KR20040095173A - Friction clutch, in particular for a motor vehicle - Google Patents

Abstract

PURPOSE: A friction clutch of a vehicle is provided to restrict axial deformation of a first predamper guide washer by contacting the center of the first guide washer to the second guide washer. CONSTITUTION: Two guide washers(8,12) are rotated and fastened to an input element and an output element, and a damper plate(13) is rotated and fixed to the input element or the output element. An elastic member(14) is embedded to windows(8F,12F,13F) of the guide washers and the damper plate and operated circumferentially. A damping unit is composed of friction units axially operated in the center of the first guide washer. A friction clutch combines two rotary input elements with the output element. The center of the first guide washer is contacted to the second guide washer by contact units(T,D).

Description

Friction clutch {FRICTION CLUTCH, IN PARTICULAR FOR A MOTOR VEHICLE}

The present invention relates to a friction clutch for automobiles.

In automobiles, the friction clutch ensures torque continuity and filters vibrations from the engine, as well as friction grip between the pressure plate and the engine flywheel, thus providing the ability to transfer torque between the rotational input element and the rotational output element. do.

For example, in the prior art according to French Patent Publication No. 2 804 190 (French Patent Application 00 00950), two guide washers are rotatably fixed to an input element or an output element, and rotationally fixed to the output element or an input element. A damping plate comprising a damper plate, a circumferentially elastic member embedded in the guide washer and a window provided in the damper plate, and a means for coupling comprising a chucking means axially acting on the central portion of the first guide washer. Friction clutches for automobiles are already known which are intended to combine two substantially coaxial rotational input elements and output elements.

The damping means generally comprise energy accumulating means (in particular springs) and energy dissipating means comprising friction means.

More specifically, the damping means is arranged in the friction device of the clutch. The input element is formed by a friction disk, and the output element is formed in particular by a hub which is intended to be coupled to the gearbox input shaft.

The damping means forms a predamper of this friction means. The predamper includes a friction washer that is elastically forced to the central portion of the first guide washer by an axially acting elastic washer.

Moreover, the friction device further comprises a main damper. The second guide washer of the predamper forms a damper plate of the main damper. The friction disk is fixed to the first guide washer of the main damper. An elastic damper acting in the axial direction is interposed between the friction washer and the guide washer of the main damper supported by this elastic member in the axial direction.

However, the first guide washer of the predamper is largely drilled due to the presence of a window with a spring acting in the circumferential direction, and a relatively small diameter of the first guide washer of the predamper. Therefore, the first guide washer of the predamper is not stiff in the axial direction and tends to deform under the influence of the elastic washer acting in the axial direction (the first guide washer of the predamper is formed conical). This deformation can cause parasitic friction between the damper plate and the first guide washer of the predamper.

One solution is to preconform the first guide washer of the predamper into a conical shape so as to be flat under the influence of the load of the elastic member acting in the axial direction. However, these loads are variable, especially depending on the vehicle or engine. As a result, the predeformation of the guide washer depends on the load applied to it. Thus, such predeformation is undesirable for reasons of standardization.

Another solution can be configured to increase the thickness of the first predamper guide washer. However, increasing the axial size of the first predamper guide washer is difficult because of the configuration between the guide washer of the predamper and the damper plate of the main damper.

It is an object of the present invention, in particular, to limit the axial deformation of the first predamper guide washer to which the elastic washer exerts force.

To this end, the object of the present invention is a friction clutch for an automobile intended to combine two substantially coaxial rotational input and output elements of the type described in French Patent Publication No. 2 804 190, wherein the friction clutch for the automobile is a first. And means for contacting the central portion of the first guide washer with respect to the second guide washer.

Accordingly, the first guide washer supported on the second guide washer is not substantially deformed and does not come into contact with the damper plate, which may cause disturbing friction.

According to the optional features of the friction clutch,

The contact means comprises a substantially axial lug abutting against a substantially radial tooth on the second guide washer, fixed to the center of the first guide washer,

The damper plate is defined by an inner contour with radial recesses allowing passage of the contact lugs of the first guide washer,

The friction means comprise a friction member that is elastically forced against the central portion of the first guide washer by an axially acting elastic member,

The friction member is rotatably connected to the damper plate with a circumferential gap,

The damping means is arranged in the friction device of the clutch, the input element is formed by a friction disk and the output element is formed by a hub, which is in particular intended to be coupled to the gearbox input shaft,

The damping means form a predamper of the friction device,

The friction device further comprises a main damper, the second guide washer of the predamper forming a damper plate of the main damper, the damper plate of the predamper and the main damper respectively having a circumferential gap and without a circumferential gap. Rotatably connected to, the friction disk is fixed to the first guide washer of the main damper,

An elastic member acting in the axial direction is interposed between the friction washer and the guide washer of the main damper, which the elastic member supports elastically,

The axially acting elastic member is rotatably connected to the guide washer it supports.

The invention will be better understood by looking at the following detailed description, which is provided by way of example only and with reference to the accompanying drawings.

1 is an upper half view of an axial cross section of a friction clutch according to the invention,

2 is a bottom half view of the axial section of the friction clutch according to the invention,

3 is a perspective view of an element of a predamper of the friction clutch shown in FIGS. 1 and 2;

4 is a perspective view of a second guide washer of the predamper;

5 is a perspective view of a damper plate of the predamper;

6 shows the internal contour of the damper plate of the predamper,

7 is a perspective view of a first guide washer of the predamper;

Explanation of symbols for the main parts of the drawings

1: friction disc 2: cylindrical hub

3, 4: guide washers 5, 6: annular bearing

8: annular damper plate 9: helical spring

1 and 2 show a friction clutch (denoted by reference numeral E as a whole) which is an example described for an automobile.

This friction clutch E comprises a friction device with damping means comprising a main damper A1 and a predamper A2. These dampers A1 and A2 are mounted between a rotational input element such as a friction disk 1 and a rotational output element such as a cylindrical hub 2 for transmitting rotational torque to a driven shaft such as an input shaft of a gearbox. . The input and output elements are substantially coaxial.

In a known form, the friction disc 1 is intended to be gripped between an engine flywheel rotatably fixed to a driven shaft, such as a crankshaft of an internal combustion engine, and a pressure plate actuated by coupling means. The hub 2 comprises a longitudinal internal flute for rotationally connecting the hub 2 to the end of the driven shaft.

The main damper comprises two guide washers 3, 4 fixed to each other and rotatably mounted on the hub 2 by each of the annular bearings 5, 6. The friction disc 1 is fixed to the first guide washer 3 by rivets 7.

The annular damper plate 8 (shown separately in FIG. 4) is arranged coaxially with them between the two guide washers 3, 4, and with a predetermined set of teeth on the outer periphery of the hub 2. The inner peripheral portion includes a set of interdigitated teeth having a circumferential gap. 4 shows the teeth D of the inner set on the damper plate 8 forming a substantially radial protrusion intended to cooperate with complementary outer recesses on the hub 2.

A circumferentially elastic member, such as a high rigid helical spring 9, is embedded in the window 10 in the guide washers 3, 4 and the window 11 in the annular damper plate 8. The first group of elastic members 9 are housed in the above-described windows 10 and 11 without gaps in the circumferential direction, and from the start of rotation the rotational torque between the guide washers 3 and 4 and the damper plate 8 is prevented. Engage in delivery. The second group of elastic members 9 is embedded in the window 10 in the guide washer without the circumferential gap and is embedded in the window 11 in the annular damper plate 8 with a predetermined circumferential gap. Rotation only if the respective movement between 3 and 4 and the annular damper plate 8 exceeds a predetermined value corresponding to the circumferential gap between the elastic member 9 and the window 11 of the damper plate 8. It is involved in the transmission of torque.

Thus, the first group of elastic members 9 permanently transmits torque, and the second group of elastic members 9 provides for the angular movement between the guide washers 3, 4 and the annular damper plate 8 above. Torque is transmitted only when it is larger than the predetermined value. Thereby, damping of vibration and torque irregularities is achieved, and the second group of elastic members allows the respective motions between the guide washers 3 and 4 and the annular damper plate 8 to exceed the limit as in the idle position. Only works.

The predamper A2 forms a connection between the annular damper plate 8 of the main damper and the hub 2. In figure 3 some elements of the predamper A2 can be seen.

This predamper A2 comprises a first and a second guide washer. The first guide washer of the predamper is a washer 12 (shown separately in FIG. 7) which is rotatably fixed to the damper plate 8. This is because the lug P of the outer periphery is fitted into the complementary notch C provided in the inner contour of the window 11 in the main damper plate 8 to be fixed in rotation with the main damper plate 8 (FIG. 3). 4 and 7). The lug P also forms an axial bracing element with respect to the first and second guide washers of the predamper A2 by the cooperation of the damper plate 8 surface with these shoulders P. . The second guide washer of the predamper is formed by the annular damper plate 8 itself.

The annular damper plate 13 of the predamper (shown separately in FIG. 5) is disposed between the annular damper plate 8 and the washer 12, for example by engaging an outer circumferential set of teeth on the hub 2. Is rotated to FIG. 5 shows a notch 11 provided on the inner circumference of the damper plate 8 intended to cooperate with complementary outer teeth on the hub 2. Thus, the damper plate 13 of the predamper is rotatably connected to the hub 2 without a circumferential gap.

A circumferentially elastic member 14, such as a helical spring having a relatively low stiffness, is provided with an annular damper plate 8 of the main damper for transmitting a rotational torque between the annular damper plate 8 and the hub 2, It is built in the windows 8F, 12F, 13F in the washer 12 and the annular damper plate 13 of the predamper. In a form similar to the main damper, the elastic members 13 are classified into two groups. Thus, some elastic members 1 are mounted in the above-mentioned windows without circumferential gaps and are involved in the transmission of torque from the start of rotation, while the other elastic members 14 are annular damper plates 8 and guide washers. It is mounted in the windows 8F and 12F of (12) without the circumferential gap, and is mounted in the window 13F in the annular damper plate 13 of the predamper with a predetermined circumferential gap, and the damper plate 8 And, on the one hand, the guide washer 12 and, on the other hand, are involved in the transmission of the rotational torque only when the angular movement between the annular damper plate 13 of the predamper is larger than the aforementioned circumferential gap.

Therefore, all the elastic members 9 and 14 cause damping of vibration and torque irregularities absorbed by the pre-damper and the main damper to four levels, and this damping level is gradually increased. This is because the elastic members 14 of the predamper A2 form two damping levels that vary depending on whether they are mounted with or without a circumferential gap in their corresponding windows. Furthermore, at the end of the run of the main damper A1, the elastic members 9 of these dampers A1 form two additional damping levels which depend on whether they are mounted with or without a circumferential gap in their corresponding windows. do.

In order to damp the vibrations and irregularities absorbed by the elastic members 14, 9, friction means located between the guide washers 3, 4 of the main damper are engaged with the predamper A2 and the main damper A1. .

Regarding the predamper A2, the first friction means is formed by the bearings 5 and 6 that cooperate with the hub 2.

The bearing 6 for centering the guide washer 4 of the main damper comprises a truncated conical inner circumference which contacts on the truncated conical surface 15 of the hub 2. The bearing 6 comprises a finger 16 which extends parallel to the axis of rotation and is engaged in a corresponding orifice 16A in the guide washer 4 to connect the bearing 6 and the washer 4 together for rotation. do.

The bearing 5 of the first guide washer 3 is in axial contact with the shoulder 17 on the hub 2 formed by the radial end face of the outer tooth on the hub.

An elastic axial compression washer 18 is mounted in contact between the guide washer 3 and the bearing 5 to force the bearing 5 in contact with the frustoconical surface 15 of the hub 2. .

The elastic washer 18 is rotationally fixed with the bearing 5 by the cooperation of lugs and complementary notches.

In the embodiment shown, the bearings 5, 6 are made of fiber reinforced plastic material, if possible, and exert relatively moderate friction on the hub 2.

The second friction means combined with the predamper comprises an axial direction on the friction washer 19 disposed between the first guide washer 3 and the guide washer 12 of the predamper and the guide washer 12 of the predamper. The contacting state includes an elastic axial compression washer 20 mounted in contact between the first guide washer 3 and the friction washer 19 to force this friction washer 19.

The friction washer 19 is forced by the elastic washer 20 relative to the center of the guide washer 12 (ie radially inside).

The elastic washer 20 is rotationally fixed to the guide washer 3 of the main damper by the cooperation of lugs and complementary notches.

In order to prevent any undesirable deformation of the washer 12, the first guide washer 12 of the predamper is relatively precisely perforated (see FIG. 7), and the predamper A2 is [damper plate 8 Means for contacting the central portion of the first guide washer 12 with respect to the second guide washer of the predamper.

Preferably, as can be seen in particular in FIG. 3, the contact means is in contact with the substantially radial teeth D of the second guide washer of the predamper (damper plate 8 of the main damper). And a substantially axial lug T extending the inner contour of the central portion of the first guide washer 12.

5 and 6, the inner contour of the damper plate 13 of the predamper is defined by the separation sector of the notch N. Some such separating sectors have a radial recess G which allows the passage of the contact lug T of the first guide washer 12 of the predamper.

The friction washer 19 is rotatable at its outer circumference with an end of the elastic member 14 mounted with a friction washer 19 and a circumferential gap in the window 13F in the annular damper plate 13 of the predamper. Lugs (not shown) for connection. Accordingly, the friction washer 19 is rotatably connected to the damper plate 13 of the predamper with a circumferential gap. The angular movement between the damper plate 13 and the assembly formed by the damper plate 8 of the main damper and the guide washer 12 is in the circumferential gap of the elastic member 14 in the window in the damper plate 13. The friction washer 19 does not rotate with the annular damper plate 13 of the predamper when the corresponding predetermined value is exceeded.

As for the main damper A1, the first friction means firstly comprises a friction washer disposed between the guide washer 3 of the main damper, secondly the main guide washer 12 and the damper plate 13 of the predamper. 22).

In order to force the friction washer 22 to axially contact on the guide washer 12 of the predamper 12 and secondly on the damper plate 13 of the predamper, the elastic axial compression washer 23 is formed of the main damper. It is mounted in contact between the guide washer 3 and the friction washer 22.

This is because the friction washer 22 is fixed to the guide washer 12 by fitting the lug 24 into the window 12F of the guide washer 12. The lug 24 is supported on the damper plate 13 of the predamper.

The elastic washer 23 is rotatably fixed to the guide washer 3 of the main damper by the cooperation of lugs and complementary notches.

The second friction means of the main damper comprises a friction washer 25 arranged between the guide washer 4 of the main damper and the annular damper plate 13.

The friction washer 25 is rotatable to the damper plate 8 of the main damper by fitting the peripheral lugs 26 in a complementary notch C provided in the inner contour of the window 11 of the damper plate 8 of the main damper. Is fixed.

Under the influence of the compressive force of the elastic washer 23 transmitted through the lug 24 and the damper plate 13, the friction washer 25 is driven between the friction washer 25 and the second guide washer 4. Forced in axial contact with the washer 28. This drive washer 28 cooperates with the damper plate 8 with a circumferential gap. This fits with the circumferential gap in the window 11 of the damper plate 8 in which the lug 29 extending in the axial direction of the drive washer 28 has the elastic member 9 with the circumferential gap. Because it becomes.

Moreover, drive washer 28 is rotationally secured to friction washer 30 by fitting the end of complementary notch error lug 29 in such friction washer 30. This friction washer 30 is actuated elastically by an elastic axial compression washer 31 supported on the friction washer 30 and the first guide washer 3.

The elastic washer 31 is rotationally fixed to the first guide washer 3 by the cooperation of lugs and complementary notches.

The function of the friction clutch E, in particular the continuation of the four damping levels, is described in general in French Patent Publication No. 2 804 190, for example. However, a specific form of the function of the friction clutch E shown in the figure will be described below.

In the tickover of the internal combustion engine coupled to the clutch E according to the invention, the main damper A1 behaves similarly to the rigid member because of the relatively high rigidity of the elastic member 9 and is supplied by the engine crankshaft. The rotated torque is transmitted directly by the friction disk 1 to the annular damper plate 8 of the main damper, which forms the input member of the predamper A2.

At the end of the operation of the second damping level of the predamper, the damper plate 3 of the predamper is first rotatable to the damper plate 8 of the main damper, which forms the guide washer 12 of the predamper and the guide washer of the main damper. And secondly to two friction washers (22, 25). In addition, the damper plate 13 of the predamper is fixed to the friction washer 19. For this reason, at the end of the movement of the predamper, the friction between the friction washer 19 and the guide washer 12 is blocked while the friction between the friction washer 19 and the elastic washer 20 is maintained. The blocked friction is firstly the friction between the friction washer 22 and the elastic washer 23, and secondly the driving washer cooperating with the friction washer 25 and the circumferential clearance with the damper plate 8 of the main damper. The friction between 28 changes.

When the second damping level of the main damper is activated, the drive washer 28 moves with the damper plate 8 to block the friction between the friction washer 25 and the drive washer 28.

However, the blocked friction firstly turns into friction between the friction washer 30 and the elastic washer 31 and secondly between the drive washer 28 and the second guide washer 4.

The present invention is not limited to the embodiment described above. In particular, it may be provided, if necessary, with a main damper having means for contacting the center of the guide washer of the main damper with respect to the other guide washer of this main damper.

According to the friction clutch for automobile according to the present invention, it is possible to limit the axial deformation of the first pre-damper guide washer in which the elastic washer is forced.

Claims (10)

Two guide washers (8, 12) rotatably fixed to the input element (1) or the output element (2), and a damper plate (13) rotatably fixed to the output element (2) or the input element (1); A circumferentially elastic member 14 embedded in the guide washers 8 and 12 and the windows 8F, 12F and 13F provided in the damper plate 13, and the center of the first guide washer 12; Intended to couple two substantially coaxial rotational input elements 1 and output elements 2 of the type comprising damping means A2 with friction means 19, 20 acting axially on the float. In a friction clutch for automobile, And means (T, D) for contacting the central portion of the first guide washer (12) against the second guide washer (8). Friction clutch. The method of claim 1, The contact means comprise a substantially axial lug T which abuts against the substantially radial teeth D on the second guide washer 8 and is fixed to the center of the first guide washer 12. Characterized by Friction clutch. The method of claim 2, The damper plate 13 is characterized in that it is defined by an inner contour with radial recesses allowing passage of the contact lugs of the first guide washer. Friction clutch. The method according to any one of claims 1 to 3, The friction means comprises a friction member 19 which is elastically forced against the central portion of the first guide washer 12 by an elastic member 20 acting axially. Friction clutch. The method of claim 4, wherein The friction member 19 is characterized in that it is rotatably connected to the damper plate 13 with a circumferential gap. Friction clutch. The method according to any one of claims 1 to 5, The damping means are arranged in the friction device of the clutch, the input element being formed by a friction disc 1, the output element being in particular formed by a hub 2 intended to be coupled to the gearbox input shaft. By Friction clutch. The method of claim 6, The damping means is characterized in that to form a pre-damper (A2) of the friction device. Friction clutch. The method of claim 7, wherein The friction device further comprises a main damper A1, the second guide washer of the predamper A2 forms a damper plate 8 of the main damper, and the predamper A2 and the damper of the main damper. The plates 13, 8 are each rotatably connected to the hub 2 with no circumferential gap and with a circumferential gap, the friction disc 1 being fixed to the first guide washer 3 of the main damper. Characterized in that Friction clutch. The method according to claim 4 or 8, The elastic member 20 acting in the axial direction is interposed between the guide washer 3 and the friction member 19 of the main damper elastically supported by the elastic member 20. Friction clutch. The method of claim 9, The axially acting elastic member 20 is characterized in that it is rotatably connected to the guide washer 3 on which it is supported. Friction clutch.