Vehicle braking device and control method thereof

Abstract

The invention relates to a vehicle braking device and a control method thereof.The vehicle braking device comprises a braking clamp unit, the braking clamp unit is provided with a brake pad support, the brake pad support is of a three-section type, and the upper-section brake pad support and the lower-section brake pad support are arranged on a clamp pin shaft of a braking clamp in a sliding mode; the brake clamp unit further comprises an elastic piece used for driving the upper-section brake pad support and the lower-section brake pad support to move towards the middle-section brake pad support, and guide structures used for enabling the upper-section brake pad support and the lower-section brake pad support to move away from each other when the middle-section brake pad support is pushed out are arranged between the middle-section brake pad support and the upper-section brake pad support and between the middle-section brake pad support and the lower-section brake pad support. When the middle-section brake pad support is retracted or the upper-section brake pad support and the lower-section brake pad support are pushed out, the upper-section brake pad support and the lower-section brake pad support move oppositely under the action of the elastic piece and the guide structure and collide with the middle-section brake pad support to achieve slag removal. According to the control method of the vehicle braking device, accurate control over the braking force is achieved, and braking force failure caused by too high temperature is avoided.

Description

Technical Field

[0001] This application relates to the field of rail vehicles, specifically a vehicle braking device with segmented brake pad support, and proposes a control method for the braking device. Background Technology

[0002] With the continuous and rapid development of rail transit and the increasing station spacing, there are more and more subway vehicles with speeds exceeding 100 km / h. According to heat capacity calculations and braking distance calculations, the tread braking with brake shoes as the main friction material has insufficient heat load and cannot meet the braking requirements at an initial speed of 100 km / h. Therefore, a disc braking type with a higher heat load has been adopted, namely composite brake pads with cast iron brake discs. The composite brake pads are integrally heat-treated and pressed, with unloading grooves on the friction surface. During braking, the vehicle's kinetic energy is converted into thermal energy through frictional heat generation. During the friction process, the composite brake pads will produce waste particles of a certain size, which accumulate in the unloading grooves, affecting braking performance. Moreover, the braking force is related to the air pressure input to the brake cylinder. Once the pressure is determined, the braking force is usually a fixed value, and it is impossible to adjust the appropriate braking force according to the current braking conditions of the vehicle, resulting in resource waste. During continuous braking, the surface temperature of the brake pads rises without monitoring and adjustment. Once the temperature exceeds the limit, cracks and chipping will occur in the brake disc and brake pads, affecting driving safety.

[0003] In order to ensure the stability of friction performance, the existing brake pad structure has a relatively tight arrangement of friction blocks, which makes it impossible to discharge waste in time, affecting the braking effect. At the same time, the braking force is fixed and cannot be adjusted, and the temperature continues to rise, increasing the wear of the brake pads. Summary of the Invention

[0004] In view of the problems existing in the prior art, the present invention proposes a vehicle braking device with segmented brake pad support and a control method for the braking device, which can comprehensively solve the above problems, clean up waste during braking, adjust braking force, and have temperature control function for brake pads.

[0005] Therefore, the specific technical solution adopted by the present invention is as follows: A vehicle braking device includes a brake caliper unit, wherein the brake caliper unit has a brake pad support for fixing the brake pads, characterized in that: the brake pad support includes an upper brake pad support, a middle brake pad support, and a lower brake pad support, the upper brake pad support and the lower brake pad support are slidably disposed on the clamping pin of the brake caliper, the brake caliper unit further includes an elastic element for driving the upper brake pad support and the lower brake pad support to move toward the middle brake pad support, a guide structure is provided between the middle brake pad support and the upper brake pad support, and between the middle brake pad support and the lower brake pad support, the guide structure is used to cause the upper brake pad support and the lower brake pad support to move away from each other when the middle brake pad support is pushed out, and when the middle brake pad support is retracted or the upper brake pad support and the lower brake pad support are pushed out, the upper brake pad support and the lower brake pad support move toward each other under the action of the elastic element and the guide structure and collide with the middle brake pad support to achieve slag removal.

[0006] This invention designs the brake pad support as a three-section structure. The middle section brake pad support can be driven independently by a rear motor to output braking force, while the upper and lower sections are driven by brake calipers to output braking force. During normal use, braking is applied using the middle section brake pad support. When the middle section brake pad support extends, the upper and lower sections move backward. When a change in braking force is needed, the middle section brake pad support retracts, and the upper and lower sections merge, causing them to collide with the middle section brake pad support. This impact and vibration shakes off any waste material carried on the brake pads, completing the waste material cleaning function.

[0007] Furthermore, a temperature sensor can be installed on the brake pad support to measure the temperature on the back of the brake pad. When the temperature is high, the braking force input can be reduced to prevent the temperature from rising further. Additionally, different friction coefficients can be set for the middle brake pad and the upper and lower brake pads, allowing for high-friction and low-friction settings, resulting in more precise friction control.

[0008] This invention also relates to a control method for the aforementioned vehicle braking device, characterized in that, during initial braking, the middle brake pad support is pushed out, and the temperature of the middle brake pad is read in real time during the pushing out process. A first temperature limit is set. When the temperature of the middle brake pad reaches the first temperature limit, the middle brake pad support is pushed back, and the upper and lower brake pad supports are pushed out and quickly tightened under the action of the elastic element and the guide structure, colliding with the middle brake pad support. The vibration generated by the collision causes the waste material to be shaken off, thus achieving waste material cleaning. Then, the temperature of the upper and lower brake pads is read in real time. When the temperature of the upper or lower brake pad reaches the first temperature limit, the upper and lower brake pad supports are retracted, and it is determined whether the temperature of the middle brake pad has dropped below a second temperature limit. If the temperature of the middle brake pad is lower than the second temperature limit, the middle brake pad support can be pushed out. If the temperature of the middle brake pad exceeds the second temperature limit, the brake pad with the lower temperature is selected for braking, and the corresponding brake pad support is pushed out. The first temperature limit is higher than the second temperature limit.

[0009] The control method of the vehicle braking device of the present invention achieves precise control of braking force and avoids braking force failure due to excessive temperature. Attached Figure Description

[0010] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 This is a schematic diagram of one embodiment of the brake caliper unit.

[0012] Figure 2 This is a perspective view of the brake pad support in Embodiment 1 of the brake caliper unit.

[0013] Figure 3 This is an exploded view of the brake pad support in Embodiment 1 of the brake caliper unit.

[0014] Figure 4 This is a perspective view of the brake pad support in Embodiment 2 of the brake caliper unit.

[0015] Figure 5 This is an exploded view of the brake pad support in Embodiment 2 of the brake caliper unit.

[0016] The icon numbers are illustrated below: 1. Upper brake pad support; 2. Middle brake pad support; 3. Lower brake pad support; 4. Drive motor; 5. Mounting bushing; 61. Upper elastic element; 62. Lower elastic element; 7. Spring tube; 8. Guide block; 91. Upper guide rod; 92. Lower guide rod; 10. Brake cylinder; 11. Brake pad; 12. Clamp lever. Detailed Implementation

[0017] To further illustrate the various embodiments, the present invention provides accompanying drawings, which are part of the disclosure of the present invention. These drawings are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these drawings, those skilled in the art should be able to understand other possible implementation methods and the advantages of the present invention. The components in the drawings are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0018] Example 1 like Figure 1The diagram shows a brake caliper unit for a vehicle braking system, specifically a disc brake. As shown, the brake caliper unit includes a brake cylinder 10, a brake caliper, and brake pads 11. The brake caliper mainly includes a caliper lever 12 and a brake pad holder for fixing the brake pads 10. The brake cylinder 10 is located at the rear end of the caliper lever 12 and outputs braking force. The torque output by the brake cylinder acts on the caliper lever 12, causing the brake pads 10, fixed on the brake pad holder, to grip the brake disc, thereby achieving braking. A gap adjuster is located inside the brake cylinder and is used to adjust the disc-pad gap. Figure 1 The example shown is a brake caliper unit of a disc brake. Other forms exist, such as a brake cylinder that drives a brake lever via an eccentric shaft to clamp the brake disc, with the clearance adjuster located at the rear end of the caliper lever.

[0019] like Figure 2 , Figure 3 As shown, the brake pad support of the brake caliper unit in this embodiment includes a middle brake pad support 2, an upper brake pad support 1 and a lower brake pad support 3, which are slidably disposed on the caliper pin and located on the upper and lower sides of the middle brake pad support 2, respectively. A drive motor 4 is fixed to the back of the middle brake pad support 2. The housing of the drive motor 4 is fixed to the housing of the brake caliper, and the output head of the drive motor 4 is fixed to the back of the middle brake pad support 2. The drive motor 4 is used to drive the middle brake pad support 2 to move back and forth. Figures 2 to 3 As shown, mounting bushings 5 ​​are provided on the back of both the upper brake pad support 1 and the lower brake pad support 3. The upper brake pad support 1 and the lower brake pad support 3 are slidably mounted on the clamping pin of the brake caliper via the mounting bushings 5. Simultaneously, the upper brake pad support 1 and the lower brake pad support are rotatably mounted on the clamping rod via the mounting bushings, ensuring that the brake pad supports on both sides are parallel to the brake disc. The brake cylinder drives the clamping rod to move, clamping the brake pad supports to achieve braking. The braking surfaces of the brake pad supports on both sides are kept parallel to the brake disc by brake pad support hangers (not shown in the figure). Alternatively, a brake pad anti-wear mechanism of the sliding groove-pull rod type can be used. Since the brake pad supports are segmented, in this embodiment, the clamping pin located at the front end of the clamping rod is also segmented. The upper clamping pin passes through the upper mounting bushing to fix the upper brake pad support to the front end of the clamping lever of the brake caliper, and the lower clamping pin passes through the lower mounting bushing to fix the lower brake pad support to the front end of the clamping lever of the brake caliper.

[0020] In this embodiment, guide structures are provided between the middle section brake pad support 2 and the upper section brake pad support 1, and between the middle section brake pad support 2 and the lower section brake pad support 3. Specifically, as follows: Figure 2 , Figure 3As shown, the guiding structure includes a dovetail-shaped guide block 8 on the back of the middle brake pad support 2, and working surfaces on the side of the upper brake pad support 1 and lower brake pad support 3 near the middle brake pad support 2 that mate with the upper and lower guide surfaces of the guide block 8. The upper and lower guide surfaces of the guide block 8 converge towards the braking direction. In this embodiment, the upper and lower guide surfaces of the guide block 8 are planar, but they can also be curved surfaces. The function of this guiding structure is to cause the upper brake pad support 1 and the lower brake pad support 3 to move in opposite directions under the sliding action of the guide block 8 and the working surfaces when the middle brake pad support 2 is pushed out by the motor. That is, when the middle brake pad support is pushed out, the upper brake pad support 1 moves upward and the lower brake pad support 3 moves downward. Figure 2 , Figure 3 As shown, the vehicle braking device of this embodiment also has an elastic element for driving the upper brake pad support 1 and the lower brake pad support 3 to move towards the middle brake pad support 2. This elastic element includes an upper elastic element 61 and a lower elastic element 62 sleeved on the clamping pin. The upper elastic element 61 abuts against the upper end face of the mounting bushing 5 corresponding to the upper brake pad support 1, and the lower elastic element 62 abuts against the lower end face of the mounting bushing 5 corresponding to the lower brake pad support 3. When the drive motor 5 drives the middle brake pad support 2 to retract, the upper brake pad support 1 and the lower brake pad support 3 are reset by the upper elastic element 61 and the lower elastic element 62 respectively abutting against the mounting bushings fixed to the upper brake pad support 1 and the lower brake pad support 3, that is, the upper brake pad support 1 and the lower brake pad support 3 move towards the middle brake pad support 2 respectively. This allows the upper brake pad support 1 and the lower brake pad support 3 to move towards each other under the action of the elastic element and the guiding structure, and to collide with the middle brake pad support 2, thereby shaking off the powder or debris generated by the brake pads during braking. The same collision can also occur when the upper brake pad support 1 and the lower brake pad support 3 are extended, and the process is similar to that of the extension of the middle brake pad support 3.

[0021] The vehicle braking device of this invention also includes a temperature sensor for detecting the brake pad temperature. The temperature sensor is installed in a mounting hole on the back of the brake pad holder. Specifically, one temperature sensor needs to be installed on the middle brake pad holder 2 to detect the temperature of the middle brake pad. The upper and lower brake pad holders can each have a temperature sensor installed, or both can have temperature sensors installed. By detecting the temperature of the middle and upper brake pads, segmented control of the brake pad holders is achieved, preventing brake force attenuation due to excessively high brake pad temperature, thereby realizing precise control of braking force.

[0022] The control method for the vehicle braking device in this embodiment is as follows: During initial braking, the middle brake pad support 2 is extended. During this extension, a temperature sensor on the middle brake pad support continuously monitors the temperature of the middle brake pads, setting a first temperature limit of 450℃. When the temperature of the middle brake pads reaches this first limit, the middle brake pad support 2 retracts, and the brake cylinder drives the clamp lever to extend the upper brake pad support 1 and the lower brake pad support 3. At this point, the upper brake pad support 1 and the lower brake pad support 3 quickly tighten under the action of the elastic element and guide structure, colliding with the middle brake pad support 2. The vibration generated by the collision causes the waste material to be shaken off, achieving waste material cleaning. At this time, the upper brake pad support 1 and the lower brake pad support 3 participate in the braking force output; then, the temperature of the upper brake pad and / or the lower brake pad is read in real time. When the temperature of the upper or lower brake pad reaches the first temperature limit of 450℃, the upper brake pad support 1 and the lower brake pad support 3 are retracted, and it is determined whether the temperature of the middle brake pad has dropped below the second temperature limit of 200℃. If the temperature of the middle brake pad is lower than the second temperature limit of 200℃, the middle brake pad support 2 can be pushed out. If the temperature of the middle brake pad exceeds the second temperature limit of 200℃, the brake pad with the lower temperature is selected for braking, and the corresponding brake pad support is pushed out. In this embodiment, the first temperature limit and the second temperature limit are given as reference values. Generally, the first temperature limit is set within a certain range according to the material. In this embodiment, the brake pads on the middle brake pad support and the brake pads on the upper and lower brake pad supports are DC-70 powder metallurgy brake pads for railway passenger cars produced by CRRC Qishuyan Locomotive & Rolling Stock Technology Research Institute Co., Ltd. The recommended range for the first temperature limit is 425-475℃; the recommended range for the second temperature limit is 175-225℃.

[0023] Example 2 In the vehicle braking device of the present invention, the elastic element and guiding structure of the brake caliper unit can also take other forms, such as... Figure 4 , Figure 5 As shown, in this embodiment, the brake pad support of the vehicle braking device has an elastic element that is a spring tube 7 installed between the back of the upper brake pad support 1 and the back of the lower brake pad support 3. The tension of the spring tube 7 enables the upper brake pad support 1 and the lower brake pad support 3 to reset, allowing them to collide with the intermediate brake pad support 2 at the end of the reset phase to remove debris. Figure 4 , Figure 5In this embodiment, the guiding structure includes a guide block 8 fixed to the back of the middle brake pad support 2, an upper guide rod 91 disposed on the back of the upper brake pad support 1, and a lower guide rod 92 disposed on the back of the lower brake pad support 3. The guide block 8 has two guide surfaces located on its upper and lower sides. The lower part of the upper guide rod 91 cooperates with the upper guide surface of the guide block 8, and the upper part of the lower guide rod 92 cooperates with the lower guide surface of the guide block 8. The upper and lower guide surfaces of the guide block 8 converge towards the braking direction. When the middle brake pad support 2 is pushed out by the motor, with the cooperation of the guide block 8, the upper guide rod 91, and the lower guide rod 92, the upper brake pad support 1 and the lower brake pad support 3 move upward and downward respectively, using the brake pads on the middle brake pad support 2 to rub against the brake disc, thereby performing braking. When the drive motor 5 retracts the middle section brake pad support 2, under the pulling force of the spring tube 7 and the cooperation of the guide block 8 with the upper guide rod 91 and the lower guide rod 92, the upper section brake pad support 1 and the lower section brake pad support 3 move towards the middle and collide with the middle section brake pad support 2, thereby achieving slag removal. This process is the same as in Example 1.

[0024] The brake pad support of this invention is mainly composed of three sections cast and welded from metal materials, which are then fitted with three brake pads of corresponding sizes and mounted on the brake caliper. When air braking is applied, the brake pad support moves towards the brake disc and eventually clamps the brake disc, achieving a vehicle deceleration effect through friction.

[0025] In this embodiment, the upper brake pad support has an upper interface with the clamp, namely a circular bushing, which can be installed in conjunction with the clamp pin. A small hole is opened on the back of the brake pad support for connecting a temperature sensor to monitor the temperature of the upper brake pad in real time. Small bent ribs are welded to both sides of the back, fitting snugly against the middle brake pad support. Two bent hollow tubes, each containing a spring, are welded to the middle section and connected to the lower brake pad support at the same position. The back of the middle brake pad support is connected to the output head of the drive motor, which is then fixed to the clamp or frame. The drive motor can extend or retract the middle brake pad support. The middle brake pad support can accommodate brake pads with different friction coefficients than the upper and lower sections, achieving braking force adjustment. Meanwhile, steel plates of a specific shape are welded to both sides of the back. These steel plates cooperate with the bending ribs of the upper and lower brake pad supports. When the middle brake pad support extends, the cooperating inclined surfaces will push the upper and lower brake pad supports to move up and down respectively, clearing the middle position. After the middle brake pad support is pushed out, it will brake first. When the middle section is released, it will retract under the drive of the motor shaft. At this time, the spring connection between the upper and lower sections will be stretched and will bounce back to the middle together. Under the rapid merging action, the waste will be shaken off, completing the waste cleaning function. The lower brake pad support is mostly the same as the upper section, except that a locking device for the limit brake pad is added at the lower end (belonging to the existing technical field). After the brake pad is installed from bottom to top, the locking device ensures that the brake pad will not fall out.

[0026] Initially, the middle section brake pad is used for braking. When the temperature is too high, it is replaced with the upper and lower sections. During the replacement process, waste materials are cleaned up. Different friction coefficient brake pads can be installed on the upper and lower section brake pad holders and the middle section brake pad holder, and the braking force can also be adjusted to meet the current requirements for disc brake pads.

[0027] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A vehicle braking device, comprising a brake caliper unit, the brake caliper unit having a brake pad holder for fixing brake pads, characterized in that: The brake pad support includes an upper brake pad support (1), a middle brake pad support (2), and a lower brake pad support (3). The upper brake pad support (1) and the lower brake pad support (3) are slidably mounted on the clamping pin of the brake caliper. The brake caliper unit also includes an elastic element for driving the upper brake pad support (1) and the lower brake pad support (3) toward the middle brake pad support (2). The middle brake pad support (2) is positioned between the upper brake pad support (1) and the lower brake pad support (3). A guide structure is provided between the section brake pads (3). The guide structure is used to make the upper section brake pad (1) and the lower section brake pad (3) move away from each other when the middle section brake pad (2) is pushed out. When the middle section brake pad (2) is retracted or when the upper section brake pad (1) and the lower section brake pad (3) are pushed out, the upper section brake pad (1) and the lower section brake pad (3) move towards each other under the action of the elastic element and the guide structure and collide with the middle section brake pad (2) to achieve slag removal.

2. The vehicle braking device according to claim 1, characterized in that, The upper brake pad support (1) and the lower brake pad support (3) are both provided with mounting bushings. The upper brake pad support (1) and the lower brake pad support (3) are slidably mounted on the clamping pin of the brake caliper through the mounting bushings (5).

3. The vehicle braking device according to claim 2, characterized in that, The clamp pin is located at the front end of the clamp rod and is segmented. The clamp pin passes through the mounting bushing to fix the brake pad support to the brake caliper.

4. The vehicle braking device according to claim 3, characterized in that, The elastic element includes an upper elastic element (61) and a lower elastic element (62) sleeved on the clamp pin. The upper elastic element (61) abuts against the upper end face of the mounting bushing (5) of the upper brake pad support (1), and the lower elastic element (62) abuts against the lower end face of the mounting bushing (5) of the lower brake pad support (3); or the elastic element is a spring tube (7) installed between the back of the upper brake pad support (1) and the back of the lower brake pad support (3).

5. The vehicle braking device according to claim 1, characterized in that, The guiding structure includes a dovetail-shaped guide block (8) on the back of the middle brake pad support (2), and working surfaces that cooperate with the upper and lower guide surfaces of the guide block (8) on the side of the upper brake pad support (1) and the lower brake pad support (3) near the middle brake pad support (2). The upper and lower guide surfaces of the guide block (8) converge toward the braking direction. The upper and lower guide surfaces of the guide block (8) are planar or curved surfaces.

6. The vehicle braking device according to claim 1, characterized in that, The guiding structure includes a guide block (8) fixed to the back of the middle section brake pad support (2), an upper guide rod (91) set on the back of the upper section brake pad support (1), and a lower guide rod (92) set on the back of the lower section brake pad support (3). The guide block (8) has two guide surfaces located on the upper and lower sides. The lower part of the upper guide rod (91) cooperates with the upper guide surface of the guide block (8), and the upper part of the lower guide rod (92) cooperates with the lower guide surface of the guide block (8). The upper and lower guide surfaces of the guide block (8) converge towards the braking direction. The upper and lower guide surfaces of the guide block (8) are planar or curved surfaces.

7. The vehicle braking device according to claim 1, characterized in that, There is also a drive motor for driving the middle section brake pad support (2) to move back and forth. The housing of the drive motor is fixed to the brake caliper, and the output head of the drive motor is fixed to the back of the middle section brake pad support (2).

8. The vehicle braking device according to claim 2, characterized in that, It also includes a temperature sensor for detecting the temperature of the brake pads, the temperature sensor being installed in a mounting hole on the back of the brake pad support.

9. The control method for the vehicle braking device according to claim 8, characterized in that, During initial braking, the middle section brake pad support (2) is pushed out. During the pushing out process, the temperature of the middle section brake pad is read in real time, and a first temperature limit is set. When the temperature of the middle section brake pad reaches the first temperature limit, the middle section brake pad support (2) is pushed back. The upper section brake pad support (1) and the lower section brake pad support (3) are pushed out and quickly tightened under the action of the elastic element and the guide structure, and collide with the middle section brake pad support (2). The vibration generated by the collision causes the waste material to be shaken off, realizing the waste material cleaning. Then, the upper section brake pad support (1) and the lower section brake pad support (3) are read in real time. The temperature of the upper and lower brake pads is determined. When the temperature of the upper or lower brake pad reaches the first temperature limit, the upper brake pad support (1) and the lower brake pad support (3) are retracted. It is then determined whether the temperature of the middle brake pad has dropped below the second temperature limit. If the temperature of the middle brake pad is lower than the second temperature limit, the middle brake pad support (2) can be pushed out. If the temperature of the middle brake pad exceeds the second temperature limit, the brake pad with the lower temperature is selected for braking, and the corresponding brake pad support is pushed out. The first temperature limit is higher than the second temperature limit.

10. The control method for the vehicle braking device according to claim 9, characterized in that, The first temperature limit ranges from 425 to 475°C, and the second temperature limit ranges from 175 to 225°C.

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