A choke structure for a brake valve

Abstract

The application provides a flow resistance structure of a brake valve and belongs to the technical field of hydraulic brake. The flow resistance structure of the brake valve comprises a valve body provided with an oil inlet hole and a working oil hole, a piston assembly is slidably connected to the inner cavity of the valve body, an oil supply flow channel is formed between the piston assembly and the inner cavity wall of the valve body and is communicated with the oil inlet hole and the working oil hole, the flow resistance structure further comprises a compression spring, a flow resistance piece linked with the piston assembly and a sealing assembly abutting against the wall surface of the oil supply flow channel, the valve body is provided with a limiting surface at the communication position of the oil inlet hole and the oil supply flow channel, one end of the compression spring acts on the piston assembly and the other end acts on the sealing assembly so that the sealing assembly abuts against the limiting surface, the flow resistance piece is located on the side of the sealing assembly abutting against the limiting surface, and an oil passing flow channel is formed between the flow resistance piece and the sealing assembly and is communicated with the oil inlet hole and the oil supply flow channel. The flow resistance structure of the brake valve has the advantage of improving the sealing performance of the valve body.

Description

Technical Field

[0001] The invention belongs to the technical field of hydraulic braking and relates to a flow-blocking structure of a brake valve. Background Art

[0002] The brake valve is a device that controls the hydraulic braking of engineering machinery vehicles. It includes a valve body with an inner cavity. The valve body has an oil inlet hole connected to the oil tank and a working oil hole connected to the brake. The valve body is penetrated by a piston assembly that controls the flow direction of the oil and a linkage piston connected to the brake pedal. When the driver steps on the brake pedal, the linkage piston can drive the piston assembly to move to achieve braking. For example, the full hydraulic brake valve application number disclosed in Chinese patent literature is: CN200920306571.2.

[0003] Furthermore, the valve body is provided with a piston assembly, which is provided with a connecting groove connecting the oil inlet hole and the working oil hole. The oil inlet hole and the working oil hole are opened and closed by the movement of the piston assembly. For example, a fully hydraulic brake valve CN201620072353.7 is disclosed in Chinese patent literature. On this basis, in order to improve the pressure stability in the valve body, those skilled in the art may conceive of embedding a sealing ring in the piston assembly that abuts against the valve body, and improving the sealing between the valve body and the piston assembly by reducing the gap between the valve body and the piston assembly by deforming the sealing ring. This is a conventional use method of the sealing ring using its own characteristics. However, the piston assembly needs to be opened and closed by its own movement, which means that the sealing ring must move relative to the valve body with the piston assembly in a deformed state, causing the sealing ring to fail due to wear, resulting in the inability to ensure the sealing between the valve body and the piston assembly. Summary of the Invention

[0004] The purpose of the present invention is to address the above-mentioned problems existing in the prior art and to propose a flow-blocking structure for a brake valve to solve the problem of poor sealing inside the valve body.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] and a valve body having a plurality of valves, the plurality of valves has a plurality of valves connected to the plurality of valves, and a plurality of plurality of valves are connected to the plurality of valves.

[0007] In the present application, the flow-blocking structure forms three different states according to the position of the piston assembly, namely, the initial state, the gap elimination state and the flow-blocking state.

[0008] Initial state: The driver has not stepped on the brake pedal, and the piston assembly is in the initial position. Specifically, in the initial state, the sealing component abuts against the wall of the oil supply channel, limiting the oil entering from the oil inlet to enter the oil supply channel only through the oil flow channel. Based on this flow structure, since the piston assembly is in the initial position and stationary, the position of the flow blocker connected to the piston assembly is also determined. The sealing component abuts against the limit surface under the elastic force of the compression spring, so that the position of the sealing component is determined and stationary. This determines the relative position of the flow blocker and the sealing component, and forms an oil flow channel connecting the oil inlet and the oil supply channel between one side of the sealing component and the flow blocker.

[0009] Eliminate the gap state: When the driver presses the brake pedal, the piston assembly begins to move toward the working oil hole (i.e., upward as shown in the diagram in the manual). Since the obstruction member is linked to the piston assembly, the obstruction member moves upward relative to the sealing assembly, causing the cross-sectional area of ​​the oil flow channel through which the oil passes to continuously decrease until the obstruction member abuts against one side of the sealing assembly. Specifically, since one end of the compression spring acts on the piston assembly, the one end of the compression spring will move with the movement of the piston assembly, while the other end of the compression spring still abuts against the sealing assembly, allowing the sealing assembly to remain in place when the piston assembly drives the obstruction member to move. Since the obstruction member is located on the side of the sealing assembly that abuts the limit surface, when the obstruction member moves upward relative to the sealing assembly with the piston assembly, the obstruction member can abut against the sealing assembly to close the oil flow channel;

[0010] Blocking state: The driver continues to depress the brake pedal, and the piston assembly continues to move toward the working oil hole (i.e., upward as shown in the diagram in the manual). When the blocking member abuts against the sealing assembly, the blocking member drives the sealing assembly to move synchronously with the piston assembly. Specifically, because the sealing assembly only abuts against the wall of the oil supply channel and has no connection with other components, when the piston assembly continues to move upward, the blocking member abutting against one side of the sealing assembly can drive the sealing assembly to move synchronously with the piston assembly, thereby ensuring the sealing of the valve body during the movement of the piston. Furthermore, in the process of the blocking member driving the sealing assembly to move synchronously, the sealing assembly also has a tendency to move toward the oil inlet hole under the action of the elastic force of the compression spring, and the blocking member and the sealing assembly are tightly pressed against each other under the action of the two-way combined force.

[0011] When the cam is opened, the oil in the oil outlet is turned off, and the oil inlet is turned off, so that the oil in the oil outlet is turned off, and the oil inlet is turned off. When the cam is opened, the oil in the oil outlet is turned off, and the oil in the oil outlet is turned off. When the cam is opened, the oil in the oil outlet is turned off, and the oil in the oil outlet is turned off. When the cam is opened, the oil in the oil outlet is turned off, and the oil in the oil outlet is turned off. When the cam is opened, the oil in the oil outlet is turned off, and the oil in the oil outlet is turned off.

[0012] In the aforementioned flow-blocking structure of the brake valve, the piston assembly comprises a support surface, a sealing assembly comprising a support seat, a first sealing ring abutting against the wall of the oil supply passage, and a spacer sleeve disposed outside the flow blocker. The first sealing ring is positioned between the support seat and the spacer sleeve. One end of the compression spring abuts the support surface, while the other end abuts the support seat, forcing the spacer sleeve against the limit surface. The gaps between the flow blocker and the support seat, and between the first sealing ring and the spacer sleeve, form the aforementioned oil flow passage. When the piston assembly is in an initial state, oil entering through the oil inlet hole sequentially passes through the gaps between the flow blocker and the support seat, and between the first sealing ring and the spacer sleeve, and enters the oil supply passage. The first sealing ring is disposed between the support seat and the spacer sleeve. The first sealing ring securely abuts the spacer sleeve against the inner wall of the valve body, ensuring a gap between the spacer sleeve and the flow blocker. Furthermore, the spacer sleeve stabilizes the deformation of the first sealing element, ensuring a gap between the first sealing pot and the spacer sleeve, thereby ensuring stable communication between the oil inlet hole and the oil supply passage when the piston assembly is in the initial state.

[0013] In the aforementioned flow-blocking structure of the brake valve, the valve body includes an upper valve body, a lower valve body connected to the upper valve body, and a support member slidably connected to the piston assembly. The support member is fixed at the connection between the upper and lower valve bodies. The limiting surface is the side surface of the support member, and the spacer abuts the limiting surface. The limiting surface is provided with a guide groove connecting the oil flow channel and the oil inlet. This structure determines the position of the support member, slides the piston assembly to the support member, and abuts the side surface of the support member, so that the piston assembly and the sealing assembly are both based on the support member, thereby facilitating the relative positional relationship between the piston assembly and the sealing assembly. The guide groove guides the oil entering through the oil inlet, clarifies the oil flow path, and ensures the stability of the connection between the oil inlet and the oil flow channel.

[0014] In the above-mentioned flow-blocking structure of the brake valve, the piston assembly includes a main piston slidably connected to a support member and a balancing piston located in the oil supply channel. The balancing piston has a connecting portion embedded in the main piston and a sliding portion that divides the oil supply channel into an oil supply chamber and a working chamber. The sliding portion is connected to the connecting portion to form the above-mentioned support surface. The compression spring is sleeved outside the connecting portion. The flow blocker is connected to the main piston. This structure allows the flow blocker and the sealing assembly to be located at the connection between the main piston and the balancing piston. Specifically, one end of the main piston is positioned between the support member and the connecting portion, which is equivalent to the flow blocker being sleeved outside the connecting portion through the main piston. The compression spring is also sleeved outside the connecting portion and supported by the sliding portion. This clarifies the relative position between the support surface and the flow blocker, improves the positional accuracy between the sealing assembly and the flow blocker, and ensures the stability of the oil connection.

[0015] In the above-mentioned flow-blocking structure of the brake valve, the oil inlet hole is connected to the working chamber, the working oil hole is connected to the working chamber, a gap is formed between the outer ring of the first sealing ring and the wall of the working chamber, the support seat has a groove, the first sealing ring has a movable portion and a positioning portion, the positioning portion is connected to the movable portion, and the positioning portion is embedded in the groove so that the movable portion abuts against the wall of the working chamber. The outer ring diameter of the first sealing ring is smaller than the inner diameter of the working chamber so that a gap is left between the outer ring of the first sealing ring and the wall of the working chamber, the positioning portion is embedded in the groove so that the first sealing ring is positioned on the support seat, and the support seat reacts to the positioning portion so that the positioning portion abuts against the wall of the working chamber to block the passage of oil, thereby achieving flow blocking while reducing the contact area between the first sealing ring and the wall of the working chamber, reducing the movement resistance of the first sealing ring, and improving the closeness between the first sealing ring and the flow-blocking component.

[0016] In the aforementioned flow-blocking structure of the brake valve, the support seat has a flange for the first sealing ring to abut against and an inclined rib. The rib and flange are connected to form the aforementioned groove. The first sealing ring has a notch between the positioning portion and the movable portion. The positioning portion engages the groove, allowing the rib to engage within the notch. The rib abuts the inner side of the movable portion, allowing the outer side of the movable portion to abut against the wall of the working chamber. The notch and the groove provide bidirectional clamping between the support seat and the first sealing ring. Furthermore, the inclined rib, leveraging the notch, presses the first sealing ring against the wall of the working chamber, improving the sealing effect.

[0017] In the aforementioned brake valve's flow-blocking structure, a first retaining ring and a second retaining ring are secured to the outer wall of the primary piston. The flow-blocking member is sleeved onto the exterior of the primary piston and secured between the first and second retaining rings. A second sealing ring is embedded in the outer wall of the primary piston, positioned between the first and second retaining rings and abutting the flow-blocking member. The first and second retaining rings secure the flow-blocking member to the exterior of the primary piston, while the second sealing ring prevents oil from passing between the flow-blocking member and the primary piston, further improving pressure stability within the valve body.

[0018] In the aforementioned flow-blocking structure of the brake valve, the flow-blocking member comprises an annular flow-blocking portion and a flow-guiding portion flush with the end face of the main piston. The spacer sleeve is mounted outside the flow-blocking portion with a first gap therebetween. The first sealing ring is mounted outside the flow-guiding portion with a second gap therebetween. The diameter of the flow-guiding portion is smaller than that of the flow-blocking portion, and the two are connected to form a step surface. A third gap is defined between the step surface and the first sealing ring. The first gap communicates with the second gap via the third gap, and the first gap is larger than the third gap. This structure clarifies that the inner ring of the first sealing ring is larger than the flow-guiding portion and smaller than the flow-blocking portion. When the piston assembly moves, the flow-blocking portion and the sealing ring abut against each other upward and downward, eliminating the third gap and separating the oil inlet from the oil supply channel. The spacer sleeve and the flow-guiding portion define the relative positional relationship between the flow-blocking member and the first sealing ring and provide guidance for oil flow. The gap size setting also achieves a damping effect, limiting the oil inlet flow rate, preventing the wall pressure oil from impacting the piston assembly, and improving the pressure stability of the brake valve.

[0019] In the aforementioned brake valve's flow-blocking structure, the inner wall of the spacer sleeve has an annular retaining edge that abuts the first sealing ring. The stepped surface has a clearance opening for the retaining edge to engage. The distance between the stepped surface and the first sealing ring is greater than the height of the retaining edge. When the flow-blocking member moves toward the working oil port with the piston assembly, the retaining edge prevents the spacer sleeve from dislodging. The clearance opening and the spacing ensure close contact between the stepped surface and the first sealing ring, improving sealing performance and maintaining pressure stability within the valve body.

[0020] In the aforementioned flow-blocking structure of the brake valve, the support seat includes a support platform capable of abutting against the end face of the primary piston. The balancing piston is disposed on the support platform. The support platform is provided with at least two communicating holes connecting the oil flow channel and the working chamber. The communicating holes are spaced circumferentially. A bayonet is provided at the connection between the connecting portion and the sliding portion. The compression spring is conical in shape, with the small end of the compression spring embedded in the bayonet and the large end abutting against the support platform. The distance between the support platform and the end face of the primary piston is no less than the distance between the step surface and the first sealing ring. The communicating holes guide the oil entering the working chamber to prevent the pressure oil from impacting the balancing piston. The bayonet fixes the position of the compression spring. The conical structure enhances the support of the compression spring on the support platform. Furthermore, by setting the distance, the compression spring always has a tendency to drive the first sealing ring toward the step surface within a limited stroke, thereby improving sealing performance and ensuring pressure stability within the valve body.

[0021] Compared with the prior art, the flow-blocking structure of a brake valve provided by the present invention has the following advantages:

[0022] 1. This application eliminates the existing method of controlling the oil passage by opening a groove on the outer wall of the piston, and breaks through the existing method of using seals. On the basis of guiding the oil through the oil flow channel formed by the sealing assembly and the baffle, a compression spring is used as a trigger mechanism. When the piston assembly moves toward the working oil hole, the compression spring causes the sealing assembly to move relative to the piston assembly and abut against the baffle, eliminating the oil flow channel and improving the response speed of the brake valve.

[0023] 2. This application sets the spacing so that the sealing assembly always has a tendency to move relative to the piston assembly under the elastic force of the compression spring. Combined with the movement of the piston assembly, the flow blocking member and the sealing assembly are always closely attached to each other under the action of external force, thereby ensuring sealing and improving the pressure stability of the brake valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a cross-sectional view when the brake pedal is not depressed, the piston assembly is stationary, and the flow-blocking structure is in its initial state.

[0025] Figure 2 yes Figure 1 A partial enlarged view of .

[0026] Figure 3 This is a cross-sectional view of the flow-blocking structure in the flow-blocking state after the brake pedal is depressed and the piston assembly moves.

[0027] Figure 4 yes Figure 3 A partial enlarged view of .

[0028] Figure 5 It is a schematic diagram of the overall structure of the support seat.

[0029] Figure 6 It is a schematic diagram of the overall structure of the support.

[0030] Figure 7 It is a schematic diagram of the overall structure of the brake valve.

[0031] In the figure, 1. valve body; 11. oil inlet hole; 12. working oil hole; 13. oil supply channel; 131. oil supply chamber; 132. working chamber; 14. upper valve body; 15. lower valve body; 16. support member; 161. limit surface; 162. guide groove; 17. control oil hole; 18. oil return hole; 2. piston assembly; 21. support surface; 22. main piston; 23. balance piston; 231. connecting part; 232. sliding part; 233. bayonet; 234. balance oil channel; 24. first retaining ring; 25. second retaining ring; 26. second sealing ring; 3. flow blocking member; 3 1. Flow-blocking portion; 32. Flow-guiding portion; 33. Step surface; 331. Yield; 4. Sealing assembly; 41. Support seat; 411. Groove; 412. Flanged edge; 413. Retaining edge; 414. Support platform; 415. Connecting hole; 42. First sealing ring; 421. Movable portion; 422. Positioning portion; 423. Recess; 43. Spacer; 431. Retaining edge; 5. Compression spring; 6. Oil flow channel; 61. First gap; 62. Second gap; 63. Third gap; 7. Brake pedal; 8. Pedal connecting rod assembly; 9. Third sealing ring; 10. One-way valve. DETAILED DESCRIPTION

[0032] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solutions of the present invention, but the present invention is not limited to these embodiments.

[0033] like Figure 1 and Figure 7 As shown, the flow-blocking structure of the brake valve includes a valve body 1 and a piston assembly 2 slidably connected to the valve body 1. The valve body 1 includes a lower valve body 15 with a control oil hole 17 and an oil return hole 18, an upper valve body 14 with an oil inlet hole 11 and a working oil hole 12, and a support member 16 slidably connected to the piston assembly 2. The support member 16 is fixed at the connection between the upper valve body 14 and the lower valve body 15. An oil supply channel 13 connecting the oil inlet hole 11 and the working oil hole 12 is formed between the piston assembly 2 and the inner cavity wall of the valve body 1. The piston assembly 2 includes a main piston 22 that is inserted into the lower valve body 15 and is slidably connected to the support member 16, and a balance piston 23 that is inserted into the lower valve body 15. The balance piston 23 has a connecting portion 231 embedded in the main piston 22 and a sliding portion 232 that divides the oil supply channel 13 into an oil supply chamber 131 and a working chamber 132. The sliding portion 232 is connected to the connecting portion 231 to form a support surface 21. Figure 2As shown, the flow-blocking structure includes a compression spring (5), a flow-blocking member 3 connected to the main piston 22, and a sealing assembly 4 abutting against the wall of the oil supply channel 13. The side of the support member is a limiting surface 161 located at the connection point between the oil inlet hole 11 and the oil supply channel 13. The compression spring 5 is sleeved outside the connecting portion 231. One end of the compression spring 5 acts on the piston assembly 2, and the other end acts on the sealing assembly 4 to make the sealing assembly 4 abut against the limiting surface 161. The flow-blocking member 3 is located on the side of the sealing assembly 4 abutting against the limiting surface 161, and an oil flow channel 6 connecting the oil inlet hole 11 and the oil supply channel 13 is formed between the flow-blocking member 3 and the sealing assembly 4. Figure 6 As shown, a guide groove 162 is provided on the limiting surface 161, which connects the oil flow channel 6 and the oil inlet hole 11. Figure 1 and Figure 2 As shown, the piston assembly is in the initial position, at which time the oil passage 6 is open. When the piston assembly 2 slides toward the working oil hole 12, the compression spring 5 keeps the sealing component 4 stationary in a portion of the moving path of the piston assembly 2. When the piston assembly 2 continues to slide toward the working oil hole 12, as shown in FIG. Figure 3 and Figure 4 As shown, the blocking member 3 abuts against the sealing assembly to close the oil flow passage 6 .

[0034] The sealing assembly 4 includes a support seat 41, a first sealing ring 42 that abuts against the wall of the oil supply channel 13, and a spacer 43 that is sleeved outside the baffle 3. The first sealing ring 42 is located between the support seat 41 and the spacer 43. One end of the compression spring 5 abuts against the support surface 21, and the other end abuts against the support seat 41 so that the spacer 43 abuts against the limit surface. The gap between the baffle 3 and the support seat 41, the first sealing ring 42 and the spacer 43 forms the above-mentioned oil flow channel 6. The flow blocking member 3 has an annular flow blocking portion 31 and a flow guiding portion 32 flush with the end surface of the main piston 22. The spacer 43 is sleeved on the outside of the flow blocking portion 31 with a first gap 61 therebetween. The first sealing ring 42 is sleeved on the outside of the flow guiding portion 32 with a second gap 62 therebetween. The diameter of the flow guiding portion 32 is smaller than the diameter of the flow blocking portion 31 and the two are connected to form a step surface 33. A third gap 63 is formed between the step surface 33 and the first sealing ring 42. The first gap 61 is connected to the second gap 62 through the third gap 63, and the first gap 61 is larger than the third gap 63. The inner wall of the spacer 43 has an annular retaining edge 431 that abuts against the first sealing ring 42. A clearance opening 331 is provided on the step surface 33 for the retaining edge 431 to be embedded. The distance between the step surface 33 and the first sealing ring 42 is greater than the height of the retaining edge 431. Figure 5As shown, the support seat 41 has a support platform 414 that can abut against the end face of the main piston 22, and the balance piston 23 is passed through the support platform 414. The support platform 414 is provided with at least two communicating holes 415 connecting the oil flow channel 6 and the working chamber 132. The communicating holes 415 are arranged at intervals along the circumferential direction. The connection between the connecting portion 231 and the sliding portion 232 is provided with a bayonet 233. The compression spring 5 is conical, and the small end of the compression spring 5 is embedded in the bayonet 233, and the large end abuts against the support platform 414. The distance between the support platform 414 and the end face of the main piston 22 is not less than the distance between the step surface 33 and the first sealing ring 42.

[0035] The oil inlet hole 11 is connected to the oil supply chamber 131, and the working oil hole 12 is connected to the working chamber 132. There is a gap between the outer ring of the first sealing ring 42 and the cavity wall of the working chamber 132. The support seat 41 has a flange 412 for the first sealing ring 42 to abut against and an inclined rib 413. The rib 413 is connected to the flange 412 to form a groove 411. The first sealing ring 42 has a movable part 421 and a positioning part 422 connected to the movable part 421. There is a recess 423 between the positioning part 422 and the movable part 421. The positioning part 422 is embedded in the groove 411 so that the rib 413 is embedded in the recess 423. The rib 413 abuts against the inner side of the movable part 421 so that the outer side of the movable part 421 abuts against the cavity wall of the working chamber 132. The outer wall of the main piston 22 is clamped with a first retaining ring 24 and a second retaining ring 25, the baffle 3 is sleeved on the outside of the main piston 22 and fixed between the first retaining ring 24 and the second retaining ring 25, and the outer wall of the main piston 22 is embedded with a second sealing ring 26 located between the first retaining ring 24 and the second retaining ring 25 and abutting against the baffle 3.

[0036] The oil inlet hole 11 is connected to the working oil hole 12 through the oil supply chamber 131 and the working chamber 132 in sequence. A third sealing ring 9 is provided between the oil supply chamber 131 and the working chamber 132. The third sealing ring 9 abuts against the outer wall of the balancing piston 23 to separate the oil supply chamber 131 and the working chamber 132. A balancing oil passage 234 connecting the oil supply chamber 131 and the working chamber 132 is opened on the balancing piston 23, and a one-way valve 10 is provided in the balancing oil passage 234.

[0037] like Figure 7As shown, the brake valve is connected to the brake pedal 7 via the pedal connecting rod assembly 8. When the driver does not step on the brake pedal 7, the oil inlet hole 11 is connected to the working oil hole 12. When the driver steps on the brake pedal 7, oil is controlled to flow into the oil hole 17, and the main piston 22 is driven to move along the support member 16 toward the working oil hole 12 by the oil pressure. During the process of the main piston 22 driving the balance piston 23 to move, the sealing component 4 moves relative to the balance piston 23 under the elastic force of the compression spring 5 until the sealing component 4 abuts against the balance piston 23, eliminating the oil flow channel 6. As the balance piston 23 moves further, the balance piston 23 abuts against the third sealing ring 9, forming a sealed cavity in the oil supply chamber 131. Chamber, as the balancing piston 23 moves further, the oil pressure in the oil supply chamber 131 is greater than the working chamber 132 connected to the working oil hole 12. At this time, the one-way valve 10 opens under the action of the oil pressure, allowing the oil in the oil supply chamber 131 to flow to the working chamber 132 through the balancing oil channel 234, providing the required pressure oil for the brake valve braking. During this process, the sealing component 4 always maintains good sealing performance under the bidirectional force of the compression spring 5 and the main piston 22, ensuring the pressure stability in the brake valve; when the driver releases the brake pedal 7, the sealing component 4 still maintains sealing, allowing the piston assembly 2 to move back smoothly.

[0038] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Persons skilled in the art may make various modifications, additions, or substitutions to the described specific embodiments without departing from the spirit of the present invention or exceeding the scope of the appended claims.

[0039] Although this article uses more valve body 1, oil inlet hole 11, working oil hole 12, oil supply channel 13, oil supply chamber 131, working chamber 132, upper valve body 14, lower valve body 15, support member 16, limit surface 161, guide groove 162, control oil hole 17, oil return hole 18, piston assembly 2, support surface 21, main piston 22, balancing piston 23, connecting part 231, sliding part 232, bayonet 233, balancing oil channel 234, first retaining ring 24, second retaining ring 25, second sealing ring 26, flow blocking member 3, flow blocking part 31, guide The terms flow portion 32, step surface 33, clearance opening 331, sealing assembly 4, support seat 41, groove 411, flange 412, rib 413, support platform 414, communicating hole 415, first sealing ring 42, movable portion 421, positioning portion 422, recess 423, spacer 43, retaining edge 431, compression spring 5, oil flow channel 6, first gap 61, second gap 62, third gap 63, brake pedal 7, pedal connecting rod assembly 8, third sealing ring 9, and one-way valve 10 are used herein, but the use of other terms is not excluded. These terms are used merely to more conveniently describe and explain the essence of the present invention; interpreting them as any additional limitations is contrary to the spirit of the present invention.

Claims

1. A flow-blocking structure for a brake valve, comprising a valve body (1) provided with an oil inlet hole (11) and a working oil hole (12), wherein a piston assembly (2) is slidably connected to an inner cavity of the valve body (1), and an oil supply channel (13) communicating with the oil inlet hole (11) and the working oil hole (12) is formed between the piston assembly (2) and the inner cavity wall of the valve body (1), characterized in that: The flow-blocking structure further comprises a compression spring (5), a flow-blocking member (3) linked to the piston assembly (2), and a sealing assembly (4) abutting against the wall of the oil supply channel (13); the valve body (1) has a limiting surface (161) located at the connection point between the oil inlet hole (11) and the oil supply channel (13); one end of the compression spring (5) acts on the piston assembly (2), and the other end acts on the sealing assembly (4) to make the sealing assembly (4) abut against the limiting surface (161); the flow-blocking member (3) is located on the side of the sealing assembly (4) abutting against the limiting surface (161), and a gap connecting the oil inlet hole (11) and the oil supply channel (13) is formed between the flow-blocking member (3) and the sealing assembly (4). The oil flow passage (6) is provided, wherein the piston assembly (2) has a supporting surface (21), the sealing assembly (4) comprises a supporting seat (41), a first sealing ring (42) abutting against the wall of the oil supply flow passage (13), and a spacer (43) sleeved outside the flow blocking member (3), wherein the first sealing ring (42) is located between the supporting seat (41) and the spacer (43), one end of the compression spring (5) abuts against the supporting surface (21), and the other end abuts against the supporting seat (41) so that the spacer (43) abuts against the limiting surface (161), and the gap between the flow blocking member (3) and the supporting seat (41), the first sealing ring (42) and the spacer (43) forms the above-mentioned oil flow passage (6).

2. The flow-blocking structure of a brake valve according to claim 1, characterized in that: The valve body (1) comprises an upper valve body (14), a lower valve body (15) connected to the upper valve body (14), and a support member (16) slidably connected to the piston assembly (2), wherein the support member (16) is fixed at the connection between the upper valve body (14) and the lower valve body (15), the limiting surface (161) is a side surface of the support member (16), the spacer (43) abuts against the limiting surface (161), and a guide groove (162) is provided on the limiting surface (161) that connects the oil flow channel (6) and the oil inlet hole (11).

3. The flow-blocking structure of a brake valve according to claim 2, characterized in that: The piston assembly (2) comprises a main piston (22) slidably connected to a support member (16) and a balancing piston (23) located in an oil supply channel (13). The balancing piston (23) comprises a connecting portion (231) embedded in the main piston (22) and a sliding portion (232) for dividing the oil supply channel (13) into an oil supply chamber (131) and a working chamber (132). The sliding portion (232) is connected to the connecting portion (231) to form the above-mentioned supporting surface (21). The compression spring (5) is sleeved outside the connecting portion (231). The flow blocking member (3) is connected to the main piston (22).

4. The flow-blocking structure of a brake valve according to claim 3, characterized in that: The oil inlet hole (11) is in communication with the working chamber (132), the working oil hole (12) is in communication with the working chamber (132), a gap is provided between the outer ring of the first sealing ring (42) and the cavity wall of the working chamber (132), the support seat (41) has a groove (411), the first sealing ring (42) has a movable portion (421) and a positioning portion (422), the positioning portion (422) is connected to the movable portion (421), and the positioning portion (422) is embedded in the groove (411) so that the movable portion (421) abuts against the cavity wall of the working chamber (132).

5. The flow-blocking structure of a brake valve according to claim 4, characterized in that: The support seat (41) has a flange (412) for the first sealing ring (42) to abut against and a rib (413) arranged obliquely. The rib (413) is connected to the flange (412) to form the groove (411). The first sealing ring (42) has a recess (423) located between the positioning portion (422) and the movable portion (421). The positioning portion (422) is embedded in the groove (411) so that the rib (413) is embedded in the recess (423). The rib (413) abuts against the inner side of the movable portion (421) so that the outer side of the movable portion (421) abuts against the cavity wall of the working cavity (132).

6. The flow-blocking structure of a brake valve according to claim 3, characterized in that: The outer wall of the main piston (22) is clamped with a first retaining ring (24) and a second retaining ring (25); the flow blocking member (3) is sleeved outside the main piston (22) and fixed between the first retaining ring (24) and the second retaining ring (25); the outer wall of the main piston (22) is embedded with a second sealing ring (26) located between the first retaining ring (24) and the second retaining ring (25) and abutting against the flow blocking member (3).

7. The flow-blocking structure of a brake valve according to claim 3, characterized in that: The flow blocking member (3) comprises an annular flow blocking portion (31) and a flow guiding portion (32) flush with the end surface of the main piston (22); the spacer (43) is sleeved outside the flow blocking portion (31) and a first gap (61) is defined between the two; the first sealing ring (42) is sleeved outside the flow guiding portion (32) and a second gap (62) is defined between the two; the diameter of the flow guiding portion (32) is smaller than the diameter of the flow blocking portion (31) and the two are connected to form a step surface (33); a third gap (63) is defined between the step surface (33) and the first sealing ring (42); the first gap (61) is connected to the second gap (62) through the third gap (63); and the first gap (61) is larger than the third gap (63).

8. The flow-blocking structure of a brake valve according to claim 7, characterized in that: The inner wall of the spacer (43) has a ring-shaped retaining edge (431) that abuts against the first sealing ring (42), and the step surface (33) is provided with a clearance opening (331) for the retaining edge (431) to be embedded, and the distance between the step surface (33) and the first sealing ring (42) is greater than the height of the retaining edge (431).

9. The flow-blocking structure of a brake valve according to claim 7, characterized in that: The support seat (41) has a support platform (414) capable of abutting against the end face of the main piston (22), the balancing piston (23) is passed through the support platform (414), and the support platform (414) is provided with at least two communicating holes (415) connecting the oil flow channel (6) and the working chamber (132), the communicating holes (415) are arranged at intervals along the circumferential direction, and the connection between the connecting portion (231) and the sliding portion (232) has a bayonet (233), the compression spring (5) is conical, the small end of the compression spring (5) is embedded in the bayonet (233), and the large end abuts against the support platform (414), and the distance between the support platform (414) and the end face of the main piston (22) is not less than the distance between the step surface (33) and the first sealing ring (42).

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