Dovetail-shaped motor train unit powder metallurgy brake pad with asymmetric steel backing

Abstract

A dovetail type motor train unit powder metallurgy brake pad with an asymmetric steel backing comprises a left brake pad body and a right brake pad body which are of a left-right asymmetric structure. The left brake pad and the right brake pad respectively comprise a left steel backing, a right steel backing, a friction block and a spring buckle. The friction surface of the friction block is octagonal, and the friction block restrains excessive rotation of the friction block by interlocking and arranging a limiting boss on the steel backing; and a double-conical-surface belleville spring is arranged between each friction block and the left steel backing or the right steel backing. By optimizing the shape, the arrangement and the number of the friction blocks, the stress distribution of the brake pad is balanced, and the damage of a friction pair caused by the concentration of thermal stress is reduced; by adopting the mode that the double-conical-surface belleville spring is matched with the frustum of the back plate, the problem that the surface of the back plate is scratched by the edge of the belleville spring can be effectively solved, and continuous and effective floating design is ensured.

Description

Technical Field

[0001] The utility model relates to a motor vehicle brake piece, in particular to a dovetail-shaped motor vehicle powder metallurgy brake piece with an asymmetric steel back. Background Art

[0002] Brake pads for EMU trains are key actuators in the train's braking system, playing a vital role in the train's safe operation. With the advancement of EMU train technology and the continuous increase in operating speeds, higher requirements are being placed on the brake pads' stability and reliability. Existing brake pads utilize hexagonal friction blocks with central heat dissipation holes. Due to the limitations of the block's shape, the block's layout doesn't fit the steel backing's profile well, resulting in uneven distribution. This can easily lead to concentrated thermal stress during high-speed, heavy-load braking. Long-term use can damage the brake friction pair and reduce the service life of the brake pad and disc.

[0003] When a train brakes, the brake cylinder instantly releases a tremendous force, impacting the brake pad components. To extend the life of the brake pad components and prevent fatigue fractures that could lead to brake failure or other safety incidents, the brake pad design must incorporate elastic elements for shock absorption and longitudinal adjustment. For optimal braking performance, the brake pad friction block and the brake disc surface must maintain maximum contact and fit. Therefore, the friction block should be capable of adaptive deflection adjustment to minimize eccentric wear during braking.

[0004] Existing brake pads utilize a floating adjustment mechanism that combines a standard disc spring with a spherical backing plate. This mechanism creates a linear contact between the inner edge of the disc spring and the spherical backing plate, hoping to leverage the spherical surface's deflection and the disc spring's floating adjustment capabilities. However, actual use has shown that because the disc spring is much harder than the backing plate and has a smaller contact area, repeated scratching can cause grooves to form on the backing plate's surface. This can lead to the friction pad losing its ability to deflect and float, resulting in a shortened brake pad lifespan due to uneven wear, insufficient braking force due to a reduction in actual friction area, and reduced braking performance. Utility Model Content

[0005] The technical problem to be solved by the present invention is to overcome the above-mentioned deficiencies of the prior art and provide a dovetail-type EMU powder metallurgy brake pad with an asymmetric steel back that can effectively solve the problem of scratches on the back plate surface by the edge of the disc spring.

[0006] The technical solution adopted by the utility model to solve its technical problems is: a dovetail-type EMU powder metallurgy brake pad with an asymmetric steel back, comprising a left brake pad and a right brake pad, the left brake pad and the right brake pad being of a left-right asymmetric structure; the left brake pad comprises a left steel back, a friction block and a spring clip; the right brake pad comprises a right steel back, a friction block and a spring clip; the friction block comprises a back plate and a friction body, the friction surface of the friction block is octagonal, the friction block restrains excessive rotation of the friction block by interlocking and arranging a limiting boss on the left steel back and the right steel back; a double-conical disc spring is arranged between each friction block and the left steel back or the right steel back; the double-conical disc spring cooperates with the cone of the back plate of the friction block.

[0007] Furthermore, the double-conical disc spring is a double-conical structure that gradually becomes thinner from the outer circle to the inner circle, and the double-conical disc spring is installed in the disc spring countersunk hole of the left steel back or the right steel back.

[0008] Furthermore, a frustum and a pin are provided at the center of the back plate of the friction block; an annular groove is provided at the top of the pin; the inner annular surface of the spring clip cooperates with the annular groove, the outer annular surface of the spring clip cooperates with the clip countersunk hole of the left steel back or the right steel back, the frustum cooperates with the concave conical surface of the double-conical disc spring, and the friction block is installed on the left steel back or the right steel back.

[0009] Furthermore, 9 friction blocks are installed on the left brake pad, and 10 friction blocks are installed on the right brake pad.

[0010] Furthermore, four of the limiting bosses are provided on the left steel back, and five of the limiting bosses are provided on the right steel back.

[0011] Furthermore, the friction block is formed by sintering the back plate and the friction body together by powder metallurgy.

[0012] Furthermore, the dovetail of the left steel back or the right steel back is integrally cast with the steel back, and the left steel back and the right steel back are in a left-right asymmetric structure.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] (1) The structure of the utility model adopts a double-conical disc spring and a back plate cone, which can effectively solve the problem of the disc spring edge scratching the back plate surface and ensure the continuous effectiveness of the floating mechanism;

[0015] (2) In the preferred embodiment of the present invention, the brake pad optimizes and reduces the shape of the friction blocks, increases the number of friction blocks, rearranges the fit between the friction blocks and the steel back, and balances the stress distribution of the brake pad, thereby reducing the damage to the friction pair caused by thermal stress concentration. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the structure of the dovetail-shaped EMU powder metallurgy brake pad with an asymmetric steel back according to the present invention;

[0017] Figure 2 for Figure 1 The front structural diagram of the steel back of Example 1 of the present utility model is shown;

[0018] Figure 3 for Figure 1 The reverse side structural diagram of the steel back of Example 1 of the present utility model is shown;

[0019] Figure 4 for Figure 1 The schematic diagram of the friction block structure of Example 1 of the present utility model is shown;

[0020] Figure 5 for Figure 1 The schematic diagram of the spring buckle structure of Example 1 of the present utility model is shown;

[0021] Figure 6 for Figure 1 The schematic diagram of the double-conical disc spring structure of Example 1 of the present invention is shown;

[0022] Figure 7 for Figure 1 A partial cross-sectional view of Example 1 of the present utility model is shown;

[0023] Figure 8 It is a schematic diagram of the structure of a powder metallurgy brake pad in the prior art;

[0024] Figure 9 for Figure 8 The partial cross-sectional view. DETAILED DESCRIPTION

[0025] In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "center", "up", "down", "left", "right", "inside" and "outside" are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0026] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0027] Example 1

[0028] Refer to the attached Figures 1-9, this embodiment is a dovetail-type EMU powder metallurgy brake pad with an asymmetric steel back, including a left brake pad and a right brake pad, the left brake pad and the right brake pad are of left-right asymmetric structure; the left brake pad includes a left steel back 5, a friction block 4 and a spring clip 2; the friction block 4 includes a back plate 41 and a friction body 42; the right brake pad includes a right steel back 1, a friction block 4 and a spring clip 2; the friction surface of the friction block 4 is octagonal, and the friction block 4 is restrained from excessive rotation by interlocking and providing a limiting boss 6 on the left steel back 5 and the right steel back 1; a double-conical disc spring 3 is provided between each friction block 4 and the left steel back 5 or the right steel back 1; the double-conical disc spring 3 cooperates with the cone 411 of the back plate 41.

[0029] The double-conical disc spring 3 is a double-conical structure that gradually becomes thinner from the outer circle to the inner circle. The double-conical disc spring 3 is installed in the disc spring countersunk hole 7 of the left steel back 5 or the right steel back 1.

[0030] A frustum 411 and a pin 412 are provided at the center of the back plate 41; an annular groove 413 is provided at the top of the pin 412; the inner annular surface 21 of the spring clip 2 cooperates with the annular groove 413, the outer annular surface 22 of the spring clip 2 cooperates with the clip countersunk hole 8 of the left steel back 5 or the right steel back 1, the concave conical surface 31 of the double-conical disc spring 3 cooperates with the frustum 411 of the back plate 41, and the friction block 4 is installed on the left steel back 5 or the right steel back 1.

[0031] Nine friction blocks 4 are mounted on the left brake pad, and ten friction blocks 4 are mounted on the right brake pad.

[0032] The left steel back 5 is provided with four limiting bosses 6 , and the right steel back 1 is provided with five limiting bosses 6 .

[0033] The friction block 4 is formed by sintering a back plate 41 and a friction body 42 together by powder metallurgy.

[0034] The dovetail of the left steel back 5 or the right steel back 1 is integrally cast with the steel back, and the left steel back 5 and the right steel back 1 are in a left-right asymmetrical structure.

[0035] The brake pad structure of this embodiment utilizes a double-conical disc spring 3 mated with a frustum 411 of a back plate 41, achieving surface-to-surface contact rather than line-to-surface contact as in the prior art. This effectively eliminates the problem of disc spring edges scratching the back plate surface, ensuring the continued effectiveness of the floating mechanism. By optimizing and reducing the friction block shape and increasing the number of friction blocks, the alignment of the friction blocks with the steel backing is reconfigured, balancing the brake pad's stress distribution and reducing damage to the friction pair caused by thermal stress concentration.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the specific implementation methods of the present invention, so that those skilled in the art can more fully understand the present invention, and do not limit the scope of protection of the present invention; ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A dovetail-shaped EMU powder metallurgy brake pad with an asymmetric steel back, comprising a left brake pad and a right brake pad, wherein the left brake pad and the right brake pad are in a left-right asymmetric structure; characterized in that: The left brake pad comprises a left steel back (5), a friction block (4) and a spring buckle (2); the right brake pad comprises a right steel back (1), a friction block (4) and a spring buckle (2); the friction block (4) comprises a back plate (41) and a friction body (42); the friction surface of the friction block (4) is octagonal, and the friction block (4) is restrained from excessive rotation by interlocking and setting a limiting boss (6) on the left steel back (5) and the right steel back (1); a double-conical disc spring (3) is set between each friction block (4) and the left steel back (5) or the right steel back (1); the double-conical disc spring (3) cooperates with the cone (411) of the back plate (41) of the friction block (4).

2. The dovetail-shaped EMU powder metallurgy brake pad with an asymmetric steel back according to claim 1 is characterized in that: The double-conical disc spring (3) is a double-conical structure with gradually thinner surfaces from the outer circle to the inner circle. The double-conical disc spring (3) is installed in the disc spring countersunk hole (7) of the left steel back (5) or the right steel back (1).

3. The dovetail-shaped EMU powder metallurgy brake pad with an asymmetric steel back according to claim 1 or 2, characterized in that: A frustum (411) and a pin (412) are provided at the center of the back plate (41); an annular groove (413) is provided at the top of the pin (412); the inner annular surface (21) of the spring buckle (2) cooperates with the annular groove (413), the outer annular surface (22) of the spring buckle (2) cooperates with the buckle countersunk hole (8) of the left steel back (5) or the right steel back (1), the concave conical surface (31) of the double-conical disc spring (3) cooperates with the frustum (411) of the back plate (41), and the friction block (4) is installed on the left steel back (5) or the right steel back (1).

4. The dovetail-shaped EMU powder metallurgy brake pad with an asymmetric steel back according to claim 1 or 2, characterized in that: Nine friction blocks (4) are installed on the left brake plate, and ten friction blocks (4) are installed on the right brake plate.

5. The dovetail-shaped EMU powder metallurgy brake pad with an asymmetric steel back according to claim 3 is characterized in that: Nine friction blocks (4) are installed on the left brake plate, and ten friction blocks (4) are installed on the right brake plate.

6. The dovetail-shaped EMU powder metallurgy brake pad with an asymmetric steel back according to claim 1 or 2, characterized in that: The left steel back (5) is provided with four position-limiting bosses (6), and the right steel back (1) is provided with five position-limiting bosses (6).

7. The dovetail-shaped EMU powder metallurgy brake pad with an asymmetric steel back according to claim 3 is characterized in that: The left steel back (5) is provided with four position-limiting bosses (6), and the right steel back (1) is provided with five position-limiting bosses (6).

8. The dovetail-shaped EMU powder metallurgy brake pad with an asymmetric steel back according to claim 1 or 2, characterized in that: The friction block (4) is formed by sintering a back plate (41) and a friction body (42) together by powder metallurgy.

9. The dovetail-shaped EMU powder metallurgy brake pad with an asymmetric steel back according to claim 3 is characterized in that: The friction block (4) is formed by sintering a back plate (41) and a friction body (42) together by powder metallurgy.

10. The dovetail-shaped EMU powder metallurgy brake pad with an asymmetric steel back according to claim 1 or 2, characterized in that: The dovetail of the left steel back (5) or the right steel back (1) is integrally cast with the steel back, and the left steel back (5) and the right steel back (1) are in a left-right asymmetrical structure.

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