Parking brake device for railway vehicle

Abstract

The invention discloses a parking brake device for a railway vehicle. The parking brake device aims to overcome the defects that an existing parking brake device adopting a spring energy storage mode is large in weight, high in cost and low in reliability. A brake piston is adopted to drive a brake shoe to brake wheels, a parking structure is additionally arranged, the parking structure comprises a control pressing block and a connecting rod driving the control pressing block to move, the moving stroke of the control pressing block comprises a limiting position and a non-limiting position except the limiting position, and a linkage rod is fixedly connected to the brake piston. The moving stroke of the linkage rod comprises a braking position and a non-braking position, the braking piston drives the brake shoe to abut against the wheel at the braking position, and the braking piston retreats to enable the brake shoe to be separated from the wheel at the non-braking position; when the control pressing block is located at the limiting position, the control pressing block can limit the linkage rod to be separated from the braking position by reaching the limiting position. By arranging a pneumatic parking structure, the fatigue risk of an energy storage spring is avoided, and the advantages of being low in cost, high in reliability and small in occupied space are achieved.

Description

Technical Field

[0001] The invention relates to the field of rail transit braking, and more particularly to a parking brake device for rail vehicles. Background Art

[0002] The spring energy storage parking brake device widely used in rail transit vehicles currently has a core braking principle based on compressed air driving the control piston to compress the energy storage spring (usually a coil spring) to achieve braking by storing mechanical energy. When the parking brake needs to be applied, the system releases the compressed air, and the elastic potential energy of the energy storage spring is converted into mechanical thrust, pushing the brake push rod to make the brake shoe press against the wheel. To maintain the braking state, traditional devices rely on mechanical structures to lock the screw nut mechanism or similar rotating transmission parts to prevent them from rotating to relieve parking.

[0003] However, this technology has significant defects: first, the manufacturing requirements and lubrication requirements of rotating parts such as lead screws, nuts, bearings, and energy storage springs are high. The energy storage spring and parking brake piston assembly are bulky as a whole. The complex structure of the device leads to high manufacturing and maintenance costs, making it difficult to adapt to the requirements of lightweight and space-sensitive models such as subways and light rails. In addition, the mechanical reliability problem is prominent. The lead screw nut and bearing are prone to jamming due to grease drying or metal fatigue in a long-term vibration environment. The energy storage spring will produce plastic deformation under cyclic loads, resulting in a decrease in the brake holding force. In addition, the increased viscosity of the grease in a low-temperature environment may cause hysteresis or even failure. Summary of the invention

[0004] The present invention overcomes the shortcomings of the existing spring energy storage structure parking brake, which has high cost, heavy weight and low reliability, and provides a parking brake device for rail vehicles, which can reduce the space occupied by the structure, reduce weight, reduce manufacturing and maintenance costs and improve reliability.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions: A parking brake device for a rail vehicle, comprising: Brake shoe, which moves in the radial direction of the wheel; The brake piston is arranged in the brake cylinder and is connected to the brake shoe transmission. The brake piston is elastically connected to a piston spring. The air pressure generated by the air pressure in the brake cylinder is opposite to the elastic force of the piston spring. The combined force of the air pressure and the elastic force drives the brake piston to move. The parking structure includes a parking box shell, a control pressing block and a connecting rod for driving the control pressing block to move; Among them, the moving stroke of the control pressure block includes a restricted position and a non-restricted position other than the restricted position. A linkage rod is connected to the brake piston. The moving stroke of the linkage rod includes a braking position and a non-braking position. In the braking position, the brake piston drives the brake shoe to press on the wheel. In the non-braking position, the brake shoe retreats and disengages from the wheel. When the control pressure block is in the restricted position, the control pressure block can reach the restricted position to limit the linkage rod from disengaging from the braking position.

[0006] The movement of the brake piston is limited by the control block and the connecting rod, and it is kept in the braking position. This setting allows the brake piston to maintain the current braking position even if the air pressure in the brake cylinder disappears, thereby maintaining the contact between the brake shoe and the wheel. The movement of the linkage rod is limited by the control block to ensure the certainty of the switching of the braking state. The use of a connecting rod structure to drive the control block simplifies the control structure and reduces the failure rate. Even if the pneumatic system fails, the mechanical locking structure can still maintain the braking state to avoid the risk of slipping.

[0007] This solution is more scalable than the mechanical solution. When the parking brake pneumatic control cannot be unlocked due to a malfunction, the control pressure block can be forcibly moved to a non-restricted position through external operation to remove interference with the linkage rod, ensuring that the brake shoe is reliably separated from the wheel, and providing more redundancy for vehicle movement.

[0008] Preferably, along the radial direction of the wheel, the brake shoe is connected to a brake rod assembly, the brake rod assembly is inserted into the brake cylinder and slidably connected to the brake cylinder, and a brake wedge is provided at the lower part of the brake piston, and when the brake piston moves, the wedge surface of the brake wedge pushes the brake rod assembly to move. The function of the structure is to push the brake rod assembly through the wedge surface of the brake wedge to amplify the force, thereby increasing the braking pressure of the brake shoe on the wheel.

[0009] Preferably, the top of the brake cylinder is provided with an air brake inlet and outlet, and the piston spring is connected to the lower part of the brake piston. When the top of the brake cylinder is inflated, the air pressure in the brake cylinder increases, and the brake piston is forced to overcome the mechanical force of the piston spring and moves downward; conversely, if the air pressure is less than the elastic force, the brake piston moves in the opposite direction and no longer applies force to the brake shoe to abut against the wheel.

[0010] Preferably, the connecting rod comprises a hinge point, a control rod and a driver, the control rod comprises a long rod and a short rod, the connection between the long rod and the short rod is hingedly connected to the hinge point, the driver drives the control rod to rotate around the hinge point, and the control pressing block is pushed and displaced by the short rod. The connecting rod is used to drive the movement of the control pressing block. Specifically, when the connecting rod is driven by the driver to rotate, the short rod will drive the driving pressing block to follow, thereby moving to the restricted position or leaving the restricted position.

[0011] Preferably, the driver comprises a parking cylinder and a parking piston slidably connected in the parking cylinder, a parking spring is elastically connected below the parking piston, a parking rod is fixedly connected above the parking piston, a parking brake air inlet and outlet are provided at the top of the parking cylinder, and the parking rod and the long rod are movably connected. The driver is pneumatically controlled to supply air to the parking cylinder, and the parking piston is driven to move up or down according to the pressure difference between the force generated by the air pressure in the parking cylinder and the elastic force, thereby driving the long rod to move. Restricted by the hinge point, the control rod can only rotate clockwise or counterclockwise.

[0012] Preferably, the driver comprises a hand lever, the long rod and the hand lever are movably connected, and the hand lever extends out of the parking box housing. When the driver is controlled by hand, the hand lever extending out of the parking box pulls the rotation of the control rod.

[0013] Preferably, a hoop is mounted on the long rod and slidably connected thereto, and the hoop is fixedly connected to the parking rod. The long rod and the parking rod are movably connected through the sliding cooperation between the hoop and the long rod.

[0014] Preferably, the long rod is provided with an oblong hole, and the end of the hand lever is provided with a barb, which is inserted into the oblong hole. The long rod and the hand lever are movably connected through the sliding fit between the barb and the oblong hole.

[0015] Preferably, the end of the short rod is inserted into the deep groove in the middle of the control pressing block, and the end of the short rod can slide in the groove during rotation. This structure is used to allow the short rod to always drive the control pressing block during the rotation process.

[0016] Preferably, a deep groove is provided in the middle of the control pressure block, and a wedge surface is provided at one end close to the linkage rod. When the linkage rod has a slight height change during braking due to brake shoe clearance, manufacturing process or other reasons, the control pressure block can increase or decrease its displacement to always press on the linkage rod, thereby ensuring the fit between the brake shoe and the wheel.

[0017] Compared with the prior art, the present invention has the following beneficial effects: (1) Mechanical locking replaces spring energy storage to avoid the risk of energy storage spring fatigue; (2) Dual protection of mechanical locking and manual unlocking to ensure safety redundancy under extreme working conditions; (3) The compact structure greatly reduces the volume and weight of the parking cylinder, reducing installation space requirements and maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the air brake application and parking relief state of the present invention; Figure 2 yes Figure 1 The enlarged view of point A in the middle; Figure 3 It is a schematic diagram of the air brake relief and parking relief states of the present invention; Figure 4 is a schematic diagram of the air brake and parking application state of the present invention; In the figure: Brake shoe 1, wheel 2, brake piston 3, brake cylinder 4, piston spring 5, parking box housing 6, control pressure block 7, restricted position 8, non-restricted position 9, linkage rod 10, non-braking position 11, braking position 12, brake rod assembly 13, brake wedge 14, air brake air inlet and outlet 15, hinge point 16, control rod 17, long rod 18, short rod 19, parking cylinder 20, parking piston 21, parking spring 22, hand lever 23, brake wedge surface 24, pressure block guide seat 25, parking rod 26, control pressure block wedge surface 27, parking brake air inlet and outlet 28. DETAILED DESCRIPTION

[0019] The present disclosure is further described below in conjunction with the accompanying drawings and embodiments.

[0020] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0021] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0022] In the present disclosure, terms such as "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "side", "bottom" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. They are relational words determined only for the convenience of describing the structural relationships of the various parts or elements of the present disclosure, and do not specifically refer to any part or element in the present disclosure and should not be understood as limitations on the present disclosure.

[0023] In the present disclosure, terms such as "fixed connection", "connected", "connection", etc. should be understood in a broad sense, indicating that it can be fixedly connected, integrally connected or detachably connected; it can be directly connected or indirectly connected through an intermediate medium. For relevant scientific research or technical personnel in this field, the specific meanings of the above terms in the present disclosure can be determined according to specific circumstances, and they cannot be understood as limitations on the present disclosure.

[0024] Example: A parking brake device for a rail vehicle, Figure 1 As shown, it includes a brake shoe 1, a brake piston 3 and a parking structure.

[0025] The brake shoe 1 moves in the radial direction of the wheel 2; the brake shoe 1 abuts against the wheel 2 and applies a braking force to the wheel 2 through friction.

[0026] Brake piston 3, brake piston 3 is arranged in brake cylinder 4 and is transmission-connected with brake shoe 1. Brake cylinder 4 is provided with piston spring 5, brake piston 3 is elastically connected with piston spring 5, and brake piston 3 and brake cylinder 4 are sealed and connected. Air brake inlet and outlet 15 are arranged at the top of brake cylinder 4. The pressure generated by the air pressure in brake cylinder 4 is opposite to the elastic force of piston spring 5, and the combined force of air pressure and elastic force drives brake piston 3 to move. When the top of brake cylinder 4 is inflated, the air pressure in brake cylinder 4 increases, and brake piston 3 is forced to overcome the mechanical force of piston spring 5 and move downward; on the contrary, if the air pressure is less than the elastic force, brake piston 3 moves in the opposite direction and no longer applies force to brake shoe 1 against wheel 2.

[0027] The piston spring 5 is used to control the return of the brake piston 3 .

[0028] Along the radial direction of the wheel 2, the brake shoe 1 is connected with a brake rod assembly 13, the brake rod assembly 13 is inserted into the brake cylinder 4 and is slidably connected with the brake cylinder 4, and a brake wedge 14 is provided at the lower part of the brake piston 3. When the brake piston 3 moves, the wedge surface 24 of the brake wedge 14 pushes the brake rod assembly 13 to move. The function of the structure is to push the brake rod assembly 13 through the wedge surface 24 of the brake wedge 14 to amplify the force, thereby increasing the braking force of the brake shoe 1 on the wheel 2.

[0029] In some embodiments, the end of the brake rod assembly 13 away from the brake shoe 1 is cylindrical, which is easier to contact with the wedge surface 24. In other embodiments, the brake wedge surface 24 is provided with a slide groove, and the end of the brake rod assembly 13 is slidably connected in the slide groove.

[0030] Ginseng Figure 1 and Figure 2 As shown, the parking structure is a safety device for keeping the brake shoe 1 in contact with the wheel 2 when the train is parked for a long time. Even if the brake cylinder 4 loses pressure, the brake shoe 1 can still be ensured to be in contact with the wheel 2. The parking structure includes a parking box housing 6, a control pressure block 7, and a control rod 17 for driving the control pressure block 7 to move. The control pressure block 7 and the control rod 17 for driving the control pressure block 7 to move are arranged inside the parking box housing 6.

[0031] The control pressing block 7 is slidably connected in the pressing block guide seat 25, and the control pressing block 7 has a degree of freedom in a moving direction. The control rod 17 rotates to drive the control pressing block 7 to move. The moving stroke of the control pressing block 7 includes a restricted position 8 and a non-restricted position 9 other than the restricted position 8.

[0032] A linkage rod 10 is connected to the brake piston 3, and the moving stroke of the linkage rod 10 includes a braking position 12 and a non-braking position 11. At the braking position 12, the brake piston 3 drives the brake shoe 1 to fit the wheel 2. At the non-braking position 11, the brake piston 3 retreats and the brake shoe 1 is separated from the wheel 2.

[0033] Reference Figure 4 When the control pressure block 7 is in the limiting position 8, the control pressure block 7 can reach the limiting position 8 to limit the linkage rod 10 from leaving the braking position 12. Through the above operation, even if the gas loss of the brake cylinder 4 reduces the pressure, the existence of the control pressure block 7 can also ensure that the brake shoe 1 abuts against the wheel 2.

[0034] The connecting rod includes a hinge point 16, a control rod 17 and a driver. The control rod 17 includes a long rod 18 and a short rod 19. In some embodiments, the long rod 18 and the short rod 19 are an integrated structure and are L-shaped. The connection between the long rod 18 and the short rod 19 is hingedly connected to the hinge point 16. The driver drives the control rod 17 to rotate around the hinge point 16. The driver drives the control rod 17 to rotate; the control pressing block 7 is driven to move by the short rod 19. Specifically, when the control rod 17 is driven by the driver to rotate, the short rod 19 will drive the control pressing block to move with it, so as to move to the restricted position 8 or leave the restricted position 8. The end of the short rod 19 is inserted into the deep groove of the control pressing block 7. When the short rod 19 moves, the short rod 19 pushes the side wall of the deep groove to drive the control pressing block 7 to move. By adjusting the depth of the deep groove, the short rod is in the deep groove within the travel range of the short rod and can push the deep groove to move. Another way is that the end of the short rod 19 is a gas strut, the length of the gas strut can be compressed and shortened, and the end of the gas strut is hingedly connected to the control pressing block 7. Other active connection modes can also be included, and are not limited to this.

[0035] The driver includes a parking cylinder 20 and a parking piston 21 slidably connected in the parking cylinder 20, a parking spring 22 is elastically connected below the parking piston 21, a parking rod 26 is fixedly connected above the parking piston 21, a parking brake air inlet and outlet 28 is provided at the top of the parking cylinder 20, and the parking rod 26 is movably connected to the long rod 18. The driver is pneumatically controlled to supply air to the parking cylinder 20. According to the pressure difference between the force generated by the air pressure in the parking cylinder 20 and the elastic force, the parking piston 21 moves up or down, driving the long rod 18 to move, and the control rod 17 rotates clockwise or counterclockwise under the restriction of the hinge point 16.

[0036] Similar to the movement of the brake cylinder 4, when the air pressure in the parking cylinder 20 increases, the parking piston 21 overcomes the elastic force of the parking spring and moves downward, and the parking rod 26 moves downward; conversely, the parking rod 26 moves upward. The top of the brake cylinder 4 is sealed and slidably connected to the linkage rod 10, but the present invention is not limited thereto. Similarly, the top of the parking cylinder 20 is also sealed and slidably connected to the parking rod 26.

[0037] The driver comprises a hand lever 23, the long rod 18 and the hand lever 23 are movably connected, and the hand lever 23 extends out of the parking box housing 6. When the driver is controlled by hand, the rotation of the control rod 17 is pulled by the hand lever 23 extending out of the parking box.

[0038] In the embodiment, the driver includes both the parking cylinder 20 and the hand lever 23, so as to realize manual and automatic dual driving.

[0039] In some embodiments, a hoop is mounted on the long rod 18 and slidably connected, and the hoop is connected to the parking rod 26. Through the sliding fit between the hoop and the long rod 18, the movable connection between the long rod 18 and the parking rod 26 is achieved.

[0040] In other embodiments, the long rod 18 is provided with an oblong hole, and the end of the hand lever 23 or the parking lever 26 is provided with a barb, which is inserted into the oblong hole. The long rod 18 is movably connected with the hand lever 23 and the parking lever 26 through the sliding fit between the barb and the oblong hole.

[0041] The control pressure block 7 is provided with a wedge surface at one end close to the linkage rod 10. When the top position of the linkage rod 10 changes to a certain extent due to the clearance of the brake shoe 1, the manufacturing process or other reasons, the control pressure block 7 can be compensated by changing the moving distance of the control pressure block 7, so that the inclined surface of the control pressure block 7 is always pressed on the top of the linkage rod 10, thereby ensuring the abutment between the brake shoe 1 and the wheel 2. The angle of the wedge surface is configured to generate forces for moving the control pressure block 7 upward and horizontally through the wedge surface, wherein the friction force on the pressure block guide seat 25 generated by the upward force is greater than the force in the horizontal direction, thereby generating self-locking. This structure can prevent the control pressure block 7 from being separated from the restricted position 8 due to the vibration of the linkage rod 10.

[0042] The movement of the brake piston 3 is limited by using the control pressure block 7 and the connecting rod to keep it in the braking position 12. This setting enables the brake piston 3 to maintain the current braking position 12 even if the air pressure in the brake cylinder 4 disappears, thereby maintaining the contact of the brake shoe 1 with the wheel 2. The change in the top position of the linkage rod 10 is compensated by the stroke of the control pressure block 7 to ensure the certainty of the braking state. The connecting rod structure is used to drive the control pressure block 7, which simplifies the structure and reduces the failure rate. Even if the pneumatic system fails, the mechanical locking structure can still maintain the braking state to avoid the risk of slipping.

[0043] This solution is more scalable than the mechanical solution. When the air circuit failure makes it impossible to unlock the vehicle when parked, the control pressure block 7 can be forced to move to the non-restricted position 9 through external operation to remove the interference with the linkage rod 10, ensuring that the brake shoe 1 is reliably separated from the wheel 2, and providing more redundancy for the movement of the vehicle.

[0044] Working principle: Ginseng Figure 1 , Figure 3 and Figure 4 As shown, by supplying air to the brake cylinder 4, the air pressure in the brake cylinder 4 is increased, the brake piston 3 moves downward, and the wedge surface 24 of the brake wedge 14 contacts the brake rod assembly 13, generating a force amplification effect, pushing the brake shoe 1 to abut the wheel 2; conversely, when the air pressure in the brake cylinder 4 decreases, the brake piston 3 is pushed upward by the elastic force of the piston spring 5, and the brake wedge 14 no longer provides the abutment force between the brake shoe 1 and the wheel 2, and the brake shoe 1 and the wheel 2 are separated.

[0045] When the parking brake is applied (the air brake must be applied), the parking cylinder 20 is exhausted, the air pressure in the parking cylinder 20 is reduced, the parking piston 21 moves upward, and the parking rod 26 is pushed upward, driving the control rod 17 linked thereto to rotate, so that the short rod 19 pushes the control pressure block 7 to the limit position 8, so that even if the brake cylinder 4 loses air, the linkage rod 10 will be constrained and cannot move upward, thereby ensuring that the brake shoe 1 abuts against the wheel 2; When the parking brake needs to be released, it is only necessary to reverse the operation to inflate the parking cylinder 20, so that the control rod 17 rotates, so that the short rod 19 pushes the control pressure block 7 to the non-restricted position 9, releases the constraint on the linkage rod 10, and releases the parking brake.

[0046] Another driving mode is to pull the hand lever 23 extending out of the parking box housing 6 and manually control the rotation of the control rod 17 to also achieve the release of the parking brake.

[0047] The embodiments described above are only preferred solutions of the present invention and are not intended to limit the present invention in any form. Other variations and modifications are possible without exceeding the technical solutions described in the claims.

Claims

1. A parking brake device for a rail vehicle, characterized in that: include: Brake shoe, which moves in the radial direction of the wheel; The brake piston is arranged in the brake cylinder and is connected to the brake shoe transmission. The brake piston is elastically connected to a piston spring. The air pressure generated by the air pressure in the brake cylinder is opposite to the elastic force of the piston spring. The combined force of the air pressure and the elastic force drives the brake piston to move. The parking structure includes a parking box shell, a control pressing block and a connecting rod for driving the control pressing block to move; Among them, the moving stroke of the control pressure block includes a restricted position and a non-restricted position other than the restricted position. A linkage rod is fixedly connected to the brake piston. The moving stroke of the linkage rod includes a braking position and a non-braking position. In the braking position, the brake piston drives the brake shoe to fit the wheel. In the non-braking position, the brake piston retreats and the brake shoe is separated from the wheel. When the control pressure block is in the restricted position, the control pressure block can reach the restricted position to limit the linkage rod from being separated from the braking position.

2. A parking brake device for a rail vehicle according to claim 1, characterized in that: Along the radial direction of the wheel, the brake shoe is connected to a brake rod assembly, which is inserted into the brake cylinder and slidably connected to the brake cylinder. A brake wedge is provided at the lower part of the brake piston. When the brake piston moves, the wedge surface of the brake wedge pushes the brake rod assembly to move.

3. A parking brake device for a rail vehicle according to claim 1, characterized in that: The top of the brake cylinder is provided with air brake inlet and outlet ports, and the piston spring is connected to the lower part of the brake piston.

4. A parking brake device for a rail vehicle according to claim 1, characterized in that: The connecting rod includes a hinge point, a control rod and a driver. The control rod includes a long rod and a short rod. The connection between the long rod and the short rod is hingedly connected to the hinge point. The driver drives the control rod to rotate around the hinge point. The driver drives the control rod to rotate; the control pressure block is pushed and displaced by the short rod.

5. A parking brake device for a rail vehicle according to claim 4, characterized in that: The driver includes a parking cylinder and a parking piston slidably connected in the parking cylinder, a parking spring is elastically connected below the parking piston, a parking rod is fixedly connected above the parking piston, a parking brake air inlet and outlet is arranged on the top of the parking cylinder, and the parking rod and the long rod are movably connected.

6. A parking brake device for a rail vehicle according to claim 4, characterized in that: The driver comprises a hand lever, a long rod and the hand lever are movably connected, and the hand lever extends out of the parking box shell.

7. A parking brake device for a rail vehicle according to claim 5 or 6, characterized in that: A hoop is sleeved on the long rod and slidably connected thereto, and the hoop is fixedly connected to the parking rod.

8. A parking brake device for a rail vehicle according to claim 5 or 6, characterized in that: The long rod is provided with an oblong hole, and the end of the hand-operated rod is provided with a barb, which is inserted into the oblong hole.

9. A parking brake device for a rail vehicle according to claim 4, characterized in that: The end of the short rod is inserted into the deep groove of the control pressing block.

10. A parking brake device for a rail vehicle according to claim 1, characterized in that: The control pressure block is provided with a wedge surface at one end close to the linkage rod.

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