I-D type dovetail steel back brake pad without anti-rotation platform

Abstract

The invention discloses an I-D type swan neck steel back brake pad without an anti-rotation platform, which is applied to EMUs with a speed grade of 200-250 km / h. It includes a steel back substrate, and a friction unit is arranged on the upper surface of the steel back substrate. The three friction blocks of the first friction unit are arranged in a stepped manner on one side of the steel back substrate close to the first straight edge, and the friction blocks of the first friction unit are deflected 10-15° compared with the first straight edge; the second friction unit is arranged on the side of the first friction unit away from the first straight edge, and the three friction blocks in the second friction unit are respectively arranged in contact with the corresponding three friction blocks in the first friction unit; the three friction blocks of the third friction unit are arranged in an inverted "pin" shape on the right side of the second friction unit, and the three friction blocks of the third friction unit are in contact with each other pairwise. A brake pad without an anti-rotation platform and with a larger effective friction area is provided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high-speed train braking equipment, and particularly relates to an I-D type dovetail steel back brake pad without anti-rotation platform. BACKGROUND

[0002] The brake pad of a high-speed motor car is usually made of a dovetail steel back with a plurality of friction blocks arranged therein. According to the national standard, in order to facilitate the arrangement of the friction blocks, the manufacturers of the brake pad of the motor car reduce the size of the friction blocks, so that the traditional brake pad of the motor car has an effective friction area of about 280-290 cm2. However, such design has the following problems.

[0003] 1. The smaller effective friction area increases the pressure on the friction blocks, which intensifies the eccentric wear of the brake pad, greatly reduces the service life of the brake pad, and has certain safety hazards.

[0004] 2. A plurality of anti-rotation platforms are needed to avoid the deflection of the friction blocks during braking, which reduces the braking friction and causes safety hazards. However, the installation of the friction blocks is more troublesome after the anti-rotation platforms are added, and the travel of the brake during braking is longer and the friction heat generated per unit area is higher in the actual use process due to the use of the friction blocks with small friction area, so the friction blocks are more likely to be high-temperature bonded with the surrounding anti-rotation platforms and then fail, which causes safety hazards.

[0005] 3. The traditional brake pad of the motor car only considers whether the friction blocks can be arranged on the dovetail steel back during the arrangement and installation of the friction blocks, and ignores the stress on the edges of the friction blocks during braking, which causes the collapse of individual friction blocks during braking, greatly reducing the service life of the brake pad. SUMMARY

[0006] To solve the above problems, the present application provides an I-D type dovetail steel back brake pad without anti-rotation platform, which is implemented as follows.

[0007] An I-D type dovetail steel-backed brake pad without an anti-rotation platform, which is applied to EMUs with a speed grade of 200 - 250 km / h, includes a steel back substrate. The outer contour edge of the steel back substrate includes a long arc edge and a short arc edge that is arranged at an interval and in the same orientation as the long arc edge. The left ends of the long arc edge and the short arc edge are connected by a first straight edge, and the first straight edge is perpendicular to the long arc edge and the short arc edge respectively. The right ends of the long arc edge and the short arc edge are connected by a second straight edge, and the side of the second straight edge close to the long arc edge is rounded. A friction unit is arranged on the upper surface of the steel back substrate. The friction unit includes a first friction unit, a second friction unit and a third friction unit. Each friction unit includes three friction blocks, and each friction block is sintered by a friction body in the shape of a regular quadrilateral prism, a skeleton and a pin;

[0008] The three friction blocks of the first friction unit are arranged in a stepped manner on one side of the steel back substrate close to the first straight edge, and the friction blocks of the first friction unit are deflected 10 - 15° compared with the first straight edge;

[0009] The second friction unit is arranged on the side of the first friction unit away from the first straight edge, and the three friction blocks in the second friction unit are respectively arranged in contact with the corresponding three friction blocks in the first friction unit;

[0010] The three friction blocks of the third friction unit are arranged in an inverted "pin" shape on the right side of the second friction unit, and the three friction blocks of the third friction unit are in contact with each other pairwise.

[0011] Preferably, the side length of the friction body is 48 mm, and the high edge of the friction body is chamfered with a radius of 10 mm. A heat dissipation through hole with a diameter of 14 mm is also opened on the friction body.

[0012] As a further improvement, a plurality of installation grooves are opened on the upper surface of the steel back substrate, and a plurality of fixing grooves concentric with the installation grooves are opened on the lower surface of the steel back substrate. The fixing grooves and the installation grooves are connected through pin holes. The friction blocks are adapted and installed in the installation grooves through a detachable claw-shaped disc spring, and the pin penetrates through the pin hole and extends into the fixing groove. One end of the pin away from the friction body is clamped by a disc spring adapted to the fixing groove.

[0013] Preferably, the installation groove is 1 - 3 mm deep, and a steel back ball socket is also opened in the installation groove;

[0014] The fixing groove is 4 - 6 mm deep;

[0015] On one side of the framework close to the mounting groove, a ball protrusion adapted to the shape of the steel back ball socket is provided, and a gap of 0.6 mm to 1.2 mm is provided between the ball protrusion and the steel back ball socket.

[0016] As a further improvement, the claw-shaped disc spring includes a mounting ring adapted to the mounting groove. A plurality of fan-shaped arc plates are fixedly arranged in a circumferential array on the inner circle of the mounting ring, and the short arc side of the fan-shaped arc plate is adapted to the maximum outer diameter of the ball protrusion. And the upper surface of the fan-shaped arc plate is flush and abutted against the lower surface of the framework.

[0017] Preferably, the thickness of the fan-shaped arc plate is 0.8 mm.

[0018] Preferably, the three friction blocks in the third friction unit are deflected 35 to 55° compared with the first straight edge.

[0019] The beneficial effects of the present invention are as follows:

[0020] 1. By providing nine friction blocks with regular quadrilateral prism friction bodies on the steel back matrix of the I-D type dovetail steel back, and the second friction unit is arranged on the side of the first friction unit away from the first straight edge, the three friction blocks in the second friction unit are respectively arranged in abutment with the corresponding three friction blocks in the first friction unit, and the three friction blocks in the third friction unit are arranged in pairwise abutment with each other, while increasing the effective friction area of the friction bodies of the friction blocks, there is no need to add an anti-rotation platform, and the friction blocks are limited by abutting against each other to prevent rotation during the braking process, resulting in a reduction in the friction effect.

[0021] 2. By increasing the effective friction area of the friction bodies, the friction heat per unit area on the friction blocks during the braking process is reduced. At the same time, the three friction blocks of the three friction units are arranged in an inverted "pin" shape on the right side of the second friction unit, leaving a large gap at the position where the highest friction temperature occurs near the outer circle in the middle circle of the dovetail steel back to discharge the high-temperature grinding chips in a timely manner, reducing the probability of adhesion between the friction blocks and improving the heat dissipation capacity of the overall structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is an exploded structural schematic diagram of the present invention.

[0023] Figure 2 It is a front view structural schematic diagram of the present invention.

[0024] Figure 3 It is a structural schematic diagram of the division of the inner, middle and outer circles of the steel back matrix when the present invention is used in cooperation with the shaft disc.

[0025] Figure 4 It is a diagram of the division of the inner, middle and outer circles of the steel back matrix when the present invention is used in cooperation with the wheel disc, and an analysis diagram of the friction force direction.

[0026] Figure 5 This is a front view structural diagram of the steel backing substrate of the present invention.

[0027] Figure 6 This is a rear view structural diagram of the steel backing substrate of the present invention.

[0028] Figure 7 This is a schematic diagram of the claw-shaped disc spring structure of the present invention. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention.

[0030] In the description of this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" and "second" may explicitly or implicitly include one or more of that feature.

[0031] like Figures 1-7 As shown, this invention provides an ID-type dovetail steel-backed brake pad without a turntable, applicable to EMUs with speeds of 200-250 km / h. It includes a steel-backed base 1, the outer contour edge of which includes a long arc edge 11a and a short arc edge 11b oriented in the same direction as and spaced apart from the long arc edge 11a. The left ends of the long arc edge 11a and the short arc edge 11b are connected by a first straight edge 11c, which is perpendicular to both the long arc edge 11a and the short arc edge 11b. 1b, the right ends of the long arc edge 11a and the short arc edge 11b are connected by the second straight edge 11d. The side of the second straight edge 11d near the long arc edge 11a is rounded. The upper surface of the steel backing substrate 1 is provided with a friction unit. The friction unit includes a first friction unit 2a, a second friction unit 2b and a third friction unit 2c. Each friction unit includes three friction blocks 2. Each friction block 2 is sintered from a regular quadrilateral prism-shaped friction body, a skeleton 22 and a pin 23.

[0032] The three friction blocks 2 of the first friction unit 2a are arranged in a stepped manner on one side of the steel back substrate 1 close to the first straight edge 11c, and the friction blocks 2 of the first friction unit 2a are deflected 10 - 15° compared with the first straight edge 11c;

[0033] The second friction unit 2b is arranged on one side of the first friction unit 2a away from the first straight edge 11c, and the three friction blocks 2 in the second friction unit 2b are respectively arranged in contact with the corresponding three friction blocks 2 in the first friction unit 2a;

[0034] The three friction blocks 2 of the third friction unit 2c are arranged in an inverted "pin" shape on the right side of the second friction unit 2b. The three friction blocks 2 of the third friction unit 2c are in contact with each other pairwise, and the three friction blocks 2 in the third friction unit 2c are deflected 35 - 55° compared with the first straight edge 11c.

[0035] The I-D type dovetail steel back brake pad is used by two symmetrically arranged steel back substrates 1 acting together. On the dovetail steel back, from the short arc edge 11b towards the long arc edge 11a, it is successively divided into an inner ring 1a, a middle ring 1b, and an outer ring 1c by two circles concentric with the wheel disc or shaft disc. Among them, the wheel disc diameter for the I-D type dovetail steel back is 355 mm, and the shaft disc diameter is 335 mm. And the ratio of the number of friction blocks 2 distributed on the inner ring 1a, the middle ring 1b, and the outer ring 1c of a single steel back substrate 1 is 2:3.5:3.5 or 2:3:4.

[0036] For the I-D type dovetail steel back brake pad used in high-speed EMUs at 200 - 250 km / h, the highest frictional heat generated during braking is usually concentrated at the position where the middle ring 1b is close to the outer ring 1c. The main reasons for this situation are as follows: 1. From the inner ring 1a towards the outer ring 1c, under the same angular velocity, the relative angular velocity between the steel back substrate 1 and the wheel disc or shaft disc gradually increases, and the generated frictional heat also gradually increases; 2. One side of the inner ring 1a away from the outer ring 1c or one side of the outer ring 1c away from the inner ring 1a is not blocked. The frictional heat energy generated by the outer ring 1c and the inner ring 1a during braking can be quickly exchanged with the outside world. At the same time, the high-temperature wear debris generated by the inner ring 1a and the outer ring 1c can be discharged in time, taking away a large amount of frictional heat.

[0037] Such as Figure 3 And Figure 4As shown, since the friction blocks 2 of the first friction unit 2a are all deflected by 10~15° relative to the first straight edge 11c, and the three friction blocks 2 in the third friction unit 2c are all deflected by 35~55° relative to the first straight edge 11c, a large gap is formed between the third friction unit 2c and the second friction unit 2b, located at the middle ring 1b of the steel backing substrate 1. This gap gradually increases towards the outer ring 1c, effectively creating a heat dissipation space to ensure sufficient heat dissipation capacity for the brake pads at this location. This gap also allows for the flow of wear debris, further improving heat dissipation. Furthermore, after the two steel backing substrates 1 are joined together, a large gap is also left at the joint between the middle ring 1b and the outer ring 1c, gradually increasing towards the outer ring 1c, which also improves the heat dissipation capacity of the brake pads at the highest temperature.

[0038] Furthermore, such as Figure 3 as well as Figure 4 As shown, since the friction blocks 2 of the first friction unit 2a are all deflected by 10~15° relative to the first straight edge 11c, and the three friction blocks 2 of the first friction unit 2a are arranged in a stepped manner on the side of the steel backing base 1 near the first straight edge 11c, the three friction blocks 2 in the second friction unit 2b are respectively abutted against the corresponding three friction blocks 2 in the first friction unit 2a. This ensures that the gap area between every four adjacent friction blocks 2 remains unchanged. At the same time, the inclined stepped arrangement allows the edges of the friction blocks 2 to fit more closely to the edges of the steel backing base 1, preventing the friction body from protruding too much from the dovetail steel backing and being squeezed and broken during braking. If the deflection angle is too large, it is easy to cause the nine square friction blocks 2 to be unable to be effectively arranged on a single ID-type dovetail steel backing, and the edge shape of the steel backing base 1 cannot be fitted.

[0039] Furthermore, such as Figure 4 As shown, the frictional force generated during braking forms an angle of approximately 75-80° with the edge of the friction block 2 it passes through in the tangential direction. Compared to the frictional force being perpendicular to the edge, this arrangement better prevents the edge of the friction block 2 from being subjected to excessive impact and breaking at the moment of contact with the wheel disc or axle disc. If the deflection angle is too small, the angle between each side of the friction block 2 and the frictional force will be closer to perpendicular, which can easily lead to a greater impact and reduce the service life of the brake pads.

[0040] Preferably, the friction body has a side length of 48mm, and its high edge is chamfered with a radius of 10mm. The friction body also has heat dissipation holes with a diameter of 14mm. The contact length between the three friction blocks 2 in the first friction unit 2a and the corresponding three friction blocks 2 in the second friction unit 2b is at least 33-36mm, and the three friction blocks 2 in the second friction unit 2b are respectively abutted against the corresponding three friction blocks 2 in the first friction unit 2a. This increases the effective friction area of ​​the friction blocks 2 without requiring an additional anti-rotation platform for limiting movement.

[0041] The ID-type dovetail steel-backed brake pad provided by this invention has an effective friction area of ​​346 cm², which is much larger than the 280-300 cm² effective friction area of ​​traditional brake pads. At the same time, the heat dissipation capacity of the ID-type dovetail steel-backed brake pad provided by this invention is also significantly better than that of traditional ID-type dovetail steel-backed brake pads.

[0042] The maximum temperature of the brake pads provided by this invention during braking and the maximum temperature of conventional brake pads during braking are shown in Table 1:

[0043] Table 1.

[0044]

[0045] As can be easily seen from Table 1, the maximum temperature of the brake pads provided by this invention is significantly lower than that of traditional brake pads. This reduces frictional heat while increasing the effective friction area, effectively extending the service life of the brake pads. Furthermore, it can be seen that the temperature rise of the brake pads provided by this invention is smaller as vehicle speed increases, thus confirming that the brake pads provided by this invention have better high-speed adaptability.

[0046] As a further improvement, the upper surface of the steel backing base 1 is provided with a plurality of mounting grooves 12, and the lower surface of the steel backing base 1 is provided with a plurality of fixing grooves 13 concentric with the mounting grooves 12. The fixing grooves 13 are connected to the mounting grooves 12 through pin holes. The friction block 2 is adapted and installed in the mounting groove 12 by a detachable claw-shaped disc spring 3, and the pin 23 passes through the pin hole and extends into the fixing groove 13. The end of the pin 23 away from the friction body is clamped by a disc spring 4 adapted to the fixing groove 13.

[0047] like Figures 5-7As shown, in traditional brake pads, the inner ring 1a of the disc spring protrudes to one side, resulting in a small contact area between the disc spring and the frame 22. When used with the frame 22, the high pressure generated by this small area can cause the disc spring to become stuck inside the frame 22, damaging the frame 22. Simultaneously, this reduces the disc spring's circumferential adjustment capability, keeping the brake pad in a tilted state and further exacerbating uneven wear. Therefore, as a further improvement, the mounting groove 12 is 1-3mm deep, and a claw-shaped disc spring 3 with an internal groove is detachably installed within the mounting groove 12. The mounting groove 12 also has a steel-backed ball socket. Figure 7 As shown, the claw-shaped disc spring 3 includes a mounting ring 31, which is adapted to the mounting groove 12. A plurality of fan-shaped arc plates 32 are circumferentially fixed to the inner ring 1a of the mounting ring 31. The short arc edge 11b of the fan-shaped arc plate 32 is adapted to the maximum outer diameter of the pin 23. Furthermore, the upper surface of the fan-shaped arc plate 32 is flush with and fits against the lower surface of the frame 22. The upper surface of the fan-shaped plate 32 is designed to match the lower surface of the frame 22, which can effectively increase the contact area between the claw-shaped disc spring 3 and the frame 22, resulting in lower pressure under the same braking clamping force. At the same time, by fixing several fan-shaped plates 3232 in a circumferential array on the inner ring 1a of the mounting ring 31, the stiffness of the inner ring 1a structure can be reduced, and the elasticity of the inner ring 1a structure can be enhanced. Through this design, the maximum deformation of each fan-shaped plate 32 in the inner ring 1a can reach 1mm, avoiding the inner ring 1a structure from being embedded in the frame 22 under high pressure, which would damage the structure of the frame 22 and cause structural skewing.

[0048] Preferably, the thickness of the fan-shaped plate 32 is 0.8 mm.

[0049] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A brake pad of I-D type dovetail steel back without anti-rotation platform, applied to a motor train unit of a speed grade of 200-250km / h, comprising a steel back base body, an outer contour edge of the steel back base body comprising a long arc edge and a short arc edge disposed in the same direction and spaced apart from the long arc edge, left ends of the long arc edge and the short arc edge being connected by a first straight edge, the first straight edge being perpendicular to the long arc edge and the short arc edge respectively, right ends of the long arc edge and the short arc edge being connected by a second straight edge, a side of the second straight edge close to the long arc edge being chamfered, characterized in that, an upper end surface of the steel back base body is provided with a friction unit, the friction unit comprising a first friction unit, a second friction unit and a third friction unit, each of the friction units comprising three friction blocks, each of the friction blocks being sintered from a friction body in the shape of a regular quadrilateral prism, a skeleton and a pin; the three friction blocks of the first friction unit are arranged in a stepped manner on the side of the steel back base body close to the first straight edge, and the friction blocks of the first friction unit are all deflected by 10-15° compared to the first straight edge; the second friction unit is arranged on the side of the first friction unit away from the first straight edge, and the three friction blocks in the second friction unit are arranged in close contact with the corresponding three friction blocks in the first friction unit respectively; the three friction blocks of the third friction unit are arranged in an inverted "V" shape on the right side of the second friction unit, and the three friction blocks of the third friction unit are arranged in close contact with each other in pairs; a side length of the friction body is 48mm, and a high ridge of the friction body is chamfered with a radius of 10mm, and a heat dissipation through hole with a diameter of 14mm is formed on the friction body; a plurality of installation grooves are formed on the upper end surface of the steel back base body, a plurality of fixing grooves concentric with the installation grooves are formed on the lower end surface of the steel back base body, the fixing grooves and the installation grooves are communicated through pin holes, the friction blocks are adapted and installed in the installation grooves through a detachable claw-shaped disc spring, and the pins penetrate through the pin holes and extend into the fixing grooves, and one end of the pin away from the friction body is clamped by a butterfly spring adapted to the fixing groove. the installation grooves are 1-3mm deep, and a steel back ball socket is formed in the installation grooves; 2. The I-D type dovetail steel-backed brake pad without anti-rotation tab as claimed in claim 1, wherein, the fixing grooves are 4-6mm deep; a ball protrusion adapted to the shape of the steel back ball socket is arranged on the side of the skeleton close to the installation groove, and the ball protrusion and the steel back ball socket are spaced apart by 0.6-1.2mm. the claw-shaped disc spring comprises a mounting ring adapted to the installation groove, an inner circle of the mounting ring is fixedly provided with a plurality of fan arc plates in an array around the circumference, a short arc edge of the fan arc plate is adapted to the maximum outer diameter of the ball protrusion, and an upper end surface of the fan arc plate is flush and attached to a lower end surface of the skeleton.

3. The I-D type dovetail steel-backed brake pad without anti-rotation tab as recited in claim 2, wherein, a thickness of the fan arc plate is 0.8mm.

4. The I-D type dovetail steel-backed brake pad without anti-rotation tab as recited in claim 3, wherein, the three friction blocks in the third friction unit are all deflected by 35-55° compared to the first straight edge.

5. The I-D dovetail steel-backed brake pad without anti-rotation tab of claim 1 wherein, ​

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