CN111699329A

CN111699329A - Two-part piston for integration into a clutch mechanism

Info

Publication number: CN111699329A
Application number: CN201880089096.XA
Authority: CN
Inventors: A.多尔
Original assignee: Valeo Embrayages SAS
Current assignee: Valeo Embrayages SAS
Priority date: 2017-12-18
Filing date: 2018-12-17
Publication date: 2020-09-22
Anticipated expiration: 2038-12-17
Also published as: EP3728890A1; CN111699329B; WO2019121588A1; FR3075291B1; FR3075291A1

Abstract

The invention relates to a piston (1) configured to be mounted around a rotation axis (O) in a clutch mechanism of a vehicle, the piston (1) comprising: -an axial extent face (11) comprising an actuation ring (11A) for engagement with a disc stack of a clutch mechanism, -a radially extending face (12), -first connection means (11B) extending from the actuation ring (11A) and/or second connection means (12B) extending at least partially axially from the radially extending face (12), the first and/or second connection means (11B, 12B) being arranged to connect the axially extending face (11) to the radially extending face (12), the axially extending face (11) and the radially extending face (12) together defining, in an assembled state, the first and/or second connection means (11B, 12B) of the opening (10C).

Description

Two-part piston for integration into a clutch mechanism

Technical Field

The present invention relates to the field of clutch mechanisms for vehicles. More particularly, the present invention relates to the field of pistons for such clutch mechanisms.

Background

Document DE102016220571 describes a dual clutch mechanism comprising at least one clutch formed by an outer disc support and an inner disc support, which together accommodate a stack of coupling discs and friction discs, wherein the coupling discs are rotatably fixed to the outer disc support and the friction discs are rotatably fixed to the inner disc support. The outer disc carrier may be connected to an input hub of the clutch mechanism, which is coupled to the drive shaft, while the inner disc carrier may be connected to an output of the clutch mechanism, which is coupled to the drive shaft.

A piston including actuating fingers is provided to actuate the clutch. When the piston is actuated, it transmits axial loads from the hydraulic actuator of the actuation system. The piston then applies an axial load on the disc stack and axially displaces the discs. The coupling plate and the friction plates are then pressed by the fingers of the piston against a reaction element formed by a radial portion of the outer plate carrier. The outer and inner disc carriers of the clutch are then rotationally coupled together. The drive shaft torque is then transmitted from the drive shaft to the propeller shaft via the outer disc carrier and the inner disc carrier.

The piston described in this document aims to remedy the drawbacks known in the prior art and comprises the provision of a piston that can reduce the oscillations of the engine torque when transmitting axial loads to the disc stack. To this end, the said document proposes a piston comprising a first series of fingers and a second series of fingers intended to press on the stack of discs at separate diameters.

However, a first drawback of this solution comes from the fact that the oscillation of the engine torque is greater if there is a parallelism fault between the fingers of the first series of fingers and/or the second series of fingers. A second drawback of this solution comes from the fact that: each finger of the first and second series of fingers exerts a contact pressure on the disc stack such that the axial load transmitted by the piston may be unevenly distributed between the fingers of the first and second series of fingers. Another drawback of this solution comes from the fact that: quality control of such pistons is made more difficult by the dimensional control of the fingers in the first and second series of fingers, which is necessary to avoid any parallelism failure of these fingers relative to the other fingers.

Disclosure of Invention

The object of the present invention is to solve at least one of the above drawbacks and to propose a piston for a clutch mechanism which allows to reduce oscillations of the engine torque when the piston transmits axial loads to its respective disc stack.

To this end, the object of the invention is a piston configured to be mounted around an axis of rotation in a clutch mechanism of a vehicle, the piston comprising:

an axial extension comprising an actuating ring intended to engage with a disc stack of a clutch mechanism,

-a radially extending portion of the outer surface of the outer shell,

-first connecting means extending from the actuating ring and/or second connecting means extending at least partially axially from the radially extending portion, the first and/or second connecting means being arranged to connect the axially extending portion to the radially extending portion such that in an assembled state the axially extending portion and the radially extending portion together with the first and/or second connecting means delimit an opening, in particular an opening having a closed contour.

The radially extending portion represents a radially extending rotational form, and the axially extending portion represents an axially extending rotational form.

The actuation ring denotes a ring having radial contact portions intended to cause engagement of a disc stack of the clutch mechanism.

Such an actuating ring may advantageously ensure axial contact of the piston against the discs of the disc stack. Such discs axially confine the disc stack and are arranged to be actuated by the piston. In this way, according to the invention, the radial contact surface of the actuating ring is pressed against the discs of the disc stack when an axial load is applied on the piston. The axial load transmitted from the actuation system to the piston is then balanced evenly across the disc by the actuation ring. Any parallelism failure in the piston is thus advantageously limited. When the piston engages the disc stack of the clutch mechanism, oscillations in engine torque are greatly reduced.

Furthermore, such an actuating ring contributes to the quality control of the piston. In fact, contrary to the manufacture of the pistons with fingers of the prior art, which require dimensional control operations to avoid any parallelism failure, the radial contact surfaces of the actuating ring can be easily checked and corrected by machining operations.

In particular, the piston is advantageously made in two parts, namely an axially extending part and a radially extending part. Such a configuration allows the piston to be able to pass through the outer disc holder via the actuation ring while engaging the disc stack. Advantageously, the first and/or second connecting means are formed by teeth.

The first connecting means, which are separated by the opening, are then advantageously used to pass through the outer disc carrier of the clutch mechanism. The first connecting means, in particular the teeth of the axially extending portion delimited by the opening, are then advantageously used to pass internally through the outer disc carrier of the clutch mechanism and are fixed to the radially extending portion of the piston arranged externally of the outer disc carrier.

According to an advantageous embodiment of the invention, the actuating ring of the axial extension has a continuous circular form. The continuous circular form of the actuation ring ensures that the actuation ring is in contact with the surface of said disc of the disc stack over the entire circular contour.

According to another advantageous embodiment of the invention, the actuating ring of the axial extension has a discontinuous circular form. The discontinuous circular form of the actuating ring helps to lubricate the contact area of the actuating ring with the disc.

The discontinuous circular form may advantageously comprise a groove formed on the radial contact surface of the actuating ring. These grooves are advantageously formed by radial contact surfaces in the form of a continuous circle. Advantageously, such a radial contact surface is free from parallelism defects. Such a groove advantageously has a depth and/or thickness, dimensioned to ensure that the axial load is distributed evenly over the profile of the actuating ring. In other words, the recess is advantageously dimensioned to avoid the formation of contact points, compared to the fingers of the piston known in the prior art.

According to a particular feature, at least the first connection means comprise a stop arranged to receive the radially extending portion. The stop of the coupling device allows the radially extending portion to be received against the axially extending portion before they are coupled together.

According to another particular feature, the at least one first connection means comprises blocking means arranged to hold the radially extending portion against the stop. The blocking means facilitates the interconnection of the axially extending portion and the radially extending portion.

The blocking means firstly allows the radially extending portion to be held axially against the stop in the blocking position and secondly allows the radially extending portion and the axially extending portion to be connected together. Such a connection advantageously allows axial loads received by the radially extending portion from the actuation system to be transferred to the axially extending portion carrying the actuation ring.

According to a variant embodiment of the invention, the stop is formed by an undercut of the material of the connecting means, for example said tooth. The material undercut allows for the formation of a housing that accommodates the radially extending portion. Advantageously, the stop is formed to block the radially extending portion axially in an axial direction opposite to the direction of orientation of the first connection means and to block the radially extending portion radially.

According to another variant embodiment of the invention, the blocking means comprise a recess in the connecting means, which recess is arranged to receive a locking washer. Such blocking means facilitate the operation of connecting the axially extending portion to the radially extending portion. Advantageously, the connection is easily removable. In this connection, the axial extension is axially blocked between firstly the radial surface of the stop and secondly the radial surface of the locking washer.

The stop and/or the blocking means are formed, for example, radially inside the connecting means, in particular inside the teeth.

Advantageously, when the teeth are formed radially inside the connection means, the outer radial end of the radial extension is flush with the axial portion of the stop. This arrangement allows the radially extending portion to be correspondingly received in the stop so as to be radially retained therein.

Advantageously, when the blocking means are formed radially inside the connecting device, the axial dimension of the stop is greater than the axial thickness of the radially extending portion. This arrangement allows the formation of a stop means on the axial face of the stop.

Advantageously, the stop may be formed by the axial end thereof opposite the actuating ring. The radially extending portion is then arranged against an axial end of the connecting device. Advantageously, the radially outer end of the radially extending portion is flush with the radially outer end of the connecting means. In other words, the radially extending portion does not extend beyond the axially extending portion of the connecting means. The radially extending portion may then be secured to the axially extending portion attachment means by a stop formed by a continuous or discontinuous weld bead. The bead is advantageously along a circular line formed by the contact points of the connecting means of the axially extending portion against the radially extending portion.

According to the different variants proposed, the positioning of the axially extending portion and the radially extending portion with respect to each other can be advantageously achieved by means of a robotized arm.

According to an embodiment of the invention, the blocking means is formed by a bead. The weld bead allows at least the connection means of the axially extending portion to be secured to the radially extending portion. More particularly, the end of the connecting means is fixed to the radially outer end of the radially extending portion. Advantageously, the weld bead is continuous or discontinuous. When the weld bead is continuous, it is produced in a continuous manner along a circular line formed by the contact points of the connecting means of the axially extending portion against the radially extending portion.

When the weld bead is discontinuous, it is produced in a discontinuous manner on a circular line formed by the contact points of the connecting means of the axially extending portion against the radially extending portion, wherein spot welds are then formed along the circular line.

Advantageously, the stop is formed by a first notch in a tooth arranged to receive the first locking washer and the blocking means is formed by a second notch in said tooth arranged to receive the second locking washer. Thus, the radially extending portion is blocked in the axial direction between the first locking washer and the second locking washer.

According to a proposed embodiment, the axially extending portion comprises connection means called first connection means and the radially extending portion comprises connection means called second connection means of the axial connection. In particular, the first and second connection means are arranged axially against each other so as to fix the axially extending portion and the radially extending portion to each other.

According to this proposed embodiment, the radially extending portion is lifted to the axially extending portion such that the first and second connecting means abut each other at their respective axial ends. Such accumulation is advantageously achieved by a robotic arm. Then, the ends of the first and second connecting means are fixed to each other by welding.

The features described above in relation to the connection means are advantageously applicable to each connection means of the axial extension.

According to another aspect, the object of the invention is a flange assembly arranged to be integrated in a clutch mechanism, the flange assembly comprising a first flange formed by a piston as described herein and a second flange formed by an outer disc carrier of the clutch mechanism. The piston and the outer disc holder are in particular mutually interlocked.

The term "interlock" refers to two parts that engage one another so that they cannot be separated from one another without disassembly of the assembly.

According to a particular feature of the flange assembly of the invention, the outer disc support comprises a radial wall and an axial wall defining a cavity housing the axial extension of the piston. The connecting means of the axial extension extends from a hole formed in a circular pattern in the radial wall of said outer disc support to the outside of the outer disc support for fixing to the radial extension of the piston.

The piston advantageously comprises two parts, an axially extending part and a radially extending part, which are connected together, which advantageously allows the arrangement of the axially extending part from the inside of the outer disc carrier and the radially extending part from the outside of the outer disc carrier. In this configuration, the radial wall of the outer disc holder is then held between the axially extending portion of the piston and the radially extending portion of the piston. The axially extending portion and the radially extending portion are connected together, for example, by welding, adhesive, snap fastening, or by any other suitable means known to those skilled in the art.

According to a particular feature of the flange assembly of the invention, the connecting means and the opening of the axial extension are dimensioned to allow axial play of the piston relative to the outer disc carrier. This axial play allows axial movement of the piston when actuated by the actuation system.

According to another particular feature of the flange assembly according to the invention, the connecting means and the opening of the axial extension are dimensioned to allow radial play of the piston relative to the outer disc support. This radial play allows a radial movement of the piston when the piston and the outer disc carrier are mounted on the clutch mechanism.

According to another aspect, the object of the invention is a clutch mechanism for a vehicle transmission, comprising a flange assembly as described herein, wherein the clutch mechanism comprises a stack of discs, an outer disc carrier carrying at least one disc of the stack of discs. According to the invention, the actuating ring of the piston is axially placed on the disc.

According to another aspect, the object of the invention is a method of assembling a flange assembly as described herein, the flange assembly comprising:

-a piston comprising:

-an axial extension formed by an actuating ring from which the connection means extend, and

-a radially extending portion of the outer surface of the outer shell,

an outer disc holder comprising an axial wall and a radial wall which together delimit a cavity inside, the radial wall comprising holes distributed in a circular pattern,

the method comprises the following steps:

in the mounting step, the axially extending portion of the piston and the outer disc carrier are arranged with respect to each other such that the actuating ring is received in the cavity, the connecting means of the axially extending portion protruding outside the outer disc carrier.

This mounting step of the assembly process allows, in a particularly inventive manner, the axial extension of the piston to be connected from the outside of the outer disc carrier to the radial extension thereof. Thus, this mounting step facilitates the operation of mounting the flange assembly. This assembly method advantageously allows a reduction in production costs, in particular in the case of mass production.

According to an embodiment, the assembly method comprises an approaching step, wherein the radially extending portion of the piston is arranged from outside the outer disc holder against the connecting means of the axially extending portion. The approaching step is advantageously performed after the mounting step.

The coupling means of the axial extension, in particular the teeth, may advantageously comprise a stop as described herein.

According to another embodiment, the assembly method comprises an assembly step, wherein the radially extending part is held against the connecting means of the axially extending part by blocking means.

Advantageously, in the assembly step, the radially extending portion is fixed to the axially extending portion.

Drawings

Further characteristics and advantages of the invention will emerge firstly from the following description and secondly from a number of exemplary embodiments given purely for information, without limitation, with reference to the attached schematic drawings, in which:

FIG. 1 shows a perspective view of a piston for a clutch mechanism according to a first embodiment of the invention, wherein the piston comprises an axial extension and a radial extension,

FIG. 2 shows a front view of a flange assembly of the clutch mechanism, comprising the piston shown in FIG. 1 and the outer disc carrier of the clutch mechanism, the piston and the disc carrier being interlocked,

FIG. 3 shows a cross-sectional view along line A-A of FIG. 2, wherein the axial extensions are arranged inside the outer disc carrier and the radial extensions are arranged outside the outer disc carrier, wherein the axial and radial extensions are connected together by their respective connecting means,

figure 4A shows a cross-sectional view of a flange assembly integrated into a clutch mechanism and comprising a piston, according to a second embodiment of the invention, wherein the connecting means of the axial extension comprises a stop arranged to receive the radial extension,

FIG. 4B shows a detail of FIG. 4A, in which the radially extending part of the piston is fixed to the connecting means of the axially extending part by blocking means formed by welding, in particular by a weld bead,

fig. 5 shows a detail of fig. 4B corresponding to a third embodiment of the piston of the invention, in which the axially extending portion and the radially extending portion are connected by blocking means formed by a recess arranged to receive a locking washer.

Detailed Description

In this context, the term "axial/radial" and the term "inner/outer" are used with respect to the axis of the piston.

In the remainder of the description, the terms "actuating ring" and "ring" are used interchangeably.

As shown in fig. 1, a piston 1 according to the invention is shown. The piston 1 is intended to be integrated in a clutch mechanism 100, which clutch mechanism 100 is advantageously mounted on a transmission of a motor vehicle. The piston 1 is intended to be mounted around the axis of rotation O of the clutch mechanism 100. The piston 1 is formed, for example, by connecting together two separate parts, an axially extending part 11 and a radially extending part 12. The axial extension 11 is of rotary form and extends axially about the axis of rotation O. The radially extending portion 12 is of a rotary form and extends radially about the axis of rotation O. The axially extending portion 11 is arranged to engage with a disc stack 201 of a clutch 200 of the clutch mechanism 100, while the radially extending portion 12 is arranged to be engaged by an

actuator

41, 42 of an actuation system 40 of the clutch mechanism 100, as shown in fig. 4A and described below.

The axially extending portion 11 and the radially extending portion 12 are intended to be connected together to form the piston 1. The axial extension 11 comprises an actuation ring 11A intended to engage the disc stack 201 of the clutch mechanism 100. The connecting means 11B of the axial extension 11 (referred to as first connecting means 11B) extends axially from the ring 11A. The first connecting means 11B are separated by an opening 11C. In the assembled state of the piston 1, the opening 11C is delimited by the axial extension 11 and the radial extension 12. It will be understood that in the non-assembled state, the opening 11C of the axial extension 11 is open towards the outside in the case where the axial extension 11 and the radial extension 12 are separated from each other, whereas the opening 11C is closed, i.e. defined at its contour by the axial extension 11 and the radial extension 12, when the axial extension 11 and the radial extension 12 are joined together.

The radially extending portion 12 extends axially from the radially extending portion 12 by means of a connecting means 12B (referred to as second connecting means 12B) for cooperating with the first connecting means 11B of the axially extending portion 11. When assembling the piston 1, the first connecting means 11B and the second connecting means 12B are in contact with each other at their free axial ends. The free axial ends of the connection means correspond to the connection means of the first and second connection means 11B, 12B of the axial and

radial extensions

11, 12 intended to abut against each other. According to the first embodiment, the axially extending portion 11 and the radially extending portion 12 are then fixed together by welding or bonding of their respective connecting means 11B, 12B.

The main advantage of such a piston 1 comprising two axial and radial portions is that it allows the disc stack 201 of the clutch mechanism 100 to be engaged by a ring 11A, which ring 11A rests on the disc stack 201 by means of a radial contact surface 11A'. In contrast to the pistons known from the prior art, in which a series of actuating fingers rest on the disc stack 201, the ring 11A facilitates dimensional control of its radial contact surface 11A'. The parallelism failure of the piston 1 is then greatly limited.

The actuating ring 11A of the axial extension 11 has a continuous circular form. Thus, the radial contact surface 11A' of the ring 11A is flat. Due to the flat form of the radial contact surface 11A', it is possible to ensure that the actuation ring 11A is in contact with the surface of a disc 201A (e.g. as shown in fig. 4A) of the disc stack 201 over the entire circular contour of the actuation ring 11A.

Fig. 2 and 3 illustrate a flange assembly 12 according to the present invention. The flange assembly 12 includes a first flange formed by the piston 1 according to the first embodiment described above and a second flange formed by the outer disc carrier 2 of the clutch mechanism 100. The outer disc carrier 2 is intended to carry at least the discs 201A of the disc stack 201 of the clutch mechanism 100. Such an outer disc holder 2 may advantageously be associated with the inner disc holder 4. The outer disc holder 2 and the inner disc holder 4 are then arranged radially with respect to each other. This arrangement of the inner disc holder 2 and the outer disc holder 4 allows accommodating the disc stack 201 of the clutch mechanism 100. In other words, the outer disc holder 2 radially delimits the disc stack 201 on the outside, while the inner disc holder 4 radially delimits the disc stack 201 on the inside.

The outer disc holder 2 is formed by at least an axial wall 21 and a radial wall 22, which delimit a cavity C therebetween, which is arranged to accommodate the

disc stack

201, 301. The axial extension 11 is received in the cavity C, so that the first connection means 11B of the axial extension 11 protrude from the hole 23 towards the outside of the outer disc holder 2. The holes 23 are formed in a circular pattern on the radial wall 22 of the outer disc holder 2 so as to face the first connecting means 11B of the axially extending portion 11. Each first connecting means 11B penetrates into a hole 23 of the radial wall 22 and projects with its free end beyond the radial wall 22 of the outer disc holder 2. It will be appreciated that the actuating ring 11A is then received in the cavity C. Then, the free end of the first connecting means 11B corresponds to the free end of the second connecting means 11B of the radially extending portion 12 in order to connect them together. Then, the piston 1 and the outer disc holder 2 are interlocked. The radial wall 22 of the outer disc holder 2 is then axially retained between the axially extending portion 11 and the radially extending portion 12 of the piston 1.

In this interlocking arrangement of the flange assembly 12, the opening 11C of the piston 1 and the connection means 11B are advantageously formed to allow axial movement of the piston 1 relative to the outer disc carrier 2. The actuating ring 11A of the piston 1 may then be used to engage the discs 201A of the

disc stack

201, 301.

Fig. 4A shows a flange assembly 12 comprising a piston 1 according to a second embodiment of the invention. The flange assembly 12 is shown mounted on the clutch mechanism 100. The clutch mechanism 100 is a radial dual clutch mechanism, wherein the first clutch 200 and the second clutch 300 are arranged in a radial configuration with respect to each other such that the first clutch 200 is arranged radially outside the second clutch 300.

However, the present invention is not limited to such a clutch mechanism, and may be advantageously applied to an axial dual clutch in which clutches are arranged axially relative to each other along the rotational axis O of the clutch mechanism 100.

In the illustrated clutch mechanism 100, the

clutches

200, 300 each comprise a

disc stack

201, 301 that is lubricated by cooling oil during operation of the clutch mechanism 100. The first and

second clutches

200, 300 each comprise an

outer disc carrier

2, 3 and an inner disc carrier 4, 5, between which its

respective disc stack

201, 301 is accommodated. Each

disc stack

201, 301 is formed by a coupling disc 201A, 301A and a

friction disc

201B, 301B, the coupling disc 201A, 301A being intended to be rotationally coupled to the

outer disc support

2, 3, and the

friction disc

201B, 301B being intended to be rotationally coupled to the inner disc support 4, 5.

The

outer disc carriers

2, 3 of the

clutches

200, 300 are rotationally coupled to the input web 70 of the clutch mechanism 100. The input web 70 is rotationally fixed to an input hub 71, the input hub 71 itself being coupled to a drive shaft (not shown). The

outer disc carriers

2, 3 are radially supported by radial roller bearings 80 arranged between the outer disc carrier 2 of the first clutch 200 and the support 50 of the clutch mechanism 100. The inner disc carrier 4 of the first clutch 200 is coupled to the first output hub 72, and the inner disc carrier 5 of the second clutch 300 is coupled to the second output hub 73. The first and

second output hubs

72, 73 are intended to be coupled to first and second drive shafts (not shown), respectively. The radial bearing 81 is advantageously arranged radially between the

outer disk carriers

2, 3 of the first clutch 200 adjacent to one another. The first axial bearing 82 is arranged axially between the inner disc carriers 4, 5 of the clutch mechanism 100. The second axial bearing 83 is arranged axially between the outer disc carrier 3 of the second clutch 300 and the support 50 of the clutch mechanism 100.

The actuation system 40 carried by the support 50 of the clutch mechanism 100 is configured to actuate the first piston 1 of the first clutch 200 via the first actuator 41 and to actuate the second piston 6 of the second clutch 300 via the second actuator 42. As shown, the first piston 1 of the first clutch 200 is a variant of the piston 1 of the invention according to the second embodiment, while the second piston 6 of the second clutch 300 corresponds to the piston 6 with the actuating fingers 60 to engage the disc stacks 201, 301 of the

respective clutches

200, 300. Fig. 4A first shows the piston 1 of the first clutch 200 comprising the actuating ring 11A according to the invention and the piston 6 of the second clutch 300 comprising the actuating fingers 60, such actuating fingers 60 being known from the prior art. Thus, the configuration of the clutch mechanism 100 of FIG. 4A allows for more clear differentiation of certain features of the present invention.

The second piston 6 comprises a radially extending portion 62 intended to be actuated by the second actuator 41. The actuating fingers 60 extend axially from the radially outer end of the radially extending portion 62 of the second piston 6 and pass through the outer disc carrier 3 of the second clutch 300 from the outside so as to penetrate the inside of the outer disc carrier 3 of the second clutch 300. More specifically, the actuating fingers 60 of the second piston 6 pass through the holes 33 formed in a circular pattern on the radial wall 32 of the outer disc carrier 3 of the second clutch 300. The actuating fingers 60 then engage the disc stack 301 of the second clutch 300 such that each actuating finger 60 of the second piston 6 exerts a contact pressure on the disc stack 301 of the second clutch 300. It is understood that when the clutch mechanism 100 is disassembled, the second piston 6 and the outer disc carrier 3 of the second clutch 300 are separated by axially separating them from each other without a specific disassembling operation.

The first piston 1 comprises an axially extending portion 11 and a radially extending portion 12. In a second embodiment of the piston 1 according to the invention, the axially extending portion 11 of the first piston 1 is formed by its actuating ring 11A, from which actuating ring 11A the connecting means 11B axially extend. The connecting means 11B of the axially extending portion 11 passes through the holes 23 formed in a circular pattern on the radial wall 22 of the outer disc carrier 2 of the first clutch 200 to protrude outside the outer disc carrier 2. The coupling means 11B of the axially extending portion 11 respectively comprise a stop 13 formed radially inside the coupling means 11B. The stop 13 of each connecting means 11B is formed by an undercut of the material of the respective connecting means 11B so as to form a housing able to house the radially extending portion 12 of the first piston 1. The radial face 13A of the stop 13 axially blocks the radially extending portion 12 of the first piston 1. The radially outer end 12A of the radially extending portion 12 of the first piston 1 is flush with the axial face 13B of the stopper 13. The radially extending portion 12 of the first piston 1 is then axially centered by the radially extending portion 12 of the first piston 1. Thus, the stop 13 is configured to axially and radially abut the radially extending portion 12 of the first piston 1 against the connecting means 11B of the axially extending portion 11 of the first piston 1.

In the assembled state of the first piston 1, the actuation ring 11A engages with the discs 201A of the disc stack 201 of the first clutch 200. Such a disc 201A corresponds to the coupling disc 201A, which is preferably made of a metallic material. In a similar manner to the first embodiment, the actuating ring 11A comprises a radial contact surface 11A' which abuts against the coupling disc 201A of the first clutch 200.

In order to axially hold the radially extending portion 12 against the stop 13 of each connection means 11B of the axially extending portion 11, a blocking means 14 is provided. It will be appreciated that the first piston 1 is advantageously assembled from the outside of the outer disc carrier 2 of the first clutch 200. Naturally, the flange assembly 12 according to the present invention is preferably formed prior to assembly of the clutch mechanism 100.

Fig. 4B shows a blocking device 14 provided for the piston 1 according to the second embodiment. The blocking means 14 are formed here by beads 15 which can be produced continuously or discontinuously along the circular line of contact of the connecting means 11B of the axial extension 11 with the radial extension 12 of the first piston 1.

Fig. 5 shows a third embodiment of a piston 1 according to the invention, which is similar to the second embodiment described in fig. 4A and 4B. In this second embodiment, the stopper 13 of each connecting device 11B is formed such that the notch 16 is formed radially on the axial face 13B of the stopper 13 inside the connecting device 11B. Such a recess 16 is advantageously arranged to accommodate a locking washer when the radially extending portion 12 of the first piston 1 is arranged axially against the radial face 13A of the stop member 13. Then, the radially extending portion 12 of the piston 1 of the third embodiment is axially blocked by the radial face 13A of the stopper 13 and the radial face 17A of the lock washer 17.

In contrast to the second embodiment, in the third embodiment, when the radially extending portion 12 is pressed against the radially facing surface 13A of the stopper 13, the axially facing surface 13B of the stopper 13 protrudes axially beyond the radially extending portion 12.

Of course, the features, variants and different embodiments of the invention can be combined with one another in various combinations, as long as they are not incompatible or mutually exclusive with one another. In particular, it is envisaged that variants of the invention only include a selection of the features described below, in isolation from the other features described, if such a selection of features is sufficient to confer technical advantages or to distinguish the invention from the prior art.

Claims

1. A piston (1) configured to be mounted around an axis of rotation (O) in a clutch mechanism (100) of a vehicle, the piston (1) comprising:

-an axial extension (11) comprising an actuation ring (11A) for engagement with a disc stack (201) of a clutch (200) of a clutch mechanism (100),

-a radially extending portion (12),

-first connection means (11B) extending from the actuating ring (11A) and/or second connection means (12B) extending at least partially axially from the radially extending portion (12), the first and/or second connection means (11B, 12B) being arranged to connect the axially extending portion (11) to the radially extending portion (12),

wherein, in the assembled state, the axial extension (11) and the radial extension (12) delimit an opening (10C) together with the first and/or second connection means (11B, 12B).

2. Piston (1) according to claim 1, characterised in that said first and/or second connection means (11B, 12B) are formed by teeth.

3. Piston (1) according to any one of the preceding claims, wherein the actuating ring (11A) of the axial extension (11) has a continuous circular form.

4. Piston (1) according to any one of the preceding claims, characterized in that at least a first connecting means (11B) comprises a stop (13) arranged to accommodate a radially extending portion (12), said stop being in particular formed by an undercut of the material of said connecting means (11B).

5. Piston (1) according to the preceding claim, wherein said at least one first connection means (11B) comprises blocking means (14) arranged to hold the radially extending portion (12) against the stop (13).

6. Piston (1) according to the preceding claim, characterized in that said blocking means (14) comprise a bead (15) or said connecting means (11B) have a recess (16) arranged to receive a locking washer (17).

7. Piston (1) according to the preceding claim, characterized in that said stop (13) is formed by a first recess (16) in said first connecting means (11B) arranged to receive a first locking washer (17), and said blocking means (14) is formed by a second recess (16) in said first connecting means (11B) arranged to receive a second locking washer (17).

8. Piston (1) according to any one of claims 5 to 7, characterized in that the stop (13) and the blocking means (14) are formed radially inside the connecting means (11B).

9. Piston (1) according to any one of the preceding claims, wherein the axially extending portion (11) comprises first connecting means (11B) and the radially extending portion (12) comprises second axially extending connecting means (12B), wherein the first connecting means (11B) and the second connecting means (12B) are intended to axially abut against each other in order to connect the axially extending portion (11) and the radially extending portion (12) together.

10. A flange assembly (12) arranged to be integrated in a clutch mechanism (100), the flange assembly (12) comprising a first flange formed by a piston (1) according to any one of the preceding claims and a second flange formed by an outer disc carrier (2) of the clutch mechanism (100), characterized in that the piston (1) and the outer disc carrier (2) are mutually interlocked.

11. The flange assembly (12) according to the preceding claim, wherein the outer disc support (2) comprises an axial wall (21) and a radial wall (22) which together delimit internally a cavity (C) receiving the axial extension (11) of the piston (1), wherein the connection means (11B) of the axial extension (11) extend from holes (23) formed in a circular pattern on the radial wall (22) of the outer disc support (2) to the outside of the outer disc support (2) for connection to the radial extension (12) of the piston (1).

12. A clutch mechanism for a vehicle transmission, comprising a flange assembly (12) according to any one of claims 11 or 12, the clutch mechanism (100) comprising a disc stack (201), an outer disc carrier (2) carrying at least one disc (201A) of the disc stack (201), characterized in that the actuating ring (11A) of the piston (1) is axially placed on the disc.

13. A method for assembling a flange assembly (12) according to any one of claims 11 or 12, the flange assembly (12) comprising:

-a piston (1) comprising:

-an axial extension (11) formed by an actuating ring (11A) from which the connecting means (11B) extend, and

-a radially extending portion (12),

-an outer disc support (2) comprising an axial wall (21) and a radial wall (22) which together delimit a cavity (C) internally, the radial wall (22) comprising holes (23) distributed in a circular pattern,

the method is characterized in that the method comprises:

-in the mounting step, the axial extension (11) of the piston (1) and the outer disc support (2) are arranged with respect to each other such that the actuating ring (11A) is housed in the cavity (C), the connection means (11B) of the axial extension (11) protruding outside the outer disc support (2).

14. Method of assembly according to the preceding claim, characterized in that:

-in the approaching step, the radially extending portion (12) of the piston (1) is arranged from outside the outer disc holder (2) against the connecting means (11B) of the axially extending portion (11).

15. The assembling method is characterized in that:

-in the assembly step, the radially extending portion (12) is held against the first connection means (11B) by blocking means (14).