EP3728890A1

EP3728890A1 - Two-part piston, the piston being intended for integration in a clutch mechanism

Info

Publication number: EP3728890A1
Application number: EP18830213.7A
Authority: EP
Inventors: Arnaud DOLE
Original assignee: Valeo Embrayages SAS
Current assignee: Valeo Embrayages SAS
Priority date: 2017-12-18
Filing date: 2018-12-17
Publication date: 2020-10-28
Also published as: WO2019121588A1; CN111699329A; FR3075291A1; FR3075291B1; CN111699329B

Abstract

The invention relates to a piston (1) that is configured to be mounted about an axis of rotation (O) in a clutch mechanism for a vehicle, the piston (1) comprising: - a face of axial extent (11) comprising an actuation ring (11A) intended to engage a stack of disks of a clutch of the clutch mechanism, - a face of radial extent (12), - first connection means (11B) extending from the actuation ring (11A) and/or second connection means (12B) extending at least in part axially from the face of radial extent (12), the first and/or second connection means (11B, 12B) being arranged so as to connect the face of axial extent (11) to the face of radial extent (12), the face of axial extent (11) and the face of radial extent (12) together delimiting, in the assembled state, the first and/or second connection means (11B, 12B) of the openings (10C).

Description

PISTON IN TWO PARTS. THE PISTON IS INTENDED TO EQUIP A

CLUTCH MECHANISM

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

Document DE 10 2016 220 571 discloses a clutch mechanism with two clutches comprising at least one clutch formed by an outer disk carrier and an inner disk carrier, which together receive a stack of coupling disks and friction disks. , the coupling disks being secured in rotation to the outer disk carrier and the friction discs being rotatably connected to the inner disk carrier. The outer disk carrier can be secured to an input hub of the clutch mechanism coupled to a motor shaft and the inner disk carrier can be secured to an output hub of the clutch mechanism coupled to a transmission shaft. A piston comprising actuating fingers is provided for actuating the clutch. When the piston is actuated, it transmits an axial load from a hydraulic actuator of an actuating system. The piston then applies the axial load against the stack of disks and moves the latter axially. The coupling discs and the friction discs are then pressed by the piston fingers against a reaction member formed by a radial portion of the outer disc carrier. The outer disk carrier and the inner disk carrier of the clutch are then rotatably coupled to each other. The torque of the motor shaft is then transmitted from the motor shaft to the transmission shaft via the outer and inner disk carriers.

The piston described in this document seeks to solve a disadvantage known from the prior art and is to provide a piston that can reduce the oscillation of the engine torque when it transmits the axial load to the stack of disks. For this, the cited document proposes a piston comprising a first series of fingers and a second series of fingers respectively for pressing the stack of disks on a separate diameter. However, a first disadvantage of this solution comes from the fact that when a lack of parallelism exists between fingers of the first series of fingers and / or the second series of fingers, the oscillation of the motor torque is then more accentuated. A second disadvantage of this solution arises from the fact that each of the fingers of the first and second series of fingers exerts contact pressure on the stack of discs so that the axial load transmitted by the piston can be unequally distributed between the fingers of the fingers. the first and second sets of fingers. Another disadvantage of this solution comes from the fact that the quality control of such a piston is made difficult by the dimensional control of the fingers of the first and second series of fingers in order to avoid any lack of parallelism with respect to each other. .

The present invention aims to overcome at least one of the aforementioned drawbacks and to provide a piston for clutch mechanism to reduce the oscillation of the engine torque when the piston transmits an axial load to its corresponding disk stack. For this purpose, the subject of the invention is a piston configured to be mounted about an axis of rotation in a vehicle clutch mechanism, the piston comprising an axial elongation bearing comprising an actuating ring intended to engage a stack of disks of a clutch of the clutch mechanism,

a radial elongation bearing, first connecting means extending from the actuating ring and / or second connecting means extending at least partly axially from the radial elongation bearing, the first connecting means extending from the actuating ring and / or the second connecting means extending at least partly axially from the radial elongation bearing, the first and / or second connection means being arranged to connect the axial elongation range to the radial elongation range, such as the axial elongation range and the radial elongation range, delimiting in the assembled state together the first and / or second means for connecting the openings, in particular openings having a closed periphery.

Radial elongation range refers to a radially extending form of revolution and an axial elongation range refers to an axially extending form of revolution. An actuating ring designates a ring having a radial bearing face intended to engage a stack of disks of the clutch mechanism.

Such an actuating ring advantageously makes it possible to ensure axial support of the piston against a disk of the stack of disks. Such a disc axially delimits the stack of discs and is arranged to be actuated by the piston. In this way, according to the invention when an axial load is exerted on the piston, a radial bearing face of the actuating ring then presses the disk of the stack of disks. The axial load transmitted from the actuating system to the piston is then evenly balanced on said disk by the actuating ring. The parallelism defects of the piston are then advantageously limited. The oscillation of the engine torque is then greatly reduced when the piston engages the stack of disks of the clutch mechanism.

In addition, such an actuating ring facilitates the quality control of the piston. Indeed, unlike the manufacture of a finger piston of the prior art requiring dimensional control operations to avoid any parallelism defect, the radial bearing face of the actuating ring can be easily controlled and rectified by a machining operation.

The piston is particularly advantageously made in two parts, namely the axial elongation range and the radial elongation range. Such a configuration allows the piston to be able to pass through an outer disk carrier while engaging the stack of disks by an actuating ring. Advantageously, the first and / or second connection means are formed by teeth.

The first connection means separated by the openings are then advantageously used to pass through an outer disk carrier of the clutch mechanism. The first connection means, in particular teeth of the axial elongation range, delimited by the openings are then advantageously used to pass through an outer disk carrier of the clutch mechanism from the inside and come to be secured within the range of radial elongation of the piston disposed outside the outer disk carrier.

According to an advantageous embodiment of the invention, the ring of actuation of the axial elongation range is of continuous circular shape. A continuous circular shape of the actuating ring makes it possible to guarantee a surface contact of the actuating ring against said disk of the stack of disks on a whole circular contour.

According to another advantageous embodiment of the invention, the actuating ring of the axial elongation range is of discontinuous circular shape. A discontinuous circular shape of the actuating ring facilitates the lubrication of the contact area of the actuating ring with said disc.

A discontinuous circular shape may advantageously comprise ridges formed on the radial bearing face of the actuating ring. These grooves are advantageously formed from a radial bearing face of continuous circular shape. Advantageously, such a radial bearing face does not have parallelism defects. Such streaks advantageously have a depth and / or thickness dimensioned to ensure an evenly distributed axial load on the contour of the actuating ring. In other words, the grooves are advantageously dimensioned to prevent the formation of contact points, unlike the fingers of the pistons known from the prior art. According to a particular characteristic, at least a first connection means comprises an abutment arranged to receive the radial elongation range. The abutment of said connecting means makes it possible to accommodate the radial elongation range against the axial elongation range before they are assembled to one another.

According to another particular characteristic, the at least one first connection means comprises a locking means arranged to maintain the radial elongation range against the stop. The locking means facilitates the assembly of the axial elongation span and the radial elongation range to one another.

The locking means makes it possible, on the one hand, to axially hold the radial elongation bearing against the stop in a locked position and, on the other hand, to assemble the radial elongation bearing and the bearing. axial elongation to one another. Such an assembly advantageously makes it possible to transmit an axial load received by the radial elongation range from the actuating system to the axial elongation range carrying the actuating ring. According to an alternative embodiment of the invention, the stop is formed by a release of material from the connection means, for example of said tooth. The release of material allows the formation of a housing receiving the range of radial elongation. Advantageously, the stop is formed to axially block the radial elongation range in an axial direction opposite to the orientation direction of the first connection means and to radially block the radial elongation range.

According to another embodiment of the invention, the locking means comprises a notch in the connection means arranged to receive a locking washer. Such a locking means facilitates the assembly operation of the axial elongation range to the radial elongation range. Advantageously, this assembly is easily removable. In this assembly solution, the axial elongation range is locked axially between, on the one hand, a radial face of the abutment, and, on the other hand, a radial face of the locking washer.

The abutment and / or the locking means are for example formed (s) radially inside the connection means, in particular of said tooth.

Advantageously, when the abutment is formed radially inside the connecting means, an outer radial end of the radial elongation bearing surface is flush with an axial face of the abutment. This configuration allows the radial elongation range to be received in correspondence in the abutment to be held radially.

Advantageously, when the locking means is formed radially inside the connecting means, the abutment comprises an axial dimension greater than the axial thickness of the radial elongation span. This configuration allows the formation of the locking means on the axial face of the stop.

Advantageously, the stop may be formed by its axial end opposite the actuating ring. The radial elongation range is then arranged to bear against the axial end of the connection means. Advantageously, the outer radial end of the radial elongation span is flush with the outer radial end of the connecting means. In other words, the radial elongation range does not extend beyond the connecting means of the axial elongation range. The radial elongation range can then be secured to the connecting means of the axial elongation range by a means blocking formed by a continuous or discontinuous weld seam. The weld bead advantageously follows a circular line formed by the contact points of the connection means of the axial elongation range against the radial elongation range.

According to the various variants envisaged, the positioning of the axial elongation span and the radial elongation range relative to one another can advantageously be achieved by robotic arms.

According to one embodiment of the invention, the locking means is formed by a weld bead. The weld seam makes it possible to secure at least the connection means of the axial elongation range to the radial elongation range. More particularly, the end of said connection means is secured to the outer radial end of the radial elongation span. Advantageously, the weld bead is continuous or discontinuous. When the weld bead is continuous, it is made continuously on the circular line formed by the contact points of the connecting means of the axial elongation range against the radial elongation range. When the weld bead is discontinuous, it is made discontinuously on the circular line formed by the contact points of the connection means of the axial elongation range against the radial elongation range, welding points are then formed along the circular line.

Advantageously, the stop is formed by a first notch in a tooth adapted to receive a first locking washer and the locking means is formed by a second notch in said tooth adapted to receive a second locking washer. Thus, the radial elongation range is locked axially between the first lock washer and the second lock washer.

According to one embodiment envisaged, the axial elongation range comprises the connecting means, said first connecting means, and the radial elongation range comprises connecting means, said second connecting means, extending axially. In particular, the first connection means and the second connection means are arranged to abut axially against each other to secure the axial elongation range and the radial elongation range to one another. According to this envisaged embodiment, the radial elongation range is brought closer to the axial elongation range so that the first connection means and the second connection means bear against each other by their axial ends. respectively. Such a combination is advantageously achieved by automated mechanical arms. The ends of the first connection means and the second connection means are then secured to each other by welding.

The characteristics described above in relation to said connection means are advantageously applicable to each of the connection means of the axial elongation range. According to another aspect, the subject of the invention is a set of flanges arranged to equip a clutch mechanism, the set of flanges comprising a first flange formed by a piston as described herein, and a second flange formed by an outer disk carrier of the clutch mechanism. The piston and the outer disk carrier are in particular entangled with one another. The term "entangled" means two pieces entangled with each other so as not to be separable, without a disassembly operation, one of the other when they are taken isolation of any set.

According to a particular characteristic of the set of flanges of the invention, the outer disk carrier comprises a radial wall and an axial wall delimiting a cavity in which is received the axial elongation range of the piston. The connecting means of the axial elongation span extending outside the outer disk carrier from holes formed circularly on the radial wall of said outer disk carrier to be secured to the radial elongation range of the piston.

The piston advantageously comprising two parts, namely an axial elongation bearing and a radial elongation bearing assembled to one another, makes it possible to arrange the axial elongation bearing from the inside of the outer disk carrier and the range of radial elongation from outside the outer disk carrier. In this configuration, the radial wall of the outer disk carrier is then taken between the axial elongation range of the piston and the radial elongation range of the piston. The range of axial elongation and the reach radial elongation are for example assembled to one another by welding, gluing, latching, or any other suitable means known to those skilled in the art.

According to a particular feature of the set of flanges of the invention, the connection means and the openings of the axial elongation range are dimensioned to allow axial play of the piston relative to the outer disk carrier. Such axial clearance allows axial displacement of the piston when it is actuated by the actuating system.

According to another particular characteristic of the set of flanges of the invention, the connecting means and the openings of the axial elongation range are dimensioned to allow radial play of the piston relative to the outer disk carrier. Such a radial clearance allows the radial displacement of the piston during mounting of the piston and the outer disk carrier on the clutch mechanism.

According to another aspect, the invention relates to a clutch mechanism for a vehicle transmission comprising a set of flanges as described herein, the clutch mechanism comprises a stack of disks, the outer disk carrier carrying at least one disk of a stack of disks. According to the invention, the actuating ring of the piston is axially supported on said disk.

According to another aspect, the subject of the invention is a method of assembling a set of flanges as described herein, the set of flanges comprising: a piston comprising:

an axial elongation bearing formed by an actuating ring from which connecting means extend and

a range of radial elongation,

an outer disk carrier comprising a radial wall and an axial wall delimiting together a cavity internally, the radial wall comprising circularly distributed holes,

said method comprising:

in a mounting step, the axial elongation range of the piston and the outer disk carrier are arranged relative to one another so that the ring the actuating means is housed in the cavity, the connection means of the axial elongation range emerging outside the outer disk carrier.

This assembling step of the assembly method makes it particularly inventive to be able to achieve the assembly of the axial elongation range of the piston to its radial elongation range from outside the outer disk carrier. Thus, such a mounting step facilitates the assembly operation of the set of flanges. Such an assembly method advantageously makes it possible to reduce manufacturing costs, particularly in the case of mass production.

According to one embodiment, the assembly method comprises a step of approximation, in which the radial elongation range of the piston is arranged, from outside the outer disk carrier, bearing against the connection means of the span. axial elongation. The approximation step is advantageously carried out successively at the mounting step.

The connection means, in particular the teeth, of the axial elongation range may advantageously comprise a stop as described herein.

According to another embodiment, the assembly method comprises an assembly step, in which the radial elongation bearing surface is held against the connecting means of the axial elongation bearing surface by a locking means.

Advantageously, in the assembly step, the radial elongation range is secured to the axial elongation range.

Other characteristics and advantages of the invention will become apparent from the description which follows, on the one hand, and from several exemplary embodiments given by way of nonlimiting indication with reference to the appended schematic drawings on the other hand, on which :

FIG. 1 illustrates a perspective view of a piston for a clutch mechanism according to a first embodiment of the invention, in which the piston comprises an axial elongation bearing and a radial elongation bearing,

FIG. 2 illustrates a front view of a set of flanges of a clutch mechanism, the set of flanges comprising the piston illustrated in FIG. 1 and a holder outer disks of a clutch mechanism, the piston and the disk carrier being entangled with each other.

FIG. 3 illustrates a sectional view AA of FIG. 2, in which the axial elongation bearing surface is disposed inside the outer disk carrier and the radial elongation bearing surface is disposed on the outside of the carrier. outer discs, the axial and radial elongation bearing being assembled to one another by their respective connecting means,

FIG. 4A illustrates a cross-sectional view of the set of flanges fitted to a clutch mechanism and comprising a piston according to a second embodiment of the invention in which the connection means of the axial elongation span comprise an abutment arranged to receive the radial elongation range,

FIG. 4B illustrates a detail of FIG. 4A in which the radial elongation range of the piston is secured to the connecting means of the axial elongation bearing by a locking means formed by welding, in particular a weld seam, FIG. 5 illustrates a detail corresponding to FIG. 4B for a third embodiment of the piston of the invention in which the axial elongation span and the radial elongation span are assembled by a locking means formed by an arranged notch to receive a lock washer.

In this document, the terms "axial / radial" and "inner / outer" are used with reference to a piston axis.

In the remainder of the description, the terms "actuation ring" and "ring" will be used interchangeably.

As illustrated in Figure 1, there is shown a piston 1 according to the invention. The piston 1 is intended to equip a clutch mechanism 100 advantageously mounted on a transmission of a motor vehicle. The piston 1 is intended to be mounted around an axis of rotation O of the clutch mechanism 100. The piston 1 is formed for example by the assembly of two distinct parts from one another, namely a range axial elongation member 11 and a radial elongation bearing surface 12. The axial elongation bearing surface 11 is of revolution shape and extends axially about the axis of rotation O. The elongation range radial 12 is of revolution shape and extends radially around the axis of rotation O. The axial elongation range 11 is arranged to engage a stack of disks 201 of a clutch 200 of the clutch mechanism 100, then that the radial elongation range 12 is arranged to be engaged by actuators 41, 42 of an actuating system 40 of the clutch mechanism 100, as shown in Figure 4A and will be described later.

The axial elongation span 11 and the radial elongation range 12 are intended to be joined to each other to form the piston 1. The axial elongation range 11 comprises an actuating ring 11A intended to engage the stack of disks 201 of the clutch mechanism 100. Connecting means 11B, said first connecting means 11B, the axial elongation range 11 extend axially from the ring

A. The first connection means 11B are spaced apart by openings 11C. In the assembled state of the piston 1, the openings 11C are delimited by the axial elongation bearing surface 11 and the radial elongation bearing surface 12. It will thus be understood that in the unassembled state, when the elongation range axial 11 and the range of radial elongation

12 are separated from each other, the openings 11C of the axial elongation bearing surface 11 are open towards the outside, whereas, when the axial elongation bearing surface 11 and the radial elongation bearing surface 12 are assembled to one another, the openings 11C are closed, that is to say bounded on their contour by the axial elongation range 11 and by the radial elongation range 12.

The radial elongation span 12 extends axially by connection means 12B, called second connection means 12B, from the radial elongation bearing surface 12 to cooperate with the first connection means 11B of the axial elongation bearing surface 11. When the piston 1 is assembled, the first connection means 11B and the second connection means 12B come into contact with one another by their free axial ends. The free axial ends of the connection means corresponding connection to the ends of the first connection means 11 B, and second connecting means 12B axial and radial elongation bearing 11, 12 for bearing against each other. According to the first embodiment, the axial elongation range 11 and the radial extension range 12 are then secured by welding or gluing their respective connecting means 11B, 12B to each other. A main advantage of such a piston 1 having two axial and radial portions results from the fact of allowing to engage the stack of disks 201 of the clutch mechanism 100 by means of a ring 11A supported by a side d radial support 11 A 'against this stack of discs 201. Unlike the known pistons of the prior art in which a series of actuating fingers bear against the stack of discs 201, the ring 11A facilitates the dimensional control its radial bearing face 11 A '. The parallelism defects of the piston 1 are then substantially limited.

The actuating ring 11A of the axial elongation range 11 is of continuous circular shape. Thus, the radial bearing face 11A 'of the ring 11A is flat. With this flat shape of the radial bearing face 11 A ', it is possible to guarantee a surface contact of the actuating ring 11A against a disk 201A - shown in FIG. 4A, for example - of the stack of discs 201 over the entire circular contour of the actuating ring 11 A.

Figures 2 and 3, there is shown a set of flanges 12 according to the invention. The set of flanges 12 comprises a first flange formed by a piston 1 according to the first embodiment described above and by a second flange formed by an outer disk carrier 2 of the clutch mechanism 100. The outer disk carrier 2 is intended to carry at least the disk 201 A of the stack of disks 201 of the clutch mechanism 100. Such an outer disk carrier 2 can be advantageously associated with an inner disk carrier 4. The outer disk carrier 2 and the internal disk carriers 4 are then radially arranged relative to each other. Such an arrangement of the inner and outer disk carriers 2, 4 makes it possible to receive the stack of disks 201 of the clutch mechanism 100. In other words, the outer disk carrier 2 radially delimits the stack from the outside. of disks 201 and the inner disk carrier 4 delimits radially from inside the stack of disks 201.

The outer disk carrier 2 is formed by at least one axial wall 21 and a radial wall 22 delimiting between them a cavity C arranged to receive the stack of disks 201, 301. The axial elongation range 11 is housed in the cavity C so that the first connecting means 11B of the axial extension range 11 emerge outwardly of the outer disk carrier 2 from holes 23. The holes 23 are formed circularly on the radial wall 22 of the outer disk carrier 2 to be against the first means of connection 11B of the axial elongation span 11. Each first connecting means 11B enters a hole 23 of the radial wall 22 and emerges from its free end beyond the radial wall 22 of the outer disk carrier 2. It will be understood that while the actuating ring 11A is housed in the cavity C. The free ends of the first connection means 11B then come into correspondence with the free ends of the second connection means 11B of the radial elongation bearing surface 12 to be secured to each other. to each other. The piston 1 and the outer disk carrier 2 are then entangled with each other. The radial wall 22 of the outer disk carrier 2 is then taken axially between the axial elongation bearing surface 11 and the radial elongation bearing surface 12 of the piston 1.

In this entangled configuration of the set of flanges 12, the openings 11C and the connection means 11B of the piston 1 are advantageously formed to allow axial mobility of the piston 1 relative to the outer disk carrier 2. The actuating ring 11A of the piston 1 can then be used to engage the disk 201 A of the stack of disks 201, 301.

In Figure 4A, there is shown the set of flanges 12 comprising a piston 1 according to a second embodiment of the invention. The flange assembly 12 is shown as mounted on a clutch mechanism 100. The clutch mechanism 100 is a radial dual clutch mechanism in which a first clutch 200 and a second clutch 300 are disposed in a radial configuration. relative to each other so that the first clutch 200 is disposed radially outwardly relative to the second clutch 300.

The invention is however not limited to such a clutch mechanism and can be advantageously applied to an axial double clutch mechanism in which the clutches are axially arranged relative to each other along the axis. O rotation of the clutch mechanism 100.

In the clutch mechanism 100 shown, the clutches 200, 300 each comprise a stack of disks 201, 301 lubricated by a cooling oil during operation of the clutch mechanism 100. The first clutch 200 and the second clutch 300 each comprise an outer disk carrier 2, 3 and an inner disk carrier 4, 5 housing between them their respective disk stack 201, 301. Each disk stack 201, 301 is formed by coupling discs 201A, 301A intended to be coupled in rotation to its outer disk carrier 2, 3 and by friction discs 201B, 301B intended to be coupled in rotation to its door -Inside discs 4, 5.

The outer disc carriers 2, 3 of the clutches 200, 300 are rotatably coupled to an inlet web 70 of the clutch mechanism 100. The entry web 70 is rotatably connected to an inlet hub 71 itself. coupled to a motor shaft (not shown). The outer disk carriers 2, 3 are radially supported by a radial rolling bearing 80 disposed between the outer disk carrier 2 of the first clutch 200 and a support 50 of the clutch mechanism 100. The inner disk carrier 4 of the first clutch 200 is coupled to a first output hub 72 and the inner disk carrier 5 of the second clutch 300 is coupled to a second output hub 73. The first and second output hubs 72, 73 are respectively intended to be coupled to a first transmission shaft and to a second transmission shaft (not shown). A radial bearing 81 is advantageously arranged radially between the outer disk carriers 2, 3 of the first clutch 200 adjacent to each other. A first axial bearing 82 is arranged axially between the inner disk carriers 4, 5 of the clutch mechanism 100. A second axial bearing 83 is disposed axially between the outer disk carrier 3 of the second clutch 300 and the support 50 of the clutch mechanism. clutch 100.

An actuating system 40 carried by the support 50 of the clutch mechanism 100 is arranged to actuate a first piston 1 of the first clutch 200 via a first actuator 41 and to actuate a second piston 6 of the second clutch.

300 by means of a second actuator 42. As illustrated, the first piston 1 of the first clutch 200 is a variant of the piston 1 of the invention according to a second embodiment, while the second piston 6 of the second clutch 300 corresponds to a piston 6 comprising actuating fingers 60 for engaging the stack of disks 201,

301 of the clutch 200, 300 corresponding. FIG. 4A represents, on the one hand, a piston 1 of the first clutch 200 comprising an actuating ring 11A according to the invention and a piston 6 of the second clutch 300 comprising actuating fingers 60, such fingers of actuation 60 being known from the prior art. Thus, the configuration of the clutch mechanism 100 of FIG. 4A makes it possible to distinguish more clearly the particular characteristics of the invention. The second piston 6 comprises a radial elongation bearing 62 intended to be actuated by the second actuator 41. Actuating fingers 60 extends axially from the outer radial end of the radial elongation bearing 62 of the second piston 6. and come through the outer disk carrier 3 of the second clutch 300 from the outside to penetrate inside the outer disk carrier 3 of the second clutch 300. More particularly, the actuating fingers 60 of the second piston 6 pass through holes 33 the circular fingers 32 of the outer disk carrier 3 of the second clutch 300. The actuating fingers 60 then engage the stack of disks 301 of the second clutch 300 so that each actuating finger 60 of the second piston 6 exerts a contact pressure on the stack of disks 301 of the second clutch 300. It will be understood that, during disassembly of the embra 100, the second piston 6 is separable from the outer disk carrier 3 of the second clutch 300 separating them axially from each other without requiring any particular disassembly operation.

The first piston 1 comprises an axial elongation bearing 11 and a radial elongation bearing surface 12. In this second embodiment of the piston 1 according to the invention, the axial elongation bearing surface 11 of the first piston 1 is formed by its actuating ring 11A from which axially extending connection means 11B. The connection means 11B of the axial elongation span 11 pass through holes 23 formed circularly on a radial wall 22 of the outer disk carrier 2 of the first clutch 200 to emerge on the outside of this outer disk carrier 2. The means connection 11B of the axial elongation span 11 each comprise a stop 13 formed radially inside the connection means 11B. The abutment 13 of each connection means 11B is formed by a clearance of material from the corresponding connection means 11B, to form a housing that can receive the radial elongation range 12 of the first piston 1. A radial face 13A of the abutment 13 makes it possible to axially stop the radial elongation range 12 of the first piston 1. An outer radial end 12A of the radial elongation bearing surface 12 of first piston 1 is flush with an axial face 13B of the abutment 13. The axial elongation range 11 of the first piston 1 is then axially centered by means of the radial elongation bearing surface 12 of the first piston 1. Thus, the stop 13 is configured to maintain axially and radially the radial elongation bearing surface 12 of the first piston 1 against the connecting means 11B of the axial elongation range 11 of the first piston 1. In the assembled state of the first piston 1, the actuating ring 11A engages a disk 201A of the stack of disks 201 of the first clutch 200. Such a disk 201 A corresponds to a coupling disc 201A preferably metallic material. Similarly to the first embodiment, the actuating ring 11A comprises a radial bearing face 11 A 'bearing against the coupling disc 201 A of the first clutch 200.

In order to axially maintain the radial elongation bearing surface 12 against the abutment 13 of each connection means 11B of the axial elongation bearing surface 11, there is provided a locking means 14. It will be understood that the assembly of the first piston 1 is advantageously made from outside the outer disk carrier 2 of the first clutch 200. Of course, the set of flanges 12 according to the invention is formed preferentially before assembly of the clutch mechanism 100.

In Figure 4B, there is shown the locking means 14 provided for the piston 1 according to the second embodiment. This blocking means 14 is here formed by a weld bead 15 that can be made continuously or discontinuously following a circular line of contact of the connection means 11B of the axial extension range 11 with the radial elongation bearing surface 12 of the first piston 1.

In Figure 5, there is shown a third embodiment of the piston 1 according to the invention and similar to the second embodiment described in Figures 4A and 4B. In this second embodiment, the abutment 13 of each connection means 11B is formed so that a notch 16 is formed radially inside the connection means 11B on the axial face 13B of the abutment 13. Such a notch 16 is advantageously arranged to receive a locking washer 17, this when the radial elongation range 12 of the first piston 1 is disposed axially against the radial face 13 A of the abutment 13. The radial elongation range 12 of the piston 1 of this third embodiment is then locked axially by the radial face 13A of the abutment 13 and by a radial face 17A of the locking washer 17.

Unlike the second embodiment, in the third embodiment, the axial face 13B of the abutment 13 protrudes axially from the radial elongation bearing surface 12 when it is pressed against the radial face 13A of the abutment 13. . Of course, the features, variants and different embodiments of the invention may be associated with each other, in various combinations, to the extent that they are not incompatible or exclusive of each other. It will be possible to imagine variants of the invention comprising only a selection of characteristics subsequently described in isolation from the other characteristics described, if this selection of characteristics is sufficient to confer a technical advantage or to differentiate the invention compared in the state of the art.

Claims

RE VENDIC ATION S

A piston (1) configured to be mounted about an axis of rotation (O) in a vehicle clutch mechanism (100), the piston (1) comprising: an axial elongation bearing (11) comprising a an actuating ring (11A) for engaging a stack of disks (201) of a clutch (200) of the clutch mechanism (100),

a radial elongation bearing (12),

first connecting means (11B) extending from the actuating ring (11A) and / or second connecting means (12B) extending at least partly axially from the radial elongation bearing ( 12), the first and / or second connecting means (11B, 12B) being arranged to connect the axial elongation span (11) to the radial elongation range (12), the axial elongation range (11). and the radial elongation span (12) defining, in the assembled state, the first and / or second connection means (11B, 12B) of the openings (10C).

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

3. Piston (1) according to any one of the preceding claims, characterized in that the actuating ring (11 A) of the axial elongation range (11) is of continuous circular shape.

4. Piston (1) according to any one of the preceding claims, characterized in that at least a first connection means (11B) comprises a stop (13) arranged to receive the radial elongation bearing (12), said stop being in particular formed by a clearance of material of said connection means (11B).

5. Piston (1) according to the preceding claim, characterized in that the at least one first connection means (11B) comprises a locking means (14) arranged to maintain the radial elongation range (12) against the stop ( 13).

6. Piston (1) according to the preceding claim, characterized in that the locking means (14) comprises a weld bead (15) or comprises in said connection means (11B) a notch (16) arranged to receive a washer blocking (17).

7. Piston (1) according to the preceding claim, characterized in that the stop (13) is formed by a first notch (16) in said first connection means (11B) arranged to receive a first locking washer (17) and the locking means (14) is formed by a second notch (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 abutment (13) and the locking means (14) are formed radially inside said connection means (11B).

9. Piston (1) according to any one of the preceding claims, characterized in that the axial elongation span (11) comprises the first connection means (1 1 B), and the radial elongation span (12) comprises the second axially extending connecting means (12B), the first connection means (11B) and the second connection means (12B) being intended to bear axially against one another to secure the range of axial elongation (11) and the radial elongation range (12) to each other.

10. Set of flanges (12) arranged to equip 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 disk carrier (2) of the clutch mechanism (100), characterized in that the piston (1) and the outer disk carrier (2) are entangled with each other.

11. Set of flanges (12) according to the preceding claim, characterized in that the outer disk carrier (2) comprises an axial wall (21) and a radial wall (22) defining together from the inside a cavity (C) in which the axial elongation span (11) of the piston (1) is received, the connecting means (11B) of the axial elongation span (11) extending outside the outer disk carrier (2). ) from holes (23) formed circularly on the radial wall (22) of said outer disk carrier (2) to be secured to the radial elongation range (12) of the piston (1).

12. Clutch mechanism for a vehicle transmission comprising a set of flanges (12) according to any one of claims 11 or 12, the clutch mechanism (100) comprises a stack of disks (201), the carrier outer discs (2) carrying at least one disc (201A) of a stack of discs (201), characterized in that the actuating ring (11A) of the piston (1) bears axially against said disc.

13. A method of assembling a set of flanges (12) according to any one of claims 11 to 12, the set of flanges (12) comprising:

a piston (1) comprising:

an axial elongation bearing (11) formed by an actuating ring

(11 A) from which connection means (11B) extend and,

a radial elongation bearing (12),

an outer disk carrier (2) comprising an axial wall (21) and a radial wall (22) defining a cavity (C) internally, the radial wall (22) comprising circularly distributed holes (23);

said method being characterized in that it comprises:

in a mounting step, the axial elongation span (11) of the piston (1) and the outer disk carrier (2) are arranged relative to each other so that the actuating ring (11 A) is housed in the cavity (C), the means of connection (11B) of the axial elongation span (11) emerging outside the outer disk carrier (2).

14. A method of assembly according to the preceding claim, characterized in that: in a step of approximation, the radial elongation range (12) of the piston (1) is disposed from outside the outer disk carrier (2). ), bearing against the connection means (11B) of the axial elongation range (11).

15. Assembly method, characterized in that:

in an assembly step, the radial elongation span (12) is held against the first connection means (11B) by a locking means (14).