Disc brake for a commercial vehicle and brake pad of a disc brake

Abstract

A disc brake for a commercial vehicle, comprising a brake caliper (1) extending over a brake disc, two brake pads (2) arranged therein, movable in opposite directions towards the brake disc, each having a pad carrier plate (3) and a friction lining (4) attached thereto, which are arranged under preload by pad retaining springs (8) formed from a spring wire in a pad recess (9) of a vehicle-side brake carrier (5) limited in the direction of rotation of the brake disc by brake carrier horns (6), is designed such that each pad retaining spring (8) has two legs (10, 12) in the same direction, connected at their ends by an axially twisted torsion section (13), the free ends of which are directed in opposite directions towards each other and angled apart from each other to form a plug element (11), both of which are attached to the associated pad carrier plate (3) or the brake carrier (5),while the torsion section (13) is supported on a component that is relatively radially movable, the plug-in elements (11) are offset from each other at a predetermined angle in the direction of rotation of the torsion section (13) before assembly when the torsion section (13) is relaxed.

Description

[0001] The invention relates to a disc brake for a commercial vehicle according to the preamble of claim 1 and to a brake pad of a disc brake.

[0002] US 5 193 652 A and JP S55 - 54 730 A each disclose a disc brake and FR 2 770 600 A1 discloses a brake pad for a disc brake.

[0003] The brake pad holder of a disc brake is disclosed, for example, in DE 10 2007 049 979 A1.

[0004] For this purpose, the brake pads are guided in a pad recess of the stationary brake carrier and, depending on the direction of rotation of the brake disc, are supported during a braking process by brake carrier horns that limit the pad recesses in the circumferential direction of the brake disc.

[0005] For radial support of the brake pads, a pad retaining bracket spanning a mounting opening of the brake caliper is provided. This bracket rests against pad retaining springs connected to the respective backing plate of the brake pads, so that the brake pads are held under preload in the pad slots. This at least reduces the generation of rattling noises.

[0006] From the prior art, lining retaining springs are known which are designed in the sense of leaf springs, accepting disadvantages which are described in detail in the aforementioned DE 10 2007 049 979 A1.

[0007] To avoid these disadvantages, this document proposes manufacturing the brake pad retaining spring from a spring wire. This spring wire has a progressive spring characteristic that can be influenced by various parameters to adapt the spring force to the specific situation. These include, for example, the weight of the brake pad or a desired radial play.

[0008] When the brake is applied, the brake pad is subjected to high compressive and lateral forces, which, moreover, transmit the lateral forces resulting at the friction surface of the brake pad via the friction lining into the pad backing plate and subsequently into the brake caliper or brake carrier. The lateral forces acting on the brake pad are absorbed primarily by the trailing edge of the backing plate.

[0009] However, problems arise insofar as, due to the limited installation space, the narrow sides of the pad carrier plate, which rest against the brake carrier horns, cannot prevent a rotational movement during a braking process.

[0010] This rotational movement has a negative impact on the brake pad's clearance and its wear behavior, especially in the form of uneven wear.

[0011] A brake pad retaining spring made of spring wire is also known from DE 27 42 295 A1. In this document, the brake pad retaining spring, referred to as a torsion and bending spring, is supported on two support surfaces on the brake carrier, while one leg of the spring engages in a groove on a side wall of the brake pad and presses it towards the bottom of the pad well.

[0012] The problem here, however, is that the clear width between the parallel legs of the pad retaining spring must at least correspond to the thickness of the brake carrier in this area. Furthermore, the configuration of the pad backing plate and the brake carrier is relatively complex to manufacture, since the brake pad—that is, the pad backing plate and the friction lining—must be provided with a corresponding groove for the placement of the angled plug-in element.

[0013] The invention is based on the objective of further developing a disc brake of the generic type in such a way that its functional reliability is improved with minimal design and manufacturing effort.

[0014] This problem is solved by a disc brake having the features of claim 1.

[0015] First of all, it should be noted that the new pad retaining spring, of which at least one, preferably two, are assigned to each brake pad, is very inexpensive to manufacture and install.

[0016] Furthermore, the progressive spring action of the brake pad retainer can induce stronger micro-movements in the brake pad, thus preventing or eliminating corrosion between the brake pad and the brake carrier. Simultaneously, the amplitude of radial vibrations of the brake pad within the brake carrier is reduced, resulting in minimized rattling noises.

[0017] Depending on the application, the pad retaining springs can act as compression or tension springs and can be used on the brake carrier or brake caliper regardless of the available installation space.

[0018] According to the invention, the new pad retaining springs are either attached to the pad carrier plate or to the brake carrier, in particular to an associated brake carrier horn.

[0019] In the latter case, the pad retaining spring can remain in place when changing the brake pads, i.e., replacement along with the worn brake pad is not necessary.

[0020] Depending on the intended use, the brake pad is assigned one or two retaining springs, with only one spring being used if the disc brake is designed to be directionally oriented. In this case, the retaining spring is positioned on the leading edge. However, the retaining spring can also be located centrally or only on the trailing edge.

[0021] In principle, the brake pad retaining spring can be formed from a spring wire with a round or non-round cross-section, with receiving holes provided on the brake carrier or the pad backing plate into which the plug-in elements are inserted. These plug-in elements can be secured by positive locking or friction locking. The cross-sectional dimension of the receiving holes can correspond approximately to the cross-sectional dimension of the plug-in elements, thus ensuring that they are held largely without play.

[0022] The mounting holes are arranged tangentially one behind the other, so that the legs are aligned axially parallel and run in one plane. The clear distance between the two parallel legs corresponds approximately to the thickness of the pad carrier plate if the mounting holes are provided in the pad carrier plate, or to the thickness of the brake carrier in this area if the mounting holes are arranged in the brake carrier.

[0023] The torsion section provided according to the invention, which connects the two legs, is supported by a component that is relatively radially movable relative to the pad carrier plate or the brake carrier. That is, when the plug-in elements are attached to the pad carrier plate, the torsion section is supported by the brake carrier or a brake carrier horn.

[0024] If, on the other hand, the plug-in elements are held in the brake carrier, the torsion section is supported against the pad carrier plate or a pad retaining bracket that spans a mounting opening of the brake caliper, whereby, depending on whether the pad retaining spring is to act as a tension or compression spring, the torsion section rests against the underside of the pad retaining bracket or against its top side.

[0025] The spring force is provided by the fact that, according to the invention, the plug-in elements are offset from each other at a predetermined angle in the direction of rotation of the pad retaining spring before assembly, with the torsion section relaxed. The strength of the spring force is influenced by the wire thickness, i.e., the wire diameter, the spring wire material, and the angle between the plug-in elements before installation.

[0026] During assembly, the plug-in elements are pressed together by the position of the receiving holes, which, as mentioned, are tangentially arranged one behind the other, so that the torsion section twists, resulting in the spring force.

[0027] Further advantageous embodiments of the invention are characterized in the dependent claims.

[0028] Exemplary embodiments of the invention are described below with reference to the accompanying drawings.

[0029] They show: Fig. 1. A top view of a part of a disc brake according to the state of the art Fig. 2a - 2d a lining retaining spring according to the invention in different views as a detail Fig. 3. The pad retaining spring installed in a disc brake in different views Fig. Figures 4-6 each show a further embodiment of the mounting pad retaining spring according to the invention in a schematic front view.

[0030] In the Fig. Figure 1 shows a partial section of a disc brake according to the prior art, with a brake caliper 1 overlapping a brake disc (not shown), two brake pads 2 arranged therein, movable in opposite directions towards the brake disc, each having a pad carrier plate 3 and a friction lining 4 attached thereto, which are arranged under preload by pad retaining springs 8 formed from a spring wire in a pad recess 9 of a vehicle-side brake carrier 5 which is limited in the direction of rotation of the brake disc by brake carrier horns 6.

[0031] In order to press the respective brake pad 2 into the pad shaft 9 under spring pressure, the pad retaining spring 8, consisting of a spring wire, is attached to the associated pad carrier plate 3, the pad retaining spring 8 being supported under preload on a pad retaining bracket 7, which is attached at both ends to the brake caliper 1 and spans a mounting opening of the brake caliper 1 transversely to the longitudinal extent of the brake pad 2.

[0032] The pad retaining spring 8 according to the invention is to be installed as a separate component prior to assembly in the Fig. Figures 2a) to 2d) show that the plug-in elements 11 are offset from each other at an angle in the direction of rotation when the torsion section 13 is relaxed, the strength of the spring force being determined by the wire thickness, the wire diameter and the angle between the two plug-in elements 11 and being changeable in the desired configuration.

[0033] The pad retaining spring 8 has two legs 10, 12 oriented in the same direction, connected at their ends in the mounted position by the axially twisted torsion section 13, one of which is shorter than the other. The free ends of the legs 10, 12 are in the Fig. 2a) - 2c) are directed towards each other in opposite directions and at a distance from each other, each forming the aforementioned plug-in element 11. In the case of the Fig. In contrast, in the illustrated example of the pad retaining spring 8 in 2d), the plug-in elements 11 are aligned in the same direction and run parallel and spaced apart from each other.

[0034] For example, in the Fig. 3a), which shows the pad retaining spring 8 in a side view in its mounted position, while the Fig. 3b) which shows a narrow side view, it can be seen that the plug-in elements 11 are attached to the associated pad carrier plate 3 of the brake pad 2.

[0035] For this purpose, the plug-in elements 11 are inserted into receiving bores 14 of the support plate 3 and held in place, whereby fastening is also possible by riveting, deformation to a rivet head or by a screw connection.

[0036] In the example after the Fig. 3 the torsion section 13 is supported on the associated brake carrier horn 6, wherein the force direction of the pad retaining spring 8 is designed such that the pad carrier plate 3 is displaced in the direction away from the brake carrier horn 6.

[0037] Whether the pad retaining spring 8 is used as a compression or tension spring depends solely on the installation position of the pad retaining spring 8.

[0038] In the Fig. In the example shown in Figure 4, the fastening of the lining retaining spring 8 is arranged at the base of the lining support plate 3, which rests on the bottom of the lining shaft 9, while the torsion section 13 is supported on the bottom of the lining shaft 9.

[0039] In the Fig. In the example shown in Figure 5, where the pad retaining spring 8 is arranged on the upper edge region of the pad support plate 3, i.e., the edge region facing away from the pad shaft 9, the pad retaining spring 8 is supported on the underside of a The pad retaining bracket 7 acts as a compression spring and pushes the pad support plate 3 downwards towards the bottom of the pad shaft 9.

[0040] In contrast, the backing plate 3 is used in the Fig. The example shown in 6 is pulled upwards, for which the pad holder 8 is supported on the top of the pad holder bracket 7.

[0041] Crucial for the functionality of the pad retaining spring 8 is that the legs 10, 12 are arranged axially parallel and in a plane X, as is particularly evident in the Fig. 3a) is recognizable. Reference symbol list 1 brake caliper 2 brake pads 3. Support plate 4 friction lining 5 brake carriers 6 brake carrier horns 7 pad retaining clips 8 Pad retaining spring 9 Cover shaft 10 thighs 11 Plug-in element 12 thighs 13 Torsion section 14 Mounting hole

Claims

Disc brake for a commercial vehicle, comprising a brake caliper (1) extending over a brake disc, two brake pads (2) arranged therein, movable in opposite directions towards the brake disc, each having a pad carrier plate (3) and a friction lining (4) attached thereto, which are arranged under preload by pad retaining springs (8) formed from a spring wire in a pad recess (9) of a vehicle-side brake carrier (5) limited in the direction of rotation of the brake disc by brake carrier horns (6), characterized in that each pad retaining spring (8) has two legs (10, 12) in the same direction, connected at their ends by an axially twisted torsion section (13), the free ends of which are directed in opposite directions towards each other or aligned in the same direction and each angled at a distance from each other to form plug-in elements (11), both of which are attached to the associated pad carrier plate (3) or the brake carrier (5),while the torsion section (13) is supported on a component that is relatively radially movable, the plug-in elements (11) are offset from each other at a predetermined angle in the direction of rotation of the torsion section (13) before assembly when the torsion section (13) is relaxed. Disc brake according to claim 1, characterized in that the pad carrier plate (3) or the brake carrier (5) is provided with receiving bores (14) for the plug-in elements (11). Disc brake according to claim 1 or 2, characterized in that the plug-in elements (11) are held largely without play in the receiving bores (14). Disc brake according to one of the preceding claims characterized in that the plug-in elements (11) are held in a form-fit or material-fit manner. Disc brake according to one of the preceding claims, characterized in that in the mounted position of the pad retaining spring (8) the legs (10, 12) run parallel to the axis and in a plane (X). Disc brake according to one of the preceding claims, characterized in that the receiving bores (14) are arranged tangentially one behind the other. Disc brake according to one of the preceding claims, characterized in that the torsion section (13) is supported on the brake carrier horn (6). Disc brake according to one of the preceding claims, characterized in that the component on which the torsion section (13) is supported is designed as a pad retaining bracket (7), as a pad carrier plate (3) or as a brake carrier (5). Disc brake according to one of the preceding claims, characterized in that the torsion section (13) rests against the underside or the top side of the pad retaining bracket (7). Disc brake according to one of the preceding claims, characterized in that the clear distance between the legs (10, 12) corresponds approximately to the thickness of the pad carrier plate (3). Brake pad of a disc brake, comprising a pad carrier plate (3) and a friction lining (4) attached thereto, characterized in that at least one pad retaining spring formed from a spring wire is arranged on the pad carrier plate (3), which has two axially parallel legs (10, 12) in the same direction, connected at their ends by an axially twisted torsion section (13), the free ends of which are directed in opposite directions towards each other and angled at a distance from each other, each forming a plug element (11), both of which are attached to the associated pad carrier plate (3).

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