FR3053085A1 - RECEIVER HYDRAULIC CYLINDER FOR A HYDRAULIC CONTROL SYSTEM OF A CLUTCH - Google Patents

Abstract

The invention relates to a hydraulic receiver cylinder (1) for a hydraulic control system of a clutch; the hydraulic receiver cylinder (1) comprising: - an annular guide tube (2) having a wall (4) having an orifice (23); an annular piston (7) mounted axially movable inside a blind cavity (16) defined by the guide tube (2); - an outer body (13) having a feed inlet formed by a through cavity (24) opening opposite the orifice (23); - a male connector (25) attached to the inside of the through cavity (24) of the outer body (13); - an annular seal (29) housed in the through cavity (24) and compressed between the male end (25) and the outer wall (4) so as to ensure a seal between the blind cavity (16) and the inner channel (28) of the spigot (25).

Description

Technical Field The invention relates to the field of hydraulic control systems. It relates more particularly to a hydraulic cylinder receiver for a control system of a motor vehicle clutch.

Technological background

The document FR2789140 discloses a hydraulic receiver cylinder, according to the state of the art. The receiving hydraulic cylinder comprises a guide tube defining an annular blind cavity and an annular piston axially movable in the blind cavity so as to define a variable volume chamber. The outer wall of the guide tube has a supply port. The hydraulic cylinder receiver further comprises a body surrounding the guide tube which is intended to ensure the attachment of the hydraulic cylinder receiver on the vehicle frame. The outer body has a cavity which receives a connecting male end to be connected to a fluid supply duct; said cavity being connected to the supply port formed in the outer wall of the guide tube by a bore of the outer body which passes radially through the outer body.

A tubular sealing cartridge is mounted in the bore of the outer body so as to seal between the guide tube and the outer body, on the one hand, and between the outer body and the cavity receiving the male end connection, on the other hand. The tubular sealing cartridge comprises an internal channel which, on the one hand, opens radially facing the supply orifice formed in the outer wall of the guide tube and which, on the other hand, is cranked in such a way that the inner channel opens facing the cavity receiving the male connection end. The tubular sealing cartridge carries two annular seals which are disposed on either side of the end of the inner channel opening facing the cavity receiving the connecting male end and which are mounted in annular grooves formed on the outer periphery of the tubular sealing cartridge. Furthermore, an annular sealing gasket is compressed between the radially inner end of the tubular sealing cartridge and a surface facing the outer wall of the guide tube, around the supply orifice. , in order to prevent liquid leakage between the guide tube and the outer body. In order to ensure a satisfactory compression of the above-mentioned annular sealing gasket, the tubular cartridge is compressed radially inwards in the radial bore of the outer body and is then welded against the outer body in this position.

A hydraulic receiver cylinder of the aforementioned type is not fully satisfactory. In particular, if the compression in the bore of the seal cartridge and its welding on the outer body allow precise control of the compression of the O-ring, they increase the complexity of the manufacture of such a receiver hydraulic cylinder. summary

An idea underlying the invention is to provide a hydraulic cylinder receiver for a hydraulic control system that is simple and provides a seal reliably between the male end to be connected to a fluid supply conduit and the blind cavity of the guide tube.

According to one embodiment, the invention provides a hydraulic receiver cylinder; the receiving hydraulic cylinder comprising: - an annular guide tube having a wall defining a blind cavity and having an orifice; an annular piston mounted axially movable along an axis X inside the blind cavity and defining with said blind cavity a hydraulic chamber of variable volume; an outer body surrounding the guide tube; said outer body having a feed inlet formed by a through cavity opening opposite the orifice; - A connecting male end to be connected to a hydraulic fluid supply duct; the male end being fixed inside the cavity of the outer body and having an inner channel having an end opening at a first end of the male end, facing the orifice; an annular seal housed in the through cavity and compressed between, on the one hand, a first surface which is formed on the first end of the male end around the end of the inner channel and, on the other hand a second surface which is provided on the wall and which borders the orifice, so as to ensure a seal between the blind cavity and the inner channel of the male end; the first surface and the second surface being complementary in shape to each other.

Thus, such a hydraulic receiver cylinder is simple and has no additional sealing cartridge since the male end has an inner channel which opens directly opposite the orifice of the wall of the guide tube and the seal annular is directly compressed between the male end and the wall of the guide tube.

In addition, thanks to the geometrical characteristics of the first surface and the second surface, the annular seal is compressed homogeneously, which ensures a seal in a reliable and durable manner.

According to other advantageous embodiments, such a hydraulic receiver cylinder may have one or more of the following characteristics.

According to a first embodiment, the first surface and the second surface are plane and parallel to each other. According to a second embodiment, the first surface and the second surface are respectively concave and convex.

According to one embodiment, the first surface and the second surface are parallel to each other, which allows a perfectly uniform compression of the annular seal.

According to one embodiment, the first surface and the second surfaces are cylindrical surfaces inscribed in cylinders of revolution having an axis parallel to the axis X.

According to one embodiment, the first and second surfaces have substantially identical radii of curvature.

According to one embodiment, the wall is formed by a cylindrical outer wall and a cylindrical inner wall which is connected to the outer wall by a bottom wall; the external partition, the internal partition and the bottom partition defining the blind cavity, the external partition having the orifice.

According to one embodiment, the second surface is formed on the outer wall.

According to one embodiment, the annular seal has an ellipsoidal section, the largest dimension is oriented in the direction of compression of said seal between the first and second surfaces.

In another embodiment, the seal is an O-ring.

According to another embodiment, the annular seal is made of elastomer, for example ethylene-propylene-diene monomer (EPDM).

According to a first embodiment, the male endpiece is fixed in the through cavity by a connecting pin comprising two branches forming substantially a U; each branch passing through an opening in the outer body and opening into the cavity and each of the branches being housed in an annular groove on the male end.

According to a second embodiment, the male endpiece is mounted in force in the cavity. In an advantageous variant, the male end has an outer shape of a fir-tree.

According to a third embodiment, the male end is fixed in the cavity by a bayonet attachment.

According to an embodiment, the cavity has a radial orientation and the male end has a bent shape.

According to one embodiment, the invention also provides a motor vehicle comprising a receiver hydraulic cylinder mentioned above.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood, and other objects, details, features and advantages thereof will become more clearly apparent from the following description of several particular embodiments of the invention, given solely for the purposes of the invention. illustrative and not limiting, with reference to the accompanying drawings. - Figure 1 is a partial view in axial section of a hydraulic receiver cylinder in which the connecting male end to be connected to a fluid supply duct is not shown. FIG. 2 is a cross-sectional view of the hydraulic receiving cylinder of FIG. 1; the male connection end being mounted in the cavity of the supply inlet. - Figure 3 is a detailed schematic view of the hydraulic cylinder receiver of Figure 3 illustrating the compression of the seal between the male end and the guide tube. - Figure 4 is an axial sectional view of a hydraulic cylinder receiver according to a second embodiment. - Figure 5 is a detailed schematic view of the hydraulic cylinder receiver of Figure 4 illustrating the compression of the seal between the male end and the guide tube. - Figure 6 is an axial sectional view of a hydraulic cylinder receiver according to a third embodiment. - Figure 7 is an axial sectional view of a hydraulic cylinder receiver according to a fourth embodiment. FIG. 8 is a detailed perspective view of the cavity of the feed inlet of the hydraulic receiving cylinder of FIG. 7; FIG. 9 is a detailed perspective view of one end of the male end of the cylinder; hydraulic receiver of Figure 7.

Detailed description of embodiments

In the description and the claims, the terms "external" and "internal" as well as the "axial" and "radial" orientations will be used to designate, according to the definitions given in the description, elements of the receiving hydraulic cylinder. By convention, the "radial" orientation is directed orthogonally to the sliding axis X of the piston of the hydraulic receiver cylinder determining the "axial" orientation and, from the inside towards the outside, away from said axis. The terms "external" and "internal" are used to define the relative position of one element with respect to another, with reference to the X axis, an element close to the axis is thus described as internal as opposed to an outer member located radially peripherally. Furthermore, the terms "back" AR and "forward" AV are used to define the relative position of one element relative to another in the axial direction.

Figure 1 shows a hydraulic cylinder receiver 1 of a control system of a clutch. The hydraulic receiver cylinder 1 is intended to cooperate with the diaphragm of a clutch, not shown, in order to move the clutch between an engaged position and a disengaged position. Such a hydraulic receiver cylinder 1 is intended to be connected to an emitter hydraulic cylinder, not shown, via a fluid supply duct. The fluid is for example oil. The transmitter hydraulic cylinder is intended to be connected by a control rod to an actuating element, such as a pedal or an electric actuator. When the driver presses on such a pedal, the hydraulic cylinder emitter expels fluid towards the hydraulic cylinder receiver 1 so as to move the clutch from its engaged position to its disengaged position.

The hydraulic receiver cylinder 1 comprises a guide tube 2, metal, annular shape providing an internal space 3 for the passage of a transmission shaft, not shown, such as an input shaft of a gearbox. The guide tube 2 comprises an outer cylindrical wall 4 and an inner cylinder wall 5 which is connected to the outer wall 4 by a bottom wall 6. The outer wall 4 has an axial dimension smaller than that of the inner wall 5. The internal and external partitions 5 and the bottom wall 6 together define a blind cavity 16 inside which is mounted axially movable an annular piston 7. The annular piston 7 thus defines with the blind cavity 16 an annular chamber with variable volume .

The annular piston 7 carries at its rear end a dynamic seal 8 ensuring the sealing of the annular chamber variable volume. Furthermore, the annular piston 7 carries at its front end a rotary stopper 9. The rotary stopper 9 comprises a ring 10 which is fixed to the annular piston 7, another ring 11 which is intended to bear against the fingers of the diaphragm the clutch and rolling bodies 12, such as balls, interposed between the two rings 10, 11. The annular piston 7 is for example molded of plastic.

Furthermore, the hydraulic cylinder receiver 1 comprises an outer body 13 which is intended to ensure the attachment of the hydraulic cylinder receiver 1 on the chassis of the vehicle. To do this, the outer body 13 comprises for example ears, not shown, which are each equipped with an orifice for the passage of fastener against a wall of the vehicle, as described in document FR2730532.

The outer body 13 surrounds the guide tube 2 and is attached thereto. To do this, in the embodiment shown, the outer body 13 comprises, on the one hand, a rear edge 14 bearing against the bottom wall 6 of the guide tube 2 and, on the other hand, elastic tabs 15 whose end is engaged in a groove on the outer surface of the outer wall 4 of the guide tube 2. The outer body is molded in a polymer, such as polyamide 6-6.

The outer body 13 comprises a forward bearing shoulder 17 for a preload spring 18 which acts between the outer body 3 and the annular piston 7. Such a preload spring 18 is intended to ensure a permanent support of the one of the rings 11 of the rotary stop 9 against the fingers of the diaphragm.

Furthermore, the hydraulic receiver cylinder 1 comprises a protective bellows 19, elastomeric material, which avoids polluting the blind cavity 16 with impurities. The protective bellows 19 surrounds the preload spring 18 and has a rear end having a bead 20 mounted in a groove on the outer body 3 and a front end having a bead 21 mounted in a groove on a sleeve 22 integral with the piston ring 7.

In order to ensure a supply of fluid to the blind cavity 16, the outer wall 4 of the guide tube 2 comprises, near the bottom wall 6, an orifice 23 and the outer body 3 comprises a feed inlet formed by a cavity 24, tubular in shape and radially oriented, which passes through the outer body 13 and which opens opposite the orifice 23. The feed inlet is intended to receive a connecting male end, not shown on the Figure 1, adapted to connect the hydraulic cylinder receiver 1 to a hydraulic cylinder transmitter via a supply duct.

In Figures 2 and 3, there is a male connector 25 mounted inside the cavity 24 according to a first embodiment. The male end 25 is bent in the direction of the hydraulic cylinder emitter to prevent it being the supply duct, flexible, which forms an angle, which would be likely to damage it. The spigot 25 is molded in a polymer, such as polyamide 6-6. The male end 25 is held in the engaged position inside the cavity 24 by a connection pin 26. The connection pin 26 comprises two branches 26a, 26b forming a substantially U. Each branch 26a, 26b of the connecting pin 26 passes through a respective opening in the outer body 13 and opening into the cavity 24 of the feed inlet. Furthermore, the male endpiece 25 has an annular groove 27 which is adapted to come opposite the orifices in the outer body 3 when the spigot 25 is mounted in the cavity 24 of the feed inlet. Thus, the two branches 26a, 26b of the connection pin 26 are able to position themselves in the annular groove 27 when they are engaged in the openings in the outer body 13, which makes it possible to block the male end 25 to Inside the cavity 24. Advantageously, each branch 26a, 26b has a curved portion in order to adapt to the annular shape of the annular groove 27 formed on the male endpiece 25. The connection pin 26 is made of metal, for example. Such a connection pin 26 is for example described in FR2808071 A1.

Advantageously, the annular groove 27 is equipped with projecting elements or flats, not shown, which are intended to cooperate with the branches 26a, 26b of the connection pin 26 so as to prevent the rotation of the male end 25 inside the cavity 24 of the feed inlet. The spigot 25 has an inner channel 28 which is intended to conduct fluid between the fluid supply duct, not shown, and the blind cavity 16. To do this, the inner channel 28 has an end that opens out facing of the orifice 23 formed on the outer wall 4 of the guide tube 2.

Furthermore, as shown in detail in Figure 3, an annular seal 29 is compressed between the male end 25 and the outer wall 4 of the guide tube 2 so as to seal between the blind cavity 16 and the inner channel 28 of the spigot 25. The connecting pin 26, the annular groove 27 and the openings in the outer body 13 and through which the branches 26a, 26b pass are dimensioned and localized, some by relative to others so as to maintain on the annular seal 29 the compression force required.

The annular seal 29 is compressed between, on the one hand, a first surface 30 which is formed on the end of the spigot 5, around the end of the inner channel 28, and on the other hand a second surface 31 which is formed on the outer wall 4 of the guide tube 2 around the orifice 23.

The first and second surfaces 30, 31 are here inscribed in cylinders of revolution whose axis extends parallel to the axis X. Advantageously, the first and the second surfaces 30, 31 are inscribed in cylinders of revolution having identical rays. In other words, the first and second surfaces 30, 31 are parallel to each other. Thus, the compression of the annular seal 29 is made homogeneously.

The annular seal 29 is for example made of ethylene-propylene-diene monomer (EPDM). The seal may be toric or have any other section, square, ellipsoidal or rectangular. Advantageously, the section of the seal 29 is ellipsoidal.

In Figures 4 and 5, there is a male connector 25 mounted inside the cavity 24 according to a second embodiment.

As in the previous embodiment, the spigot 25 is held in the engaged position inside the cavity 24 by a connection pin 26. However, this embodiment differs from the embodiment described above in that, on the one hand, the end of the spigot 25 is flat and in that, on the other hand, the zone of the external partition 4 bordering the orifice 23 and against which the gasket 29 rests is also plane. In other words, the first surface 32 and the second surface 33 between which the annular seal 29 is compressed are flat and parallel to each other, which also makes it possible to obtain a compression of the gasket. annular sealing 29 in a homogeneous manner.

Figure 6 illustrates a spigot 25 mounted within the cavity according to a third embodiment. In this embodiment, the spigot end 25 is forcibly mounted in the cavity 24 of the feed inlet. In order to facilitate the force mounting of the spigot 25 in the cavity 24 while ensuring a satisfactory attachment, the spigot 25 has an outer surface 34 of the pion-fir type.

Figures 7, 8 and 9 show a spigot 25 mounted inside the cavity 24 according to a fourth embodiment. In this embodiment, the attachment of the spigot 25 inside the cavity 24 is provided by a bayonet attachment. To do this, as shown in FIGS. 7 and 8, the feed inlet is provided with two lugs 35, 36 which project towards the radial axis defining the direction of the cavity 24. Each of the lugs 35, 36 is adapted to slide in a respective groove 37, illustrated in Figure 9, which has a first portion 38 and a second portion 39. The first portion 38 is parallel to the sliding direction of the spigot 25 within the cavity 24 and thus serves to guide the lug 35, 36 during the sliding of the male end 25. The second portion 39 extends perpendicular to the direction of the male end 25 inside the cavity 24. Thus , the pins 35, 36 are positioned in the second portion 39 of the groove 37 so as to maintain the male end 25 in the cavity 24, when, after sliding the male end 25 into the cavity 24, the endpiece male 25 is rotated inside e cavity 24.

Although the invention has been described in connection with several particular embodiments, it is obvious that it is not limited thereto and that it comprises all the technical equivalents of the means described and their combinations if they are within the scope of the invention. The use of the verb "to include", "to understand" or "to include" and its conjugated forms does not exclude the presence of other elements or steps other than those set out in a claim.

In the claims, any reference sign in parentheses can not be interpreted as a limitation of the claim.

Claims (14)

A hydraulic receiver cylinder (1) comprising: - an annular guide tube (2) having a wall (4, 5, 6) defining an annular blind cavity (16), the wall having an orifice (23); - An annular piston (7) mounted axially movable along an axis X within the blind cavity (16) and defining with said blind cavity (16) a hydraulic chamber variable volume; an outer body (13) surrounding the guide tube (2); said outer body (13) having a feed inlet formed by a through cavity (24) opening opposite the orifice (23); - A male connector (25) for connection to be connected to a hydraulic fluid supply duct; the male end (25) being fixed inside the cavity (24) of the outer body (13) and having an inner channel (28) having an end opening at a first end of the male end ( 25) opposite the orifice (23); - an annular seal (29) housed in the through cavity (24) and compressed between, on the one hand, a first surface (30, 32) which is provided on the first end of the spigot (25) around the end of the inner channel (28) and, on the other hand, a second surface (31, 33) which is provided on the wall and which borders the orifice (23), so as to ensure a seal between the blind cavity (16) and the inner channel (28) of the spigot (25); the first surface (30, 32) and the second surface (31, 33) being complementary in shape to each other. The hydraulic receiver cylinder (1) according to claim 1, wherein the first surface (30, 32) and the second surface (31, 33) are plane and parallel to each other or respectively concave and convex. 3. Hydraulic cylinder receiver (1) according to claim 1 or 2, wherein the wall is formed by a cylindrical outer wall (4) and a cylindrical inner wall (5) which is connected to the outer wall by a bottom wall ( 6); the external partition, the internal partition and the bottom partition defining the blind cavity, the external partition having the orifice. 4. hydraulic receiver cylinder (1) according to claim 3, wherein the second surface (31, 33) is provided on the outer wall. 5. Hydraulic cylinder receiver (1) according to one of claims 1 to 4, wherein the first surface (30, 32) and the second surface (31, 33) are parallel to each other. 6. Hydraulic cylinder receiver (1) according to any one of claims 1 to 5, wherein the first surface (30) and the second surfaces (31) are cylindrical surfaces inscribed in cylinders of revolution having an axis parallel to the X axis. The hydraulic receiver cylinder (1) according to claim 6, wherein the first and second surfaces (30, 31) have substantially identical radii of curvature. 8. hydraulic cylinder receiver (1) according to any one of claims 1 to 7, wherein the annular seal (29) has an ellipsoidal section whose largest dimension is oriented in the direction of compression of said seal of sealing between the first and second surfaces (30, 32; 31, 33). 9. Hydraulic cylinder receiver (1) according to any one of claims 1 to 8, wherein the annular seal (29) is elastomeric. 10. Hydraulic cylinder receiver (1) according to any one of claims 1 to 9, wherein the spigot (25) is fixed in the through cavity (24) by a connecting pin (26) comprising two branches (26a). , 26b) substantially forming a U; each of the branches (26a, 26b) passing through an opening in the outer body (13) and opening into the cavity (24) and each of the branches (26a, 26b) being housed in an annular groove (27) provided on the male end (25). 11. Hydraulic cylinder receiver (1) according to any one of claims 1 to 10, wherein the spigot (25) is mounted in force in the cavity (24). 12. Hydraulic cylinder receiver (1) according to claim 11, wherein the male end (25) has an outer shape (34) in fir-tree. 13. Hydraulic cylinder receiver (1) according to any one of claims 1 to 10, wherein the spigot (25) is fixed in the cavity (24) by a bayonet attachment. 14. Hydraulic cylinder receiver according to any one of claims 1 to 13, wherein the cavity (24) has a radial orientation and wherein the male end (25) has a bent shape.