WO2018078257A1

WO2018078257A1 - Brake caliper with axial compression of a seal between an actuator casing and a caliper body

Info

Publication number: WO2018078257A1
Application number: PCT/FR2017/052903
Authority: WO
Inventors: Philippe Bourlon
Original assignee: Foundation Brakes France
Priority date: 2016-10-25
Filing date: 2017-10-23
Publication date: 2018-05-03
Also published as: FR3057924A1; FR3057924B1

Abstract

The invention relates to a vehicle brake caliper. The caliper (2) comprises a caliper body (20) and an electromechanical actuator (3). The caliper body (20) comprises a planar surface (23), a barrel (24) protruding from the planar surface (23), and a piston drive shaft (41). The actuator (3) comprises a casing (37) that is attached to the caliper body (20) while being centered on the shaft (24) and pressed against the planar surface (23). The casing (37) comprises a groove (7) in which a seal (6) is accommodated which is overmolded in the groove (7). The seal (7) is situated between the caliper body (20) and the actuator casing (37), while being compressed between the caliper body (20) and the actuator casing (37) along the direction of the axis (X-X) of the drive shaft. Figure 4

Description

BRAKE CALIPER WITH AXIAL COMPRESSION OF A SEAL BETWEEN AN ACTUATOR CASE AND A CALIPER BODY

DESCRIPTION

TECHNICAL AREA

The invention relates to vehicle brakes. More specifically, it relates to the mechanical connection between an electromechanical actuator and a disc brake caliper body.

STATE OF THE PRIOR ART

Motor vehicles are equipped with disc brakes. Each disc brake includes a stirrup and pads which are intended to grip a disc. The disc is secured to the hub of a wheel of the vehicle.

The stirrup comprises a stirrup body and an electromechanical actuator which is screwed to the stirrup body. A seal is placed between the actuator housing and the caliper body to provide a seal between these two parts.

There is a need to simplify the joint assembly between the actuator block and the caliper body, while ensuring a good seal between the actuator housing and the caliper block. The invention aims to satisfy this need.

STATEMENT OF THE INVENTION

In this respect, the subject of the invention is a brake caliper for a vehicle. The stirrup comprises a stirrup body comprising a flat surface, a barrel protruding from the flat surface, and a drive shaft of a brake piston, which is located at least partially inside the barrel.

The caliper body comprises an electromechanical brake actuator coupled to the drive shaft, comprising a casing attached to the caliper body being centered on the barrel and resting on the flat surface. According to the invention, the housing has a groove housing the gasket, the gasket being overmolded in the groove, the gasket being located between the caliper body and the actuator housing, and the gasket being compressed between the body stirrup and actuator housing in the direction of the shaft of the drive shaft.

Thanks to the invention, the seal is compressed axially in the direction of the axis of the drive shaft instead of being compressed radially relative to this axis. This results in greater ease of installation of the seal and a better seal between the actuator housing and the caliper body. Furthermore, the seal is easy to manufacture, and the risk of forgetting the installation of the seal is limited.

Preferably, the seal extends around the barrel being compressed between the actuator housing and the flat surface.

The invention also relates to an electromechanical actuator for a brake caliper as defined above. The actuator comprises a housing comprising a groove housing the gasket, the gasket being overmolded in the groove, the groove being oriented so as to compress the gasket between the housing and the caliper body in the direction of the axis of the gasket. drive shaft.

The invention also relates to a brake comprising the stirrup as defined above, and a method of manufacturing the stirrup.

The manufacturing method comprises a step of assembling the actuator to the yoke, wherein the seal is compressed between the yoke body and the actuator housing in the direction of the axis of the yoke. drive shaft.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be better understood on reading the description of exemplary embodiments, with reference to the appended drawings in which:

Figure 1 is a perspective view of a brake caliper for a vehicle, according to the preferred embodiment of the invention;

Figure 2 is a front view of an actuator of the stirrup according to the preferred embodiment; Figure 3 is a partial schematic representation in longitudinal section of the actuator;

Figure 4 is an elevational representation of the caliper body according to the preferred embodiment. DETAILED PRESENTATION OF PARTICULAR EMBODIMENTS

Figure 1 shows a disc brake 1 of a vehicle wheel. The brake 1 comprises a stirrup 2 and two pads (not shown) which are intended to grip a disc (not shown). The disc is rigidly secured to the hub of the wheel (not shown) to be braked. The brake 1 is an electromechanical brake used in particular when parking the vehicle.

The stirrup 2 comprises a body 20, a brake piston 4, an electromechanical actuator 3 mechanically connected to the body 20, and a seal which is compressed between the actuator 3 and the stirrup body 20. The stirrup 2 is of floating type.

The body 20 houses the piston in a piston housing cylinder 22. The piston 4 is movable in translation relative to the stirrup body 20, in a direction of displacement of the piston XX, under the effect of the actuator 3. The displacement of the piston 4 in the axial direction XX makes it possible to bring the skids closer to each other. from each other to brake the wheel.

In the following description, an axial direction is a direction parallel to the direction of movement of the piston X-X. A circumferential direction is a direction about this axis and a radial direction is a direction orthogonal to this axis. The term "downstream" corresponds to the direction of movement of the piston 4, to brake the wheel. The term "upstream" refers to the opposite direction of the downstream term in the axial direction X-X.

With reference to FIG. 2, the housing cylinder of the piston 22 is delimited by a plane bearing surface 23 and by a cylindrical barrel 24 which protrudes from the plane bearing surface 23 upstream and which is located substantially at center of the plane bearing surface 23.

The plane bearing surface 23 is substantially orthogonal to the direction of movement of the piston XX. It takes the form of a disc that surrounds the barrel 24. The shaft 24 is cylindrical. It is centered on the direction of movement of the piston XX which forms a generatrix of the shaft 24. The flat bearing surface 23 and the shaft 24 are concentric around the axis of movement of the piston XX.

The barrel 24 has an external lateral face having a substantially smooth cylindrical external surface SL. It houses at its center an input shaft 41 of the piston which forms a female coupling portion and which partially extends beyond the barrel 24 upstream.

The shaft 24 also has a disk-shaped upstream flat surface 27 which is substantially parallel to the plane bearing surface 23.

The shaft 24 facilitates the centering of the actuator 3 on the caliper body 20 and facilitates the mechanical coupling of the input shaft 41 to the output shaft 32 of the actuator 3.

With reference to FIGS. 1 to 3, the electromechanical actuator 3 comprises a motor 30, a transmission device 31 and a casing 37.

The motor 30 is configured to drive the transmission device 31 to move the piston 4 in the axial direction X-X.

The transmission device 31 comprises the output shaft 32 which is intended to be coupled to the input shaft 41, being coaxial with the direction of movement of the piston X-X.

The output shaft 32 forms a coupling male portion for coupling with the input shaft 41 of the piston.

The actuator 3 comprises a housing 38 for housing the motor 30 and a housing 39 for housing the transmission device 31. The motor housing 38 and the casing 39 of the transmission device together form the casing 37 of the actuator.

The housing 38 of the engine has a generally cylindrical shape.

The housing 39 of the transmission device has a generally cylindrical shape and is centered around the output shaft 32. It comprises an ear 51 at its periphery for fixing the actuator 3 to the stirrup body 20. The casing 39 of the transmission device 39 also has an inner surface Si located around the output shaft 32 and bearing on the upstream surface 27, when the actuator 3 is attached to the stirrup body 20.

The housing 39 of the transmission device comprises a groove 7 located at the periphery of the inner surface Si and radially between the output shaft 32 and the lug 51.

The groove 7 forms a housing of the seal 6. It comprises a bottom wall 74 and two side surfaces 72, 73 opposite to each other and interconnected by the bottom wall 74.

The first side wall 73 is an inner side wall. The second side wall 72 is an outer side wall located radially at the periphery of the inner side wall 73. The two side walls 72, 73 extend substantially axially and parallel to one another.

The seal 6 is housed in the groove 7, being in plane bearing against each of the walls 72, 73, 74. The seal 6 seals at the junction of the housing 39 of the transmission device and the surface of the support plan 23.

The casing 39 is in plane bearing on the plane bearing surface 23 being centered around the barrel 24, when the actuator 3 is connected to the caliper body 20. The casing 39 then compresses the seal 6 in the direction of the barrel. XX axis of the input shaft 41, against the plane bearing surface 23.

The actuator 3 is fixed to the caliper body 20 by fastening means 5 which comprise the lug 51 of the casing 39 of the transmission device, an lug 53 integral with the caliper body, and a screw 50.

The lug 53 of the stirrup body 20 is situated at the periphery of the plane bearing surface 23. It is traversed by a hole which is oriented along an axis YY which is parallel to the displacement axis XX of the piston, in being offset from the axis of displacement X-X of the piston. The ear hole 53 of the caliper body is threaded.

The ear 51 of the actuator is also traversed by a hole which is intended to come opposite that of the ear 53 of the stirrup body. The screw 50 is inserted into the holes of the ears 51 and 53, the thread of the screw cooperating with the thread of the hole of the ear 53 of the stirrup body. The screw 50 and at least one of the two lugs 51, 53 thus form clamping means of the actuator 3 relative to the stirrup body 20.

The stirrup 2 is manufactured in the following manner. The casing 37 of the actuator is manufactured by molding. The seal 6 is made by overmoulding in the groove 7 of the casing 39 of the transmission device.

The actuator 3 is then connected to the caliper body 20, the output shaft 32 of the actuator being coupled to the input shaft 41 of the caliper body.

The inner surface Si then bears on the upstream surface 27. The seal 6 surrounds the drum 24. It is compressed axially in the groove 7, between the casing 39 of the transmission device and the flat bearing surface 23 .

The axial compression of the seal 6 facilitates the mounting of the seal between the casing 39 of the transmission device and the caliper body 20. A greater tightening of the casing 39 on the caliper body 20 further compresses the seal. seal 6 axially and tends to improve the seal between the actuator 3 and the stirrup body 20.

Of course, various modifications can be made by the invention which has just been described above.

In an alternative embodiment (not shown), the direction of movement of the piston X-X is shifted relative to the direction of the input shaft 41, while preferably remaining parallel to this direction. In this case, the seal 6 is compressed axially in the direction of the input shaft 41.

In an alternative embodiment (not shown), the seal 6 is mounted in the groove 7 and then attached to the housing 39 of the transmission device 39, for example by clipping.

In an alternative embodiment (not shown), the side walls 72, 73 are inclined with respect to the direction of the axis XX of the drive shaft 41. NOMENCLATURE REFERENCE TO FIGURES

1: disc brake

2: brake caliper

3: electromechanical actuator

4: piston

5: fastening means

6: seal

7: groove

20: caliper body

22: piston housing cylinder

23: flat support surface

24: barrel

27: upstream flat surface

30: engine

31: transmission device

32: output shaft of the actuator

37: actuator housing

38: motor housing

39: casing of the transmission device

41: piston input shaft

50: screws

51: ear of the stirrup

53: ear of the actuator

72: outer side wall

73: inner side wall

74: bottom wall

SL: lateral surface of the barrel

Si: internal surface of the actuator housing

XX: direction of the axis of the piston displacement shaft YY: direction of the axis of the clamping means

Claims

A brake caliper (2) (1) comprising:

a stirrup body (20) comprising:

a flat surface (23),

a shank (24) protruding from the flat surface (23), and

a drive shaft (41) of a brake piston, located at least partially inside the shaft (24),

an electromechanical actuator (3) brake coupled to the drive shaft (41), comprising a housing (37) attached to the stirrup body (20) being centered on the shaft (24) and resting on the surface plane (23),

characterized in that the housing (37) comprises a groove (7) in which is housed a seal (6) which is overmolded in the groove (7),

the seal (7) being located between the caliper body (20) and the actuator housing (37), and being compressed between the caliper body (20) and the actuator housing (37) in the direction of the axis (XX) of the drive shaft.

2. Caliper (2) according to the preceding claim, wherein the seal (6) extends around the barrel (24) being compressed between the actuator housing (37) and the flat surface (23).

Electromechanical actuator (3) for a brake calliper (2) according to claim 1, comprising a housing (37) comprising a groove (7) housing a seal (6), the groove (7) being oriented from in order to compress the seal (6) between the casing (37) and a caliper body (20) in the direction of the axis (XX) of a brake piston drive shaft (41), the seal (6) being overmolded in the groove (7).

A vehicle disc brake (1) comprising a yoke (2) according to any of claims 1 and 2.

5. A method of manufacturing a brake caliper (2) according to any one of claims 1 to 2, comprising:

a step of assembling the actuator (3) to the yoke (2), wherein the seal (6) is compressed between the yoke body (20) and the actuator housing (37) in the direction of the axis (XX) of the drive shaft.