EP2766624A1

EP2766624A1 - Device for controlling a cluch

Info

Publication number: EP2766624A1
Application number: EP12773058.8A
Authority: EP
Inventors: Claudio Canini
Original assignee: Renault SAS
Current assignee: Renault SAS
Priority date: 2011-10-14
Filing date: 2012-09-19
Publication date: 2014-08-20
Also published as: WO2013054016A1; FR2981418A1; BR112014008830A2; FR2981418B1

Abstract

The invention relates to a device (1) for controlling a clutch, which comprises two main members, including: a clutch-release bearing (30), which is arranged such that it is mounted so as to be translatably movable relative to the housing of said clutch; and a fork (10), which is arranged such that it is mounted so as to be tiltably movable relative to the housing of said clutch, and which includes two bearing portions suitable for engaging with two corresponding bearing portions (34) of said clutch-release bearing in order to translatably move said bearing due to the tilting of the fork. According to the invention, the bearing portions of one of said two main members form grooves, and the bearing portions of the other of said two main members form bulges, each of which engage with the edges of the corresponding groove via point or linear contacts.

Description

FIELD OF THE INVENTION The present invention relates generally to the means for disengaging an engine, in particular to change a gear ratio.

It relates more particularly to a control device of a clutch, comprising two main organs including:

a clutch abutment which is arranged to be mounted mobile in translation relative to the casing of said clutch, and

- u mad rch ette which is agen cée can be mounted mob he e in tilting relative to the housing of said clutch and which comprises two bearing portions adapted to come into contact with two corresponding bearing portions of said abutment clutch to move the latter in translation through the tilting of the fork.

It applies more particularly to the cable control of a friction clutch.

BACKGROUND

A friction clutch is generally equipped with first and second friction discs interposed relative to one another, the first friction discs being locked in rotation on an input shaft, and the second friction discs being rotatably locked. on an output tree.

In the engaged position, these discs are pressed against each other by a diaphragm, so that the rotational speeds of the input and output shafts are the same.

When the driver presses on the clutch pedal, the diaphragm translates in such a way that it releases the discs, so that the input and output shafts are free to rotate at different speeds.

The connection between the clutch pedal and the diaphragm is then performed by a clutch control device as mentioned above, the fork is connected at its upper end to a traction cable actuated by the clutch pedal, and the stop is located in abutment against the diaphragm to push it back when the driver presses on the clutch pedal.

In particular, a ring-shaped clutch abutment is known. engaged on the input shaft, having a rear face bearing against the diaphragm and a flat front face against which the two cam-shaped arms of the fork rest.

It is unfortunately observed that this type of control device is sensitive to aging, in that the wear of the fork, the clutch abutment and the traction cable causes a significant increase in the friction of the different elements on each other. other, to become annoying for the driver when he must depress the clutch pedal.

Another disadvantage of this type of control device is that, when the fork pivots, the bearing portions of the fork slide on the front face of the clutch abutment, so that the force generated by these supports has a positive effect. variable position and is not constantly confused with the axis of translation of the clutch abutment. It then follows an increase in friction generated by the translation of the clutch abutment, and even a risk of jamming of this clutch abutment.

OBJECT OF THE INVENTION

In order to overcome the aforementioned drawbacks of the state of the art, the present invention proposes a control device that is not very sensitive to aging.

More particularly, there is provided according to the invention a control device as defined in the introduction, wherein the support portions of one of said two main organs form grooves and the bearing portions of the other of said two main organs form bulges which each rely on the edges of the corresponding groove by point or linear contacts.

Thus, regardless of the inclination of the fork relative to the clutch abutment, the contact surface between these two main bodies has a substantially zero area, so that the effort that the driver must provide on the pedal of 'clutch to overcome friction is very reduced.

The use of bulges and grooves also ensures good aging of the control device, in that the contact surfaces will have, after aging, an area that has only very slightly increased.

Advantageously, said fork has a recess which is adapted to be engaged on a finger of the housing of said clutch so that the fork is movable in tilting relative to the finger about a tilting axis and has a mobility game in translation on the finger along an orthogonal axis said axis of tilting and the axis of translation of the clutch abutment.

In this way, when the fork tilts with respect to the clutch abutment, the recess provided on the fork slides naturally on the housing finger so that each of the bulges remains in abutment against the two edges of the corresponding groove. provided on the clutch release.

The point where then applies the force generated by the fork on the clutch abutment thus has an invariable position, which avoids any jamming of the clutch abutment.

Other advantageous and non-limiting features of the control device according to the invention are the following:

- The bearing portions of one of said two main members have symmetrical surfaces of revolution about the same axis perpendicular to the axis of translation of the clutch abutment;

- said bearing portions have spherical surfaces, that is to say surfaces corresponding to portions of spheres;

- Said grooves are profiled along the same axis perpendicular to the axis of translation of the clutch abutment;

the fork comprises an elongate body, one end of which has a housing for receiving one end of a pulling cable and of which another end has two arms each pierced with a hole for receiving a ball, a portion emerged from the surface of each ball forming said support portion;

each ball is engaged in force in said reception opening;

- There are provided return means for holding the two support portions of the fork in contact with two corresponding bearing portions of said clutch abutment;

said return means comprises a spring blade having an annular body mounted on the clutch abutment, and two arms which extend from the annular body and which cooperate with the grooves to take the sandwich fork; - The annular body of said leaf spring is movably mounted in translation on the clutch abutment along an axis orthogonal to the axis of tilting of the fork and the axis of translation of the clutch abutment.

DETAILED DESCRIPTION OF AN EXEMPLARY EMBODIMENT The following description with reference to the accompanying drawings, given by way of non-limiting examples, will make it clear what the invention consists of and how it can be implemented.

In the accompanying drawings:

- Figure 1 is a schematic perspective view of a control device according to the invention;

- Figure 2 is a schematic perspective view of the leaf spring of the control device of Figure 1;

FIG. 3 is a schematic plan view of the control device of FIG. 1;

- Figure 4 is a schematic sectional view along the plane B-B of Figure 3;

- Figure 5 is a schematic sectional view along the plane A-A of Figure 3; and

FIG. 6 is a detailed view of zone VI of FIG. 5.

In Figures 1 and 3 to 5, there is shown a control device 1 by cable of a friction clutch of a motor vehicle.

In a manner known per se, a friction clutch comprises a housing from which two input and output shafts project, and which houses at least one friction disk rotatably connected to the input shaft and a friction disc in rotation to the output shaft.

A diaphragm, located in the housing, is engaged on the input shaft. It allows, in the engaged position, to compress the friction discs one on the other so that the output shaft is coupled to the input shaft.

The control device 1 allows meanwhile, when the driver of the motor vehicle presses on the clutch pedal, to push the diaphragm to release the discs, so that the input and output shafts are free to rotate at different speeds.

The control device 1 comprises for this purpose:

a fork 10 which is mounted to tilt on a finger 70 (Figure 1) attached to the clutch housing, and which is actuated by a traction cable connected to the clutch pedal so as to switch to the disengaged position when the driver presses the clutch pedal, and

- A clutch abutment 30 which is slidably mounted on the input shaft of the clutch, along a translation axis A1, so as to be able to push the diaphragm by its front face when the fork 10 tilts.

The spindle 10 comprises a longitudinal body 1 1 along a longitudinal axis A7, one end 12 of which has a receiving housing 16 at one end of the pulling cable, and another enlarged end of which splits in two. arm 1 3 arranged to abut against the rear face of the clutch abutment 30. It has at mid-length a recess 15 (Figure 5) engaged on the finger 70 of the clutch housing to allow the fork 10 of pivot about an axis of rotation A4 orthogonal to said translation axis A1 (Figure 3).

The clutch abutment 30 comprises in turn a ring 35 (FIG. 4) cylindrical of revolution about the translation axis A1, which is slidably mounted on the input shaft and which is lined at one end by a flange 31 in the form of a flat disc. As shown in FIG. 3, the flange 31 here carries two rectangular appendices 32 which are radially aligned with the outer peripheral edge of the flange 31 and which are situated opposite each other. with respect to the translation axis A1.

The arms 13 of the fork 10 and the flange 31 of the clutch abutment 30 carry complementary bearing parts, adapted to come into contact with each other, so that the tilting of the fork 10 on the finger 70 of the The clutch housing causes the clutch abutment 30 to slide on the input shaft of the clutch.

As shown in Figure 6, according to a particularly advantageous characteristic of the invention, the support portions carried by one of the two bodies that are the fork 1 0 and the clutch abutment 30 form grooves 34, while the bearing portions carried by the other member form bulges 21 which each rest on the two edges of the groove 34 corresponding by point or linear contacts.

Here, the bulges 21 have spherical shapes, so that they rest on the two edges of the corresponding groove 34 by point contacts. Alternatively, these bulges could have cylindrical shapes, in which case they would rely on the two edges of the corresponding groove by linear contacts.

In the embodiment of the invention which is shown in the figures, the body 1 1 of the fork 1 0 generally has an isosceles triangle shape, with two sides 1 1 A, 1 1 B and a base 1 1 C ( Figures 1 and 3).

It is bordered, on its two sides 1 1A, 1 1 B, by a stiffening rib 18 which extends rearwardly.

The vertex 12 of the isosceles triangle formed by the body 1 1 of the fork

10 is rounded.

It is traversed by a slot 17 which extends along the longitudinal axis A7, to a circular opening 16 located at the bottom of a recess 16A (Figure 5) provided recess in the front face of the body 1 1 of the fork 10.

This recess 16A then corresponds to the aforementioned housing housing, since it allows to retain a lug provided at the end of the pull cable. The slot 17 makes it possible to install the traction cable on the fork 10, so that this lug is housed in the recess 16A and rests on the edges of the circular opening 16.

As shown in FIG. 3, the base 1 1 C of the isosceles triangle formed by the body 1 1 of the fork 10 is in turn curved along a circular arc of diameter substantially equal to the outside diameter of the flange 31 of the abutment. clutch 30, so that its two ends form said two arms 13 and that the latter are adapted to bear on the two appendages 32 of the clutch abutment 30.

As shown in FIG. 6, each arm 13 of the body 1 1 of the fork 10 is pierced with a through bore 14 of axis A5 orthogonal to the mean plane of the body 11 of the fork 10.

Each through bore 14 has a rearward sectional reduction, so as to have a front portion 14B of large diameter and a rear portion 14A of smaller diameter separated by a shoulder 14C.

A ball 20 is then engaged in force in the front portion 14B of each through bore 14, such that each of these balls 20 bears against the side wall of the front portion 14B of the through bore 14 corresponding and against the shoulder 14C, and a part of its surface emerges at the front of this through bore 14.

The emerging portion 21 of the surface of each ball 20 then corresponds to the aforementioned bulge. This emerging portion 21 thus has a spherical shape (and more specifically a spherical cap shape) and is arranged to come into contact with the edges of the corresponding groove 34 of the clutch abutment 30.

At this stage, it will be noted that, thanks to the invention, it is possible to manufacture the body 1 1 of the fork 1 0 in a material of average hardness, inexpensive, and to make the balls in a material of high hardness, way that the fork 10 has a reduced cost and is not prone to aging.

As shown in FIGS. 4 and 6, the grooves 34 provided in the clutch abutment 30 are in turn formed by the same trough 33 which extends recessed in the rear face of the flange 31.

This g o u tt i ere 33 is i c i d i e e u a u co u rs of a stamping operation of the clutch abutment, so that it forms a rib projecting from the front face of the flange 31.

It is profiled along an axis A3 perpendicular to the translation axis A1 and extends from one to the other of the appendages 32 of the flange 31.

It has a U-shaped transverse profile, with a flat bottom and two parallel side edges that connect to the rest of the flange 1 by a rounded radius of curvature reduced.

The two lateral edges of this U are separated from each other by a distance strictly smaller than the diameter of the balls 20, so that the emergent portion 21 of the surface of the ball 20 can come to bear against the two edges of the gutter 33.

To maintain the balls 20 of the fork 10 in abutment against the two edges of the trough 33 of the clutch abutment 30, here there is provided elastic return means 50.

As shown in Figure 2, these biasing means are in the form of a leaf spring 50 cut into a metal plate and stamped to the desired shape.

This leaf spring 50 has here an annular body 51 which is secured to the clutch abutment 30, and two tabs 52 which extend radially from the outer peripheral edge of the annular body 51.

As shown in Figure 3, the annular body 51 of the spring blade 50 has two diametrically opposed openings, which are traversed by rivets 36 for fixing the spring blade 50 against the rear face of the flange 31 of the clutch abutment 30 .

As shown in Figure 1, the tabs 52 of the leaf spring 50 are each folded twice at right angles, once backwards and then again outwardly. They are more precisely folded so that their ends are applied against the rear faces of the arms 13 of the fork 1 0. They are also prestressed, so that they exert a sufficient return force to constantly maintain the balls 20 of the fork 10 against the two edges of the trough 33 of the clutch abutment 30.

As shown in Figure 2, the ends of the tabs 52 of the spring blade are further stamped so that they each have a bulge 55 projecting forwardly shaped like a spherical cap diameter greater than the parts rear 14A through holes 14 provided in the arms 13 of the fork 10.

As shown in FIG. 6, these bulges 55 are located on the tabs 52 in such a way that they naturally engage in the outlets of the rear portions 14A of the through bores 14.

It is understood here that if the tilt axis A4 of the fork 10 was fixed, the tilting of the latter would cause the gradual release of the balls 20 out of the channel 33, these progressively rising along one of the edges of that one.

As shown by the arrow F shown in Figure 3, it is then expected that the tilting axis A4 has a distance to the axis A3 of the gutter 33 which is variable.

For this, the recess 15 provided in the body 1 1 of the fork 10 has dimensions such that the fork 10 is not only movable in tilting relative to the finger 70 attached to the housing, but it also has a mounting set allowing it to translate on the finger 70 along an axis A2 orthogonal to the tilting axis A4 and to the translation axis A1 of the stop clutch 30.

In this way, thanks to the elastic return force exerted by the spring blade 50 on the arms 13 of the fork 10 to maintain the balls 20 bearing against the two edges of the trough 33 of the clutch abutment 30, the tilting of the fork 10 on the finger 70 is automatically accompanied by a sliding movement of the fork 10 on the finger 70.

Then, to ensure the bulges 55 of the spring blade 50 to remain centered on the axes A5 of the through bores 14 provided in the arms 13 of the fork 10, it is intended to mount the spring blade 50 free in translation on the abutment of clutch 30 along the axis A2.

The openings 53 provided in the spring blade 50 to secure it to the clutch abutment 30 have for this purpose oblong shapes along an axis A6 parallel to the axis A2.

In this way, when the fork 10 is translated along the axis A2, the spring blade 50 can accompany the movement of the latter.

It is also intended to place grease between the annular body 51 of the spring blade 50 and the rear face of the clutch abutment 30, to facilitate the sliding of the leaf spring 50 on the clutch abutment 30.

In summary, the control device 1 operates in the following manner.

At rest, the diaphragm holds the friction discs of the clutch against each other, and pushes the clutch abutment backwards.

Thanks to the invention, when the driver presses on the clutch pedal, the pulling cable pulls the vertex 1 2 of the fork 1 0 rearward, which causes the fork 10 to tilt on the finger 70 around the tilting axis A4.

The arms 13 of the fork 10 therefore push the clutch abutment forward, which allows to deform the diaphragm and release the friction discs.

During this movement, the balls 20 of the fork 10 being held in abutment against the edges of the trough 33 of the clutch abutment 30, the fork 10 and the spring blade 50 are translated slightly along the axis A2.

The present invention is in no way limited to the embodiments described and represented, but the skilled person will be able to make any variant within his mind.

One could in particular provide that the balls are carried by the clutch abutment and that the gutter is made hollow in the range.

It would also be possible to replace the balls by cylindrical rollers with axes parallel to that of the gutter.

It would also be possible to replace the balls with cubes and to replace the rectangular section gutter with a gutter with a circle.

Claims

1. A control device (1) for a clutch, comprising two main members (10, 30), including:

a clutch abutment (30) which is arranged to be mounted mobile in translation relative to the casing of said clutch, and

- a fork (1 0) which is arranged to be mounted movably tilt relative to the housing of said clutch and which comprises two parts of appu i (21) adapted to ven in contact with two parts of support (34). ) of said clutch abutment (30) for moving the clutch abutment (30) in translation due to the tilting of the fork (10) relative to the housing of said clutch,

characterized in that the bearing portions (34) of one of said two main members (30) form grooves (34) and the bearing portions (21) of the other of said two main members (1 0). form bulges (21) which each rest on the edges of the groove (34) corresponding by point or linear contacts.

2. Control device (1) according to the preceding claim, wherein said fork (10) has a recess (15) which is adapted to be engaged on a finger (70) of the housing of said clutch so that the fork (10) ) is movable in tilting relative to the finger (70) about a tilting axis (A4) and has a mobility game in translation on the finger (70) along an axis (A2) orthogonal to said tilting axis (A4) and the translation axis (A1) of the clutch abutment (30).

3. D ispos itif de com ma nd e (1) according to one of the preceding revendication ications, wherein the support portions (21) of one of said two main organs (10) have symmetrical surfaces of revolution about the same axis (A5) perpendicular to the translation axis (A1) of the clutch abutment (30).

4. clutch control device according to the preceding claim, wherein said bearing portions (21) have spherical surfaces.

Clutch control device according to one of the claims previous, wherein said grooves (34) are profiled along a same axis (A3) perpendicular to the axis of translation (A1) of the clutch abutment (30).

6. Control device (1) according to one of the preceding claims, wherein the fork (10) comprises an elongated body (1 1), one end (12) has a receiving housing (16) at one end. a pulling cable and whose other end has two arms (13) each pierced with a receiving hole (14) of a ball (20), a portion emerging from the surface of each ball (20) forming said support portion (21).

7. A clutch control device according to the preceding claim, wherein each ball (20) is engaged in force in said receiving hole (14).

8. D ispos itif de com ma nd e (1) according to une previous claims, in which there is provided return means (50) for holding the two support portions (21) of the range (1 0) in contact with two bearing portions (34) corresponding to said clutch abutment (30).

9. Control device (1) according to the preceding claim, wherein said biasing means comprises a spring blade (50) having an annular body (51) mounted on the clutch abutment (30), and two arms (52). which extend from the annular body (51) and cooperate with the grooves (34) to sandwich the fork (10).

10. Control device (1) according to the preceding claim, wherein the annular body (51) of said leaf spring (50) is mounted to move in translation on the clutch abutment (30) along an axis (A2) orthogonal to the tilting axis (A4) of the fork (10) and the translation axis (A1) of the clutch abutment (30).