Dovetail-shaped powder metallurgy brake pad for motor train unit

Abstract

A dovetail type motor train unit powder metallurgy brake pad comprises a left brake pad body and a right brake pad body which are of a bilateral symmetry structure, and the left brake pad body and the right brake pad body each comprise a left steel backing, a right steel backing, a friction block and a spring buckle. The friction blocks are radially distributed on the left steel backing and the right steel backing in a fan shape respectively; four friction areas are distributed on each of the left brake pad and the right brake pad; a chip removal and heat dissipation channel is formed between the friction areas; the friction area is composed of a friction block and a limiting boss. Through the optimal design of the shape and arrangement of the friction bodies and the position, size and shape of the limiting bosses, a chip removal channel of the brake pad is smoother, and therefore the stability of the friction performance of a motor train unit in the braking process is improved.

Description

Technical Field

[0001] The utility model relates to a brake pad for a multiple unit train, in particular to a dovetail-shaped powder metallurgy brake pad for a multiple unit train. Background Art

[0002] For existing brake pads of high-speed trains with a dovetail structure, disc springs are mostly used as buffer and shock-absorbing adjustment elements between the steel back and the friction block. During the braking process, the friction body will rotate, affecting the braking effect. Therefore, relevant professional technicians adopt the design of mutual self-locking between the limit boss and the friction body to prevent excessive rotation of the friction body during the braking process. In the prior art, due to unreasonable designs in the shape, size and arrangement of the friction body as well as the position, size and height of the limit boss, the chip removal channel is not smooth, resulting in unstable friction performance, uneven temperature field distribution in actual use conditions, and friction chips accumulating in the gap between the friction body and the steel back, leading to the failure of the disc spring or the friction chips being sandwiched between the brake disc and the friction body, causing abnormal wear. Summary of the Utility Model

[0003] The technical problem to be solved by the utility model is to overcome the above-mentioned deficiencies of the prior art and provide a dovetail-shaped powder metallurgy brake pad for a multiple unit train that makes the chip removal channel smoother, thereby increasing the stability of friction performance during the braking process.

[0004] The technical solution adopted by the utility model to solve its technical problem is: a dovetail-shaped powder metallurgy brake pad for a multiple unit train, including a left brake pad and a right brake pad, the left brake pad and the right brake pad are in a left-right symmetrical structure; the left brake pad includes a left steel back, a friction block and a spring buckle; the right brake pad includes a right steel back, a friction block and a spring buckle; the friction blocks are radially distributed in a fan shape on the left steel back and the right steel back respectively; 4 friction areas are distributed on each of the left brake pad and the right brake pad; chip removal and heat dissipation channels are formed between the friction areas; the friction area is composed of the friction block and a limit boss.

[0005] Further, the friction block includes a back plate and a friction body; a pin shaft is arranged at the center of the back plate; an annular groove is arranged at the top of the pin shaft; the inner ring surface of the spring buckle is matched with the annular groove, and the outer ring surface of the spring buckle is matched with the counterbore of the left steel back or the right steel back to install the friction block on the left steel back or the right steel back; an elastic element is arranged between each friction block and the left steel back or the right steel back.

[0006] Further, the elastic element is a disc spring, and a spherical surface is arranged on the back plate to cooperate with the disc spring.

[0007] Further, the elastic element is a double-cone disc spring, and a conical platform is arranged on the back plate to cooperate with the double-cone disc spring.

[0008] Furthermore, a total of seven radial chip removal and heat dissipation channels are formed between the friction areas, and the width of the chip removal and heat dissipation channels is 3-16 mm.

[0009] Furthermore, the friction areas are respectively friction areas A-H; the friction area A is located on the left side of the center line of the brake pad and includes three of the friction blocks; the friction area B includes three of the friction blocks and a first limiting boss; the friction area C includes two of the friction blocks, a second limiting boss and a third limiting boss; the friction area D includes one of the friction blocks and a fourth limiting boss; the friction area E is located on the right side of the center line of the brake pad and includes three of the friction blocks; the friction area F includes three of the friction blocks and a fifth limiting boss; the friction area G includes two of the friction blocks, a sixth limiting boss and a seventh limiting boss; the friction area H includes one of the friction blocks and an eighth limiting boss.

[0010] Furthermore, the chip removal and heat dissipation channels are channels I-VII; the channel I is located between the friction area D and the friction area C, the channel II is located between the friction area C and the friction area B, the channel III is located between the friction area B and the friction area A, the channel IV is located between the friction area A and the friction area E; the channel V is located between the friction area E and the friction area F, the channel VI is located between the friction area F and the friction area G, and the channel VII is located between the friction area G and the friction area H.

[0011] Furthermore, the first limiting boss provides limiting constraints for two of the friction blocks within the friction area B at the same time; the second limiting boss, the third limiting boss and the fourth limiting boss are all located in the long side direction of the friction block they limit.

[0012] Furthermore, the fifth limiting boss provides limiting constraints for two of the friction blocks within the friction area F at the same time; the sixth limiting boss, the seventh limiting boss and the eighth limiting boss are all located in the long side direction of the friction block they limit.

[0013] Furthermore, the interval between the limiting bosses is 12-55 mm.

[0014] Furthermore, the friction surface of the friction block is a rectangular shape with chamfers at four corners.

[0015] Compared with the prior art, the utility model has the following beneficial effects:

[0016] (1) Through calculation and comparative analysis, the structure of the present utility model balances the moments perpendicular to the brake disc on both sides of the pressure rod of the brake caliper, optimizes the shape and arrangement of the friction blocks, divides the friction blocks into 8 friction areas, and distributes them in a fan-shaped radial form on the steel back to form a radial chip removal and heat dissipation channel with a channel width of 3-16 mm; by increasing the gap between the friction areas, a good chip removal and heat dissipation channel is formed, effectively improving the temperature uniformity of the brake disc, reducing the thermal stress of the brake disc, and increasing the effective service life of the brake pad;

[0017] (2) Elastic elements are arranged between the friction blocks and the steel back of the brake pad of the present utility model, and the elastic elements are disc springs or double-cone disc springs; when the elastic element is a disc spring, a spherical surface is used on the back plate for cooperation; when the elastic element is a double-cone disc spring, a truncated cone is used on the back plate for cooperation; adding elastic elements between the brake pad friction blocks and the steel back can effectively absorb the instantaneous impact caused by the brake caliper on the brake pad structural parts, reduce the risk of material fatigue fracture caused by long-term high-frequency braking, and eliminate the assembly error of each friction block on the brake pad, making the brake pad friction block fit the brake disc and improving the braking efficiency. The cooperation of a spherical surface with a disc spring or a truncated cone with a double-cone disc spring enables the friction block to have a proper yaw function, and under the action of the centrifugal force of the brake disc, the mixture of ice and snow and abrasive debris is smoothly discharged along the radial channel of the brake pad, avoiding problems such as metal inlay of the brake pad, abnormal wear, brake disc damage, and large fluctuations in the friction coefficient under ice and snow weather conditions;

[0018] (3) In a preferred embodiment, the number of radial chip removal and heat dissipation channels is set to 7, and the width of each channel is 3-16 mm, further improving the temperature uniformity of the brake disc, reducing the thermal stress of the brake disc, and increasing the effective service life of the brake pad;

[0019] (4) The present utility model is provided with limit bosses for preventing excessive rotation of the friction blocks in some friction areas, and the distance between the bosses is 12-55 mm. Larger-diameter cutting tools can be used during processing, which can effectively reduce the mechanical processing time and reduce the manufacturing cost of the brake pad. Description of the Drawings

[0020] Figure 1 is a front structural schematic diagram of the dovetail-type EMU powder metallurgy brake pad of the present utility model;

[0021] Figure 2 is a K-K sectional structural schematic diagram of Embodiment 1 of the present utility model;

[0022] Figure 3 is Figure 2 the structural schematic diagram of the friction block of Embodiment 1 of the present utility model shown;

[0023] Figure 4Schematic diagram of the K-K sectional structure of Embodiment 2 of the present utility model;

[0024] Figure 5 is Figure 4 Schematic diagram of the friction block structure of Embodiment 2 of the present utility model as shown;

[0025] Figure 6 is Figure 1 Schematic diagram of the steel back structure of the dovetail-type powder metallurgy brake pad for EMUs of the present utility model as shown;

[0026] Figure 7 is Figure 1 Schematic diagram of the spring buckle structure of the dovetail-type powder metallurgy brake pad for EMUs of the present utility model as shown. Detailed implementation manners

[0027] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by terms such as "center", "upper", "lower", "left", "right", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model.

[0028] The present utility model will be further described in detail below with reference to the drawings and embodiments.

[0029] Embodiment 1

[0030] Referring to Figs. Figure 1-3 , 6, and 7, a dovetail-type powder metallurgy brake pad for EMUs in this embodiment includes a left brake pad and a right brake pad, and the left brake pad and the right brake pad have a left-right symmetric structure; the left brake pad includes a left steel back 1, a friction block 3, and a spring buckle 6; the right brake pad includes a right steel back 2, a friction block 3, and a spring buckle 6; the friction blocks 3 are radially distributed in a fan shape on the left steel back 1 and the right steel back 2 respectively; 4 friction areas are distributed on each of the left brake pad and the right brake pad; chip removal and heat dissipation channels are formed between the friction areas; the friction areas are composed of the friction blocks 3 and the limit bosses.

[0031] The friction block 3 includes a back plate 31 and a friction body 32; a pin shaft 311 is provided at the center of the back plate 31; an annular groove 312 is provided at the top of the pin shaft 311; the inner ring surface 61 of the spring buckle 6 cooperates with the annular groove 312, and the outer ring surface 62 of the spring buckle 6 cooperates with the counterbore 16 of the left steel back 1 or the right steel back 2 to install the friction block 3 on the left steel back 1 or the right steel back 2; an elastic element is provided between each friction block 3 and the left steel back 1 or the right steel back 2.

[0032] The elastic element is a disc spring 4, and the disc spring 4 is installed in the disc spring counterbore 15 of the left steel back 1 or the right steel back 2. The inner diameter hole of the disc spring 4 is matched with the spherical surface 313 provided on the back plate 3.

[0033] A total of 7 radial chip removal and heat dissipation channels are formed between the friction areas, and the average width of the chip removal and heat dissipation channels is 10 mm.

[0034] The friction areas are respectively friction areas A - H; the friction area A20 is located on the left side of the brake pad center line and includes three of the friction blocks 3, and interlocking is achieved within the area; the friction area B21 includes three of the friction blocks 3 and a first limiting boss 11. An interlocking relationship is formed between the two lower friction blocks 3. The upper friction block 3 is offset towards the center to adapt to the shape of the left steel back 1. To prevent its excessive rotation, a first limiting boss 11 is added to limit it, and at the same time, the middle friction block 3 is limited; the friction area C22 includes two of the friction blocks 3, a second limiting boss 12 and a third limiting boss 13, and both the second limiting boss 12 and the third limiting boss 13 are located in the long side direction of the limited friction block 3; the friction area D23 includes one of the friction blocks 3 and a fourth limiting boss 14, and the fourth limiting boss 14 is located in the long side direction of the friction block; the friction area E24 is located on the right side of the brake pad center line and includes three of the friction blocks 3, and interlocking is achieved within the area; the friction area F25 includes three of the friction blocks 3 and a fifth limiting boss 71. An interlocking relationship is formed between the two lower friction blocks 3. The upper friction block 3 is offset towards the center to adapt to the shape of the right steel back 2. To prevent its excessive rotation, a fifth limiting boss 71 is added to limit it, and at the same time, the middle friction block 3 is limited; the friction area G26 includes two of the friction blocks 3, a sixth limiting boss 72 and a seventh limiting boss 73, and both the sixth limiting boss 72 and the seventh limiting boss 73 are located in the long side direction of the limited friction block 3; the friction area H27 includes one of the friction blocks 3 and an eighth limiting boss 74, and the eighth limiting boss 74 is located in the long side direction of the friction block.

[0035] The chip removal and heat dissipation channels are channels I - VII; the channel I is located between the friction area D23 and the friction area C22, the channel II is located between the friction area C22 and the friction area B21, the channel III is located between the friction area B21 and the friction area A20, the channel IV is located between the friction area A20 and the friction area E24; the channel V is located between the friction area E24 and the friction area F25, the channel VI is located between the friction area F25 and the friction area G26, and the channel VII is located between the friction area G26 and the friction area H27.

[0036] The average spacing between the limiting bosses is 35 mm. The friction surface of the friction block 3 is a rectangular shape with chamfers at four corners.

[0037] In this embodiment, the disc spring 4 of the brake pad structure cooperates with the spherical surface 313 on the back plate 31 to form an elastic floating structure, which can realize the self-adaptive adjustment of the friction block 3, make the friction block 3 fit the brake disc surface, and improve the braking efficiency. The disc spring 4 is an elastic element, which can effectively absorb the instantaneous impact of the caliper on the brake pad structure during braking, reduce the risk of material fatigue fracture caused by long-term high-frequency braking, and at the same time eliminate the machining errors generated during the assembly of the brake pad, so that the friction block 3 fits the brake disc.

[0038] The relatively large width of the chip removal and heat dissipation channel in this embodiment of the brake pad structure increases the gap between the friction areas, forms a good chip removal and heat dissipation channel, effectively improves the temperature uniformity of the brake disc, reduces the thermal stress of the brake disc, and improves the effective service life of the brake pad.

[0039] The steel back is an integral metal structure formed by machining after casting. There are 8 limiting bosses on each steel back, and the average spacing between the bosses is 35 mm. When machining, larger diameter tools can be used, reducing the machining time and the manufacturing cost of the brake pad.

[0040] Embodiment 2

[0041] The difference between this embodiment and Embodiment 1 is only that the average width of the chip removal and heat dissipation channel is 16 mm; the average spacing between the limiting bosses is 12 mm.

[0042] The rest is the same as Embodiment 1.

[0043] Embodiment 3

[0044] The difference between this embodiment and Embodiment 1 is only that the average width of the chip removal and heat dissipation channel is 3 mm; the average spacing between the limiting bosses is 55 mm.

[0045] The rest is the same as Embodiment 1.

[0046] Embodiment 4

[0047] Refer to Figure 1 、 4 -7, the difference between this embodiment and Embodiment 1 is only that the elastic element is a double-cone disc spring 5, and a conical platform 314 is provided on the back plate 31, which cooperates with the double-cone disc spring 5 to form an elastic floating structure. The surface-to-surface contact can keep the double-cone disc spring 5 absorb the impact of the caliper on the brake pad structure during braking, and at the same time avoid the risk of scratching the back plate by the sharp edge of the disc spring 4, so that the friction block 3 always fits the brake disc surface, ensuring the effective friction area of the brake pad and improving the braking efficiency.

[0048] The rest is the same as in Embodiment 1.

[0049] Embodiment 5

[0050] The difference between this embodiment and Embodiment 1 is that the average width of the chip removal and heat dissipation channel is 16 mm; the average interval between the limiting bosses is 12 mm. The elastic element is a double-cone disc spring 5. A conical platform 314 is provided on the back plate 31, which cooperates with the double-cone disc spring 5 to form an elastic floating structure. The surface-to-surface contact can keep the double-cone disc spring 5 absorb the impact caused by the clamp on the brake pad structure during braking, and at the same time can avoid the risk of the sharp edge of the disc spring 4 scratching the back plate, so that the friction block 3 always fits the brake disc surface, ensuring the effective friction area of the brake pad and improving the braking efficiency.

[0051] The rest is the same as in Embodiment 1.

[0052] Embodiment 6

[0053] The difference between this embodiment and Embodiment 1 is that the average width of the chip removal and heat dissipation channel is 3 mm; the average interval between the limiting bosses is 55 mm. The elastic element is a double-cone disc spring 5. A conical platform 314 is provided on the back plate 31, which cooperates with the double-cone disc spring 5 to form an elastic floating structure. The surface-to-surface contact can keep the double-cone disc spring 5 absorb the impact caused by the clamp on the brake pad structure during braking, and at the same time can avoid the risk of the sharp edge of the disc spring 4 scratching the back plate, so that the friction block 3 always fits the brake disc surface, ensuring the effective friction area of the brake pad and improving the braking efficiency.

[0054] The rest is the same as in Embodiment 1.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the specific implementation manners of the present invention, so as to enable those skilled in the art to better understand the present invention, rather than limiting the protection scope of the present invention; those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; 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 invention.

Claims

1. A dovetail-type powder metallurgy brake pad for EMU, comprising a left brake pad and a right brake pad, wherein the left brake pad and the right brake pad are symmetrically structured left and right; characterized in that, The left brake pad includes a left steel back (1), a friction block (3), and a spring buckle (6); the right brake pad includes a right steel back (2), a friction block (3), and a spring buckle (6); the friction blocks (3) are radially distributed in a fan shape on the left steel back (1) and the right steel back (2) respectively; there are 4 friction areas distributed on each of the left brake pad and the right brake pad; chip removal and heat dissipation channels are formed between the friction areas; the friction area is composed of the friction block (3) and a limit boss.

2. The dovetail-type powder metallurgy brake pads for EMUs according to claim 1, characterized in that The friction block (3) includes a back plate (31) and a friction body (32); a pin shaft (311) is arranged at the center of the back plate (31); an annular groove (312) is arranged at the top of the pin shaft (311); the inner ring surface (61) of the spring buckle (6) cooperates with the annular groove (312), and the outer ring surface (62) of the spring buckle (6) cooperates with a counterbore (16) of the left steel back (1) or the right steel back (2) to mount the friction block (3) on the left steel back (1) or the right steel back (2); an elastic element is arranged between each friction block (3) and the left steel back (1) or the right steel back (2).

3. The dovetail-shaped powder metallurgy brake pads for EMUs according to claim 2, characterized in that, The elastic element is a disc spring (4), and a spherical surface (313) is arranged on the back plate (31) to cooperate with the disc spring (4).

4. The dovetail-type powder metallurgy brake pads for EMUs according to claim 2, characterized in that, The elastic element is a double-cone disc spring (5), and a conical frustum (314) is arranged on the back plate (31) to cooperate with the double-cone disc spring (5).

5. The dovetail-type powder metallurgy brake pads for EMUs according to any one of claims 1-4, characterized in that, A total of 7 radial chip removal and heat dissipation channels are formed between the friction areas, and the width of the chip removal and heat dissipation channels is 3 - 16 mm.

6. The dovetail-type powder metallurgy brake pads for EMUs according to any one of claims 1-4, characterized in that, The friction areas are respectively a friction area A (20), a friction area B (21), a friction area C (22), a friction area D (23), a friction area E (24), a friction area F (25), a friction area G (26), and a friction area H (27); the friction area A (20) is located on the left side of the brake pad center line and includes three friction blocks (3); the friction area B (21) includes three friction blocks (3) and a limit boss one (11); the friction area C (22) includes two friction blocks (3), a limit boss two (12), and a limit boss three (13); the friction area D (23) includes one friction block (3) and a limit boss four (14); the friction area E (24) is located on the right side of the brake pad center line and includes three friction blocks (3); the friction area F (25) includes three friction blocks (3) and a limit boss five (71); the friction area G (26) includes two friction blocks (3), a limit boss six (72), and a limit boss seven (73); the friction area H (27) includes one friction block (3) and a limit boss eight (74).

7. The dovetail-type powder metallurgy brake pads for EMUs according to claim 6, characterized in that, The chip removal and heat dissipation channels are channels I - VII; the channel I is located between the friction area D (23) and the friction area C (22), the channel II is located between the friction area C (22) and the friction area B (21), the channel III is located between the friction area B (21) and the friction area A (20), the channel IV is located between the friction area A (20) and the friction area E (24); the channel V is located between the friction area E (24) and the friction area F (25), the channel VI is located between the friction area F (25) and the friction area G (26), and the channel VII is located between the friction area G (26) and the friction area H (27).

8. The dovetail-shaped powder metallurgy brake pads for EMUs according to claim 6, characterized in that, The first limiting boss (11) provides limiting constraints for the two friction blocks (3) within the friction area B (21) simultaneously; the second limiting boss (12), the third limiting boss (13), and the fourth limiting boss (14) are all located in the long side direction of the friction block (3) they limit.

9. The dovetail-type powder metallurgy brake pads for EMUs according to claim 6, characterized in that, The fifth limiting boss (71) provides limiting constraints for the two friction blocks (3) within the friction area F (25) simultaneously; the sixth limiting boss (72), the seventh limiting boss (73), and the eighth limiting boss (74) are all located in the long side direction of the friction block (3) they limit.

10. The dovetail-shaped powder metallurgy brake pads for EMUs according to claim 1, characterized in that The distance between the limiting bosses is 12 - 55 mm.

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