Brake valve structure without hydraulic source for a brake system

Abstract

A brake valve structure without hydraulic source of a brake system, comprising a shell, a screw plug assembly, a piston and a piston rod, the shell is arranged in the up-down direction and has an open upper end, the screw plug assembly is installed at the open upper end of the shell, the piston is arranged in the shell and separates the inner cavity of the shell into an oil storage cavity and an oil output cavity, the piston is connected with the piston rod, the piston rod extends downward and is fixedly connected with a first spring seat, a spring is connected between the first spring seat and the bottom of the shell, the upper end of the piston rod extends out of the shell, a sealing surface is arranged on the piston rod, the sealing surface is located above the piston and has a gap, an oil hole is arranged on the piston rod, the two ends of the oil hole are respectively communicated with the oil storage cavity and the oil output cavity, two interfaces are arranged on the shell, and the two interfaces are respectively communicated with the oil storage cavity and the oil output cavity. The brake valve of the present application achieves double sealing effect during operation, avoids damage problems caused by the use of sealing rubber bowl, improves the reliability and safety of the brake valve in use, and directly reduces the cost.

Description

Technical Field

[0001] This invention relates to the field of aircraft braking system technology, and in particular to a brake valve structure for a braking system without a hydraulic power source. Background Technology

[0002] Currently, the braking system of a certain type of manned business jet in China uses a brake valve that does not require a hydraulic power source. Its structure is as follows: Figure 6 As shown, it mainly consists of a housing 1′, a screw plug 2′, a piston 3′, a spring 4′, an oil reservoir a, an oil output chamber b, a bushing 5′, a spring seat 6′, an oil supply connector 7′, an output connector 8′, and a sealing cup 9′. During braking, when the driver presses the brake pedal, the pedal pushes the piston 3′ downwards. After the sealing cup 9′ moves through the φ0.7mm hole on the bushing 5′, oil in the oil output chamber b is output to the brake wheel piston chamber, generating braking pressure to brake the wheel. When the driver releases the brake pedal, the piston 3′ moves upwards under the combined action of the braking pressure and the spring force of the spring 10′. After the sealing cup 9′ moves away from the φ0.7mm hole on the bushing 5′ (as shown in the image), the piston 3′ moves upwards. Figure 7 (As shown in the image) The oil storage chamber a and the oil output chamber b are connected. The brake pressure in the oil output chamber b is released to loosen the brake.

[0003] During operation, the sealing cup 9' of the aforementioned brake valve needs to pass through the φ0.7 small hole on the bushing 5' to move up and down. Because the φ0.7 small hole and its inner hole are prone to forming a sharp edge during machining, such as... Figure 7 As shown. The sealing cup 9′ is made of rubber. To ensure the seal between the sealing cup 9′ and the bushing 5′, the outer diameter of the sealing cup is larger than the inner diameter of the bushing. Therefore, when the sealing cup moves up and down through the small hole on the bushing 5′, the sharp edge of the φ0.7 small hole can easily scratch and damage the outer diameter of the sealing cup, thereby reducing the sealing performance at the mating point between the sealing cup and the bushing. This can lead to oil leakage inside the brake valve, causing the brake valve to be unable to output the specified brake pressure to automatically brake the wheels, ultimately resulting in brake failure and an accident that endangers the safety of the aircraft and the pilot. Summary of the Invention

[0004] The purpose of this invention is to propose a brake valve structure without a hydraulic power source for a braking system, in order to solve the above problems, improve the reliability and safety of brake valve use, and avoid accidents that endanger the safety of aircraft and pilots caused by brake valve failure.

[0005] To achieve the above objectives, the following technical solution is adopted: a brake valve structure for a braking system without a hydraulic power source, comprising a housing, a screw plug assembly, a piston, and a piston rod. The housing is arranged vertically and has an opening at its upper end. The screw plug assembly is installed at the opening at the upper end of the housing. The piston is disposed inside the housing and divides the inner cavity of the housing into an oil storage chamber and an oil output chamber. The oil storage chamber is located above the piston. The piston has a stepped hole. The piston rod is installed on the stepped hole on the piston, and the piston rod extends downward and is fixedly connected to a first spring seat. The upper half of the stepped hole on the piston has a gap with the outer wall of the piston rod, forming an annular groove. The lower half of the stepped hole slides with the piston rod. The screw plug assembly has a through hole. The upper end of the piston rod extends to the outside of the housing through the through hole. The piston rod has a sealing surface. The sealing surface is located at the opening at the upper end of the stepped hole. The vertical projection of the stepped hole is located within the sealing surface, and there is a gap between the opening at the upper end of the stepped hole and the sealing surface, allowing the piston to move vertically a predetermined distance relative to the piston rod.

[0006] The piston rod has a first oil hole at its lower end along the axial direction, and multiple second oil holes along the radial direction. The ends of the second oil holes communicate with an annular groove. The upper ends of the first oil holes communicate with the centers of the second oil holes, and the lower ends of the first oil holes communicate with the oil output chamber. A second spring seat is provided at the bottom of the housing, and a spring connects the first spring seat and the second spring seat.

[0007] The housing is provided with a first interface and a second interface. The first interface is connected to the oil storage chamber, and the second interface is connected to the oil output chamber.

[0008] The outer wall of the screw plug assembly is provided with a first sealing groove, the through hole wall of the screw plug assembly is provided with a second sealing groove, and the outer wall of the piston is provided with a third sealing groove. A first sealing ring is installed on the first sealing groove, the second sealing groove, and the third sealing groove.

[0009] Preferably, the sealing surface is a conical surface, which closes the annular groove and pushes the piston downward when the piston rod moves downward.

[0010] Preferably, the angle of the conical surface is θ, and the angle range of θ is 0 < θ ≤ 180°.

[0011] Preferably, the angle θ of the conical surface is 90°.

[0012] Preferably, the through hole wall of the screw plug assembly is provided with a guide groove in the circumferential direction, and a guide ring is installed on the guide groove.

[0013] Preferably, the screw plug assembly includes a screw plug and a support cylinder. The screw plug is threadedly connected to the housing, and the support cylinder is connected below the screw plug. The lower end of the support cylinder abuts against the upper surface of the piston. The support cylinder is located in the oil storage chamber, and there is a gap between the inner wall of the support cylinder and the outer wall of the piston rod. An oil passage hole is provided on the support cylinder.

[0014] Preferably, an annular limiting part is provided in the gap between the support cylinder and the piston rod, the annular limiting part is located above the oil passage hole, and the annular limiting part is fixedly connected to the piston rod.

[0015] Preferably, the first interface is connected to an oil supply nozzle, and the second interface is connected to an output nozzle.

[0016] Preferably, a second sealing ring is provided at the connection between the first interface and the oil supply pipe nozzle, and at the connection between the second interface and the output pipe nozzle.

[0017] Preferably, the upper end of the piston rod is connected to a push rod via a locking nut and a locking washer.

[0018] The beneficial effects achieved by this invention are as follows:

[0019] This invention provides a brake valve structure for a braking system without a hydraulic power source, which enables the brake valve to achieve a double sealing effect during operation, avoiding brake failure due to damage during the use of the sealing cup, improving the reliability and safety of the brake valve, eliminating the sealing cup and bushing parts, reducing the weight of the brake valve, and reducing the mold costs and labor costs incurred in processing the sealing cup and bushing parts, thus having good economic value. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the present invention.

[0021] Figure 2 for Figure 1 A magnified schematic diagram of the central part of the structure.

[0022] Figure 3 This is a partial enlarged schematic diagram of the piston rod.

[0023] Figure 4 This is a schematic diagram of the screw plug assembly.

[0024] Figure 5 This is a schematic diagram of the piston structure.

[0025] Figure 6 This is a schematic diagram of the brake valve in the background art.

[0026] Figure 7 for Figure 6 A magnified schematic diagram of the central part of the structure. Detailed Implementation

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0028] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0029] See appendix Figure 1-7A brake valve structure for a braking system without a hydraulic power source includes a housing 1, a screw plug assembly 2, a piston 3, and a piston rod 4. The housing 1 is arranged vertically and has an opening at its upper end. The screw plug assembly 2 is installed at the opening at the upper end of the housing 1. The piston 3 is disposed inside the housing 1 and divides the inner cavity of the housing 1 into an oil storage chamber 5 and an oil output chamber 6. The oil storage chamber 5 is located above the piston 3. The piston 3 has a stepped hole 7. The piston rod 4 is installed on the stepped hole 7 on the piston 3, and the piston rod 4 extends downward and is fixedly connected to a first spring seat 8. The upper half of the stepped hole 7 on the piston 3 has a gap with the outer wall of the piston rod 4, forming an annular groove 9. The lower half of the stepped hole 7 slides with the piston rod 4. The screw plug assembly 2 has a through hole 10. The upper end of the piston rod 4 extends to the outside of the housing 1 through the through hole 10. A sealing surface 11 is provided on the piston rod 4. The sealing surface 11 is located at the opening of the upper end of the stepped hole 7. The vertical projection of the stepped hole 7 lies within the sealing surface 11, and there is a 1mm gap between the upper opening of the stepped hole 7 and the sealing surface 11, allowing the piston 3 to move up and down a predetermined distance relative to the piston rod 4. A first oil hole 12 is provided at the lower end of the piston rod 4 along the axial direction, and multiple second oil holes 13 are provided in the radial direction of the piston rod 4. The second oil hole 13 is connected to the annular groove 9 at one end. The upper end of the first oil hole 12 is connected to the center of the second oil hole 13. The lower end of the first oil hole 12 is connected to the oil output chamber 6. A second spring seat 14 is provided at the bottom of the housing 1. A spring 15 is connected between the first spring seat 8 and the second spring seat 14. A first interface 16 and a second interface 17 are provided on the housing 1. The first interface 16 is connected to the oil storage chamber 5. The second interface 17 is connected to the oil output chamber 6. A first sealing groove 18 is provided circumferentially on the outer wall of the screw plug assembly 2. A second sealing groove 19 is provided circumferentially on the wall of the through hole 10 of the screw plug assembly 2. A third sealing groove 20 is provided circumferentially on the outer wall of the plug 3. A first sealing ring 21 is installed on the first sealing groove 18, the second sealing groove 19 and the third sealing groove 20. The first sealing ring 21 is an O-ring. Through the sealing between the piston rod 4 and the piston 3 and the sealing between the housing 1 and the piston 3, the brake valve achieves a double sealing effect when it is working. This avoids brake failure caused by damage during the use of the sealing cup, improves the reliability and safety of the brake valve, eliminates the sealing cup and bushing parts, reduces the weight of the brake valve, and reduces the mold costs and labor costs incurred in processing the sealing cup and bushing parts, which has good economic value.

[0030] To further improve the sealing effect, a sealing gasket is provided on the upper end wall of the stepped hole 7 to better fit with the sealing surface and achieve a seal, thus preventing leakage.

[0031] The sealing surface 11 is a conical surface. When the piston rod 4 moves downward, the conical surface closes the annular groove 9 and pushes the piston 3 downward. The angle of the conical surface is θ, and the angle range of θ is 0 < θ ≤ 180°. The conical surface angle θ is preferably 90°, but it can also be 60°, 120°, and 150°, etc., so that the conical surface can close the annular groove 9 when the piston rod 4 pushes the piston 3 downward.

[0032] To improve the guiding effect and prevent the piston rod 4 from deviating or tilting, a guide groove 22 is provided circumferentially on the through hole 10 of the screw plug assembly 2, and a guide ring 23 is installed on the guide groove 22.

[0033] The screw plug assembly 2 includes a screw plug 201 and a support cylinder 202. The screw plug 201 is threadedly connected to the housing 1, and the support cylinder 202 is connected below the screw plug 201. The lower end of the support cylinder 202 abuts against the upper surface of the piston 3 so that the annular groove 9 is in communication with the oil storage chamber 5 (oil storage chamber 5 and oil output chamber 6) under normal conditions. That is, the orifice at the upper end of the stepped hole 7 has a gap with the sealing surface 11. The support cylinder 202 is located in the oil storage chamber 5, and the inner wall of the support cylinder 202 has a gap with the outer wall of the piston rod 4. The support cylinder 202 is provided with an oil passage hole 203.

[0034] An annular limiting part 204 is provided in the gap between the support cylinder 202 and the piston rod 4. The annular limiting part 204 is located above the oil passage 203 so that the oil passage 203 is always in the open state. The annular limiting part 204 is fixedly connected to the piston rod 4, thereby preventing the piston rod 4 from detaching from the housing 1.

[0035] The first interface 16 is connected to an oil supply nozzle 24, which is connected to the aircraft's oil reservoir to supply oil to the brake valve for operation. The second interface 17 is connected to an output nozzle 25, which is connected to the aircraft's brake line to output oil to the wheel brake chamber.

[0036] To achieve a sealing effect, a second sealing ring 26 is provided at the connection between the first interface 16 and the oil supply pipe nozzle 24, and at the connection between the second interface 17 and the output pipe nozzle 25. The second sealing ring 26 is an O-ring.

[0037] The upper end of the piston rod 4 is connected to a push rod 29 via a locking nut 27 and a stop washer 28. The push rod 29 and the housing 1 are respectively installed on the brake pedal and the floor of the aircraft.

[0038] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A brake valve structure for a braking system without a hydraulic power source, comprising a housing (1), a screw assembly (2), a piston (3), and a piston rod (4), characterized in that: The housing (1) is arranged vertically and has an opening at the top. The screw plug assembly (2) is installed at the opening at the top of the housing (1). The piston (3) is arranged inside the housing (1) and divides the inner cavity of the housing (1) into an oil storage chamber (5) and an oil output chamber (6). The oil storage chamber (5) is located above the piston (3). The piston (3) is provided with a stepped hole (7). The piston rod (4) is installed on the stepped hole (7) on the piston (3), and the piston rod (4) extends downward and is fixedly connected to a first spring seat (8). The upper half of the stepped hole (7) on the piston (3) is connected to the piston rod (4). There is a gap between the outer walls and an annular groove (9) is formed. The lower half of the stepped hole (7) is slidably engaged with the piston rod (4). The screw plug assembly (2) is provided with a through hole (10). The upper end of the piston rod (4) extends to the outside of the housing (1) through the through hole (10). A sealing surface (11) is provided on the piston rod (4). The sealing surface (11) is located at the opening of the upper end of the stepped hole (7). The vertical projection of the stepped hole (7) is located in the sealing surface (11), and there is a gap between the opening of the upper end of the stepped hole (7) and the sealing surface (11), so that the piston (3) is relatively close to the piston. The piston rod (4) can move up and down a predetermined distance. The lower end of the piston rod (4) is provided with a first oil hole (12) along the axial direction. The piston rod (4) is provided with a plurality of second oil holes (13) along the radial direction. The end of the second oil hole (13) is connected to the annular groove (9). The upper end of the first oil hole (12) is connected to the center of the second oil hole (13). The lower end of the first oil hole (12) is connected to the oil output chamber (6). A second spring seat (14) is provided at the bottom of the housing (1). A spring (15) is connected between the first spring seat (8) and the second spring seat (14). The housing (1) is provided with a first interface (16) and a second interface (17). The first interface (16) is connected to the oil storage chamber (5), and the second interface (17) is connected to the oil output chamber (6). The outer wall of the screw plug assembly (2) is provided with a first sealing groove (18). The through hole (10) of the screw plug assembly (2) is provided with a second sealing groove (19). The outer wall of the piston (3) is provided with a third sealing groove (20). A first sealing ring (21) is installed on the first sealing groove (18), the second sealing groove (19) and the third sealing groove (20).

2. The brake valve structure of the braking system without a hydraulic power source according to claim 1, characterized in that: The sealing surface (11) is a conical surface. When the piston rod (4) moves downward, the conical surface closes the annular groove (9) and pushes the piston (3) downward.

3. The brake valve structure of the braking system without a hydraulic power source according to claim 2, characterized in that: The angle of the conical surface is θ, and the range of θ is 0 < θ ≤ 180°.

4. The brake valve structure of the braking system without a hydraulic power source according to claim 3, characterized in that: The angle θ of the conical surface is 90°.

5. The brake valve structure of the braking system without a hydraulic power source according to claim 1, characterized in that: The through hole (10) of the screw plug assembly (2) is provided with a guide groove (22) circumferentially opened on the hole wall, and a guide ring (23) is installed on the guide groove (22).

6. The brake valve structure of the braking system without a hydraulic power source according to claim 1, characterized in that: The screw plug assembly (2) includes a screw plug (201) and a support cylinder (202). The screw plug (201) is threadedly connected to the housing (1). The support cylinder (202) is connected below the screw plug (201). The lower end of the support cylinder (202) abuts against the upper surface of the piston (3). The support cylinder (202) is located in the oil storage chamber (5), and there is a gap between the inner wall of the support cylinder (202) and the outer wall of the piston rod (4). An oil passage hole (203) is provided on the support cylinder (202).

7. The brake valve structure of the braking system without a hydraulic power source according to claim 6, characterized in that: An annular limiting part (204) is provided in the gap between the support cylinder (202) and the piston rod (4). The annular limiting part (204) is located above the oil passage hole (203) and is fixedly connected to the piston rod (4).

8. The brake valve structure of the braking system without a hydraulic power source according to claim 1, characterized in that: The first interface (16) is connected to an oil supply nozzle (24), and the second interface (17) is connected to an output nozzle (25).

9. The brake valve structure of the braking system without a hydraulic power source according to claim 1, characterized in that: A second sealing ring (26) is provided at the connection between the first interface (16) and the oil supply pipe (24) and at the connection between the second interface (17) and the output pipe (25).

10. The brake valve structure of the braking system without a hydraulic power source according to claim 1, characterized in that: The upper end of the piston rod (4) is connected to a push rod (29) via a locking nut (27) and a stop washer (28).

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