing tool 20, the opening 182 concerning the two adjacent radial fingers 62 concerned. This opening? made in correspondence with the internal periphery of the slot of slot 64.

Here are expected more? openings 183, 182, their number depends on the applications, cos? such as the number of brackets 51 and orifices 63, 67.

According to the invention, a third opening 181? provided at the level of the slot of the slots 64 which separate the radial fingers 62 two by two for the passage of said tool 20, said opening concerning only one of the two adjacent radial fingers concerned and being formed by means of said slot.

Here the first 183 and the second openings 182 are circular in shape. They are regularly distributed on the same circumference of the complex.

These openings 182, 183 relate symmetrically to the affected slots 64 and the affected slots 65, respectively.

Opening 181 (here globally semicircular)? embroidered on the same circumference but not? distributed in a regular manner with respect to the other openings 182, 183. The opening 181 concerns only one of the fingers 62 concerned, the other finger being intact.

It? obtained according to the invention in the inner periphery of the affected side of the slot 66 of the affected slot 64.

Corollary this slot 66 has a tortuous shape with at its internal periphery a curved portion offset towards the other end. of the affected finger 62 (Figure 1). This buttonhole 60? identical at the level of its external periphery to the slots 65 and therefore has an orifice 67 and a radial part which ends in correspondence with its internal periphery by means of said curved part.

Six openings 181, 182, 183 are provided here for screwing six fixing screws 2, distributed in a similar manner to said openings, the head of the screws being in correspondence with said openings, while the tools 20 here belong to a screwing machine.

There are here one aperture 181, three apertures 182 and two apertures 183.

The opening 181, and therefore the screw concerned, allows an angular orientation of the flywheel 1 with respect to the crankshaft 8, which? particularly necessary when? an ignition sight is provided on the flywheel 1 or on the cover 5.

A same diaphragm can? then agree for a three screw fixing on the crankshaft 8.

According to another characteristic of the invention, the engagement clutch comprises, coinciding with the openings 181, 182, 183, passage openings 81, 82, 83 respectively. These openings are axially aligned with the openings of the diaphragm and the screws of fixing, so that each screwing tool can? passing through the diaphragm and the engagement clutch to come into contact with the head of the screws 23, hollowed here for this purpose. The recess 23 has, for example, a hexagonal or tetragonal shape and? the same for the screwing tool 20, which has a complementary shape.

How will it be? including each opening 81, 82, 83 consists of holes, coinciding with the openings 181, 182, 183, made in the washers 33, the disc 32 and the disc 34 (Figure 2). Here the clutch 3 is drilled from side to side.

There? ? made possible thanks to the conformation of the engagement clutch, the openings 82, 83 being obtained at the level of the inner circumferential edge of the windows 135, which? globally circular in shape (Figure 3). They are obtained in the space freed by the washers 131.

As can be seen in Figure 3, two of the clearances of the windows 135 are obtained in the vicinity of each of the ends. (or corners) of their inner circumferential edge, respectively of an opening 82 and of an opening 83, while the third play of the windows 135 concerns only an opening 82 in the vicinity of one of its ends. (its corners) of its inner circumferential edges.

The opening 81, here circular in shape, associated with the third opening 183? circumferentially offset for orientation reasons and therefore does not affect windows 135.

These openings 81, 82, 83 are directed inwards and are formed on either side of a tip of the rubbing washers 131 radially beneath the holes 38.

Thanks to this installation, the engagement clutch? intact at the level of its functions and its resistance is not affected beyond measure by said openings.

Thanks to the invention, can you? then form, with standard elements, in advance an engagement module comprising the flywheel 1, the pre-centered engagement clutch 3, the cover 5 fixed on the flywheel 1, the pressure plate 4 mounted on the cover 5 thanks to the tabs 43, the diaphragm 6 mounted in a rotating manner on the cover 5 and the fixing screws 2 mounted in a captive manner inside the module.

You will notice? that the openings 181,81 allow a pre-centering of the clutch with the help of, for example, a rod.

It is understood that the screws 2 are inserted into the holes 11 before arranging the gaskets 35 of the clutch 3 on the plate 1, after fixing the unitary assembly cover 5 - bending plate 4-diaphragm 6, said assembly currently being called the engagement mechanism.

Once the engagement module has been assembled, the head of the screws is trapped axially between the flywheel 1 and the clutch 3, so that this does not risk escaping, the length of the stems 22 being greater than the thickness of the flywheel 1 at the level of the inner periphery of this.

The length of the stems 22? such that said stems remain in engagement with the openings 11 when the head of the screws 21 comes to abut between the clutch 3.

Clearly understood, the passages 81 to 83 - 181 to 183 have a size smaller than the head of the screws, the size of said openings being made in such a way as to allow the passage of screwing tools 20 and? then function of the cavities? 23 of the screw head 21.

What? the manufacturer of the graft can? balance the graft module in advance, so that the placement of such a module at the end? of the crankshaft at the manufacturer of the motor vehicle is advantageously minimized, the operations to be carried out at said manufacturer being advantageously reduced in proportion.

Can't? any error may occur on the choice of fixing screws, which must not be stored by said manufacturer.

How will it be? included, the shape of the slots 64, mostly in the form of a slot open internally for a slit of small width, allows the bearing 70 to be offered maximum support in cooperation with the slots 65, 66.

The slot of the slot 64 associated with the opening 181 participates in the formation of said opening and therefore allows a gain of material for the fingers 62 involved in the opening 181.

Thanks to the orifices 63, 67 the root zone of the fingers 62, divided into two elementary fingers by the slots 65, 66, does not have an important circumferential development, hence a facilitated maneuver of the diaphragm. The fingers 62 also have the desired strength. They allow for a minimization of pressure plate lifting losses.

Well understood the buttonhole 66 can? have another shape, being for example devoid of the curved part in correspondence of its internal periphery, the slot being then pi? radially short of the others.

Likewise, the orifices 63 can have a different configuration than the orifices 67 being for example less high.

Likewise, the 131 rub washer can be connected in rotation to the hub disk 132.

While in the illustrated figures, said washer 131? of plastic material, it can? be metallic and comprise square-shaped brackets for penetrating the associated openings of said guide washers or of the disc, said washer then carrying a friction seal.

In any case, ? It is important that the columns are not installed in correspondence with the internal perimeter of the clutch engagement windows, in particular for reasons of resistance, while the passage openings of the screwing tools are obtained radially below the windows and radially above the rubbing washer properly said.

Well understood (figure 4), the head 121 of the screw 2 can? be stepped with an end part, of hexagonal shape, penetrating in part in the passages 81, 82, 83 of the clutch. What? screws cannot protrude from the module before mounting.

The columns 37 can extend beyond? of disk 32 and cross the plane of disk 32.

The module can? understand a flywheel divided as in the document FR-A-2.662.767 or can? have the constitution of the one described in the document DE-A-30 13 298.

In variant the buttonholes 65, at their extremity? internal, can be opened by means of a slit of small width which connects each slot to the central opening of the diaphragm, so that the slots 65 are identical to the slots 64. A diaphragm with eighteen fingers is thus obtained.

Finally, the rubbing washers 131 are not necessarily identical to each other, one being able to have a radial extension less than the other.

Claims (13)

CLAIMS 1. Diaphragm for engagement module, in particular for motor vehicles, of the kind comprising a peripheral part (61), forming a Belleville washer and a central part fragmented into radial fingers (62) by means of slots (64), said central part being provided with openings (181, 182, 183) for each passage of a tool (20) for screwing a fixing screw (2) of the coupling module to a driving shaft (8), in which the slots (64) of the diaphragm have a slot shape opening into the central opening, which presents the diaphragm, by means of a slit of reduced width, characterized by the fact that a third opening (181)? provided at the level of one of the slots of the slots (64) that separate the fingers of the diaphragm two by two for the passage of a tool (20) for the screwing of a fixing screw (2), said opening (181) concerning only one of the two adjacent radial fingers concerned and being formed in part by said slot. 2. Diaphragm according to claim 1, characterized in that the third aperture (181)? obtained at the internal periphery of the affected side of the slot of the affected slot (64). 3. Diaphragm according to claim 1, or 2, in which the radial fingers (62) are divided into two elementary radial fingers by means of a slot (65) characterized in that at least one of the slots (65)? locally enlarged to create a first opening (183) which allows the passage of a tool (20) for screwing in a fixing screw (2). 4. Diaphragm according to claim 3, characterized in that a second aperture (182)? provided at the level of the slots (64) which separate the fingers (62) two by two for the passage of a said screwing tool (20) said opening (182) concerning the two adjacent radial fingers (62) concerned. 5. Diaphragm according to claim 3 or 4, characterized by the fact that the slots (64) have an identical shape to the slots (65) and differ from these in that their extremity? internal? opened by a very small slit, which connects the slot of the slot (64) to the central opening of the diaphragm and by the fact that the first (183) and the second opening (182) extend symmetrically on one side and from the other of their affected buttonhole. 6. Diaphragm according to claim 5, characterized in that said first (183) and said second (182) openings are formed on the internal periphery of their associated slot. 7. Diaphragm according to any one of claims 3 to 6, characterized in that the first, second and third opening are formed on the same circumference, the third opening (181) not being distributed in a regular manner with respect to the other openings ( 182, 183). 8. Diaphragm according to any one of claims 1 to 7, characterized in that the slot (66) associated with the third opening (181) ends at its internal periphery by means of a curved part offset towards the other end. of the affected finger. 9. Engagement module comprising an engagement clutch provided with passage openings (81, 82, 83) for screwing tools of fastening screws, characterized in that it comprises a diaphragm according to any one of Figures 1 to 8, and by the fact that that the openings (181, 182, 183) of said diaphragm are axially aligned with the passage openings (81, 82, 83) of said engagement clutch. Engagement module according to claim 9, in which the engagement clutch comprises at least one friction washer (131) installed radially beneath windows (135) for housing elastic members with circumferential action (36) and columns (37 ) which connect together two guide washers (33) arranged on both sides of a disk (32), characterized by the fact that the columns (37) are installed radially beyond the of the inner circumferential edge of the windows (135), and by the fact that said passage openings (81, 82, 83) of the engagement clutch are formed radially beneath the windows (135) in the space freed by the rubbing washer (131) . 11. Coupling module according to claim 10, characterized in that the passage openings (82, 83) associated with the first (183) and second openings (182) of the diaphragm are formed in proximity to one of the corners of said edge inner circumferential. 12. Engagement module according to claim 11, characterized in that the opening (81)? associated with the third aperture (183) of the diaphragm (6) and does not affect the windows (35). 13. Coupling module according to claim 11 or 12, in which the rubbing washer (131) has a triangular shape with spikes, characterized in that the passage openings (81, 82, 83) are made on one side and the other the other of a tip of the rub washer (131).