FR3033012A1 - "DISC BRAKE COMPRISING AT LEAST ONE ELASTIC RECALL SPRING OF A BRAKE SKATE, ELASTIC RECALL SPRING, REPLACEMENT KIT AND MOUNTING METHOD" - Google Patents

Abstract

The invention proposes a motor vehicle disc brake which comprises a brake disc, a fixed support, a brake shoe axially slidably mounted in the fixed support, and at least one elastic return spring (48) of the brake shoe ( 18) to its rest position. The spring (48) has a bracket (52) which extends in a plane orthogonal to the direction of axial sliding of the brake shoe (18), to be fixed on a part of the fixed support (14), an active tab (62) extending in a plane for attachment to an associated portion of the braking shoe (18), characterized in that at least one of said lugs (52, 62) is snap-fitted on an end portion free of a pin (350a, 350f) of axial orientation.

Description

BACKGROUND OF THE INVENTION The invention relates to a disk brake comprising at least one resilient return spring of a braking pad, an elastic return spring, a replacement kit and a method of mounting. motor vehicle. The invention relates in particular to a disk brake including a resilient return spring of a brake shoe comprises means for compensating for the wear of a friction lining of the brake shoe. BACKGROUND OF THE INVENTION The invention relates for example to a motor vehicle disc brake of the type described and shown in the French patent application FR-A1-3,004,500 which comprises: a brake disc which is extends in a plane transverse to an axis of axial orientation of rotation of the disk; a fixed support relative to a chassis of the vehicle; at least one braking pad, each of which comprises a friction lining whose transverse friction face cooperates with an associated braking track of the disk, the braking pad being mounted sliding axially in the support between an active front position in which said face friction is in abutment against the associated annular track of the disk, and an inoperative rear position in which said friction face is spaced axially from said associated annular track of the disk, a determined set of operation; - At least one elastic return spring of the braking shoe to its inactive position, which is for example interposed between the braking pad and the support.

3033012 2 In a disc brake, the sliding of the brake pads to their active position is controlled by a piston. The two braking pads strongly pinch the disc to slow its rotation. The braking operation is thus an active operation. The braking pads are pushed back to their idle position by the rotating disk. It is therefore a passive operation. It happens, however, that the disc does not push the 10 brake pads with enough force to spread them away from the disc. This may for example occur when the sliding of the brake pads is of insufficient quality or seized, or if the design creates "restitution".

Although the braking pads are no longer actively tightened against the disc, each of the annular tracks of the disc nevertheless continuously rubs against the friction lining carried by the associated braking shoe. The friction linings thus undergo premature non-functional wear.

In addition, this permanent friction is likely to cause a damaging heating for certain components of the disc brake. This permanent friction also causes the appearance of a residual torque which opposes the rotation of the disc. This increases the fuel consumption of the vehicle, while decreasing the performance of the vehicle. To solve these wear and heat-up problems, the above-mentioned document proposes a disk brake in which the elastic return spring comprises means 30 for compensating a set of wear of the friction pad of the braking pad. which plastically deform when the stroke of the braking pad to its active position is greater than said determined set of operation.

3033012 3 For this purpose, the elastic return spring, which is interposed between the fixed support of the disk brake and an associated brake pad, comprises at least one axially oriented section which is elastically deformable by traction between a state of rest and a state of maximum elongation whose value is equal to the determined set of operation, the spring comprising at least one plastically deformable section, under the effect of an axial tensile force, forming said means of catching up the play. wear, this plastically deformable section being shaped to be plastically elongated when the stroke of the braking pad to its active position is greater than the determined set of operation. In this document, the elastic return spring comprises a fixing portion of the elastic return spring on the fixed support, and a connection branch, rigid and axially general orientation whose free end section is shaped to cooperate with the associated brake shoe. According to another known design, the free end section is fixed on the braking pad.

Such designs result in complex assembly and assembly to ensure cooperation of the return spring with the brake pad, or its attachment to the brake pad and the fixed support, or clevis, of the disk brake. These disadvantages also exist when the return spring does not include a plastically deformable section. BRIEF SUMMARY OF THE INVENTION In order to overcome this drawback, the invention proposes a disk brake which comprises: a brake disk which extends in a plane transverse to an axis of axial orientation of rotation of the disk; a fixed support relative to a chassis of the vehicle; - at least one braking pad which comprises a vertical transverse plate which carries a friction lining, a transverse friction face cooperates with an associated braking track of the disk, the braking pad being slidably mounted axially in the fixed support between an active forward position in which said friction face bears against the associated brake track of the disc, and an inactive rear position in which said friction face is axially spaced from said associated brake track of the disc, from a set determined operation; and at least one elastic return spring of the braking shoe to its inactive position comprising: a fixing portion of the elastic return spring on the fixed support in the form of a fixing lug which is connected to the end of a first leg of the resilient return spring and which extends in a plane orthogonal to the direction of axial sliding of the braking pad, to be fixed on an associated part of the fixed support; a connecting branch, of axial orientation parallel to the direction of sliding of the braking pad, which comprises an active tab which extends in a plane orthogonal to the direction of axial sliding of the braking pad to be fixed on a associated part of the braking shoe, characterized in that at least one of said lugs is fixed by interlocking on a free end section of an axially oriented pin. According to other characteristics of the disc brake: said tab comprises a housing which receives a cylindrical portion of said free end section; Said housing is open laterally for the mounting of said tab by radial engagement on said cylindrical portion; - said tab is shaped as a retaining toothed washer for its axial mounting by elastic interlocking on said cylindrical portion; the tab is said active tab, and said pin is carried by the braking pad; - The tab is said bracket, and said pin is carried by the fixed support; said cylindrical portion is a radial groove of said free end portion of the pin; Said pin has a radial collar for axial positioning of the pin on the part which carries it; - The pin is pressed axially force into a complementary hole formed in the part that carries it; said housing is a circular hole; The pawn is a cylindrical peg; the free end section of said axially oriented pin has a chamfered head; the resilient return spring comprises means for compensating a set of wear of the friction lining of the braking shoe, which deforms plastically when a stroke of the braking pad to its active braking position, is greater than said determined set of operation; - The elastic return spring is formed in one piece by cutting and forming a sheet of material; Said branch is a rigid branch formed in a strip which extends in a plane parallel to an axial plane. The invention proposes an axial elastic return spring from a braking pad to an inactive position, which comprises: a portion for fixing the elastic return spring on a fixed support of the disk brake, in the form of a fixing lug which is connected to the end of a first leg of the resilient return spring and which extends in a plane orthogonal to the direction of axial sliding of the braking shoe, to be fixed on an associated part of a fixed support (14) for the disc brake; a connection branch, of axial orientation parallel to the sliding direction of the braking shoe, which comprises an active tab which extends in a plane orthogonal to the direction of axial sliding of the braking pad to be fixed on a associated part of the braking pad, characterized in that at least one of said tabs comprises a housing which receives a cylindrical portion of a free end section of an axially oriented pin on which said at least one tab is fixed by interlocking. According to other characteristics of the elastic return spring: the active leg is fixed by radial engagement on a pin carried by the braking pad, and the fixing lug is fixed by elastic interlocking in the axial direction on a pin carried by said fixed support; the spring comprises means for compensating a set of wear of a friction lining of the braking shoe, which are interposed between said fixing portion and said connecting branch, and which deform plastically when a stroke braking shoe, in an axial direction of displacement to an active braking position, is greater than a determined set of operation; The spring is made in one piece by cutting and forming a sheet of material. The invention proposes a replacement kit for a motor vehicle disc brake according to the invention, characterized in that it comprises at least one braking pad and two elastic return springs matched to said braking pad, each of which is made according to the invention. The replacement kit may further include two springs for mounting the brake pad in the disc brake.

The invention also proposes a method of mounting a spring on a disk brake, characterized in that it comprises the successive steps of: a) mounting the opposite slideways; 5 - b) mounting of a braking pad; - c) mounting at least one resilient return spring by radially fitting the active tab on the associated active pin, and then axially fitting the bracket to the associated attachment pin.

BRIEF DESCRIPTION OF THE FIGURES Other features and advantages of the invention will be apparent from the following detailed description for the understanding of which reference will be made to the accompanying drawings in which: FIG. 1 is a perspective view exploded which represents a disk brake comprising an example of elastic spring in one piece according to the state of the art; FIG. 2 is a front view which shows the fixed support of the disc brake of FIG. 1 provided with slides for receiving elastic return springs of an associated braking pad; FIG. 3A is a diagrammatic perspective view which illustrates an exemplary embodiment in which each lug of a braking pad is equipped with a "radial" spring; Figure 3B is a detail view of the representation in Figure 3A; FIG. 4 is a partial perspective view illustrating the assembly of a braking pad with a radial spring in an arm of a yoke forming a fixed support provided with an attached slide; FIG. 5 is a detailed perspective view showing a resilient return spring of the plastically deformable one-piece brake shoe according to a design alternative; FIG. 6 is an end axial view illustrating a disk brake equipped with an elastic return spring of a braking pad according to the invention, in the mounted and fixed position of the spring; FIG. 7 is a perspective view of a pin for fixing or connecting the resilient return spring illustrated lo in FIG. 6; - Figures 8 and 9 are perspective views of the design illustrated in Figure 6 and which show the successive steps of mounting the resilient return spring on the disc brake.

DETAILED DESCRIPTION OF THE FIGURES In the following description, elements having identical structure or similar functions will be designated by the same references. We will adopt without limitation and without reference to the Earth's gravity, axial, vertical and transverse orientations with reference to the trihedron "A, V, T" of the figures. The axial orientation "A" is directed from back to front, parallel to an axis "B" of rotation of the disc 12. The horizontal plane is defined as being a transverse axial plane. FIG. 1 diagrammatically shows a disc brake 10 of a motor vehicle. This is a disk brake 30 10 called "floating caliper" or "sliding caliper". In known manner, the disc brake comprises a disk 12 which is rotatably mounted about an axis "B" of rotation 3033012 9 of axial orientation. The disc 12 is secured in rotation with a wheel (not shown) of the motor vehicle. The disc brake 10 comprises a support 14, also called clevis, which is fixedly mounted relative to the chassis (not shown) 5 of the vehicle. The fixed support 14 overlaps a peripheral edge 16 of the disc 12. Two opposing braking pads 18, rear and front (also called inside and outside) are mounted sliding axially in the fixed support 14 on either side of the disc 12.

The two rear brakes 18, front and rear, have a structure and an arrangement on the fixed support 14 which are symmetrically identical to a median vertical transverse plane. Subsequently, only the rear brake shoe 18 is described on the left with reference to FIG. 1, the description being applicable to the front brake shoe 18 by reversing the forward and reverse directions. The rear brake pad 18 is in the form of a vertical transverse friction support plate 19. The rear brake pad 18 has a front face 20, which is oriented towards a rear face 22 opposite the disk 12 which is in the form of an annular track. The front face 20 carries a friction lining 24 whose transverse and vertical face before friction 25 is able to cooperate with the face 22 of the disk 12. Each of the opposite transverse ends of the braking pad 18 comprises a lateral lug 26 which is slidably mounted, with play, in a slide 28 associated with an associated arm 27 of the yoke or fixed support 14.

Each slide 28 is axially oriented and has, in section by a vertical and transverse plane orthogonal to the axes A and B, a form of "C" open transversely to the associated lateral lug 26 of the braking pad 18. The slide 28 is 3033012 10 delimited transversely by a bottom 30 of axial orientation and generally vertical. In addition to the vertical bottom 30, the slide is defined by an upper horizontal bottom 33 and a lower horizontal bottom 35, both of axial orientation.

In the example shown in the figures, a slide 32 is interposed transversely between each lateral lug 26 and the associated slide 28. Each slideway 32 is a lamellar element formed by a leaf spring with a "C" section that matches the walls of the associated slideway 28 (see in particular FIG. 4). The slide has an upper sliding and support wing, of generally horizontal orientation, which is interposed between the lug 26 of the brake pad 8 and the upper bottom 33 of the housing 28, a bottom 34 of vertical orientation, which is interposed 15 between the lug 26 of the braking pad and the vertical bottom 30, and a resilient holding flange which is arranged under the lug 26 of the brake padel8. The slide 32 thus has a bottom 34 of vertical and axial orientation which is arranged facing the vertical bottom 30 of the slide 28. The slide 32 allows a determined degree of movement of the braking pad 18 in the fixed support 14, c That is, generally but not exclusively, an axial sliding movement, and a transverse sliding movement accompanying the rotation of the disc 12, during a braking action. In a nonlimiting manner, each lateral lug 26 may be equipped with a so-called mounting spring, of the type described and shown in document FR-A1-2.925.636, an example of which is illustrated in detail in FIGS. 3A, 3B and 4. FIG. 4 illustrates the assembly of a mounting spring on a lateral ear 26 and the mounting of the thus-equipped ear in an associated slideway 32.

FIGS. 3A, 3B and 4 diagrammatically show a spring 100 for mounting the braking pad 18, also called a radial spring, capable of equipping the lugs 26 with a braking pad 18 for mounting and guide the braking pad 18 5 in the associated axial slides 28 of the fixed support 14, with or without the presence of slides 32. In known manner, each spring 100 of the shoe has a lower sliding branch 102 which cooperates with a bottom horizontal lower 35 of the associated slide and which solicits 10 an upper horizontal facet of the lug 26 bearing vertically upwards against the upper horizontal bottom 33 vis-à-vis the slide 28. According to the illustrated conformation, the spring 100 is commonly called "snail spring" and has a branch 104 bearing under a lower horizontal facet of the lug 26 of the braking pad 18, this arm 104 being part of e of a fastening branch, or clip, 106 which resiliently clips the ear 26 to ensure the fixing of the shoe spring 100 on the ear 26.

The shoe spring 100 further includes a curved limb 108 which connects the attachment limb 106 to the lower limb 102 for sliding primarily to provide the resiliency of the slipper spring 100. The brake shoe 18 is thus slidably mounted in accordance with an embodiment of the invention. axial direction, parallel to the axis of rotation B of the disc 12, in the fixed support 14 on an operating stroke between: - an active front position in which the front transverse friction face 25 of the friction lining 24 is in support against the face 22 facing the disc 12; and an inactive rear position in which the front transverse friction face 25 of the friction lining 24 of the braking pad 18 is spaced axially from the associated face 223 of the disk 12 by a determined operating clearance "J1". During a braking operation, the tightening of the braking pads 18, from their inactive position to their active position, is controlled by a brake caliper 36 of the disk brake 10. In known manner, the caliper 36 comprises an arch 38 which extends axially above the fixed support 14 by covering it and two rear wings 40 and 42 which extend radially from the rear and front end edges of the arch 38 towards the axis "B". The front wing 42 extends opposite the front brake pad 18, and the rear wing 40 extends opposite the rear brake pad 18.

The stirrup 36 is here mounted to slide axially relative to the fixed support 14 by means of two parallel guide columns 44 each of which is slidably received in an associated axial bore 45 of the fixed support 14. In a known manner, rear wing 40 of the caliper 36 carries at least one axial piston 46, a transverse front face of support is likely, during a braking operation, to cooperate with the transverse face facing the rear brake pad 18 to urge it axially forward, to exert an axial force of clamping the transverse face before friction 25 of the friction lining 24 bearing against the face 22 opposite the disk 12. By reaction, the The caliper 36 slides axially rearwardly and, in a symmetrical manner, the front wing 42 urges the braking pad 18 forward to clamp the rear frictional face 25 of the friction lining 24 of the braking pad 18a. against the front face 22 opposite the disc 12. When, after the braking operation, the piston 46 stops urging the rear brake pad 18, the return of the 3033012 13 brake pads 18, from their active position to their inactive position, is generally caused by the rotation of the disc 12 which "pushes" each brake pad 18 to its inactive position.

Nevertheless, in some cases, it has been found that the repulsive force exerted by the disk 12 is not sufficient to push each of the braking pads 18 back to its respective inactive position. The friction lining 24 of the braking pads 18 thus continues to rub against the disc 12, while no action of clamping the friction linings of the braking pads by the stirrup 36 is controlled. At the end of a braking operation, to ensure that each braking pad 18 returns to an inactive position, the disk brake 10 is provided with elastic return means of the braking pad 18 to its inactive position. These elastic return means are made in the form of resilient return springs which are interposed between the braking pad 18 and the fixed support 14. The disk brake 10 comprises, by way of non-limiting example, four elastic return springs 48 , also called springs "spacers", each of which - without limitation - is here arranged between an arm 27 of the fixed support 14 and an associated side lug 26 of a brake pad 18. Thus, a brake pad 18, rear or before, is here associated with two resilient return springs 48 each of which cooperates with the friction lining plate 19. By way of non-limiting example, the four resilient return springs 48 are of the same overall design and they are arranged in the same manner on the fixed support 14. The design principle 30 of only one of these springs 48 of elastic return of the skid rear brake 18 will be described here in detail. An elastic return spring 48 is in the form of a metal strip, for example of steel, of rectangular section 3033012 14 whose width extends vertically and which is made for example by cutting, stamping and bending a metal sheet. stainless steel of constant thickness. Referring in particular to FIG. 5, an elastic return spring 48 comprises a first portion 50, referred to as a fixing portion, generally in the form of a fastening tab 52 of the spring 48 on the fixed support 14, which is connected to the end of a first rigid branch B1 and which extends in an orthogonal plane to be fixed on an associated part of the fixed support 14, for example by riveting by means of an unrepresented rivet which extends through an Circular hole 53 of the fixing lug 52. From the first rectilinear rigid branch of axial orientation B1, the elastic return spring 48 is successively extended by three other rigid straight legs B2, B3 and B4 respectively. The first branch B1 has its proximal end connected to the elbow 54, while its distal end is located axially out of the slide 28 to be connected to the second rigid branch B2.

The second rigid branch B2 is connected to the first rigid branch B1 by a first deformable first ply P1. Like the first branch B1, the second rigid branch B2 is shaped in a strip in the extension of the first rigid branch Bl.

In such a way that the first elbow-shaped fold P1 is a plastically deformable zone, this portion is weakened mechanically, here by means of a window or light F1 which is here a rectangular-shaped through cut-out. In the same way, the third rigid branch B3 is connected to the second rigid branch B2 by a second plastically deformable fold P2. The second fold P2 is a bent portion of the web of material having a window F2.

Finally, the fourth branch B4 is connected to the third rigid branch B3 by a third plastically deformable fold P3. The third fold P3 comprises a window F3 similar to the windows F1 and F2. The fourth rigid branch B4 is rectilinear and of general axial orientation parallel to the first rigid branch B1 and it is extended here by a front free end section intended to be connected directly to the associated braking shoe 18. The free end end section is here made by extending the constituent band Bi branches. According to the designs illustrated in FIG. 1 or FIG. 5, the free end end portion of the resilient return spring 48 is shaped as an active tab 62 which is bent at right angles to act directly on a screw portion. with respect to the friction lining plate (FIG. 1) or to be fixed directly to an associated part of the braking shoe 18 (FIG. 5), and for example of its friction lining plate 19. In the example illustrated in FIG. 5, the active tab 62 extends in an orthogonal plane to be fixed on an associated part of the braking pad, for example by riveting by means of a not shown rivet which extends to through a circular hole 63 of the active tab 62. In the figures, the elastic return spring 48 is shown in a "new" initial state, that is to say before any plastic deformation of the plies Pi. In this state, new or initial, the first branch B1 and the fourth rigid branch B4 are substantially parallel to each other and axially oriented by being arranged at a transverse distance from one another.

In the state - not shown - of maximum plastic deformation of the elastic return spring 48, the first and fourth rigid branches B1 and B4 are always substantially parallel, axially oriented and spaced apart from each other substantially the same distance, while the three folds Pi have been deformed plastically. For example, the thickness of the web of material is between 0.5 and 0.8 millimeters and the material is a reference stainless steel X2CrNbCu21 or reference 304L (X2CrNi18-9 / X2CrNi19-11). For example, the maximum displacement corresponding to a maximum wear "J2" is equal to about 14 millimeters. When the braking pad 18 is biased towards its active position by the piston 46, it first runs through the path 15 corresponding to the game "J1" determined operation. During this first part of the race, the braking pad 18 drives the branch B4 of the elastic return spring 48 so as to elastically tension the elastic return spring 48 between the fixing portion 50 fixed to the fixed support 14, and the B4 branch connected to the brake pad 18. The elastically deformable portions of the elastic return spring 48 then reach their maximum elongation state. Pi folds deform, first elastically, then plastically.

The front transverse face of the friction lining 24 of the braking pad 18 is further spaced, with respect to the associated annular face or track of the disk 12, by a distance equal to the wear clearance "J2". The braking pad 18 continues its axial stroke to its active position.

During this second part of the race, the elastically deformable parts being no longer able to deform "elastically", the clamping force is transmitted to the plastically deformable folds Pi of the elastic return spring 48.

The plies Pi are then plastically deformed, the elastic deformations of the plastically deformable parts being negligible compared to their plastic deformation. When the braking operation ends, the braking pad 18 is returned to its inactive position by the elastically deformable parts which resume their rest state. The braking pad 18 is thus again spaced from the disk 12 by a distance equal to the only set "J1" determined operation; the play "J2" of wear having been absorbed by the plastic deformation of plastically deformable folds Pi. The elastic return spring 48 thus ensures that the braking pad 18 is returned to its inactive position. In addition, the arrangement of plastically deformable folds Pi makes it possible to prevent the clamping force to be exerted by the piston 46 to actuate the braking pad 18 towards its active position to become too high. Furthermore, by maintaining a constant operating clearance "J1" between the braking pad 18 in the inactive position and the disk 12, the response time of the braking system remains constant regardless of the wear of the friction lining 24. At maximum complete wear of the friction lining, the elastic return spring 48 is plastically deformed and, like the worn braking pad 18, it must be replaced.

According to the two designs schematically illustrated in FIGS. 1 and 5, the resilient return spring comprises, in an integrated manner, the active tab 62 intended to "act" on the braking pad, and in particular on the trim plate 19. will now describe with reference to Figures 6 to 9 the design according to the invention means for mounting and fixing the elastic return spring 48 on the fixed support 14 and on the gland plate 19 of the braking pad 18.

More specifically, the transverse lining plate 19 is provided with an intermediate plate 120. The equipment of the lining plate 19 with such an intermediate functional plate 120 is known, and for example illustrated in FIG. 9. with further a plate of elastomeric material 122. The functions and roles of this type of intermediate plate are well known to those skilled in the art. The plate 120 is a metal plate, for example made of stainless steel, or of rigid material which is interposed axially between the friction lining support plate 19 and a member of the disk brake acting on the braking pad such as for example the piston. The plate 120 is axially secured to the braking pad, for example by means of rivets 124. The intermediate plate 120 has a face 121 intended to be in contact directly or indirectly with the piston. For mounting and fixing an elastic return spring 20 on the one hand on the fixed support 14 and on the other hand on the braking pad 18, two cylindrical pins, here identical, 350 f are used, and 350a whose design will be described in detail with reference to Figure 7. The pin 350a, 350f has a symmetry of revolution 25 about its axis. The pin 350a, 350f comprises a cylindrical section 352 for its mounting on the associated part which carries it (arm 27 of the fixed support 14 or trim plate 19), which is chamfered and which is axially pressed into a complementary hole 30 (not shown) of the associated part. Thus, as can be seen in FIGS. 6, 8 and 9, in the mounted position, each pin 350a, 350f extends generally in the axial direction corresponding to the direction of sliding of the braking pad 18. The pin 350a, 350f comprises a radial flange 354, of greater diameter than the mounting section 352, a radial annular face 355 of which is a stop face which determines the mounted axial position of the pin 350a, 350f on the associated part which carries it (arm 27 of the fixed support 14 or trim plate 19). Beyond the flange 352, the pin 350a, 350f comprises a free end portion 356 of outside diameter substantially equal to that of the flange 352 and which comprises here, without limitation, a radial groove 358 which is delimited axially by the other annular face 360 of the radial flange 352 and by an annular face vis-à-vis 362.

The free end of the section 356 is shaped as a chamfered head 364. The free end portion of the fixing lug 52 is here shaped as a retaining toothed washer 366 with radial lamellae or claws 368 which extend radially. from the edge of the hole 53, which are elastically deformable and able to be received in the radial groove 358 of the fixing pin 350f (see FIGS. 6 and 9). With this design, the bracket 52 is adapted to be fixed on the arm 27 of the fixed support 14 by axial engagement 25 and by elastic deformation of the toothed washer with claws. At the interface with the yoke or fixed support 14, the fixing pin 350f is axially engaged by force in a complementary bore - with the same axial direction as the machining and drilling operations for the realization of the bores receiving the balancers 44. resilient locking washer - made during the realization of the spring 48 - allows assembly and "imprisonment" of the bracket on the pin.

The spring 48 is thus secured to the fixed support 14 and the spring 48 resists the moment generated by the tensile force of the spring. The end portion of the active tab 62 is designed as a fork 368 open radially in the transverse direction. For this purpose, the hole 63 is open radially to delimit two lateral teeth 370. Thanks to this design, the active tab 62 is able to be fixed on the braking pad 18 by lateral interlocking of the fork 368 on the active pin 350a in the lateral groove 358 (see FIGS. 6 and 9). At its interface with the brake shoe 18, the active pin 350a is axially pressed into a complementary hole made during the manufacture of the liner plate 19. The active lug 62 of the spring 48 can then be "slipped" in the radial groove 358 of the pin 350a. Subject to a force in the axis of the piston, the braking pad is thus made "integral" with the spring 48 in the axial direction. Assembly and assembly at the factory is carried out according to the following method: a) mounting opposing slides 32; b) mounting of the brake shoe 18, equipped optionally with its two radial springs 100; c) mounting at least one elastic return spring 48 by radially fitting the active tab 62 on the associated active pin 350a, then axially fitting the fastening tab 52 on the associated attachment pin 350f. The elastic return spring 48 is mounted and fixed between the fixed support 14 and the braking pad 18. This assembly is sufficiently steep so as not to generate parasitic elasticity and therefore of additional restitution of the braking pad 18.

3033012 21 This assembly and this assembly also allow a series assembly and the maintenance, during a change of braking pad. In order to facilitate assembly, end-of-line brake sliding test and maintenance, the elastic return spring 48 is mounted and "cocked" when the brake is assembled. The spring 48, subjected to the displacement force of the braking pad 18, undergoes a moment of rotation about the radial axis, at its interface with the fixed support 14, as well as the axial translation force allowing the return brake pad to its so-called inactive position. This design allows a quick assembly of the elastic return spring 48 on the brake. It minimizes functional surfaces on the spring. Only one pawn model is needed.

The two springs equipping a braking pad at its two opposite transverse ends are identical. An assembly or kit for replacing a worn set of brake shoes 18 comprises, for each brake shoe, a nine brake pad 18 itself equipped with its active pins 350a, and at least one set of two return springs. Elastic 48. If the braking shoe is of the type equipped with pad mounting springs 100, the replacement kit comprises, for each braking pad, a new pad equipped with its two pad springs 100, one for each of its pads. two radial ears 26.

Claims (22)

REVENDICATIONS1. A disc brake (10) of a motor vehicle comprising: - a brake disc (12) which extends in a plane transverse to an axis (A) of axial rotation orientation of the disc; a support (14) fixed with respect to a chassis of the vehicle; at least one braking pad (18) which comprises a vertical transverse plate (19) which carries a friction lining (24) of which a transverse friction face (25) cooperates with an associated braking track (22) of the disk (12), the braking pad (18) being axially slidably mounted in the fixed support (14) between an active front position in which said friction face (25) bears against the associated braking track (22) of the disk (12), and an inoperative rear position in which said friction face (25) is axially spaced from said associated brake track of the disk, of a determined operating clearance (J1); and at least one elastic return spring (48) of the braking pad (18) towards its inactive position comprising: a fixing portion (50) of the elastic return spring (48) on the fixed support (14) in a fastening tab (52) which is connected to the end of a first leg (B1) of the resilient return spring (48) and which extends in a plane orthogonal to the direction of axial sliding of the braking shoe (18) for attachment to an associated portion of the fixed support (14); a connection branch (B4) of axial orientation parallel to the sliding direction of the braking shoe, which comprises an active tab (62) which extends in a plane orthogonal to the direction of axial sliding of the braking pad; brake (18) for attachment to an associated portion of the braking pad, characterized in that at least one of said tabs (52, 62) is snap-fitted on a free end portion (356) of a pin (350a, 350f) of axial orientation. Disc brake according to claim 1, characterized in that said tab (52, 62) has a housing (53, 63) which receives a cylindrical portion (358) of said free end section (356). 3. Disk brake according to claim 2, characterized in that said housing (63) is open laterally for mounting said tab (62) by radial engagement on said cylindrical portion (358). 4. Disc brake according to claim 2, characterized in that said lug (52) is shaped as a retaining toothed washer (368) for its axial mounting by elastic interlocking on said cylindrical portion (356). 5. Disc brake according to claim 3, characterized in that the tab is said active tab (62), and in that said pin (350a) is carried by the brake pad (18). 6. Disc brake according to claim 4, characterized in that the tab is said bracket (52), and in that said pin (350f) is carried by the fixed support (14). Disc brake according to claim 2, characterized in that said cylindrical portion is a radial groove (358) of said free end section (356) of the pin (350a, 350f). 8. Disk brake according to claim 1, characterized in that said pin comprises a radial collar for axial positioning of the pin on the part which carries it. 9. Disk brake according to claim 1, characterized in that the pin (350a, 350f) is pressed axially into a complementary hole formed in the part (18, 14) which carries it. Disc brake according to claim 2, characterized in that said housing (53, 63) is a circular hole. 3033012 24 Disk brake according to claim 1, characterized in that the pin (350a, 350f) is a cylindrical pin. Disc brake according to claim 1, characterized in that the free end portion (356) of said axially oriented pin (350a, 350f) has a chamfered head (364). 13. Disc brake (10) according to claim 1, characterized in that the elastic return spring (48) comprises means for catching a wear clearance (J2) of the friction lining (24) of the shoe brake (18), which deforms plastically when a stroke of the braking pad to its braking active position, is greater than said determined set of operation (J1). Disc brake (10) according to claim 1, characterized in that the elastic return spring (48) is formed in one piece by cutting and forming a sheet of material. 15. Disc brake (10) according to claim 1, characterized in that said branch (B1, B4) is a rigid branch formed into a strip which extends in a plane parallel to an axial plane. 16. Spring (48) resilient axial return of a brake pad (18), a disc brake (12), to an inactive position, wherein the elastic return spring (48) comprises: - a portion for securing (50) the resilient return spring (48) to a fixed support (14) of the disc brake in the form of a bracket (52) which is connected to the end of a first limb (B1) of the elastic return spring (48) and which extends in a plane orthogonal to the direction of axial sliding of the braking pad (18), to be fixed on an associated part 30 of a fixed support (14) disc brake; a connecting branch (B4) of axial orientation parallel to the sliding direction of the brake shoe, which comprises an active tab (62) which extends in a plane orthogonal to the direction of axial sliding of the pad; braking device (18) for attachment to an associated portion of the braking shoe, characterized in that at least one of said lugs (52, 62) has a housing (53, 63) which receives a cylindrical portion (358) of a free end portion (356) of an axially oriented pin (350a, 350f) on which said at least one leg (52, 62) is snap-fit. 17. Spring according to claim 16, characterized in that the active tab (62) is fixed by radial engagement on a pin carried by the brake pad (18), and in that the fixing lug (52) is fixed by elastic interlocking in the axial direction on a pin carried by said fixed support (14). 18. Spring according to claim 16, characterized in that it comprises means for catching a wear clearance (J2) of a friction lining (24) of the braking shoe (18), which are interposed between said fastening portion and said connecting branch (B4), and which plastically deform when a stroke of the braking shoe (18), in an axial direction of displacement to an active braking position, is greater than a determined game of operation (J1). 19. Spring according to claim 16, characterized in that it is made in one piece by cutting and forming a sheet of material. 25 20. Replacement kit for a motor vehicle disc brake according to any one of claims 1 to 15, characterized in that it comprises at least one brake pad (18) and two springs (48) matched elastic return brake shoe pad (18). 30 21. Replacement kit according to claim 20, characterized in that it further comprises two springs (100) for mounting the brake pad in the disk brake. 3033012 26 22. A method of mounting a spring according to claim 17 on a disk brake according to claims 5 and 6 taken in combination, characterized in that it comprises the successive steps of: 5 - a) mounting the opposite slides (32). ); - b) mounting a brake pad (18); c) assembling at least one resilient return spring (48) by radially fitting the active tab (62) to the associated active pin (350a), and then axially fitting the fastening tab (52) to the pin of associated fastener (350f).