High-speed train brake pad and manufacturing method thereof

Abstract

The invention provides a high-speed train brake pad and a manufacturing method thereof.The high-speed train brake pad comprises two brake back plates (1) and (2) which are arranged in a bilateral symmetry mode, and at least three rows of brake pads (I), (II) and (III) which are arranged in an arc shape are arranged on the surfaces of the brake back plates from inside to outside; the friction areas of the at least three rows of brake blocks are arranged according to the radius or diameter of the area where the brake blocks are located. The invention provides a high-speed train brake pad and a manufacturing method thereof, and provides a novel rail train brake pad which adopts a radial equal-difference surface-diameter ratio design, solves the problem of radial eccentric wear of the brake pad, is uniform and consistent in wear, large in heat dissipation area, easy to adjust and small in temperature rise, and cannot rotate when the brake pad works. The brake efficiency is high, the brake is stable, and the service life of the brake pad is prolonged.

Description

Technical Field

[0001] The invention relates to a radial equal wear ratio spherical surface direct connection self-lubricating powder metallurgy brake pad and a manufacturing method thereof, belonging to the technical field of rail transit train brake pads. Background Art

[0002] At present, disc brakes have been widely used in rail trains, high-speed trains, and light and heavy vehicles due to their compact structure, smooth braking, high braking power, safety and reliability. However, as train speeds increase, the requirements for brake pads are also increasing, and the brake pad structure design of the brake has also shown some shortcomings, and the design needs to be continuously improved to meet the growing train braking needs.

[0003] The main components of the brake are the brake disc and brake pad. Under the action of the braking force, the brake pad tightly presses the brake disc, generating friction in the opposite direction of the movement of the brake disc, thereby stopping the movement of the brake disc. The brake friction surface of the brake disc is a semi-circular shape with a width of about 130mm. When the train brakes, due to the different sizes of the inner and outer diameters, the linear speed is also different, resulting in different friction distances, and therefore different wear on the brake pad. The change in the friction area of ​​the brake pad along the radial direction must be reasonably controlled, otherwise it will cause eccentric wear of the brake pad, that is, the wear increases from the inside to the outside, resulting in gradient wear of the brake pad and accelerated wear, reducing the service life of the brake pad.

[0004] The traditional components of brake pads are composed of a back plate, a support bracket, a special-shaped disc spring, a brake block and a fixed retaining spring. The more components there are, the greater the size error will be, and the performance will also be difficult to ensure. For example, the difference in elasticity between the special-shaped disc spring and the support seat will cause each brake block to be subjected to different forces, friction and wear, which will cause a loss of braking efficiency, uneven braking, increased wear of the brake pad, and affect the service life of the brake pad. In the brake pad, the brake block is in spherical contact with the special-shaped disc spring or the support seat, which is used to adjust the brake block to be completely fitted with the brake disc. However, when braking, the brake pad is in motion, and the spherical contact between the two will also cause wear, which will affect the fit adjustment effect. The friction heat generated between the two will also increase the wear of the brake block.

[0005] At the same time, in order to improve the braking effect of the brake pad, the friction area is usually increased as much as possible in the design. However, when the brake pad and the brake disc are working, a large amount of friction heat is instantly generated, which causes the temperature of the brake pad itself to rise suddenly. The maximum temperature can reach over 500°C, which causes the physical properties of the brake pad to decay rapidly, increases wear, reduces the friction coefficient, and affects the braking effect. Therefore, the heat needs to be dissipated quickly to slow down the temperature rise of the brake pad. This requires increasing the heat dissipation area and airflow channel of the brake pad as much as possible, and taking away the heat of the brake pad through fast-flowing air to ensure the stability of the physical properties of the brake pad.

[0006] In the brake pad, whether the brake pad is connected to the spherical surface of the special-shaped spring or the brake pad is connected to the spherical surface of the support seat, when the brake pad is braking, the friction forces on the upper and lower edges of the brake pad are in the same direction but different in magnitude, that is, the friction torque of the upper edge is greater than the friction torque of the lower edge. Therefore, each brake pad is subjected to a torque in the opposite direction of the rotation of the brake disc. When this torque is greater than the reverse resistance torque of the brake pad due to fixation and friction, the brake pad may rotate, which will affect the stability of the train braking and increase the wear of the brake pad. At the same time, since the connection between the brake pad and the back plate is fixed by a retaining spring, the rotation of the brake pad is prone to the retaining spring falling off and failure, and the brake pad and the back plate fall off, which will cause serious traffic safety accidents. Summary of the invention

[0007] In view of the defects and shortcomings of the existing technology, the embodiment of the present invention proposes a radial equal wear ratio spherical direct connection self-lubricating powder metallurgy brake pad with better braking effect and a manufacturing method thereof. The technical solution is as follows: The present invention provides a high-speed train brake pad, comprising two brake back plates (1) and (2) arranged symmetrically on both sides, wherein at least three rows of brake blocks (I), (II) and (III) arranged in an arc shape are arranged on the surface of the brake back plates from the inside to the outside, and the friction areas of the at least three rows of brake blocks are arranged in equal proportion to the radius or diameter of the area where they are located.

[0008] As a preferred embodiment of the above technical solution, the brake back plate and the brake block are connected by a spherical surface.

[0009] As a preferred embodiment of the above technical solution, the brake back plate is provided with a concave spherical surface (5), the brake block has a convex spherical surface (7), a polygonal hole (6) is provided in the concave spherical surface, a clip (10) is provided at the bottom of the polygonal hole (6), a polygonal column (9) is provided on the convex spherical surface, and a clamping groove (11) is provided at the bottom of the polygonal column (9), when the polygonal column is accommodated in the polygonal hole, the convex spherical surface (7) is in contact with the concave spherical surface (5) and the clamping groove (11) is clamped with the clip (10), so as to realize the assembly of the brake block and the brake back plate.

[0010] As a preferred embodiment of the above technical solution, a lubricant groove (8) is arranged on the concave spherical surface (5) or the convex spherical surface (7), and grease is filled into the lubricant groove (8) during assembly.

[0011] As a preferred embodiment of the above technical solution, the brake blocks on each brake back plate are composed of triangular brake blocks (4) and circular or quadrilateral to dodecagonal brake blocks (3), wherein the triangular brake blocks are arranged in the two side areas, and the circular or quadrilateral to dodecagonal brake blocks are arranged in the middle area.

[0012] A method for manufacturing a high-speed train brake pad comprises the following process steps: 1) Two brake back plates (1) and (2) are symmetrically arranged; 2) At least three rows of arc-shaped brake blocks (I), (II), and (III) are arranged on the surface of the brake back plate from the inside to the outside, and the friction areas of the at least three rows of brake blocks are arranged in equal proportion to the radius or diameter of the area where they are located.

[0013] As a preferred embodiment of the above technical solution, the brake back plate and the brake block are connected by a spherical surface.

[0014] As a preferred embodiment of the above technical solution, the brake back plate is provided with a concave spherical surface (5), the brake block has a convex spherical surface (7), a polygonal hole (6) is provided in the concave spherical surface, a clip (10) is provided at the bottom of the polygonal hole (6), a polygonal column (9) is provided on the convex spherical surface, and a clamping groove (11) is provided at the bottom of the polygonal column (9), when the polygonal column is accommodated in the polygonal hole, the convex spherical surface (7) is in contact with the concave spherical surface (5) and the clamping groove (11) is clamped with the clip (10), so as to realize the assembly of the brake block and the brake back plate.

[0015] As a preferred embodiment of the above technical solution, a lubricant groove (8) is arranged on the convex spherical surface (7), and grease is filled into the lubricant groove (8) during assembly.

[0016] As a preferred embodiment of the above technical solution, the brake blocks on each brake back plate are composed of triangular brake blocks (4) and circular or quadrilateral to dodecagonal brake blocks (3), wherein the triangular brake blocks are arranged in the two side areas, and the circular or quadrilateral to dodecagonal brake blocks are arranged in the middle area.

[0017] In order to solve the problem of radial eccentric wear of brake pads, the present invention provides a radial equidistant surface ratio design, so that the wear of the friction area in each region is more consistent, and gradient wear and eccentric wear will not occur. At the same time, the present invention adopts direct spherical contact between the brake block and the back plate, so that the maximum height wear deviation of the brake block at the same transverse position on the same brake pad is 0.2mm. In addition to increasing the grease groove, the spherical contact between the brake block and the back plate reduces the wear and temperature rise between the two spherical surfaces, reduces the friction resistance of the adjustment between the two, and improves the adjustment flexibility. It further ensures that each brake pad has the same braking work, greatly reducing the eccentric wear phenomenon. The combination of brake blocks with different cross-sectional shapes, such as triangle, circle, or quadrilateral to dodecagon, effectively increases the friction heat dissipation area during braking and improves braking efficiency. The brake block is connected to the back plate with a polygonal connecting column and a polygonal hole. This not only more effectively solves the possible self-rotation of the brake block during operation, but also avoids the brake block falling off due to loosening of the fixing retaining spring caused by the self-rotation of the brake block, thereby causing traffic accidents, but also ensures that the heat dissipation airflow channel between the brake blocks is always unobstructed, thereby improving the heat dissipation effect of the airflow on the brake block. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 Schematic diagram of the structure of a radial asymmetric surface diameter ratio spherical surface direct connection self-lubricating powder metallurgy high-speed train brake pad provided in an embodiment of the present invention; Figure 2 It is the connection structure between the back plate and the brake block; Figure 3 It is the polygonal hole diagram for back plate connection; Figure 4 It is the appearance diagram of the brake block; Figure 5 It is a schematic diagram of the existing brake pad structure.

[0020] Figure 6 It is a comparison chart of test data of the existing brake pad and the brake pad provided in the embodiment of the present invention. DETAILED DESCRIPTION

[0021] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0022] The present invention provides a radial equal wear ratio spherical surface direct connection self-lubricating powder metallurgy brake pad and a manufacturing method thereof. In order to solve the problem of radial eccentric wear of the brake pad, a radial equal difference surface diameter ratio design is provided. The surface of the brake back plate is provided with at least three rows of arc-shaped brake blocks (I), (II), and (III) from the inside to the outside. The friction areas of the at least three rows of brake blocks are arranged in equal proportion to the radius or diameter of the area where they are located.

[0023] The specific solution is: Figure 1 As shown in the figure, the brake pad is divided into three brake friction zones (I), (II) and (III) from the inside to the outside. The friction area and friction radius ratio of each zone increases almost arithmetic from the inside to the outside, that is, the friction areas of each zone are: S1=7587mm2, R1=236mm; S2=10350mm2, R2=280mm S3=13112mm2, R3=324mm; S1 / R1=32, S2 / R2=36 S3 / R3=40. The wear of each zone is basically the same, solving the problem of inconsistent wear of the brake pad inside and outside.

[0024] In order to solve the problem that the commonly used brake pad components are numerous, the errors are large, and the wear of each friction brake pad is inconsistent, a method is provided to eliminate the support seat and the special-shaped disc spring component (these components have no practical effect on the adjustment of the brake pad), and adopt direct spherical contact between the brake pad and the back plate, and adopt a concave spherical surface (5) provided on the brake back plate, the brake pad has a convex spherical surface (7), a polygonal hole (6) is provided in the concave spherical surface, a clip (10) is provided at the bottom of the polygonal hole (6), a polygonal column (9) is provided on the convex spherical surface, and a clamping groove (11) is provided at the bottom of the polygonal column (9). When the polygonal column is accommodated in the polygonal hole, the convex spherical surface (7) is in contact with the concave spherical surface (5) and the clamping groove (11) is clamped with the clip (10) to realize the assembly of the brake pad and the brake back plate. In this way, the inconsistent size and performance of the support seat and the special-shaped disc spring are avoided, which causes the inconsistency of each brake pad in the height direction, so that the braking force applied to the brake disc by each brake pad is more consistent.

[0025] In order to solve the problems of wear and temperature rise that are easily generated when the brake block and the counterpart spherical surface contact each other in the traditional brake pad design, the present invention provides a self-lubricating design, in which an annular oil groove is designed on the surface of the spherical pit (ball gap) of the back plate (or brake block). Grease is filled in the oil groove during assembly. During operation, the grease penetrates between the spherical surfaces, greatly reducing the friction resistance between the spherical surfaces, making it easy to adjust the fit between the brake block and the brake disc, while reducing wear and heat generation between the two.

[0026] In order to reasonably increase the braking friction area as much as possible and at the same time increase the heat dissipation side surface area of ​​each brake block as much as possible, the present invention provides a brake pad on which the brake pad is designed to be composed of six triangular brake blocks (2) and six circular (or quadrilateral to dodecagonal) brake blocks (3). While the total working volume of the brake block remains unchanged, the volume of each single brake block is reduced as much as possible, that is, the number of brake blocks is increased, so that the total side surface area of ​​the friction block is greatly increased, that is, the heat dissipation side surface area of ​​the brake block is increased. That is, the friction area of ​​each brake pad reaches 30150mm 2 , and the side surface area is 45687mm 2 ; The ratio of the side surface area to the friction area reaches 1.52, that is, the heat dissipation area of ​​the side surface is 1.5 times the friction area that generates heat. Increasing the heat dissipation area is more conducive to the dissipation of friction heat and reduces the temperature rise of the brake block caused by friction heat. Thereby reducing the changes in various physical properties of the brake block. Therefore, in the present invention, when a brake pad is composed of two symmetrical brake components, the brake blocks on each component are symmetrically distributed, respectively consisting of six triangular brake blocks and six circular (or quadrilateral to dodecagonal) brake blocks, such as Figure 3 As shown in the figure, the triangular side surface area is the largest, which increases the heat dissipation area of ​​the brake block. The combination of two brake blocks of different shapes forms a maximum friction area and improved braking effect under the condition of ensuring sufficient air and grinding material channels.

[0027] The present invention provides a novel method to solve the problem of possible self-rotation of the brake block during operation, by changing the circular shaft and circular hole connection between the brake block and the back plate into a polygonal connection, such as Figure 4 , 5 As shown, the connection column of the brake block is a polygonal structure, and the hole of the back plate is a polygonal hole, which completely solves the problem of the brake block rotating during operation. No so-called self-tripping or mutual tripping structure is added, the structure is simple, the components are few, and it is reliable. At the same time, it also completely solves the risk of the brake block and the back plate falling off due to the self-rotation of the brake block, thereby eliminating the occurrence of traffic accidents that affect safety.

[0028] Compared with the prior art, the present invention has outstanding technical effects and the following advantages: 1. The existing brake pads are as follows Figure 5As shown in the figure, the friction area and friction radius ratios of the outer friction area, the middle friction area and the inner friction area are quite different, namely: S1 / R1 = 29 S2 / R2=39 S3 / R3=42, the surface diameter ratios of each friction area are quite different and change irregularly, and the friction work of each area increases in a certain proportion, which can easily cause inconsistent wear of each friction area of ​​the brake pad, uneven gradient wear, and accelerate the premature wear and failure of the brake pad. In the same brake pad, after the test experiment under the same conditions (such as Figure 6 ), the heights of the brake pads in the three regions after wear were measured as follows: 12.39mm in S1 region, 11.9mm in S2 region, 11.38mm in S3 region, and the maximum error of the average wear of the three regions was 1.01mm. The friction areas of the three regions of the present invention increase in equal increments with the friction radius of the three regions. In the same brake pad, after the test under the same conditions, the heights of the brake pads in the three regions after wear were measured as follows: 14.63mm in S1 region, 14.73mm in S2 region, 14.83mm in S3 region, and the maximum error of the average wear of the three regions was 0.1mm. Therefore, the wear of the friction areas in each region is more consistent, and gradient wear and eccentric wear will not occur.

[0029] 2. The present invention has a simple structure, adopts direct spherical contact between the brake block and the back plate, removes the intermediate components such as the support seat and the special-shaped spring in the prior art design, reduces the error in the height direction caused by the size and performance differences of these components, makes it easier for each brake block to apply the braking force uniformly, can play the braking role, reduce eccentric wear, and improve the stability and efficiency of braking. Through the LINK3600 high-speed train 1:1 brake power test bench test (such as Figure 6 ), the maximum height wear deviation between brake pads at the same transverse position in the same brake pad in the existing brake pad is 1.0 mm. However, the maximum height wear deviation of the brake pads at the same transverse position on the same brake pad of the present invention is 0.2 mm.

[0030] 3. The present invention adopts the method of adding a grease groove in the contact area between the brake block and the back plate spherical surface. When installing, a little grease is added to reduce the wear and temperature rise between the two spherical surfaces, reduce the friction resistance of the adjustment between the two, and improve the adjustment flexibility. It further ensures that each brake block has the same braking work, greatly reducing the phenomenon of eccentric wear. Through the LINK3600 high-speed train 1:1 brake power test bench test (such as Figure 6 ), the maximum eccentric wear at different positions of the same brake pad in the existing brake pad is 2.6mm, while in the structure of the present invention, after testing under the same conditions, the maximum eccentric wear at different positions of the same brake pad is 1.2mm.

[0031] 4. The present invention adopts a combination of brake blocks with different cross-sectional shapes, such as triangle and circle (or quadrilateral to dodecagon), which effectively increases the friction heat dissipation area during braking and improves the braking efficiency. After the LINK3600 high-speed train 1:1 brake power test bench experiment (such as Figure 6 ), the existing brake pads have a brake temperature of 616-718°C at a speed of 380 km / h. The present invention uses 12 triangular brake pads and 12 circular (or quadrilateral to dodecagonal) brake pads, totaling 24 pieces. Compared with the existing technical design that uses 12 hexagonal and 6 regular hexagonal brake pads, totaling 18 pieces, the volume of each piece is reduced, but the side surface area that mainly plays a role in heat dissipation is greatly increased. The side surface area of ​​the existing brake pad design is 39517mm 2 , the friction area is 31528mm 2 , the ratio of the side surface area to the friction area is 1.25. On the 1:1 special high-speed train test bench, at a braking force of 23KN and a speed of 380KM / hr, the measured braking distance is 7913m, the braking time is 131s, and the temperature rise is 718°C; while in this design, the ratio of the side surface area to the friction area reaches 1.52, increasing the heat dissipation area by 21.6%. Under the same braking conditions, the measured braking distance is 6934m, the braking time is 124s, and the temperature rise is 566°C. Therefore, increasing the side surface area of ​​the brake pad is beneficial to improving the heat dissipation speed of the brake block, controlling and reducing the temperature rise of each brake block, and reducing the attenuation of the physical properties of the brake block due to high temperature. Ensure that the brake block can function stably.

[0032] 6. The brake block of the present invention is connected to the back plate by a polygonal connecting column and a polygonal hole, which not only effectively solves the self-rotation phenomenon that may occur when the brake block is working, and avoids the brake block falling off due to the loosening of the fixing spring caused by the self-rotation of the brake block, thereby causing traffic accidents, but also ensures that the heat dissipation airflow channel between the brake blocks is always unobstructed, improves the heat dissipation effect of the airflow on the brake block, and reduces the temperature of the brake pad by 152-250°C compared with the original structure. Compared with the mutual trip design adopted in the brake block shape in the prior art design, the brake block self-rotation and mutual mixing affect the smoothness of the airflow channel between the brake blocks, thereby affecting the heat dissipation effect of the brake block, and at the same time has a simple structure, no change, and more beautiful.

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-speed train brake pad, comprising two brake back plates (1) and (2) arranged symmetrically on both sides, characterized in that: The surface of the brake back plate is provided with at least three rows of arc-shaped brake blocks (I), (II), and (III) from the inside to the outside, and the friction areas of the at least three rows of brake blocks are arranged in equal proportion to the radius or diameter of the area where they are located.

2. The high-speed train brake pad according to claim 1, characterized in that: The brake back plate and the brake block are connected by a spherical surface.

3. The high-speed train brake pad according to claim 2, characterized in that: The brake back plate is provided with a concave spherical surface (5), the brake block has a convex spherical surface (7), a polygonal hole (6) is provided in the concave spherical surface, a clip (10) is provided at the bottom of the polygonal hole (6), a polygonal column (9) is provided on the convex spherical surface, and a clamping groove (11) is provided at the bottom of the polygonal column (9). When the polygonal column is accommodated in the polygonal hole, the convex spherical surface (7) is in contact with the concave spherical surface (5) and the clamping groove (11) is clamped with the clip (10), so as to realize the assembly of the brake block and the brake back plate.

4. The high-speed train brake pad according to claim 2, characterized in that: A lubricant groove (8) is arranged on the concave spherical surface (5) or the convex spherical surface (7), and grease is filled into the lubricant groove (8) during assembly.

5. The high-speed train brake pad according to claim 1, characterized in that: The brake blocks on each brake back plate are composed of triangular brake blocks (4) and circular or quadrilateral to dodecagonal brake blocks (3), wherein the triangular brake blocks are arranged in the two side areas, and the circular or quadrilateral to regular dodecagonal brake blocks are arranged in the middle area.

6. A method for manufacturing a high-speed train brake pad, characterized in that: The process steps include: 1) Two brake back plates (1) and (2) are symmetrically arranged; 2) At least three rows of arc-shaped brake blocks (I), (II), and (III) are arranged on the surface of the brake back plate from the inside to the outside, and the friction areas of the at least three rows of brake blocks are arranged in equal proportion to the radius or diameter of the area where they are located.

7. The method for manufacturing a high-speed train brake pad according to claim 6, characterized in that: The brake back plate and the brake block are connected by a spherical surface.

8. The method for manufacturing a high-speed train brake pad according to claim 6, characterized in that: The brake back plate is provided with a concave spherical surface (5), the brake block has a convex spherical surface (7), a polygonal hole (6) is provided in the concave spherical surface, a clip (10) is provided at the bottom of the polygonal hole (6), a polygonal column (9) is provided on the convex spherical surface, and a clamping groove (11) is provided at the bottom of the polygonal column (9). When the polygonal column is accommodated in the polygonal hole, the convex spherical surface (7) is in contact with the concave spherical surface (5) and the clamping groove (11) is clamped with the clip (10), so as to realize the assembly of the brake block and the brake back plate.

9. The method for manufacturing a high-speed train brake pad according to claim 6, characterized in that: A lubricant groove (8) is arranged on the convex spherical surface (7), and grease is filled into the lubricant groove (8) during assembly.

10. The method for manufacturing a high-speed train brake pad according to claim 6, characterized in that: The brake blocks on each brake back plate are composed of triangular brake blocks (4) and circular or quadrilateral to tetragonal brake blocks (3), wherein the triangular brake blocks are arranged in the two side areas, and the circular or quadrilateral to tetragonal brake blocks are arranged in the middle area.

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