FR3059377A1 - PHASING DEVICE FOR FRICTION CLUTCH AND FRICTION CLUTCH DAMPER COMPRISING SUCH A DEVICE - Google Patents

Abstract

The invention relates to a phasing device (130) for a friction clutch damper, comprising: - a phasing washer (131) adapted to be partially inserted into an elastic system with a circumferential effect of the friction clutch; friction washer (133) adapted to be in contact with a flat portion of the elastic system, and - a spring washer (132) positioned between the friction washer and the phasing washer. The invention also relates to a damping device (120) for friction clutch, comprising: - a first and a second guide rings (121, 122) integral with each other and each provided with windows (125), - an elastic circumferential effect system comprising helical springs (124) housed in the windows (125) of the guide washers, and - the phasing device (130) above.

Description

TECHNICAL AREA

The present invention relates to a phasing device for a friction clutch damper ensuring an additional hysteresis effect on the damper. The invention also relates to a damping device for a friction clutch and a friction clutch comprising such a phasing device. The invention finds applications in the field of motor vehicle clutches and, in particular, in the field of friction type clutches for motor vehicles.

STATE OF THE ART

In the field of motor vehicle clutches, it is known to use a friction disc to transmit the torque between the engine and the gearbox. A conventional clutch friction disc comprises, as shown in FIG. 1, a support disc 101 made of sheet steel, in integral or floating connection with an annular web, and carrying on each of its faces a friction lining 102 consisting of a thick disc of friction material. The friction disc 100 is designed to be clamped between a pressure plate and a clutch reaction plate. These clutch plates are linked in rotation to an engine shaft not shown in Figure 1 - which can be the engine crankshaft in an application to the motor vehicle. The friction disc is fixed in rotation on a driven shaft - which can be the input shaft of the gearbox in an application to the motor vehicle - by means of its hub 103.

Thus, in the engaged position, the pressure plate ensures the adhesion of the friction disc on the reaction plate. In the clutch release phase, the pressure plate releases the friction linings, which disengages the motor shaft from the gearbox driven shaft.

A conventional friction clutch generally comprises, between the friction disc 100 and its hub 103, a torsion damping device 110 making it possible to filter the vibrations between the engine and the gearbox. In known manner, this damping device 110 comprises first and second guide washers secured to one another by means of spacers. The guide washers - of which only the first guide washer 111 is visible in Figure 1 5 can be rotatably mounted on the hub 103. In this case, the annular web is mounted floating around the hub. The support disc 101 carrying the linings 102 is then mounted integral with said web. On the contrary, the web can be rotatably mounted on the hub 103 and the guide washers 111 mounted floating around said hub. In this case, the support disc 101 is mounted integral with the guide washers 111, as shown in FIG. 1.

In the damping device 110 of FIG. 1, each of the first and second guide washers 111 comprises windows 112 formed in their thickness and adapted to each receive a helical spring of high stiffness 113. The web - not visible in FIG. 1 - also includes windows, axially facing the windows of the first and second guide washers 111, and adapted to each receive one of the helical springs 113. Several helical springs 113 are thus mounted in the guide washers and the web, circumferentially, to form an elastic system with circumferential effect. This elastic system participates in the transmission of the torque between the guide washers and the web - and therefore between the engine and the gearbox - and promotes flexibility in the transmission of torque so as to limit jolts and other acyclisms, especially when tightening and loosening the two clutch plates or during more or less sudden accelerations and decelerations.

Thus, although means are known for limiting the jolts and other acyclisms generated during the passage of the torque between the engine and the gearbox, it has been found that in certain cases, in particular in the presence of strong centrifugal effects, jolts persist during the passage of the couple. However, these jolts are uncomfortable for the driver of the vehicle and detrimental to the driving of the vehicle.

SUMMARY OF THE INVENTION

To respond to the problem mentioned above of jolts in particular during the passage of torque, the applicant proposes a phasing device adapted to bring an additional hysteresis effect in the damping device and, thus, optimize the filtration of jolts and other vibrations generated between the engine and the gearbox.

According to a first aspect, the invention relates to a phasing device for a friction clutch damper, characterized in that it comprises:

- a phasing washer adapted to be partially inserted into an elastic circumferential effect system of the friction clutch,

a friction washer adapted to be in contact with a flat portion of the elastic system, and

- an elastic washer positioned between the friction washer and the phasing washer.

This phasing device allows, when mounted in a friction clutch, to generate a hysteresis effect bringing additional flexibility to the passage of the torque between the engine and the gearbox, which results in a reduction jolts and vibrations in the vehicle and provides better driving comfort to the driver.

Advantageously, the friction washer is mounted integrally on the phasing washer.

According to a second aspect, the invention relates to a damping device for a friction clutch, comprising:

- first and second guide washers secured to each other and each provided with windows, and

- an elastic system with circumferential effect comprising helical springs, housed in the windows of the guide washers.

This damping device is characterized by the fact that it comprises a phasing device as defined above, in which the phasing washer is partially inserted between helical springs and the friction washer is in contact with the first guide washer . The damping device thus has an additional hysteresis effect compared to known damping devices.

The damping device may include one or more of the following characteristics:

- The phasing washer has locking tabs inserted between two helical springs so that said phasing washer is wedged with a predefined clearance between said helical springs;

- Each locking tab has two radially lugs, a first lug being inserted in a first helical spring, a second lug being inserted in a second helical spring;

- the pins have different shapes and / or dimensions from one another;

- Each locking tab has a double-sided cup, each side of which is wedged, respectively, in a first helical spring and in a second helical spring;

- the two faces of a double-sided cup have different shapes and / or dimensions from one another;

- The friction washer has fixing lugs fitted into notches of the phasing washer so as to secure the friction and phasing washers;

- The friction washer has anti-rotation tabs fitted into notches of the first guide washer so as to secure the friction washer and the rotating guide washer;

- The elastic washer is a so-called Belleville washer;

- The phasing device is mounted on an outer face of the first guide washer.

According to a third aspect, the invention relates to a friction clutch, in particular for a motor vehicle, comprising:

- a reaction plate intended to be locked in rotation on a driving shaft,

- a friction disc carrying friction linings and intended to be locked in rotation on a driven shaft,

a pressure plate capable of pressing the friction disc on the reaction plate, and

- a damping device, as defined above, mounted on the friction disc to filter vibrations between the driven shaft and the driving shaft.

BRIEF DESCRIPTION OF THE FIGURES

Other advantages and characteristics of the invention will appear on reading the description, illustrated by the figures in which:

- Figure 1, already described, shows a view of a friction disc according to the state of the art;

- Figure 2 shows a sectional view of a friction disc equipped with the phasing device according to the present invention;

- Figure 3 shows an exploded view of an example of phasing device îo according to the present invention;

- Figure 4 shows a semi-exploded view of a friction disc equipped with the phasing device according to the present invention;

- Figures 5A and 5B show views, respectively, front and perspective, of a friction disc equipped with the phasing device according to the present invention;

- Figures 6A and 6B show a top view and a bottom view of the phasing device according to one embodiment;

- Figures 7A and 7B show a top view and a bottom view of the phasing device according to another embodiment.

DETAILED DESCRIPTION OF AT LEAST ONE EMBODIMENT

An exemplary embodiment of a damping device and of a phasing device making it possible to bring an additional hysteresis effect to the damping device are described in detail below, with reference to the attached drawings. This example illustrates the characteristics and advantages of the invention. It is however recalled that the invention is not limited to this example.

In the figures, identical elements are identified by identical references. For reasons of readability of the figures, the size scales between the elements represented are not respected.

Traditionally, and as shown in FIG. 2, the friction disc 100 of a friction clutch comprises a support disc 101 fitted with friction linings 102 and a central orifice allowing its connection to the hub 103 of the clutch. The hub is mounted on the driven shaft 200 of the gearbox and is connected to the support disc by means of an annular web 104.

In the engaged position, a pressure plate applies a clamping force to the friction disc so as to transmit the torque produced by the engine to the gearbox. In order to limit the jolts, in particular during tightening or loosening, of the friction disc, a damping device 120, also called damper, is mounted between the friction linings 102 and the central orifice of said friction disc 100.

This damping device 120 comprises a first and a second guide washers, respectively 121 and 122, mounted in rotation around the hub 103 and secured to one another by means of spacers 123. The annular web 104 is arranged between the two guide washers 121, 122 coaxially and comprises, on its internal periphery, a set of peripheral teeth meshing in slots provided at the external periphery of the hub 103.

The damping device 120 further comprises an elastic system with a circumferential effect comprising several helical springs 124, of high stiffness, identical or different from one spring to another. The helical springs 124 are housed in windows 125 formed respectively in the guide washers 121, 122 and in the annular web 104. The helical springs are circumferentially in abutment, on the one hand, on the guide washers 121, 122 and, on the other hand, on the web 104. The elastic system with a circumferential effect thus participates in the transmission of the torque between the guide washers 121, 122 and the annular web 104.

In the example of FIG. 2, only two helical springs 124 are visible. Several helical springs, for example six, are however distributed over the circumference of the annular web and of the guide washers, as shown in Figures 4-5 described later. In the example described, the helical springs 124 are housed in pairs in the windows 125. In other words, two helical springs are mounted in the same window so that an angular displacement between the guide washers 121, 122 and the web 104 is authorized.

According to the invention, the damping device 120 comprises a phasing device 130 mounted on the first guide washer 121 and ensuring additional friction, in the damping device, during the relative angular displacement of the guide washers 121, 122 and the annular web 104. An example of such a phasing device 130 is shown in FIG. 3.

The phasing device 130 comprises a phasing washer 131, a friction washer 133 and an elastic washer 132. The phasing washer 131 is designed to be inserted at least partially between two helical springs 124. For this, the phasing washer 131 has an annular zone 131a, the surface of which is adapted to the surface of the first guide washer 121 lying between its internal periphery 121a and the periphery of the window 125. The phasing washer 131 also includes locking tabs 131b s' extending laterally from the outer periphery of the annular zone 131a. These locking tabs 131b are adapted to be inserted each in a window 125, between two helical springs 124. The phasing washer 131 further comprises notches 131e formed in the external periphery of its annular zone 131a.

The friction washer 133 is designed to be in contact with the first guide washer 121. For this, the friction washer 133 has an annular zone 133a of the same surface as the annular zone 131a of the phasing washer. One of the faces of the annular zone 133a is designed to be in contact with the first guide washer 121. The other face of this annular zone 133a has fixing lugs 133b capable of fitting into the notches 131e of the washer of phasing 131 so as to be blocked in rotation by the phasing washer 131.

The elastic washer 132 is designed to be positioned between the phasing washer 131 and the friction washer 133. The elastic washer can be, for example a Belleville washer. The elastic washer can also be a wavy washer of the Onduflex® type.

As shown in Figure 4, when mounting the phasing device

130 on the damping device 120, the friction washer 133 is deposited on the first guide washer 121. The elastic washer 132 is then deposited on the friction washer 133. The phasing washer 131 is then deposited on the elastic washer 132 of so that its locking tabs 131b are each positioned between two coil springs 124 of the same window 125. The locking tabs 131b of the phasing washer are then called between the two coil springs and the fixing tabs 133b of the washer friction are fitted into the 131st notches of the phasing washer.

In the example of FIG. 4, the phasing device 130 is mounted on the external face of the damping device 120 and, in particular, on the external face of the first guide washer 121. Those skilled in the art will understand that the device phasing can also be mounted inside the damping device 120, the locking tabs 131b of the phasing washer 131 then having forms îo different from those shown in FIGS. 2-4, adapted to be inserted between the annular web, spacers and other components of the damping device.

In FIGS. 5A and 5B, the phasing device 130 is shown mounted in the damping device 120. FIGS. 5A and 5B show the phasing washer 131 with its locking tabs 131b each called up between two helical springs 124. The phasing washer 131 is therefore held axially, with play, by the helical springs 124. The friction washer 133 is secured to the phasing washer 131 by means of the fixing lugs 133b. The elastic washer 132, between the phasing washer 131 and the friction washer 133, is calibrated so as to size the clearance between the locking tabs 131b and the springs 124.

In the examples of Figures 3-5, the friction washer 133 has three fixing lugs 133b. Those skilled in the art will understand that the number of fixing lugs can vary depending, for example, on the type of fixing chosen (fixing by clip, by interlocking, etc.). Similarly, in the examples of FIGS. 3-5, the phasing washer 131 comprises three locking tabs 131b, each locking tab being inserted and pressed between two helical springs 124 housed in the same window 125. A person skilled in the art will understand that the number of locking tabs can vary, for example, as a function of the number of helical springs and of the distribution of said helical springs in the guide washers and the annular web.

It will be understood from the above description that, in the examples of FIGS. 2-5, the phasing device 130 is mounted floating in the damping device 120 since the only connections between the phasing device and the damping device 120 are the locking tabs mounted with a clearance between the springs. Thus, a relative rotational movement of the phasing device 130 is authorized. This relative movement of the phasing device has the effect of generating a hysteresis effect between the phasing washer 131 and the first guide washer 121. The hysteresis effect is dimensioned by the play between the locking tabs 131b and the springs 124. This hysteresis effect, additional compared to the devices of the prior art, further accentuates the damping generated by the helical springs during the passage of the torque between the motor and the gearbox.

In other embodiments, not shown, the friction washer 133 is locked in rotation on the first guide washer 121. For this, anti-rotation tabs of the friction washer are provided for fitting into notches formed in the first guide washer 121. The friction washer 133 is then in friction on the phasing washer 131. In these embodiments, the phasing washer is mounted floating in the damping device 120, which allows a relative rotational movement of the phasing device 130 and the effects set out above.

The locking tabs 131b of the phasing washer 131 may be tabs with a flat structure, as shown in FIGS. 6A - 6B. In these embodiments, each locking tab 131b is a blade 131 f secured to the annular area 131a of the phasing washer and can be attached to the annular area or made in one piece with the annular area 131a, for example by cutting from a sheet. The blade 131f can be rectangular or trapezoidal in shape with a free end widened relative to the end attached to the annular zone 131a, as shown in FIGS. 6A-6B. Whatever their shape, the locking tabs 131b can be inclined relative to the plane of the annular zone 131a, for example by an angle of 30 °, 45 ° or 90 ° or any other angle depending on the position of the springs helical 124 relative to the annular zone 131a of the phasing washer.

Each locking tab 131b may include lugs 131c, 131d, positioned laterally on either side of the blade 131f. These pins 131c, 131d, for example obtained by cutting the contour of the blade 131f, can be of identical or different shapes and dimensions, the shapes and dimensions being adapted to the internal diameter of the coil springs 124. Thus, when the springs helical 124 of the damping device 120 are identical, the pins 131c, 131 d are identical. On the contrary, when two helical springs 124 in the same window 125 are different - for example because they are of different stiffness - then the lug 131c on one side of the blade 131f has a shape and / or dimensions different from l lug 131 d on the other side of the blade 131 f.

The locking tabs 131b of the phasing washer 131 can be cup tabs, as shown in FIGS. 7A - 7B. In these embodiments, each locking tab 131b is a tongue 134a secured to the annular zone 131a of the phasing washer. The tongue 134a can be attached to the annular zone or made in one piece with said annular zone 131a, for example by cutting from a sheet. Each tab 134a solidly supports a double-sided cup 134b directed towards the friction washer 133. The double-sided cup 134b is a bent piece, each face or end of which is adapted to fit into one of the coil springs 124 of a window 125 so that the double-sided cup is wedged between two consecutive helical springs. The ends of the bent part can be a flat face fitted with a 134c, 134d, as shown in FIGS. 7A-7B. Alternatively, the ends of the bent piece may be conical or domed so as to fit in the center of the coil springs. The angle of the elbow formed by the double-sided cup 134b is adapted to the spacing between two helical springs and to the diameter of the guide washers 121, 122.

Thus, the phasing device which has just been described generates, in the damping device, an additional hysteresis effect compared to the devices of the prior art, which allows optimal filtering of the jolts and other vibrations generated during the passage of the torque between the engine and the gearbox.

According to a second aspect, the invention relates to a motor vehicle clutch which comprises a reaction plate intended to be wedged in rotation on a driving shaft, a friction disc carrying friction linings and intended to be wedged in rotation on a driven shaft, a pressure plate capable of pressing the friction disc on the reaction plate and a damping device as described above. Such a damping device ensures a relatively flexible passage of torque between the engine and the gearbox.

Although described through a certain number of examples, variants and embodiments, the phasing device, the damping device and the clutch according to the invention include various variants, modifications and improvements which will become obvious to humans. of the art, it being understood that these variants, modifications and improvements form part of the scope of the invention, as defined by the claims which follow.

Claims (13)

1. Phasing device (130) for a friction clutch damper, characterized in that it comprises: 5 - a phasing washer (131) adapted to be partially inserted into an elastic system with a circumferential effect of the friction clutch, a friction washer (133) adapted to be in contact with a flat portion of the elastic system, and - An elastic washer (132) positioned between the friction washer and the phasing washer. 2. Phasing device according to claim 1, characterized in that the friction washer (133) is mounted integrally on the phasing washer (131). 3. Damping device (120) for friction clutch, comprising: - first and second guide washers (121, 122) integral with one 15 on the other and each provided with windows (125), - an elastic system with a circumferential effect comprising helical springs (124), housed in the windows (125) of the guide washers, characterized in that it comprises a phasing device (130) according to claim 1 in which the washer phasing (131) is partially inserted 20 between helical springs (124) and the friction washer (133) is in contact with the first guide washer (121). 4. Damping device according to claim 3, characterized in that the phasing washer (131) has locking tabs (131b) inserted between two helical springs (124) so that said phasing washer is wedged 25 with a clearance between said helical springs. 5. Damping device according to claim 4, characterized in that each locking tab (131b) has two radially lugs (131c, 131 d), a first lug (131c) being inserted in a first helical spring, a second lug (131 d) being inserted into a second helical spring. 30 6. Damping device according to claim 5, characterized in that the pins (131 c, 131 d) have different shapes and / or dimensions from one another. 7. Damping device according to claim 4, characterized in that each locking tab (131b) comprises a double-sided cup (134), each face (134b, 134c) is wedged, respectively, in a first helical spring and in a second helical spring. 8. Damping device according to claim 7, characterized in that the two faces (134b, 134c) of a double-sided cup (134) have different shapes and / or dimensions from one another. 9. Damping device according to any one of claims 3 to 8, characterized in that the friction washer (133) comprises fixing lugs (133b) fitted into notches (131e) of the phasing washer (131) of so as to secure the friction and phasing washers. 10. Damping device according to any one of claims 3 to 8, characterized in that the friction washer (133) has anti-rotation tabs fitted into notches in the first guide washer so as to secure the friction washer and the guide washer (121) in rotation. 11. Damping device according to any one of claims 3 to 10, characterized in that the elastic washer (132) is a so-called Belleville washer. 12. Damping device according to any one of claims 3 to 11 characterized in that the phasing device (130) is mounted on an outer face of the first guide washer (121). 13. Friction clutch, in particular for a motor vehicle, comprising: - a reaction plate intended to be locked in rotation on a driving shaft, - a friction disc carrying friction linings and intended to be locked in rotation on a driven shaft, a pressure plate capable of pressing the friction disc on the reaction plate, and - a damping device (120) mounted on the friction disc to filter vibrations between the driven shaft and the driving shaft, characterized in that the damping device conforms to any one of claims 3 to 12. 1/4 133b 2/4 3/4 120