Brake shoe capable of preventing stress concentration of shoe nose

Abstract

The utility model discloses a brake shoe capable of preventing stress concentration of a shoe nose, which belongs to the technical field of brake shoes of railway wagons and comprises a shoe back and a friction body connected to the inner side of the shoe back. A tile nose protruding outwards is arranged in the center of the tile back; the tile nose is provided with a limiting contact structure and two installation side holes symmetrically formed in the left side face and the right side face of the tile nose. The limiting contact structure is arranged on the top face of the shoe nose and used for conducting contact limiting on a brake shoe bolt which penetrates through the two installation side holes at the same time to assemble a brake shoe and a shoe holder, and the outer side face of the assembled brake shoe bolt does not make direct contact with the side edge, close to one side of the top face of the shoe nose, of any installation side hole after assembly. The structure strength of the shoe nose can be enhanced, the contact mode of the brake shoe bolt and the installation side hole is changed, the situation that the brake shoe falls off due to stress concentration of the installation side hole is prevented, and driving safety is guaranteed.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the railway freight car brake shoe technical field, concretely relates to a brake shoe of preventing stress concentration of nose. BACKGROUND

[0002] Railway transportation has the comprehensive advantages of large volume, strong continuity, relatively fast speed and low cost, and its position in the transportation system of China is increasingly improved, and it has long been responsible for the transportation of long-distance and large-volume goods. In recent years, China's railway freight cars are developing towards high speed and heavy load, and higher requirements are put forward for the braking performance of the freight cars. As the execution terminal of the vehicle basic braking, the reliability of the brake shoe is directly related to the safety of driving, and therefore improving the reliability of the brake shoe has important significance for guaranteeing the efficient and safe transportation of railways.

[0003] At present, high-friction synthetic brake shoes are widely used as braking components in China's railway freight cars. The high-friction synthetic brake shoe is generally composed of a shoe back and a friction body, wherein the shoe back is formed by shearing and stamping a steel plate, and the friction body is composed of bonding materials, reinforcing materials and friction materials. The high-friction synthetic brake shoe is formed by pressing and curing the shoe back and the prepared friction body material. However, such high-friction synthetic brake shoes are prone to be scrapped due to the fracture of the nose during operation, which not only leads to a very short service life of the brake shoe, only three to four months, resulting in frequent shoe replacement work, greatly increasing the operation and maintenance workload and cost, and seriously affecting the operation benefit, but also poses a serious threat to the safety of driving due to the scrapping of the high-friction synthetic brake shoe during operation.

[0004] The structure of the existing high-friction synthetic brake shoe is shown in the accompanying Figure 5 The upper part of the nose is mostly designed with a flat process hole, and a process hole is punched in the middle of the flat nose for positioning in the production process. However, as shown in the accompanying Figure 6 When the car is assembled and operated, the brake shoe bolt directly contacts the upper side of the installation side hole near the top side of the nose during the assembly of the brake shoe and the brake block, causing stress concentration on the upper side of the installation side hole due to direct stress, causing cracks near the installation side hole. With the increase of working time, the cracks will continue to expand and eventually lead to the fracture of the nose, which not only leads to a short service life of the high-friction synthetic brake shoe, but also seriously affects the safety of driving. Therefore, there is an urgent need to provide a brake shoe that can prevent stress concentration of the nose. UTILITY MODEL CONTENTS

[0005] The utility model aims at the above-mentioned deficiencies to provide a brake shoe that can prevent stress concentration of the nose, and aims to solve the problem that the nose is prone to fracture due to the direct contact of the brake shoe bolt with the side edge near the top side of the installation side hole. In order to achieve the above-mentioned purpose, the utility model provides the following technical scheme:

[0006] The utility model provides a brake shoe of preventing brake shoe nose stress concentration, including shoe back and the friction body connected to the inside of shoe back, the shoe back central place is equipped with the outward convex shoe nose, is equipped with the limit contact structure and two symmetrical installation side hole on the shoe nose left side face, limit contact structure is equipped with the top surface of shoe nose for the brake shoe bolt who passes through two installation side hole simultaneously to carry out contact limit to the brake shoe and the brake shoe drum assembly, makes the outside surface of brake shoe bolt after assembly not with any installation side hole near the side edge of shoe nose top surface side direct contact, wherein the shoe back is the core support framework of brake shoe, and the friction body is used for the contact friction of railway freight car wheel part, plays the brake function, the utility model discloses an additional limit contact structure of being able to limit the contact of brake shoe bolt on shoe nose changes the contact mode of brake shoe bolt and shoe nose, effectively avoids the shoe nose fracture caused by shoe nose stress concentration in actual working process, and then makes brake shoe drop -off situation, guarantees the safety of driving.

[0007] Further, the limit contact structure is an arc-shaped reinforcing rib provided on the top surface of the shoe nose and recessed inwardly; the arc-shaped reinforcing rib has an arc-shaped cross section; and the lowest point of the arc-shaped reinforcing rib is lower than the side edge of the installation side hole near the top surface of the shoe nose.

[0008] Further, the height difference between the lowest point of the arc-shaped reinforcing rib and the side edge of the installation side hole near the top surface of the shoe nose is 2-3 mm.

[0009] Further, the arc-shaped reinforcing rib has a semicircular cross section.

[0010] Further, the arc-shaped reinforcing rib is provided at the middle of the top surface of the shoe nose.

[0011] Further, the top surface of the shoe nose is a plane; and the connection between the top surface of the shoe nose and the left side surface of the shoe nose and the connection between the top surface of the shoe nose and the right side surface of the shoe nose are both connected by a circular arc.

[0012] Further, the installation side hole is a rectangular through hole.

[0013] Further, the connection between the adjacent two side edges of the installation side hole is connected by a circular arc.

[0014] The utility model has the advantages of:

[0015] 1. The utility model discloses a design can be limited to the contact of brake shoe bolt on the nose of tile, improve the structural strength of tile nose itself, and changed the contact mode of brake shoe bolt and tile nose, under the prerequisite of guaranteeing the interface size of existing brake shoe installation unchanged, effectively avoid the tile nose fracture caused by stress concentration of tile nose in the actual working process, and further cause the situation of tile falling, guarantee the safety of car running. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is the structure schematic diagram of the utility model brake shoe;

[0017] Figure 2 It is the side view of the utility model brake shoe;

[0018] Figure 3 It is the three-dimensional structure diagram of the utility model brake shoe;

[0019] Figure 4 It is the structure schematic diagram of the utility model brake shoe and tile assembly, and the brake shoe bolt is inserted into the installation side hole;

[0020] Figure 5 It is the structure schematic diagram of the existing brake shoe;

[0021] Figure 6 It is the structure schematic diagram of the existing brake shoe and tile assembly, and the brake shoe bolt is inserted into the installation side hole;

[0022] In the drawing, 1, tile back;2, friction body;3, tile nose;4, installation side hole;5, tile;6, brake shoe bolt;31, arc reinforcing rib. DETAILED DESCRIPTION

[0023] In the description of the utility model, it is understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" is based on the orientation or positional relationship shown in the drawing, and is only for the convenience of describing the utility model and simplifying the description, and therefore cannot be understood as limiting the utility model to a particular orientation, structure and operation, and therefore cannot be understood as limiting the utility model.

[0024] In the description of the utility model, "first feature" and "second feature" can include one or more features.

[0025] In the description of the utility model, "multiple" means two or more.

[0026] In the description of this utility model, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or it may include the first and second features not being in direct contact but being in contact through another feature between them.

[0027] In the description of this utility model, the terms "above", "over" and "on top" for the first feature and the second feature include the first feature being directly above or diagonally above the second feature, or simply indicate that the first feature is at a higher horizontal level than the second feature.

[0028] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," and "some examples" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0029] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but the present invention is not limited to the following embodiments.

[0030] Example 1:

[0031] See attached Figures 1-4A brake shoe designed to prevent stress concentration at the brake shoe nose includes a brake shoe back 1 and a friction body 2 connected to the inner side of the brake shoe back 1. The brake shoe back 1 has an outwardly protruding brake shoe nose 3 at its center. The brake shoe nose 3 has a limiting contact structure and two symmetrically arranged mounting side holes 4 on its left and right sides. The limiting contact structure is located on the top surface of the brake shoe nose 3 and is used to limit the contact of the brake shoe pin 6, which passes through both mounting side holes 4 to assemble the brake shoe and brake shoe support 5, preventing direct contact between the outer surface of the brake shoe pin 6 and the side of any mounting side hole 4 closest to the top surface of the brake shoe nose 3 after assembly. From the above structure, it can be seen that a brake shoe generally consists of a brake shoe back 1 and a friction body 2. The brake shoe back 1, as the core supporting frame of the brake shoe, can be made of various metal materials with sufficient mechanical strength, such as steel plates. The friction body 2 is composed of adhesive, reinforcing, and friction materials. It is connected to the inner side of the brake shoe back 1 via existing methods such as bonding or mechanical fastening. It provides contact friction to the wheels of railway freight cars, thus achieving a braking effect. The brake shoe nose 3 serves as the connection between the brake shoe and the brake shoe holder, transmitting braking force and maintaining the brake shoe's stable position. The brake shoe nose 3 is located in the center of the brake shoe back 1 and protrudes outwards. Two mounting side holes 4 are symmetrically located on the left and right sides of the brake shoe nose 3, allowing the brake shoe pin 6 to pass through, thereby connecting and fixing the brake shoe to the brake shoe holder 5. In existing brake shoes, after assembly with the brake shoe holder 5, the side of the mounting side hole 4 near the top surface of the brake shoe nose 3 will come into contact with and rub against the brake shoe pin 6, and will be continuously subjected to force, resulting in stress concentration. However, in this utility model, while ensuring that the existing brake shoe mounting interface size remains unchanged, the contact method between the brake shoe pin 6 and the brake shoe nose 3 is changed. The limiting contact structure provided on the top surface of the brake shoe nose 3 makes contact with the brake shoe pin 6 to limit the contact. This prevents the outer side of the assembled brake shoe pin 6 from directly contacting any side of the mounting side hole 4 near the top surface of the brake shoe nose 3. This effectively avoids the situation where the brake shoe nose breaks due to stress concentration during actual operation, thus preventing the brake shoe from falling off and ensuring the safety of driving.

[0032] Example 2:

[0033] See attached Figures 1-6 Based on Embodiment 1, the limiting contact structure is an inwardly recessed arc-shaped reinforcing rib 31 located on the top surface of the tile nose 3; the cross-section of the arc-shaped reinforcing rib 31 is arc-shaped; the height of the lowest point of the arc-shaped reinforcing rib 31 is lower than the side height of the mounting side hole 4 near the top surface of the tile nose 3. From the above structure, it can be seen that, according to... Figure 1As shown in Figure a, the cross-section of the arc-shaped reinforcing rib 31 is an inwardly concave arc shape. This invention provides an arc-shaped reinforcing rib 31 on the top surface of the brake shoe nose 3, which on the one hand strengthens the overall structural strength of the brake shoe nose 3. When the brake shoe pin 6 is inserted into the two mounting side holes 4 of the brake shoe nose 3, the lowest point of the arc-shaped reinforcing rib 31 will directly contact and bear force with the outer surface of the brake shoe pin 6, ensuring the reliability of the connection. On the other hand, since the height of the lowest point of the arc-shaped reinforcing rib 31 is lower than the side height of the mounting side hole 4 near the top surface of the brake shoe nose 3, the arc-shaped reinforcing rib 31 can also limit the height of the outer surface of the brake shoe pin 6 after it enters the two mounting side holes 4. This ensures that the outer surface portion of the brake shoe pin 6 located in the two mounting side holes 4 does not directly contact the side of the mounting side hole 4 near the top surface of the brake shoe nose 3, but leaves a certain gap, thereby preventing stress concentration near the mounting side holes 4.

[0034] The height difference between the lowest point of the arc-shaped reinforcing rib 31 and the side edge of the mounting side hole 4 near the top surface of the brake shoe nose 3 is 2mm-3mm. As can be seen from the above structure, the height of the lowest point of the arc-shaped reinforcing rib 31 is slightly lower than the side edge of the mounting side hole 4 near the top surface of the brake shoe nose 3. This is to prevent the brake shoe pin 6 from directly contacting the side edge of the mounting side hole 4 near the top surface of the brake shoe nose 3 after assembly. The height difference between the two can be specifically adapted to the brake shoe model. For example, the height difference between the lowest point of the arc-shaped reinforcing rib 31 and the side edge of the mounting side hole 4 near the top surface of the brake shoe nose 3 can preferably be 2mm, 2.5mm, or 3mm.

[0035] The cross-section of the arc-shaped reinforcing rib 31 is semi-circular. As can be seen from the above structure, the curvature of the arc surface of the arc-shaped reinforcing rib 31 can be adaptively set according to the actual shape and size of the brake shoe pin 6 when the brake shoe and brake shoe holder 5 are assembled. Specifically, the curvature of the arc-shaped reinforcing rib 31 can be set to 180 degrees, that is, the cross-section of the arc-shaped reinforcing rib 31 is semi-circular.

[0036] The arc-shaped reinforcing rib 31 is located in the middle of the top surface of the tile nose 3. As can be seen from the above structure, the arc-shaped reinforcing rib 31 is located in the middle of the top surface of the tile nose 3, and the center point of the top surface of the tile nose 3 and the lowest point of the arc-shaped reinforcing rib 31 are on the same straight line. This ensures that after the arc-shaped reinforcing rib 31 bears the load, it can evenly distribute the stress to the surrounding area of ​​the top surface of the tile nose 3.

[0037] Example 3:

[0038] See attached Figures 1-6Based on Embodiment 2, the top surface of the tile nose 3 is flat; the connections between the top surface of the tile nose 3 and its left side, and between the top surface of the tile nose 3 and its right side, are all made using rounded transitions. As can be seen from the above structure, using rounded transitions at the connections between the top surface of the tile nose 3 and its left side, and between the top surface of the tile nose 3 and its right side, can eliminate stress concentration at sharp corners and increase the overall structural reliability.

[0039] The mounting side hole 4 is a rectangular through hole. As can be seen from the above structure, the mounting side hole 4 is designed as a rectangular through hole to match the shape of the brake shoe pin 6.

[0040] In the mounting side hole 4, the connection between two adjacent sides is made by a rounded transition. As can be seen from the above structure, the connection between two adjacent sides of the mounting side hole 4 is made by a rounded transition, which also increases the overall structural reliability of the mounting side hole 4.

[0041] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. Any equivalent structural or procedural transformations made based on the content of the present utility model specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present utility model.

Claims

1. A brake shoe for preventing stress concentration in the brake shoe nose, characterized in that: It includes a backing plate (1) and a friction body (2) connected to the inner side of the backing plate (1); the backing plate (1) has a protruding nose (3) in the center; the nose (3) has a limiting contact structure and two mounting side holes (4) symmetrically arranged on the left and right sides of the nose (3); the limiting contact structure is located on the top surface of the nose (3) and is used to limit the contact of the brake shoe pin (6) which passes through the two mounting side holes (4) to assemble the brake shoe and the brake shoe support (5), so that the outer side of the brake shoe pin (6) after assembly does not directly contact the side of any mounting side hole (4) near the top surface of the nose (3).

2. The brake shoe for preventing stress concentration in the brake shoe nose according to claim 1, characterized in that: The limiting contact structure is an arc-shaped reinforcing rib (31) that is recessed inward on the top surface of the tile nose (3); the cross section of the arc-shaped reinforcing rib (31) is arc-shaped; the height of the lowest point of the arc-shaped reinforcing rib (31) is lower than the side height of the mounting side hole (4) on the side closest to the top surface of the tile nose (3).

3. The brake shoe for preventing stress concentration in the brake shoe nose according to claim 2, characterized in that: The height difference between the lowest point of the arc-shaped reinforcing rib (31) and the height of the side edge of the mounting side hole (4) near the top surface of the tile nose (3) is 2mm-3mm.

4. The brake shoe for preventing stress concentration in the brake shoe nose according to claim 2, characterized in that: The cross-section of the arc-shaped reinforcing rib (31) is semi-circular.

5. The brake shoe for preventing stress concentration in the brake shoe nose according to claim 2, characterized in that: The arc-shaped reinforcing rib (31) is located in the middle of the top surface of the tile nose (3).

6. The brake shoe for preventing stress concentration in the brake shoe nose according to claim 1, characterized in that: The top surface of the tile nose (3) is a plane; the connection between the top surface of the tile nose (3) and the left side surface of the tile nose (3), and the connection between the top surface of the tile nose (3) and the right side surface of the tile nose (3) are all made by arc transition.

7. The brake shoe for preventing stress concentration in the brake shoe nose according to claim 1, characterized in that: The mounting side hole (4) is a rectangular through hole.

8. The brake shoe for preventing stress concentration in the brake shoe nose according to claim 1, characterized in that: In the mounting side hole (4), the connection between two adjacent sides is made by a circular arc transition.

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