Dovetail I-B type motor train unit powder metallurgy brake pad

Abstract

A dovetail I-B type motor train unit powder metallurgy brake pad comprises a left brake pad and a right brake pad, and the left brake pad and the right brake pad 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 through interlocking and arrangement of a rotation stopping boss on the steel backing; and a belleville spring is arranged between each friction block and the left steel backing or the right steel backing. The shapes of the friction blocks are optimized and reduced, the number of the friction blocks is increased, the friction blocks are rearranged to be matched with the shape of the steel backing, torque of the inner side and the outer side of the brake pad is balanced, and the phenomena of damage caused by uneven temperature distribution of a brake disc and eccentric wear of the brake pad caused by uneven stress are prevented; the friction blocks are restrained in an interlocking and rotation stopping boss mode, a good chip removal and heat dissipation channel is kept while stress distribution of the brake pad is balanced, and the abnormal abrasion phenomenon of a brake pair due to the fact that the brake pad is mixed with hard particles due to poor chip removal is reduced.

Description

Technical Field

[0001] The utility model relates to a brake piece for an electric train, in particular to a powder metallurgy brake piece for a swallowtail IB type electric train. Background Art

[0002] The brake pads of EMU trains are key actuators in the train's braking system. Braking force is applied to the brake caliper via the brake cylinder and then transferred to the pads. The mutual friction between the brake disc and the pads consumes and absorbs the kinetic energy of the vehicle's motion, allowing the train to stop smoothly. The layout of the brake pad friction blocks has a significant impact on the temperature distribution of the brake disc. The contact and friction between the friction blocks and the brake disc is a process of mutual influence and coupling between the stress field and the temperature field. An unreasonable distribution of friction blocks will form areas of localized stress and high temperature concentration. When the thermal stress exceeds the material strength, thermal fatigue cracks will form on the disc surface and will continue to expand, affecting driving safety. A well-designed friction block layout can effectively reduce brake disc damage caused by uneven temperature distribution and prevent uneven wear of the brake pads caused by uneven braking force.

[0003] In icy and snowy conditions, friction causes the brake pads to melt the ice. Hard particles trapped in the ice then scatter onto the friction surface between the brake disc and brake pad, scratching the friction surface and forming scattered chips. As braking continues, more chips are generated. Under the influence of braking pressure and high temperature, the chips weld together to form large pieces, which can damage the brake disc and brake pad, causing abnormal wear on the friction pair. Utility Model Content

[0004] The technical problem to be solved by the present invention is to overcome the above-mentioned deficiencies of the prior art and provide a powder metallurgy brake pad for a swallowtail IB type EMU which can effectively reduce the risk of abnormal wear failure of the friction pair.

[0005] The technical solution adopted by the utility model to solve its technical problems is: a dovetail IB type EMU powder metallurgy brake pad, including a left brake pad and a right brake pad, the left brake pad and the right brake pad are in a left-right asymmetric structure; the left brake pad includes a left steel back, a friction block and a spring clip; the right brake pad includes a right steel back, a friction block and a spring clip; the friction surface of the friction block is octagonal, and the friction block restrains excessive rotation of the friction block by interlocking and arranging anti-rotation bosses on the left steel back and the right steel back; a disc spring is arranged between each friction block and the left steel back or the right steel back.

[0006] Furthermore, the disc spring is installed in the disc spring countersunk hole of the left steel back or the right steel back.

[0007] Furthermore, the friction block includes a back plate and a friction body; a convex spherical surface and a pin shaft are provided at the center of the back plate; an annular groove is provided on the top of the pin shaft; 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, and the convex spherical surface cooperates with the inner hole of the disc spring, so that the friction block is installed on the left steel back or the right steel back.

[0008] Furthermore, when the friction blocks are constrained by interlocking, the gap between the friction blocks is 1 mm; when the friction blocks are constrained by the anti-rotation bosses, the gap between the friction blocks is 5-20 mm.

[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, five anti-rotation bosses are provided on the left steel back, and six anti-rotation 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] The structure of the utility model forms an effective chip removal and heat dissipation channel by increasing the gap between the friction blocks, so that ice, snow and grinding chips are discharged smoothly, avoiding the accumulation of grinding materials and metal embedding, and reducing the risk of abnormal wear and failure of the friction pair.

[0014] Compared with the prior art, the present invention has the following beneficial effects: (1) the friction blocks are rearranged to match the shape of the steel back, balancing the torque of the inner and outer sides of the brake pad perpendicular to the brake disc, preventing damage to the brake disc caused by uneven temperature distribution and eccentric wear of the brake pad caused by uneven force; (2) the brake pad friction blocks of the present invention use an interlocking and anti-rotation boss method to restrain their excessive rotation, balancing the stress distribution of the brake pad while maintaining a good chip removal and heat dissipation channel, reducing abnormal wear of the brake pair caused by the inclusion of hard particles in the brake pad due to poor chip removal; (3) the preferred solution, by optimizing and reducing the shape of the friction blocks and increasing the number of friction blocks, adjusting the gap between the friction blocks, further preventing damage to the brake disc caused by uneven temperature distribution and eccentric wear of the brake pad caused by uneven force, and extending the service life of the brake pad. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the structure of the powder metallurgy brake pads of the Swallowtail IB type EMU of the present invention;

[0016] Figure 2 for Figure 1 The front structural diagram of the steel back of Example 1 of the present utility model is shown;

[0017] Figure 3 for Figure 1 The reverse side structural diagram of the steel back of Example 1 of the present utility model is shown;

[0018] Figure 4 for Figure 1 The schematic diagram of the friction block structure of Example 1 of the present utility model is shown;

[0019] Figure 5 for Figure 1 The schematic diagram of the spring buckle structure of Example 1 of the present utility model is shown;

[0020] Figure 6 for Figure 1 The disc spring structure diagram of Example 1 of the present utility model is shown;

[0021] Figure 7 for Figure 1 A partial cross-sectional view of Example 1 of the present utility model is shown;

[0022] Figure 8 This is a schematic diagram of the moment when the powder metallurgy brake pad of the swallowtail IB type EMU is subjected to force;

[0023] Figure 9 The figure is a schematic diagram of the torque of a powder metallurgy brake pad in the prior art when subjected to force. DETAILED DESCRIPTION

[0024] 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.

[0025] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0026] Example 1

[0027] Refer to the attached Figure 1-8In this embodiment, a powder metallurgy brake pad for a dovetail IB-type EMU includes a left brake pad and a right brake pad, and the left brake pad and the right brake pad have a left-right asymmetric structure; the left brake pad includes a left steel back 5, a friction block 4 and a spring buckle 2; the right brake pad includes a right steel back 1, a friction block 4 and a spring buckle 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 rotation-stop boss 6 on the left steel back 5 and the right steel back 1; a disc spring 3 is provided between each friction block 4 and the left steel back 5 or the right steel back 1.

[0028] The disc spring 3 is installed in the disc spring countersunk hole 7 of the left steel back 5 or the right steel back 1.

[0029] The friction block 4 includes a back plate 41 and a friction body 42; a convex spherical surface 411 and a pin shaft 412 are provided at the center of the back plate 41; an annular groove 413 is provided on the top of the pin shaft 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, and the convex spherical surface 411 cooperates with the inner hole 31 of the disc spring 3, so that the friction block 4 is installed on the left steel back 5 or the right steel back 1.

[0030] When the friction blocks 4 are constrained by interlocking, the gap between the friction blocks 4 is 1 mm; when the friction blocks 4 are constrained by the anti-rotation boss 6, the gap between the friction blocks 4 is 12 mm.

[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 five anti-rotation bosses 6 , and the right steel back 1 is provided with six anti-rotation 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] Due to standardization, the existing brake pads use a regular hexagonal friction block with a heat dissipation hole in the center and an asymmetrical steel back design. There are 8 friction blocks on the left brake pad and 9 friction blocks on the right brake pad. Figure 9To ensure that the brake pad does not experience eccentric wear, the torques perpendicular to the brake disc inside and outside the brake pad's force centerline must be equal. Because the brake pad has only one friction block, the calculation can be simplified to make the distances between the center of mass of the inner and outer friction blocks of the brake pad's force centerline equal, that is, 2*(T1+T2+T3+T4+T5)=2*(B1+B2+B3)+B4. However, due to the limitations of the friction block shape in the existing brake pad arrangement, the outer torque is significantly smaller than the inner torque, and eccentric wear occurs in actual applications.

[0036] In this embodiment, there are 9 friction blocks 4 on the left brake plate and 10 friction blocks 4 on the right brake plate. Figure 8 The friction block 4 adopts an irregular octagonal shape, and the torque perpendicular to the brake disc inside and outside the force centerline is basically balanced, that is, 2*(L1+L2+L3+L4)=2*(C1+C2+C3+C4+C5)+C6, which can effectively prevent the brake pad from wearing unevenly due to uneven force.

[0037] This embodiment optimizes and reduces the shape of the friction block 4 and increases the number of friction blocks 4, rearranges the friction blocks to match the shape of the steel back, balances the torque of the inner and outer sides of the brake pad perpendicular to the brake disc, prevents damage to the brake disc due to uneven temperature distribution and eccentric wear of the brake pad due to uneven force; the brake pad friction block 4 of this embodiment uses an interlocking and anti-rotation boss to restrain its excessive rotation, balances the stress distribution of the brake pad while maintaining a good chip removal and heat dissipation channel, and reduces abnormal wear of the brake pair caused by poor chip removal and inclusion of hard particles in the brake pad.

[0038] Example 2

[0039] The only difference between this embodiment and embodiment 1 is that when the friction blocks 4 are constrained by the anti-rotation bosses 6 , the gap between the friction blocks 4 is 20 mm.

[0040] The rest is the same as in Example 1.

[0041] Example 3

[0042] The only difference between this embodiment and embodiment 1 is that when the friction blocks 4 are constrained by the anti-rotation bosses 6 , the gap between the friction blocks 4 is 5 mm.

[0043] The rest is the same as Example 1.

[0044] Finally, it should be noted that: the above embodiments are only to illustrate the specific embodiments of the present application, to facilitate those skilled in the art to more fully understand the present application, rather than limit the scope of the present application; those skilled in the art should understand that: it can still be modified to the technical solutions recorded in the foregoing embodiments, or part or all of the technical features are replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A powder metallurgy brake pad for a swallowtail IB type EMU, 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 surface of the friction block (4) is octagonal, and the friction block (4) is restrained from excessive rotation by interlocking and providing a rotation-stop boss (6) on the left steel back (5) and the right steel back (1); a disc spring (3) is provided between each friction block (4) and the left steel back (5) or the right steel back (1).

2. The powder metallurgy brake pad for swallowtail IB type EMU according to claim 1, characterized in that: The 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 powder metallurgy brake pad for swallowtail IB type EMU according to claim 1 or 2, characterized in that: The friction block (4) includes a back plate (41) and a friction body (42); a convex spherical surface (411) and a pin shaft (412) are provided at the center of the back plate (41); an annular groove (413) is provided on the top of the pin shaft (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), and the convex spherical surface (411) cooperates with the inner hole (31) of the disc spring (3), so that the friction block (4) is installed on the left steel back (5) or the right steel back (1).

4. The powder metallurgy brake pad for swallowtail IB type EMU according to claim 1 or 2, characterized in that: When the friction blocks (4) are constrained by interlocking, the gap between the friction blocks (4) is 1 mm; when the friction blocks (4) are constrained by the anti-rotation boss (6), the gap between the friction blocks (4) is 5-20 mm.

5. The powder metallurgy brake pad for the swallowtail IB type EMU according to claim 3, characterized in that: When the friction blocks (4) are constrained by interlocking, the gap between the friction blocks (4) is 1 mm; when the friction blocks (4) are constrained by the anti-rotation boss (6), the gap between the friction blocks (4) is 5-20 mm.

6. The powder metallurgy brake pad for swallowtail IB type EMU 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.

7. The powder metallurgy brake pad for swallowtail IB type EMU according to claim 1 or 2, characterized in that: The left steel back (5) is provided with five anti-rotation bosses (6), and the right steel back (1) is provided with six anti-rotation bosses (6).

8. The powder metallurgy brake pad for swallowtail IB type EMU according to claim 3, characterized in that: The left steel back (5) is provided with five anti-rotation bosses (6), and the right steel back (1) is provided with six anti-rotation bosses (6).

9. The powder metallurgy brake pad for swallowtail IB type EMU 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.

10. The powder metallurgy brake pad for swallowtail IB type EMU 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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