FR3029875A1 - ELASTIC COMPENSATION ELEMENT FOR VEHICLE BRAKE, DISC BRAKE CALIPER, AND ASSEMBLY METHOD - Google Patents

Abstract

The invention relates to a resilient element (21) inserted into a brake, in particular a disk brake, between piston (23) and linear parking brake actuator (22, 230), passively stabilizing the parking clamping force by absorbing or restoring a mechanical energy of compression. This forms a piece of resilient metal sheet inserted between the linear actuator bearing portion (220) and the piston piston (230): an outer portion (212) retained by a shoulder (231) or narrowing formed inside. of the piston, and an inner part (213, 214) receiving the support of the linear actuator (22) before contact with the bearing portion (230) of the piston when the elastic element (21) is at rest, and a race (D21) of elastic deformation for the linear actuator when it presses on the piston. Preferably, it is a cylindrical body (211) housed inside (239) of the piston (23) and surrounding the linear actuator 22, thus operating in flexion and extension.

Description

The invention relates to an elastic element inserted into a vehicle brake, in particular a disk brake, between a piston and a brake, and a method of assembling it. a linear parking brake actuator, for stabilizing the clamping force by absorbing or restoring mechanical compression energy, passively in case of thermal deformation during parking. This elastic element forms a piece of resilient metal sheet inserted between the bearing portion of the linear actuator and that of the piston. It has an outer portion retained by a shoulder or narrowing formed inside the piston, and an inner portion receiving the support of the linear actuator before it is in contact with the bearing portion of the piston when the elastic member is at rest, thus providing an elastic deformation stroke for the linear actuator when it presses on the piston. Preferably, these outer and inner portions are formed at the ends of a cylindrical body housed within the piston and surrounding the linear actuator. An elastic element is thus obtained which stores compression energy in the support chain, while at the same time functioning itself at least partially in tension, and more particularly with a combination of internal forces in extension and flexion according to the parts concerned. It also relates to a vehicle brake and more particularly to a disc brake caliper comprising such an elastic element, and a vehicle comprising such a brake and a method of assembling such a brake. STATE OF THE ART In a vehicle, the parking brake function consists in applying and maintaining a clamping between an integral part of the chassis and a rotatable part which is connected to one or more wheels. This tightening must be reliably maintained over continuous periods that can be very long, ranging from a few minutes to several years. For reasons of reliability, and potentially regulatory obligations, it is often sought that this clamping is maintained after its initial application without external energy supply to the system and / or without additional action.

However, beyond a few minutes, there frequently occur in the system variations in geometries which may increase or decrease the initially applied clamping force. These are generally thermal variations that produce a dilation or retraction of mechanical elements contributing to maintain this effort, called here "support chain". These thermal variations occur in particular during the cooling of brakes occurring naturally during parking brakes, while they had been heated during the use of the vehicle. Changes in outside temperature may also occur during parking, in one direction or the other. In addition to the parts that press the brake linings against the friction surface, for example the elements of an actuator, the friction surface itself has a significant geometry variation due to changes in temperature. Especially since it is the one who suffers the most 20 heating under braking. For example, for a locked drum brake in a tight position, the cooling of the drum during the parking period thus creates a retraction of the friction track. As this surrounds the segments, this retraction thus increases the bearing force against the segments, and thus increases the mechanical energy accumulated in compression in the system. For example in a disc brake held in a tight position, the cooling of the disc during the parking time creates by retraction a decrease in the thickness of the disc. The gaskets which enclose it on its two faces can thus be brought closer, thus reducing the mechanical energy accumulated in compression in the system. In general, a reduction in mechanical energy accumulated in compression in the system reduces the clamping force, with the risk that it becomes insufficient to ensure the immobilization of the vehicle. In the other direction, the increase of this mechanical energy accumulate increases the forces between the elements of the support chain, which may deteriorate the system. In conventional systems actuated by a cable placed in tension within a flexible sheath, the mechanical elasticity of this assembly is sufficient to store at the initial clamping sufficient energy to maintain sufficient clamping, on the one hand, and to absorb additional energy caused by additional tightening, on the other hand. In the case of a blocking located very close to the brake, for example a mechanical transmission directly driven by an electric actuator, and which is mechanically locked or comprises an irreversible element, it is known to insert into the support chain an element elastic. Such a known elastic element is formed for example by an elastic piston in compression, made by a movable head in a hollow cylinder 15 filled with conical washers, or "Belleville", stacked axially and back to each other. Such a piston is used for example in parking actuators for drum brake. This device however has drawbacks, and for example a large number of parts, hence a complexity and cost of assembly; a significant margin of error in the stiffness obtained, of the order of about 10%; a retention of stiffness during a relatively low number of cycles compared to the needs of this application, and a loss of stiffness over time, and thus the load that can be stored or absorbed.

In FIGURE 1 is illustrated a disk brake caliper 1 known at present, comprising a housing 10 enclosing a disc 19 and its friction track between friction liners or "plates" 17, 18. In this "floating" caliper type assembly these elements are tight against the fingers 101 of the stirrup by a piston 13 moving in translation in an actuating direction A2. In service brake mode, this piston is moved in its housing 150 by a hydraulic pressure supplied by a fluid inlet 15. In parking brake mode, the piston is moved by a nut 122 fixed in rotation cooperating with a threaded rod 121 driven in rotation along the axis A2, forming a linear actuator. The screw 121 is driven by an input shaft 129 driven by a geared motor (not shown). When the screw rotates in the direction of tightening the plates, it bears on the housing 10 by an enlarged base 128, by means of an elastic washer 11 in its thickness, which is 5 made by cutting and stamping . This type of element is however difficult to achieve with sufficient reliability and stability, especially for a significant stiffness to accept and return a large load.

An object of the invention is to provide an elastic member for such an application that allows greater loadability, better accuracy, stability and reliability, but also a better cost and more simplicity in manufacturing, while responding technical constraints specific to this application.

SUMMARY OF THE INVENTION The invention proposes an elastic element intended to be inserted within a support chain, designed to transmit a bearing force by a bearing part of a linear actuator coming into contact with the bearing. a bearing portion of a piston movable in translation within a housing, so as to apply a clamping force between on the one hand one or more friction members and on the other hand at least one track of friction, thus realizing a parking brake function within a vehicle brake. This elastic element is specifically arranged, calculated and determined so as to be able to absorb a mechanical energy enabling it, passively during a holding period during which said clamping is maintained without complementary actuation: to absorb an additional energy compression mechanics appearing by thermal deformation of said support chain; or 30 - to restore a mechanical compression energy, stored during an initial application of said clamping force, so as to compensate for a reduction in the clamping force caused by thermal deformation of said support chain. According to the invention, this elastic element comprises a piece of elastic metal sheet inserted, preferably inside the piston, between the bearing portion of the linear actuator and the bearing portion of said piston, which piece of sheet metal has, with respect to the direction of movement of the linear actuator: - on the one hand an outer part whose outer contour is arranged to bear on at least one shoulder or a narrowing formed in the piston, and on the other hand an inner part whose shape is arranged to receive a support of the linear actuator in a position where it is not in contact with the bearing part of the piston when the elastic element is in a state at rest, thereby providing an elastic deformation stroke that can be traversed in whole or in part by the linear actuator when it applies a load on the piston.

Unlike known elastic washers operating in compression as illustrated for example in FIGURE 1, the elastic element according to the invention operates in tension between its outer portion retained by the rear of the piston and its inner portion which receives the linear actuator. The stiffness of the elastic member in longitudinal deformation depends on the geometry and the thicknesses and shades of sheet metal in its different parts. It can therefore be chosen according to the needs by playing on these parameters during the design or adaptation of the brake or the elastic element. Depending on the requirements of the application and depending on the stiffness chosen, the elastic deformation stroke may be chosen sufficiently small to be completely traversed by the deformation produced by the load applied by the actuator. This stroke is then limited by the support of the actuator against the piston, directly or through the inner part of the elastic element.

In certain configurations, the stiffness and the stroke can be calculated so that the load actually applied by the actuator produces a deformation less than the maximum value of this stroke. The linear actuator then comes into abutment against the piston, directly or via said inner portion, during the application to the brake disk of a determined clamping force, for example the tightening value. nominal. The assembly can also be determined so that this maximum stroke is reached with a load sufficient to store the amount of energy required to overcome a given value of retraction, in stroke or effort. The invention applies to any type of brake in which the parking brake function is activated by an actuator whose constitution does not have enough elasticity to provide the necessary compensation and / or absorption over time.

Thus, according to another aspect of the invention, there is provided a brake comprising an elastic member as set forth herein inserted within the parking brake support chain. According to one particular feature, as illustrated in more detail hereinafter, the invention proposes a disk brake caliper, in particular operating by hydraulic pressure, comprising such a resilient element interposed between the linear actuator and said piston so as to achieve absorption. and / or compensation for variations in the bearing force caused by expansion and / or retraction of said support chain. However, the invention also provides for the use of such an elastic element 20 in other types of brake, for example a drum brake. In addition, according to another aspect, the invention also relates to a vehicle or subassembly of a vehicle, in particular an automobile and / or road vehicle, comprising such a brake and in particular such a disk brake. It also relates to such a vehicle or vehicle subassembly comprising a brake containing an elastic element as set forth herein, arranged to effect absorption and / or compensation of variations in the bearing force generated by a dilation and / or retraction of the support chain, respectively. According to yet another aspect of the invention, there is provided a method 30 for manufacturing a vehicle brake comprising a step of inserting an elastic element as described here, in particular within a stirrup disc brake for a vehicle, interposed between the linear actuator and the piston of said caliper so as to absorb and / or compensate for variations in the bearing force caused by expansion and / or shrinkage respectively; of the support chain of said stirrup. Examples of advantages The invention makes it possible, for example, to produce an elastic element with greater precision and stability, fewer parts, and which can be adapted within the brake with less space constraints or to satisfy different constraints. In particular, it makes it possible to simplify or improve the performance of loss of clamping force during relaxation under load 10 in parking brake mode for the brakes with an electric actuator mounted directly on the brake mechanism or on the suspended part. of the half-train, in particular for disc brakes with motorized actuator mounted on or integrated in the caliper. In particular, thereby providing a resilient member in the plunger bearing chain, the invention makes it possible to restore or maintain a clamping force despite the displacement of the piston caused by the relaxation of the pads under load during cooling. It is thus possible to limit or eliminate the preventive or curative retightening (called "reclamping" in English), which is currently often necessary a few minutes after the parking brake is applied. Various embodiments of the invention are provided, integrating, according to all of their possible combinations, the various optional features set forth herein.

List of Figures Other features and advantages of the invention will become apparent from the detailed description of a non-limiting embodiment, and the accompanying drawings in which: FIGURE 1 is a longitudinal sectional view along the axis the piston, which illustrates a hydraulic disc brake caliper carrying a motorized parking brake actuator, provided with a resilient compensation element in the form of a compression washer, according to the prior art; FIG. 2 is a longitudinal sectional view along the axis of the piston, which illustrates a hydraulic disc brake caliper carrying a motorized parking brake actuator, provided with an elastic element according to the invention, in a first exemplary embodiment; FIGS. 3a and b are partial half-views based on FIG. 2, illustrating in more detail the behavior of the elastic element according to the invention: in FIG. 3a, in the contact position without support, and FIG. 3b, in the support position arriving at the end of deformation stroke of the elastic element; FIGURE 4, FIGURE 5 and FIGURE 6 are partial half-views illustrating exemplary alternative embodiments, for a piston similar to that of FIGURE 2 and FIGURE 3.

DESCRIPTION OF AN EXAMPLE EMBODIMENT In FIGURE 2 and FIGURE 3 is illustrated a disc brake caliper 2 carrying a motorized parking brake actuator provided with an elastic element according to the invention, in a first example of a method. of realization. In this embodiment, the caliper 2 has a hydraulic operation intended to be used as a service brake. It is clear, however, that the invention is also applicable to a purely electric stirrup. This stirrup 2 comprises a housing 20 covering the periphery of a disc 19 and enclosing its friction track between friction linings or "plates" 17, 18. The disc caliper housing 20 has an inner housing 250, one of which cylindrical portion receives a piston 23 movable in translation A2 moves in translation in an actuating direction A2.

When moving in the direction of tightening, here to the right, the piston is pressed on a friction lining 17 in a support chain comprising a brake disc 19 sandwiched between at least two friction linings 17, 18 within said stirrup. In the present example, the assembly is of type "floating" stirrup: these elements 17, 18, 19 are tightened by the piston by pressing against the fingers 201 of the stirrup, while the stirrup moves in translation relative to a "clevis" (not shown here), which is integral with the half-train.

5 It is for example integral in rotation of the yoke while the disc is carried by the wheel mounted on a hub, axis (not shown) parallel to the direction A2 and located below the figure, for example by small columns on which it slides parallel to the actuating direction A2.

In service brake mode, this piston is moved to the right in its housing 250 forming a hydraulic chamber, by a hydraulic pressure supplied by a fluid inlet 25. In parking brake mode, the piston is moved in one direction or in the other by a linear actuator 22. This is here realized by a nut 222 fixed in rotation, which cooperates with a threaded rod forming a screw 221 driven in rotation along the axis of actuation A2 by its end forming 229. The screw 121 is driven by an electric geared motor (not shown), which is fixed on the caliper housing 20.

It should be noted that other variants are provided for example with rotational drive of a nut cooperating with a fixed screw in rotation. In addition, the elastic member is also usable with a linear actuator of a different type. In the loosening direction, by moving the nut away from the disk, the screw is held for example by a simple stop device of a known type, for example a rod or circlip, or by the part of its drive shaft 129 which protrudes from the housing 20. In the direction of tightening, by displacement of the nut 222 towards the disc 19, the screw 221 is retained in translation by pressing a flange 228 30 forming a shoulder which abuts to the left on the wall of the caliper housing. The piston 23 has a bearing portion 230 located on its face facing the linear actuator, here called rear face. In the present example, this bearing portion is a concave conical bearing surface situated inside a skirt delimiting an internal volume 239. The elastic element 21 is interposed between the nut 221 and the piston 23. so as to effect absorption and / or compensation of the variations of the bearing force generated by an expansion and / or respectively a retraction of said support chain. The linear actuator 22, or the geared motor that drives it, is arranged to apply and maintain this support for a continuous period of immobilization so as to perform a parking brake function, for example by an irreversible thread geometry at within the screw-nut mechanism. In the parking brake mode, the support chain therefore comprises here the succession of the screw 221, the nut 222, the elastic element 21, the piston 23, the first seal 17, the disc 19 and the second seal 18 , as well as the stirrup housing 20 which encloses them between the bottom of the housing 150 and the stirrup fingers 201. Elastic element The elastic element 21 according to the invention is formed by a piece of elastic metal sheet disposed between the bearing portion 230 of the piston and the bearing portion 230 of the linear actuator 22, here an annular bearing obtained by a convex shape carried by the nut 221 of the screw-nut mechanism. This piece of sheet metal is for example made of elastic steel sheet, for example with a thickness of five or six tenths of 25 millimeters. For its connection with the piston, this piece of sheet metal comprises an outer portion 212 whose outer contour is arranged to bear on at least one form accident constituting a shoulder 231. As an example but not mandatory, this Shoulder having a slight angle with a radial direction, for example between 0 ° and 45 °, which can be determined as a function of the deformation mode of the elastic element. In the present example, the outer portion 212 has a 90 ° flange shape extending radially outwardly with respect to the actuating direction A2. This outer portion 212 forms an end of a hollow elongate body 211, here a cylinder preferably of revolution, which penetrates inside the internal volume 239 of the piston 23 and surrounds the linear actuator 22 for the most part, and the nut 221 in its entirety. For its connection with the actuator, this sheet metal part comprises an inner part 213, 214 extending inwards from the other end of this cylinder 211, on which the actuator support portion 220 linear comes to bear when it is driven in the direction of tightening. In the present example, the inner portion 212 of the elastic element 21 receives the bearing portion 220 of the linear actuator 22 in a conically-shaped region 213 15 substantially complementary to the bearing portion 230 of the piston 23. As a variant or in addition, the inner portion may have a shape complementary to the support portion of the linear actuator. In the present example, and preferably in all configurations comprising hydraulic operation as a service brake, the elastic member 21 has a through opening 210 arranged to communicate the inside 239 of the piston 23 to the outside 250, so as to allow a circulation of the hydraulic fluid pressurized.

In this embodiment, the inner portion 213 terminates, in its radially furthest region, with a flange 214 extending axially over a predetermined length, allowing, for example, greater stiffness and / or reliability over time. Such a collar is also provided on the outer part. It may also have different shapes, for example in the form of a radial return combined or not with such an axial extension. In an optional variant for the inner portion 213, the length of this flange 214 is determined to come into contact with the bottom of the piston before or at the same time the bearing portion 220 of this linear actuator, and transmit all or part of the F2 force applied by the linear actuator. In particular, the length of the flange 214 may be provided to abut against the piston before the bearing portion of the linear actuator, which may provide greater ease of adjustment of the allowable strain course. Operation The shape and geometry of the various parts of the elastic element, and among others the length of the cylinder, are determined so that the inner portion 213 comes into contact with the bearing portion 220 of the nut without this nut. is in contact with the piston itself, when the elastic element 21 is in a state at rest, as shown in FIGURE 3a. Once in contact with the elastic element as in FIG. 3a, when the nut continues to move towards the disk, it thus presses on the piston via the elastic element 21. This element deforms under the spring. applied force, thus storing a certain mechanical energy. In this embodiment, when the actuator 22 is activated until its nominal load is applied, the elastic element 21 is deformed over a length D21 until the nut bears against the support part 20 230 at the bottom of the piston 23 by direct compression of the sheet of the inner portion 213. As shown in FIGURE 3b, the actuator then applies its force F2 directly on the piston. Variant Examples FIGURE 4, FIGURE 5 and FIGURE 6 illustrate exemplary alternative embodiments, for a piston similar to that of FIGURES 2 and FIGURE 3, which will only be described in their differences. In other embodiments, as illustrated in FIGURE 4, the outer and inner portions 312 and 313 of the resilient member 31 are in direct continuity with one another without passing through an axial body of a length. significant. The figure illustrates the elastic element 31 in solid lines in maximum deformed position, with the nut 221 bearing against the bottom of the piston 23, and in the rest position in dashed line. The outer portion 312 here has a flange shape perpendicular to the direction A2, and bears on a shoulder of the piston 23 which surrounds its bearing portion 230. The inner portion 313 has at rest a conical shape. more open angle than the bearing portion 230 of the piston, extended by an axial collar 314. The elastic element is deformed so that the inner portion 5 approaches the piston under the effect of the support F2 of the actuator . In this example, without this being an indispensable feature, the assembly is arranged so that this inner portion 313 abuts against the inside of the piston at the nominal load. Still in other embodiments here derived from that of FIGURE 4, as illustrated in FIGURE 5, the outer and inner portions 412 and 413 of the elastic member 41 are in direct continuity with each other, and aligned with each other in the position in one of the loaded positions or at rest, here in the idle position shown in dashed line. Once loaded, as shown in solid line, the elastic member 41 deforms so that its inner portion approaches the bottom of the piston, here until the nut 221 abuts against the bearing portion 230 of the piston. As a generalizable option, the inner portion 413 is here curved inwardly into a return 414 inverted conical shape at rest (or rounded or toric), which completes its region 20 receiving the nut once in charge. Generally applicable to all embodiments, as illustrated for example in FIGURE 6, the stiffness of the elastic member 51 may be sufficiently high that a given force applied by the actuator (for example the nominal force) is entirely transmitted to the piston via this elastic element, thus making it possible to maximize the energy stored. In the example of FIGURE 6, the nut thus has a primary bearing portion 220a which bears only on the elastic element. A primary bearing portion 230a of the piston can then be seen as being formed by the form accident receiving the outer portion 512 of the elastic member, here a shoulder at the rear of the piston, which receives the applied force. as a so-called "primary" effort F2a. The resilient member is then deformed to a "primary" length D51a which is smaller than the total available stroke within the plunger. It can therefore be deformed further over an additional or "secondary" length D51b, which for example makes it possible to absorb any expansion of the elements of the support chain by limiting the increase in the load transmitted back to the actuator. and prevent it from being damaged. In this example, the nut also has a secondary bearing portion 220b distinct or may include its primary bearing portion, which can bear directly against a secondary bearing portion 230b of the piston, which receives any effort additional or "secondary" F2b, for example if the force applied exceeds the nominal value or as a safety measure in case of deterioration or collapse of the elastic element 5. This deformation characteristic without stop at the nominal force 15 may be applied to other variants or embodiments, particularly such as those described herein. In general and according to the needs, it is intended to produce in the elastic element various form accidents, for example 20 local undulations or thinning, preferably having axial symmetry or even revolution, to strengthen or soften the sheet at different locations depending on the desired stiffness and the places where it must deform.

Of course, the invention is not limited to the examples which have just been described and many adjustments can be made to these examples without departing from the scope of the invention. 3029875 - 15 - Nomenclature 1 disc brake caliper 10 caliper housing 101 caliper fingers 5 11 spring compression washer 12 linear parking actuator 120 actuator support part 121 actuator screw 122 nut the actuator 10 128 actuator screw support flange 129 actuator screw input shaft 13 brake piston 130 piston support part 15 hydraulic inlet 15 150 piston housing - hydraulic chamber 17, 18 friction pads 19 brake disc - friction tracks 2 disc brake caliper 20 caliper housing 20 201 caliper fingers 21 elastic compensation element 210 opening of the elastic element inner part 211 cylindrical element body elastic 212 outer portion of the elastic member 25 213 inner portion of the elastic member 214 flange of the inner portion 22 screw of the actuator 220 actuator support portion 220a primary bearing portion of the actuator 30 220b secondary bearing portion of the actuator 221 screw of the actuator 222 actuator nut 229 support flange of the actuator screw 23 brake piston 3029875 -16- 230 part of piston support 230 brake piston support portion 230a piston primary support portion 230b piston secondary support portion 5 239 brake piston interior space 25 hydraulic inlet 250 brake piston housing - hydraulic chamber 31, 41 elastic member 312, 412 outer portion of the elastic member 313, 412 inner portion of the elastic member 314, 414 collar / return of the inner portion 51 elastic member 511 cylindrical body of the elastic member 512 outer portion of the elastic element 15 513 inner part of the elastic element A2 actuation direction - axis of the brake piston and of the elastic element D21 elastic deformation D51a primary elastic deformation 20 D51B elastic deformation that secondary F2 support on the brake piston F2a primary support on the brake piston F2b secondary support on the brake piston

Claims (11)

REVENDICATIONS1. Elastic element (21) intended to be inserted within a support chain (20, 221, 222, 23, 17, 19, 18), designed to transmit a support force (F2) by a part of support (220) of a linear actuator (22) coming into contact with a bearing portion (230) of a piston (23) movable in translation within a housing (250), so as to apply a clamping force between on the one hand one or more friction members (17, 18) and on the other hand at least one friction track (19), thereby providing a parking brake function within a brake (2). ) of said vehicle, said elastic element being thus able to absorb mechanical energy enabling it, passively during a holding period during which said clamping is maintained without additional actuation, to absorb an additional mechanical compression energy appearing by thermal deformation of said support chain; or to restore a mechanical compression energy, stored during an initial application of said clamping force, so as to compensate for a reduction in the clamping force caused by thermal deformation of said support chain; or a combination or succession of these two effects characterized in that said elastic element (21) comprises a piece of resilient metal sheet inserted between the bearing portion (220) of the linear actuator and the bearing portion (230) of said piston, which piece of sheet metal has, relative to the direction (A2) of displacement of the linear actuator: - on the one hand an outer portion (212) whose outer contour is arranged to bear on the minus one shoulder (231) or narrowing formed in the piston, and - on the other hand an inner portion (213, 214) whose shape is arranged to receive a support of the linear actuator (22) in a position where the it is not in contact (FIGURE 3a) with the bearing part (230) of the piston when the elastic element (21) is in a state at rest, thus providing a stroke (D21) of elastic deformation which can be traversed in whole or in part by the action ur linear when it applies a load on the piston. 2. Elastic element according to the preceding claim, characterized in that the outer portion (212) has a shape extending radially outwardly at one end of an elongated hollow body (211), in particular a cylinder of revolution, which is arranged to penetrate inside (239) of the piston (23) and surround the bearing portion (222, 220) of the linear actuator, and in that the inner portion has a shape (213) of extending inwardly from the other end of said cylinder (211) and on which bears the bearing portion (220) of the linear actuator. 15 3. Elastic element according to any one of the preceding claims, characterized in that it has at least one opening (210) therethrough arranged to put the inside (239) of the piston (23) in communication with the outside (250 ), so as to allow a flow of fluid when the elastic element (21) is used with a piston that can also be actuated by a hydraulic fluid pressure. 4. Elastic element according to any one of the preceding claims, characterized in that the inner part (213) and / or the outer part ends, in its radially furthest region, by a flange (214) extending axially or forming a radial return on a given length. 5. Caliper (2) disc brake, in particular operating by hydraulic pressure, comprising at least one housing (250) receiving a piston (23) movable in translation (A2) so as to come to press on at least one seal of friction (17) within a support chain comprising a brake disk (19) sandwiched between at least two friction liners (17, 18) within said caliper, said translation being obtainable in the in the direction of the contact pressing (220, 230) of an ithear actuator (22), which is oriented in the direction of translation (A2) of the piston and arranged to apply and maintain this support for a continuous period of immobilization of 5 to perform a parking brake function, characterized in that it comprises an elastic element (21) according to any one of the preceding claims interposed between said linear actuator (22) and said piston (23) so as to realize an absor and / or compensation for variations in the bearing force generated by expansion and / or retraction of said support chain. 6. A stirrup according to the preceding claim, characterized in that it is arranged and determined so that the linear actuator bears (FIGURE 15 3b) against the piston (23), directly or through said inner portion ( 213, 214), during the application to the brake disc of a determined clamping force. A stirrup according to any one of claims 5 to 6, characterized in that the inner portion of the elastic member (21) receives the bearing portion (220) of the linear actuator (22) in a region (213) of substantially complementary shape to the bearing portion (230) of the piston (23). 8. A stirrup according to any one of claims 5 to 7, characterized in that the linear actuator (22) comprises a screw-nut mechanism (221, 222) rotated coaxially or parallel to the direction (A2). ) of the piston, by a motor or an electrically geared motor. 9. Caliper according to the preceding claim, characterized in that the screw-nut mechanism comprises a screw (221) driven in rotation and retained in translation, which cooperates with a nut (222) fixed in rotation bearing the bearing portion ( 220) of the linear actuator (22), and in that the inner portion (213) and the outer portion (212) of the elastic member are separated by a body (211) having one or more openings. vias (219) by one or more portions protruding radially outwardly of the nut. Vehicle or subassembly of a vehicle, in particular an automobile and / or road vehicle, characterized in that it comprises a disc brake caliper according to any one of claims 5 to 9 or a brake containing an elastic element according to claim 1. any of claims 1 to 4 arranged to effect absorption and / or compensation of variations in the bearing force caused by expansion and / or retraction of the support chain. 11. A method of manufacturing a vehicle brake or a brake disc caliper (2) for a vehicle, characterized in that it comprises a step of inserting an elastic member (21) according to the invention. any one of claims 1 to 4 interposed between the linear actuator (22) and the piston (23) of said stirrup so as to achieve absorption and / or compensation of variations in the bearing force caused by expansion and / or respectively a retraction of the support chain (20, 221, 222, 23, 17, 19, 18) of said stirrup.