BRAKE PAD ASSEMBLY FOR A DISK BRAKE SYSTEM AND DISK BRAKE SYSTEM

Abstract

The application relates to a brake pad assembly for a disk brake system and to a disk brake system. The proposed brake pad assembly for a disk brake system comprises a back plate having a front side for facing a brake disk of the disk brake system and a back side. The brake pad assembly further comprises a friction layer arranged at the front side of the back plate for contacting a friction surface the brake disk. The back plate comprises a back plate body having a recess on its back side. The back plate further comprises a layered structure that is received within the recess of the back plate body. The layered structure comprises a copper layer and a rubber layer. The rubber layer covers the copper layer.

Claims

1. A brake pad assembly (2) for a disk brake system, comprising a back plate (5) having a front side (4) for facing a brake disk (1) of the disk brake system and a back side (6), and further comprising a friction layer (3) arranged at the front side (4) of the back plate (5) for contacting a friction surface the brake disk (1), characterized in that the back plate (5) comprises a back plate body (7) having a recess (8) on its back side (9), wherein the back plate (5) further comprises a layered structure (10) that is received within the recess (8) of the back plate body (7), wherein the layered structure (10) comprises a copper layer (11) and a rubber layer (12) covering the copper layer (11).

2. The brake pad assembly (2) of claim 1, characterized in that the rubber layer (12) is arranged directly on a back side of the copper layer (11).

3. The brake pad assembly (2) of claim 1, characterized in that rubber layer (12) forms a part of the back side (6) of the back plate (5).

4. The brake pad assembly (2) of claim 1, characterized in that the back plate body (7) is made of steel.

5. The brake pad assembly (2) of claim 1, characterized in that the back plate body (7) comprises another recess (8′) on its back side (9), wherein the back plate (5) further comprises another layered structure (10′) that is received within the other recess (8′) of the back plate body (7).

6. The brake pad assembly (2) of claim 5, characterized in that the layered structure (10) and the other layered structure (10′) are each arranged at least partly in a region of force transmission between a pressure region (13) of the back side (6) of the back plate (5) that is configured to be pushed on by a brake piston (19) or by a caliper finger (19′) upon brake application and an edge (14, 16, 17) of the back side (6) of the back plate (5).

7. The brake pad assembly (2) of claim 1, characterized in that the copper layer (11) has a thickness of at least 1 mm and at most 2.5 mm.

8. The brake pad assembly (2) of claim 1, characterized in that the rubber layer (12) has a thickness of at least 0.2 mm and at most 5 mm.

9. The brake pad assembly (2) of claim 1, characterized in that the copper layer (11) of the layered structure (10) is cast into the recess (8) of the back plate body (7).

10. The brake pad assembly (2) of claim 1, characterized in that the copper layer (11) has an enlarged thickness in a pressure region (13) of the back side (6) of the back plate (5) that is configured to be pushed on by a brake piston (19) or by a caliper finger (19′).

11. The brake pad assembly (2) of claim 1, characterized in that the copper layer (11) has a copper content of at least 30% by weight.

12. A disk brake system comprising a brake piston and/or a caliper finger and the brake pad assembly (2) of claim 1, wherein the back side (6) of the back plate (5) contains a pressure region (13) that is configured to be pushed on by the brake piston (19) or by the caliper finger (19′) upon brake application.

13. The disk brake system of claim 12, characterized in that the layered structure (10) is arranged such that the brake piston (19) and/or caliper finger (19′) is configured to push directly onto a back side of the layered structure (10) upon brake application.

14. The disk brake system of claim 12, characterized in that the layered structure (10) is arranged at least partly between the pressure region (13) of the back side (6) of the back plate (5) and a top edge (14) of the back side (6) of the back plate (5) and/or wherein the layered structure (10) is arranged at least partly between the pressure region (13) of the back side (6) of the back plate (5) and at least one of a first side edge (16) and a second side edge (17) of the back side (6) of the back plate (5).

Description

[0020] Exemplary embodiments will be described in conjunction with the following figures.

[0021] FIG. 1 shows a schematic cross sectional illustration of a brake pad assembly and a brake disk,

[0022] FIG. 2 shows a schematic cross-sectional view of a back plate of the brake pad assembly,

[0023] FIGS. 3) to 5 show schematic views of a piston and the brake pad assembly, and

[0024] FIGS. 6 to 8 show schematic views of a caliper finger and a brake pad assembly according to another embodiment.

[0025] FIG. 1 shows a brake disk 1 of a of a disk brake system for a vehicle. The disk brake system may comprise a caliper housing, a caliper finger and a brake piston. The disk brake system further comprises a brake pad assembly 2, which may be attached to the caliper finger and/or to the brake piston. The brake pad assembly 2 has a friction layer 3, which is pushed against a friction surface of the brake disk 1 upon hydraulic or electric actuation of the disk brake system. The friction layer 3 contains a material that shows a good stopping performance and heat transfer when engaging with the brake disk 1. The friction layer 3 is attached to a front side 4 of a back plate 5, which provides structural stability to the brake pad assembly 2. The brake piston or the caliper finger is configured to push against a back side 6 of the back plate 5 to push the friction layer 3 against the brake disk 1. In most embodiments, the back plate 5 is made of a metal, in particular steel. A thickness of the back plate 5 may be, e.g., 5 mm. The friction layer 3 can have a thickness of at least 8 mm and/or at most 15 mm, for example. The material of the friction layer 3 can for instance comprise at least one of copper, iron sulphide, graphite, zinc powder, basalt, calcium carbonate, tin sulphide, zinc aluminium, phenolic resin, rubber dust and mineral fiber. These materials show good stopping performance and heat transfer when engaging with the brake disk.

[0026] FIG. 2 shows the back plate 5 in more detail. Corresponding and reoccurring features shown in the different figures are denoted using the same reference numerals. The back plate 5 comprises a back plate body 7. The back plate body 7 has a recess 8 on a back side 9 of the back plate body 7 and a flat front side forming the front side 4 of the back plate 5. The back plate 5 further comprises a layered structure 10 having a copper layer 11 and a rubber layer 12 arranged on and attached to a back side of the copper layer 11. The layered structure is received within the recess 8 on the back side 9 of the back plate body 7 and essentially fills the recess 8 completely. A back side of the layered structure 10 is formed by the rubber layer 12, which is flush with the back side 9 of the back plate body 7 such that the back plate body 7 and the layered structure 10 form the back side 6 of the back plate 5. The back side 6 of the back plate 5 is a flat surface that does not have any steps. The copper layer 11 may be cast into the back plate body 7 and may be directly attached to a bottom surface as well as to side surfaces of the recess 8 by material bonding to the back plate body 7 in some embodiments.

[0027] FIG. 3 shows the brake pad assembly 2 and the brake piston 19 of the disk brake system as viewed from the back, i.e., toward the brake disk 1. The brake piston 19 is configured to push against the back side 6 of the back plate 5. The brake piston 19 has a ring-shaped front surface, which leads to a ring-shaped pressure region 13, see FIG. 4, i.e., a ring-shaped region of the back side 6 of the back plate 5 that is exposed to an axial pressure exerted by the brake piston 19. FIG. 4 does not show the brake piston 19. The back side 6 of the back plate 5 has a top edge 14, which delimits the back plate 5 in the upward direction. The upward direction is a radial direction 15. According to the depiction of the figures, the axis of rotation (not shown) of the brake disk 1 would be arranged below the brake pad assembly 2, i.e., toward the bottom in the figures (in a direction opposite the radial direction 15). The back side 6 of the back plate 5 further has a first side edge 16, which is a leading edge on the left in the figures, and a second side edge 17, which is a trailing edge on the right. The top and side edges 14, 16, 17 delimit edge surfaces of the back plate.

[0028] FIG. 4 further illustrates suitable regions for the layered structure 10 or layered structures, as shown in FIG. 5. The suitable regions are regions of force transmission from the pressure region 13 to the top and side edges 14, 16, 17 in real case situations. These regions are indicated by the lines 18 in FIG. 4. As depicted in FIG. 5 the layered structure 10 is arranged roughly in the region indicated by the line 18 of FIG. 4. The layered structure 10 is arranged in the recess 8 of the back plate body 7 and is further arranged in parts between the pressure region 13 and the top edge 14 of the back side 6 of the back plate 5. In the example shown, the layered structure 10 is arranged such that it has an overlap with the pressure region 13. Therefore, upon application of the brake, the brake piston 19 pushes directly onto the rubber layer 12 of the layered structure 10. The copper layer 11 of the layered structure 10 may have an increased thickness in a region that overlaps with the pressure region 13 as compared with a region that does not overlap with the pressure region 13.

[0029] The back plate body 7 further comprises another recess 8′ and a further recess 8″. Another layered structure 10′ and a further layered structure 10″ are each arranged in one of the other and further recesses 8, 8′. The other and further layered structures 10′, 10″ have the features of the layered structure 10 described above. The other layered structure 10′ is arranged between the pressure region 13 and the left edge 16, while the further layered structure 10″ is arranged between the pressure region 13 and the right edge 17 for improved noise dampening.

[0030] In another embodiment, the brake pad assembly 2 may be intended to be arranged on a caliper finger side of the brake system. As shown in FIG. 6, the brake system may comprise the caliper finger 19′ (as viewed from the back, i.e., toward the brake disk 1, in the figure). The caliper finger 19′ is configured to push against a back side 6 of the back plate 5 when the brake is applied. The caliper finger 19′ is shown to exert axial pressure on the brake pad assembly 2 in the pressure region 13, which in this case comprises a left pressure region 20 and a right pressure region 21, as shown in FIG. 7. Lines denoted by reference sign 22 indicate the preferred positions of the layered structures for noise reduction.

[0031] As shown in FIG. 8 and similar to the case described for the brake piston side with regard to FIGS. 3 to 5, the layered structure 10 is arranged between the pressure region 13 (having the separate left and right regions 20, 21) and the top edge 14 of the back plate 5, the other layered structure 10′ is arranged between the left pressure region 20 and the left edge 16, and the further layered structure 10″ is arranged between the right pressure region 21 and the right edge 17. Additional layered structures 10′″, 10″″ are arranged between the left pressure region 20 and the right pressure region 21. The layered structures 10, 10′, 10″, 10′″, 10″″ are held within respective recesses arranged on the back side 9 of the back plate body 7. There can be an overlap between the pressure region 13, 20, 21 and some or all of the layered structures 10, 10′, 10″, 10′″, 10″″ in some embodiments such that the caliper finger 19′ pushes directly on the rubber layers of the layered structure.

[0032] Features of the different embodiments which are merely disclosed in the exemplary embodiments may be combined with one another and may also be claimed individually.