Brake caliper for a vehicle's braking system

Abstract

Brake caliper (10) for a braking device of a vehicle, comprising a brake pad module (20) with at least one brake pad (22) for braking contact with a brake disc of the vehicle in a braking position and a brake piston module (30) with at least one brake piston (32) for moving the brake pad module (20) from a release position to the braking position, wherein the brake piston module (30) has at least one pad retaining bolt (34) for guiding the movement of the brake pad module (20), wherein a spring device (40) is further arranged between the pad retaining bolt (34) and the brake pad module (20), which is supported on the pad retaining bolt (34) in a spring groove (36) and exerts a restoring force on the brake pad module (20) from the braking position to the release position, characterized in thatthat the at least one pad retaining bolt (34) has the spring groove (36) for supporting the spring device (40) with an extension transverse to the extension of the at least one brake pad (22) of the brake pad module (20).

Description

[0001] The present invention relates to a brake caliper for a braking device of a vehicle.

[0002] It is well known that brake calipers are used in vehicle braking systems to move a brake pad back and forth between a release position and a braking position. To achieve this movement, a brake piston is usually present which, with a change in hydraulic pressure, is able to move the brake piston into the braking position and there press it against a brake disc rotating with the wheel. The desired braking effect is created by the resulting friction between the brake pad of the brake pad module and the brake disc. After the braking process has ended, the brake pad and thus also the brake pad module must move back to the release position. This usually happens by retraction when the hydraulic pressure in the brake piston decreases.However, it can happen that the brake pad remains in contact with the brake disc, thus leaving a residual braking torque on the brake disc even after the braking process has ended. To prevent this, it has already been proposed to provide a separate spring device that can push the entire brake pad module back toward the release position.

[0003] The disadvantage of the known solutions is that residual braking torque increases wear on the brake disc and brake pad, and also represents an undesirable source of noise. Using the known spring device requires a lot of installation space, so the entire braking device must be significantly larger to overcome this disadvantage.

[0004] DE 2152 614 A, DE 196 00 605 A1 and DE 86 11 037 U1 each disclose the subject matter of the preamble of claim 1.

[0005] The object of the present invention is to remedy the above-described disadvantages in a cost-effective and simple manner. In particular, the object of the present invention is to provide a reduced residual braking torque in a cost-effective and simple manner with a small footprint.

[0006] The above object is achieved by a brake caliper having the features of claim 1. Further features and details of the invention emerge from the subclaims, the description and the drawings.

[0007] According to the invention, a brake caliper for a braking device of a vehicle is proposed. This brake caliper has a brake pad module with at least one brake pad for braking contact with a brake disc of the vehicle. This braking contact is established when the brake pad and the brake pad module are in the braking position. Furthermore, the brake caliper is equipped with a brake piston module with at least one brake piston. This brake piston serves to move the brake pad module from a release position into the braking position. To guide the movement of the brake pad module between the release position and the braking position, the brake piston module is equipped with at least one pad retaining bolt. This pad retaining bolt is equipped with a spring groove in which a spring device is supported, which is arranged between the pad retaining bolt and the brake pad module.This spring device applies a restoring force to the brake pad module from the braking position to the release position.

[0008] A brake caliper according to the invention is based on known solutions, in which one or more brake pistons generate a movement of a brake pad module from the release position to the braking position. Hydraulic pressure from the brake piston not only achieves this movement, but also exerts the desired braking force on the brake disc or brake pad module upon contact with the brake disc.

[0009] The inventive design provides support for the return movement of the brake pad module from the braking position to the release position. This support takes the form of a restoring force applied to the brake pad module by the spring device. In contrast to known solutions with external spring devices, however, the inventive design integrates the spring device into the brake caliper. This integration is based in particular on the arrangement of the spring device between the brake pad module and the pad retaining bolt. Because the pad retaining bolt is designed directly to guide the brake pad module, the desired restoring force can be applied at this point by the spring device in a particularly compact and cost-effective manner.To ensure that the spring device remains in the desired position and, in particular, to maintain constant force transfer sections between the brake pad module on the one hand and the pad retaining bolt on the other, the pad retaining bolt is equipped with a spring groove in which the spring device can be supported. As will be explained later, this spring groove can form a corresponding groove surface or groove section into which a corresponding lever arm of the spring device engages. This engagement serves to establish a defined relative position of the corresponding lever arm to the pad retaining bolt. In this defined relative position, a defined force position can also be assumed, which thus corresponds to a defined restoring force from the braking position to the release position.

[0010] A spring device within the meaning of the present invention can be a single spring or a combination of several springs. Single-piece metals, single-piece materials, or even composite materials can be used. In the simplest case, the spring device is a metal spring, which is designed as a bending spring, spiral spring, helical spring, or similarly resilient due to the material's elasticity, and can thus provide the desired restoring force. In the initial step, it is irrelevant whether this spring device is arranged freely between the two elements of the brake pad module and the pad retaining bolt, or whether it is attached to one or even both of these elements with a fastening. However, for assembly purposes, it can be expedient, as will be explained later, for the spring device to be attached either to the pad retaining bolt or to the brake pad module.This attachment can, as will also be explained, be both reversible and irreversible.

[0011] By applying the restoring force described above, a decisive advantage is achieved after the end of the braking process. This restoring force is increased in particular by the fact that a greater bending of the spring device is provided when the brake pad module moves into the braking position. Along the spring characteristic curve of the spring device, the restoring force increases or builds up when the brake pad module is moved from the release position to the braking position. It can be advantageous if the spring device already has a certain basic tension in the release position in order to avoid unwanted rattling noises. Such a basic tension orPreloading the spring device also means that a constant or essentially constant spring characteristic curve can be provided over essentially the entire range of movement between the release position and the braking position.

[0012] Once the braking process is complete, the restoring force applied or generated in this way can be used to assist the return of the brake pad module from the braking position to the release position after the counterforce of the hydraulic fluid in the brake piston has been removed. This assistance is achieved with a very compact and lightweight design, as the spring device is integrated between the elements within the brake caliper.

[0013] According to an alternative embodiment not belonging to the invention, it is provided that, in a brake caliper according to the invention, the at least one pad retaining bolt has the spring groove for supporting the spring device with an extension transverse to the direction of movement of the brake pad module. In this way, the spring device or the corresponding spring of the spring device is subjected to bending stress.

[0014] Such a spiral spring can be manufactured particularly easily and cost-effectively and, in particular, can also be equipped with a defined line of action, i.e., a defined and preferably constant spring characteristic. Such a spiral spring is preferably equipped on both sides, i.e., with two symmetrical lever arms, as explained later. With a corresponding central attachment, the lever arm of the spring device can now bend, which increases as the movement is performed from the release position to the braking position.

[0015] It can also be advantageous if, in a brake caliper according to the invention, the spring device is irreversibly attached to the brake pad module. This can be done, for example, by means of a riveted connection. This irreversible attachment secures the spring device to the brake pad module, particularly after pre-assembly. When assembling the brake caliper, the spring device can then be mounted together with the brake pad module, simplifying assembly and preventing loss of the spring device.

[0016] It is also advantageous if, in a brake caliper according to the invention, the spring device is reversibly attached to the brake pad module. Screw connections, hook connections, or general form-fitting connections are conceivable here. In this way, it is possible to design the spring device as a wear part and replace it. Even if the brake pad is still intact, the spring device can potentially be impaired by a large number of braking operations. If the spring device itself is designed as a wear part and replace it with a reversible connection, a replacement can be carried out here while retaining the brake pad module. The costs of such a replacement and the material consumption can be reduced in this way.

[0017] Further advantages can be achieved if, in a brake caliper according to the invention, the spring device has a constant or substantially constant spring characteristic curve at least in the area between the release position and the braking position.

[0018] This also includes a constant or essentially constant force distribution. This means that over the distance traveled by the brake pad module between the release position and the braking position, the corresponding spring force, i.e. the restoring force that builds up, increases linearly or essentially linearly. This spring characteristic curve is preferably constant or essentially constant for such a long time that it also takes brake pad wear into account. In repeated braking situations over the vehicle's service life, the strength or thickness of the brake pad will reduce. In order to reach the braking position, i.e. to achieve braking contact between the reduced brake pad and the brake disc, a further distance must be covered, meaning that the braking position must be reached over a greater distance from the release position.Preferably, during this larger movement, an overextension or partial overextension of the spring device is carried out, so that even if the path between the release position and the braking position changes, the linear force ratios can be maintained or substantially maintained.

[0019] It is furthermore advantageous if, in a brake caliper according to the invention, the spring device has two lever arms, in particular in a symmetrical design, for support on two pad retaining bolts that are spaced apart from one another. In order to avoid tilting within the brake caliper, a redundant and symmetrical design of the individual moving parts is usually provided. On the one hand, this is based on two or more brake pistons, which can provide a purely linear movement in a correspondingly symmetrical or essentially symmetrical manner while avoiding jamming. In the same way, the return support can also be designed in a correspondingly symmetrical or essentially symmetrical manner using the spring device in order to be able to guarantee the same advantages during the return movement from the braking position to the release position. For this purpose, two separate points of application orApplication points for the restoring force are necessary, which are provided by the spring device, either with two separate springs or, as in this design, with two separate lever arms. These are supported in particular by separate pad retaining bolts and correspondingly separate spring grooves. The symmetrical design also prevents tilting and even enables stabilization of a tilt-free movement.

[0020] In a brake caliper according to the invention, the at least one pad retaining bolt has the spring groove for supporting the spring device with an extension transverse to the extension of the at least one brake pad of the brake pad module. An orientation transverse to the extension of the brake pad is therefore in particular an orientation perpendicular or substantially perpendicular to this brake pad. In this design, the spring device is preferably arranged within the spring groove or even fastened there. By appropriately adjusting it against the direction of movement, a bending or elastic deformation of the spring device can be ensured during the movement into the braking position, so that the restoring force is built up using the same functional principle and is then available for the return movement into the release position. The integration of the spring device into the spring groove of the respective pad retaining bolt leads to an even more compact design.In particular, this also makes it possible to continue using known brake pad modules, since the functionality according to the invention has been integrated into the brake piston module.

[0021] It is also advantageous if, in a brake caliper according to the invention, the spring device is at least partially secured in the spring groove of the pad retaining bolt. This particularly applies to the embodiment described in the previous paragraph. This integration, along with the fastening, also facilitates assembly and allows the use of normal or standardized brake pad modules. The fastening also creates a loss protection feature on the bolt for the spring device.

[0022] A brake pad module for a brake caliper according to the present invention also includes the spring device. The combination of the spring device with the brake pad module provides the same advantages as those explained in detail with reference to a brake caliper according to the invention. In particular, assembly is further simplified in this way.

[0023] A brake piston module for a brake caliper according to the present invention, which has the spring device, offers the advantage, in addition to simplified assembly, that normal or standardized brake pad modules can be used. Such a brake piston module thus offers the same advantages as those explained in detail with reference to a brake caliper according to the invention.

[0024] Further advantages, features, and details of the invention will become apparent from the following description, which describes exemplary embodiments of the invention in detail with reference to the drawings. The features mentioned in the claims and in the description may be essential to the invention individually or in any combination.

[0025] It shows Fig. 1 an embodiment of a brake pad module in an alternative embodiment not belonging to the invention, Fig. 2 the embodiment of the Fig. 1 in another view, Fig. 3 the embodiments of the Fig. 1 and Fig. 2 in installed condition, Fig. 4 the design of the Fig. 3 in a different representation, Fig. 5 the embodiments of the Fig. 3 and Fig. 4 in another view, Fig. 6 an embodiment of a brake caliper according to the invention with an integrated spring device in the spring groove, Fig. 7 the embodiment of the Fig. 6 in a different view and Fig. 8 the embodiments of the Fig. 6 and Fig. 7 in a different view.

[0026] The Fig. 1 and Fig. 2 show an embodiment of a brake pad module 20. This is symmetrically designed and has a brake pad 22 on the front side. This brake pad 22 can be brought into the desired braking or frictional contact with a brake disc in a braking device of a vehicle. On the back side of the brake pad module 20, which is shown in Fig. 1 and Fig. As can be clearly seen in Figure 2, a spring device 40 is attached with a central fastening means 50 in the form of a rivet device. This spring device 40 is a bow spring or a metal spring with two symmetrical lever arms 42. At the end of the two lever arms 42, two through openings can be seen in the base plate of the brake pad module 20, which can also be referred to as guide openings, and into which the pad retaining bolts 34 are subsequently inserted during assembly.

[0027] The Fig. 3, Fig. 4 and Fig. 5 show an assembled situation of the embodiment of the Fig. 1 and Fig. 2. Two separate pad retaining bolts 34 are guided through the guide openings in the base plate of the brake pad module 20. These serve to guide the movement between the release position, as shown by the Fig. 3 to 5, and a braking position not shown in detail. Furthermore, the correlation of the spring device 40 with the pad retaining bolts 34 and the spring grooves 36 arranged therein can be seen here. The spring groove 36 is a ring-shaped, circumferential groove in which the respective lever arm 42 can engage symmetrically. In particular, based on the Fig. 5 the mode of operation can now be explained in more detail.

[0028] In Fig. 5 it can be seen that with a central brake piston 32 or two adjacently arranged brake pistons 32 of the brake piston module 30 a corresponding movement of the brake pad module 20 from the illustrated release position according to Fig. 5 into a braking position not shown downwards along the direction of movement BR. During this movement, a guide is provided between the guide openings of the brake pad module 20 and the pad retaining bolts 34. However, the end of the respective lever arm 42 of the spring device 40 remains held in the spring groove 36, so that a bending line is formed and the desired restoring force is applied by this elastic deformation of the material of the spring device 40. As soon as the brake pistons 32 reduce the hydraulic pressure, this reduction causes the brake pad module 20 to be retracted into the release position. This direction of movement BR is supported by the restoring force applied by the deformed spring device 40.During this return, this deformation is reversed by the elastic restoring forces of the spring device, so that a position with a relaxed or substantially relaxed spring device 40 is reached, as shown in the . Fig. 5 represents.

[0029] The Fig. 6 to 8 show an embodiment of a brake calliper 10 according to the invention. This is based on the same functionality as described in particular with reference to Fig. 5. However, here the spring device 40 is arranged on the brake piston module 30 and there in the spring groove 36 and preferably even fastened there. The restoring force can now build up via an outwardly projecting lever arm 42 when the brake pad module 20 is in the Fig. 6 to 8 from the release position, as shown in these figures, upwards into the braking position. This also results in an elastic deformation of the lever arm 42 of the spring device 40, so that an elastic restoring force is provided. Even if in the Fig. 6 to 8, only a single combination of a lever arm 42 and a pad retaining bolt 34 is shown, preferably a similar design with two pad retaining bolts 34 is provided, as in the Fig. 3 to 5.

[0030] The above explanation of the embodiments describes the present invention exclusively within the scope of examples. It is understood that individual features of the embodiments can be freely combined with one another, provided that they are technically feasible, without departing from the scope of the present invention.

Claims

[1] Brake caliper (10) for a braking device of a vehicle, comprising a brake pad module (20) with at least one brake pad (22) for braking contact with a brake disc of the vehicle in a braking position and a brake piston module (30) with at least one brake piston (32) for moving the brake pad module (20) from a release position into the braking position, wherein the brake piston module (30) has at least one pad retaining bolt (34) for guiding the movement of the brake pad module (20), wherein a spring device (40) is further arranged between the pad retaining bolt (34) and the brake pad module (20), which spring device is supported on the pad retaining bolt (34) in a spring groove (36) and applies a restoring force to the brake pad module (20) from the braking position into the release position, characterized bythat the at least one pad retaining bolt (34) has the spring groove (36) for supporting the spring device (40) with an extension transverse to the extension of the at least one brake pad (22) of the brake pad module (20). [2] Brake caliper (10) according to claim 1, characterized by that the spring device (40) is irreversibly attached to the brake pad module (20). [3] Brake calliper (10) according to one of the preceding claims, characterized by that the spring device (40) is reversibly attached to the brake pad module (20). [4] Brake calliper (10) according to one of the preceding claims, characterized by that the spring device (40) has a constant or substantially constant spring characteristic curve at least in the region between the release position and the braking position. [5] Brake calliper (10) according to one of the preceding claims, characterized bythat the spring device (40) has two lever arms (42), in particular of symmetrical design, for support on two spaced-apart pad retaining bolts (34). [6] Brake calliper (10) according to one of the preceding claims, characterized by that the spring device (40) is at least partially fastened in the spring groove (40) of the pad retaining bolt (34).

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