A superpressure rapid shut-off valve

Abstract

The present invention relates to the field of engine lubricating oil system design, and particularly to an overpressure quick shut-off valve. When the overpressure shut-off valve with a traditional structure is applied to the field of aviation commercial engines, affected by the external atmospheric environment, due to the piston and connecting rod structures being exposed to the external environment, when the valve is in a dusty environment, the connecting rod structure may become stuck, and the valve cannot be opened or closed normally, affecting the flight safety of the aircraft. The overpressure shut-off valve of the present invention includes two parts, a lift valve and a pilot valve, within the housing assembly. The lift valve mainly includes a seal seat assembly, a lift valve piston assembly, and a lift valve spring. The pilot valve mainly includes a pilot valve spring, a pilot valve piston assembly, a steel ball, a pilot valve seat, a base, a guide rod, a vacuum bellows, and a vacuum bellows cover. The use of a vacuum bellows on the pilot valve can sense the change in the external atmospheric environment pressure. It can achieve the function of quick opening and closing of the valve, with a compact overall structure, and can realize the miniaturization and lightweight of the valve.

Description

Technical Field

[0001] The present invention relates to the field of engine lubricating oil system design, and particularly to an overpressure quick shut-off valve. Background Art

[0002] In traditional overpressure shut-off valve products, the valve structure is a butterfly valve structure. As Figure 1 shown, it mainly drives the rotation of the butterfly plate through a piston + crank connecting rod structure to control the opening and closing of the valve. In order to match the opening and closing pressure requirements of the valve, the piston actuating mechanism of the traditional overpressure shut-off valve has a large outer dimension and a large weight.

[0003] When the traditional structure of the overpressure shut-off valve is applied to the field of commercial aviation engines, affected by the external atmospheric environment, since the piston and connecting rod structure are exposed to the external environment, when the valve is in a sandy environment, the connecting rod structure may get stuck, and the valve cannot be opened or closed normally, affecting the flight safety of the aircraft. Summary of the Invention

[0004] The purpose of the present invention is to provide an overpressure shut-off valve with lift valve actuation and pilot valve control, which uses pneumatic control to achieve the quick opening and closing function of the valve, does not rely on the conversion of linear motion to rotational motion by a connecting rod mechanism, and can solve the problems of large outer dimension and large weight of the product, as well as the sticking of the connecting rod structure in a sandy environment.

[0005] To achieve the above purpose, the technical solution of the overpressure shut-off valve of the present invention is: an overpressure quick shut-off valve, which includes two parts, a lift valve and a pilot valve, in a housing assembly, where

[0006] The cavity where the lift valve is located includes an opening cavity, an intermediate cavity, and a closing cavity from top to bottom. There is an annular stepped hole between the intermediate cavity and the closing cavity. The closing cavity has an air inlet, and the closing cavity communicates with the pressure chamber of the pilot valve through a second channel in the housing assembly. The intermediate cavity has an air outlet; the lift valve piston assembly has a lift valve piston. The upper end of the lift valve piston is sealed and installed in the opening cavity, and a downward pressure is applied to the lift valve piston through a lift valve spring. The part of the lift valve piston in the closing cavity has a valve plate capable of covering the annular stepped hole. A limit plate is provided on the lower side of the lift valve piston, and the lower end of the lift valve piston is inserted into a seal seat assembly, and the inner end face of the seal seat assembly has an air guiding groove.

[0007] The middle part of the pilot valve has a pressure sensing cavity, in which a steel ball that can move up and down is installed. The pressure sensing cavity is communicated with the opening cavity through a third channel in the housing assembly; the upper part of the pilot valve has a bellows cover, and the vacuum bellows in it exerts a downward pressure on the steel ball, and the bellows cover has an upper exhaust port; in the lower cavity of the pilot valve, there is a pilot valve piston assembly, and the pilot valve spring presses up against the pilot valve piston assembly to exert an upward pressure on the steel ball. The cavity above the pilot valve piston assembly forms a pressure cavity; when the intake pressure is lower than the set value, the steel ball blocks the intake port of the bellows cover upward, and at the same time the pressure cavity is communicated with the pressure sensing cavity; when the intake pressure is greater than or equal to the set value, the steel ball blocks the pressure cavity downward, and at the same time the pressure sensing cavity is communicated with the bellows cover.

[0008] Advantageously, the middle part of the pilot valve has a pilot valve seat and a base. The pilot valve seat has a shaft hole and a number of radial through holes communicating with the shaft hole. The steel ball is constrained at the intersection of the shaft hole and the radial through holes and can move up and down along the axis. A pressure sensing cavity is formed between the outer side of the pilot valve seat and the housing assembly; the shaft part of the base is inserted into the shaft hole of the pilot valve seat. The shaft part has a shaft hole and circumferentially distributed inclined holes, and the inclined holes communicate the shaft hole with the inner cavity of the bellows cover; the pilot valve piston assembly presses up against the steel ball through an upper push rod; the guide rod at the lower part of the vacuum bellows passes through the base and presses up against the steel ball through a lower push rod.

[0009] Advantageously, the gap between the annular stepped hole of the lift valve and the lift valve piston forms a first channel.

[0010] Advantageously, the upper end face of the lift valve piston has a counterbore for installing the lift valve spring. The valve piston assembly also includes a guide ring in the upper annular groove, and a corrugated ring, a support ring and a graphite ring are sequentially installed.

[0011] Advantageously, a switch position indication mark is also provided on the lift valve piston.

[0012] Advantageously, the main body of the seal seat assembly is an annular seal cover. A graphite ring, a retaining ring, a corrugated gasket and an elastic retaining ring are sequentially installed in the stepped hole inside it, and a spacer is also installed outside the graphite ring.

[0013] Advantageously, the main body of the pilot valve piston assembly is a pilot valve piston. It has an upper push rod at its outer bottom and an annular groove on its outer ring surface. A graphite ring and a support ring are installed in one of the annular grooves, and a guide ring is installed in the other annular groove.

[0014] Advantageously, the lower cavity of the pilot valve has a lower exhaust port.

[0015] Advantageously, the lower cavity of the pilot valve is connected to a spring seat, and the pilot valve spring is clamped between the spring seat and the pilot valve piston assembly.

[0016] Advantageously, the upper part of the vacuum bellows is provided with bolts, which pass through the bellows cover and are fixed by nuts.

[0017] Beneficial effects:

[0018] First, the overpressure shut-off valve is a pneumatic valve directly controlled by a pilot valve to actuate a lift valve, with adjustable opening and closing pressure points, enabling the function of rapid opening and closing of the valve;

[0019] Second, the pilot valve control mechanism and the lift valve actuation mechanism of the overpressure shut-off valve are arranged side by side in the valve cavity, with a compact overall structure, enabling miniaturization and lightweight of the valve;

[0020] Third, both the pilot valve control mechanism and the lift valve actuation mechanism of the overpressure shut-off valve are located in the valve cavity, which can avoid the problem of jamming of the valve control mechanism during movement in an external dust environment. Description of the drawings

[0021] Figure 1 is a schematic structural diagram of a traditional overpressure shut-off valve;

[0022] Figure 2 is an external view of the overpressure rapid shut-off valve of the present invention;

[0023] Figure 3 is a cross-sectional view of the overpressure rapid shut-off valve of the present invention at the inlet and outlet;

[0024] Figure 4 is a schematic internal structure diagram of the overpressure rapid shut-off valve of the present invention;

[0025] Figure 5 is an oblique view of the bellows cover;

[0026] Figure 6 is Figure 4 a partial enlarged view of;

[0027] Figure 7 is a front cross-sectional view of the seal seat assembly without showing the lift valve;

[0028] Figure 8 is a left view of the seal seat assembly;

[0029] Figure 9 is a cross-sectional view of the sealing structure of the lift valve piston assembly;

[0030] Figure 10 is a partial cross-sectional view of the pilot valve piston assembly;

[0031] Figure 11 is a schematic diagram of the state when the valve is fully open;

[0032] Figure 12 is a schematic diagram of the state when the valve is fully closed.

[0033] In the figure: 1 - housing assembly; 2 - lift valve spring; 3 - lift valve piston assembly; 301 - lift valve piston; 302 - graphite ring; 303 - support ring; 304 - corrugated ring; 305 - guide ring; 4 - seal seat assembly; 401 - seal cover; 402 - spacer; 403 - circlip; 404 - corrugated gasket; 405 - retaining ring; 406 - graphite ring; 5 - spring seat; 6 - pilot valve spring; 7 - pilot valve piston assembly; 701 - pilot valve piston; 702 - graphite ring; 703 - support ring; 704 - guide ring; 8 - steel ball; 9 - pilot valve seat; 10 - base; 11 - guide rod; 12 - bellows cover; 13 - vacuum bellows; 14 - nut; 15 - air inlet; 16 - air outlet; 17 - closed chamber; 18 - open chamber; 19 - first channel; 20 - second channel; 21 - third channel; 22 - upper exhaust port; 23 - intermediate chamber; 24 - pressure sensing chamber; 25 - lower exhaust port; 26 - pressure chamber Detailed implementation manners

[0034] The embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0035] In a specific embodiment of the overpressure shut-off valve of the present invention, the housing assembly contains two parts, namely a lift valve and a pilot valve. The lift valve mainly includes a seal seat assembly 4, a lift valve piston assembly 3 and a lift valve spring 2. The pilot valve mainly includes a pilot valve spring 6, a pilot valve piston assembly 7, a steel ball 8, a pilot valve seat 9, a base 10, a guide rod 11, a vacuum bellows 13 and a vacuum bellows cover 12. The vacuum bellows 13 is used on the pilot valve to sense the change of the external atmospheric pressure.

[0036] As Figure 4 shown, the cavity in the housing assembly 1 that houses the lift valve piston assembly 3 is divided into three parts, namely a closed chamber 17, an intermediate chamber 23 and an open chamber 18 according to the position. The closed chamber 17 has an air inlet 15, the intermediate chamber 23 has an air outlet 16, and there is a first channel 19 between the closed chamber 17 and the intermediate chamber 23. The part of the lift valve piston assembly 3 in the closed chamber 17 has a valve plate that can close the first channel 19. The open chamber 18 is communicated with the pressure sensing chamber 24 of the pilot valve through a third channel 21 (the internal pipeline of the housing is not shown).

[0037] A lift valve spring 2 is arranged in the open chamber 18 of the lift valve. Under the action of the lift valve spring 2, the lift valve piston assembly 3 moves downward to overcome the sliding friction force, so that the lift valve is in an open position.

[0038] As Figure 5 shown, the bellows cover 12 is provided with an upper exhaust port 22 in the area near the upper part.

[0039] The lower part of the pilot valve houses a pilot valve piston assembly 7 pushed upward by a pilot valve spring 6, and the upper part houses a guide rod 11 pushed downward by a vacuum bellows 13. The pilot valve is provided with a vacuum bellows 13 inside a bellows cover 12. The vacuum bellows 13 senses the change of the external atmospheric environment pressure with the flight altitude through an upper exhaust port 22 of the bellows cover 12. The vacuum bellows 13 exerts a force on a steel ball 8 through the guide rod 11 at the lower end. After mechanical equilibrium, it ensures that the opening and closing pressures of the valve are pressure-compensated with the change of the flight altitude.

[0040] As Figure 6 shown, the middle part of the pilot valve has an annular stepped hole structure. The aperture of the upper annular hole is larger than that of the lower annular hole. A pilot valve seat 9 is installed in the upper annular hole, and a base 10 is installed at the end of the upper annular hole. The cross-section of the pilot valve seat 9 is an "I"-shaped structure and has a shaft hole and radially distributed through holes in the circumferential direction. A steel ball 8 is placed at the intersection of the shaft hole and the radially through holes. The steel ball 8 is constrained at the central position by the radially through holes and can move up and down along the axis. The annular cavity of the pilot valve seat 9 constitutes the pressure-sensing cavity 24, and the pressure-sensing cavity 24 communicates with the third channel 21. The pilot valve piston assembly 7 exerts an upward thrust on the steel ball 8 from the lower annular hole. The base 10 has a shaft hole and obliquely distributed holes in the circumferential direction. The obliquely distributed holes connect the shaft hole with the inner cavity of the bellows cover 12. The guide rod 11 is inserted into the shaft hole of the base 10 and has a lower ejector rod with a small diameter at the end, which exerts a downward thrust on the steel ball 8.

[0041] The closing cavity 17 communicates with the pressure cavity 26 of the pilot valve piston through a second channel 20. When the gas pressure at the air inlet 15 is lower than the set value, the pilot valve piston assembly 7 overcomes the pressure of the vacuum bellows 13 under the action of the pilot valve spring 6 and pushes the steel ball 8 upward, blocking the shaft hole at the upper part of the radially through hole and conducting the shaft hole at the lower part of the radially through hole and the pressure-sensing cavity 24. At this time, the pilot valve is in the open position, and the gas in the closing cavity 17 flows to the air outlet 16 through the first channel 19.

[0042] As Figure 7 shown, the main body of the seal seat assembly 4 is a seal cover 401, which has a stepped hole inside. A graphite ring 406, a retaining ring 405, a corrugated gasket 404, and a snap ring 403 are sequentially installed in the openings at the upper and lower ends. A spacer 402 is also installed outside the graphite ring 406. Combining Figure 8 , a sunken air guide groove is provided on the inner end face of the seal cover 401.

[0043] As Figure 9As shown in the figure, the main body of the lift valve piston assembly 3 is the lift valve piston 301. There are annular grooves around the lift valve piston 301. A guide ring 305 is installed in one of the annular grooves, and a wave ring 304, a support ring 303, and a graphite ring 302 are successively installed in the other annular groove. A mechanical switch position indication mark is also set on the lift valve piston 301, including an "open" mark and a calibration mark for fully open, which can be visually inspected to indicate the open and closed states of the valve, facilitating the operator to understand the position state of the valve.

[0044] As Figure 10 shown, the main body of the pilot valve piston assembly 7 is the pilot valve piston 701, which is a cup-shaped structure and has an upper ejector rod at the outer bottom and an annular groove on the outer ring surface. A graphite ring 702 and a support ring 703 are installed in one of the annular grooves, and a guide ring 704 is installed in the other annular groove.

[0045] As Figure 11 shown, during normal operation, the gas entering through the air inlet 15 flows out through the air outlet 16 of the lift valve. The gas pressure at the air inlet 15 enters the pilot valve through the second channel 20.

[0046] As Figure 12 shown, when the gas pressure at the air inlet 15 is higher than the set value, the pilot valve piston assembly 7 moves downward under the action of the inlet gas pressure overcoming the pilot valve spring 6, and the steel ball 8 moves downward under the action of the vacuum bellows 13, causing the pilot valve to be in the fully closed position to block the shaft hole at the lower part of the radial through hole, conducting the pressure sensing chamber 24 and the inner cavity of the bellows cover 12, and connecting the gas in the opening chamber 18 to the external atmospheric environment through the third channel 21. The gas pressure at the air inlet 15 enters the air guide groove of the seal seat assembly 4 to lift the valve piston assembly 3 in the closing chamber 17 upward to the closed position to block the first channel 19, and the gas in the opening chamber 18 is discharged to the external atmospheric environment through the third channel 21.

Claims

1. A super-pressure quick shut-off valve, characterized in that: It includes a lift valve and a pilot valve inside the housing assembly (1), where The cavity where the lift valve is located includes an opening cavity (18), an intermediate cavity (23), and a closing cavity (17) from top to bottom. There is an annular stepped hole between the intermediate cavity (23) and the closing cavity (17). The closing cavity (17) has an air inlet (15). The closing cavity (17) communicates with the pressure cavity (26) of the pilot valve through the second channel (20) inside the housing assembly (1). The intermediate cavity (23) has an air outlet (16). The lift valve piston assembly (3) has a lift valve piston (301). The upper end of the lift valve piston (301) is sealed and installed in the opening cavity (18), and a downward pressure is applied to the lift valve piston (301) through the lift valve spring (2). The part of the lift valve piston (301) in the closing cavity (17) has a valve plate capable of covering the annular stepped hole. The lower side of the lift valve piston (301) has a limit plate. The lower end of the lift valve piston (301) is inserted into the seal seat assembly (4), and the inner end face of the seal seat assembly (4) has an air guiding groove; The middle part of the pilot valve has a pressure sensing cavity (24), in which a steel ball (8) that can move up and down is installed. The pressure sensing cavity (24) communicates with the opening cavity (18) through the third channel (21) inside the housing assembly (1). The upper part of the pilot valve has a bellows cover (12), and the vacuum bellows (13) inside applies a downward pressure to the steel ball (8), and the bellows cover (12) has an upper exhaust port (22). There is a pilot valve piston assembly (7) in the lower cavity of the pilot valve. The pilot valve spring (6) pushes up the pilot valve piston assembly (7) tightly to apply an upward pressure to the steel ball (8). The cavity above the pilot valve piston assembly (7) constitutes the pressure cavity (26). When the inlet pressure is lower than the set value, the steel ball (8) blocks the air inlet of the bellows cover (12) upward, and at the same time, the pressure cavity (26) communicates with the pressure sensing cavity (24). When the inlet pressure is greater than or equal to the set value, the steel ball (8) blocks the pressure cavity (26) downward, and at the same time, the pressure sensing cavity (24) communicates with the bellows cover (12).

2. The overpressure quick shut-off valve according to claim 1, characterized in that: The middle part of the pilot valve has a pilot valve seat (9) and a base (10). The pilot valve seat (9) has an axial hole and several radial through holes communicating with the axial hole. The steel ball (8) is constrained at the intersection of the axial hole and the radial through holes and can move up and down along the axis. The outside of the pilot valve seat (9) and the housing assembly (1) form the pressure sensing cavity (24). The shaft part of the base (10) is inserted into the axial hole of the pilot valve seat (9). The shaft part has an axial hole and circumferentially distributed inclined holes. The inclined holes connect the axial hole with the inner cavity of the bellows cover (12). The pilot valve piston assembly (7) pushes up the steel ball (8) tightly through an upper push rod. The guide rod (11) at the lower part of the vacuum bellows (13) passes through the base (10) and pushes up the steel ball (8) tightly through a lower push rod.

3. The overpressure rapid shut-off valve according to claim 1 or 2, characterized in that: The gap between the annular stepped hole of the lift valve and the lift valve piston (301) forms the first channel (19).

4. The overpressure quick shut-off valve according to claim 1 or 2, characterized in that: The upper end face of the lift valve piston (301) has a counterbore for installing the lift valve spring (2). The lift valve piston assembly (3) further includes a first guide ring (305) in the upper annular groove, and a corrugated ring (304), a first support ring (303), and a first graphite ring (302) are sequentially installed.

5. The overpressure rapid shut-off valve according to claim 4, characterized in that: A switch position indication mark is also provided on the lift valve piston (301).

6. The overpressure quick shut-off valve according to claim 1 or 2, characterized in that: The main body of the seal seat assembly (4) is an annular seal cover (401). A second graphite ring (406), a retaining ring (405), a corrugated gasket (404), and a snap ring (403) are sequentially installed in the stepped hole inside it. A spacer (402) is also installed outside the second graphite ring (406).

7. The overpressure rapid shut-off valve according to claim 1 or 2, characterized in that: The main body of the pilot valve piston assembly (7) is the pilot valve piston (701). It has an upper ejector rod at its outer bottom and an annular groove on its outer ring surface. A third graphite ring (702) and a second support ring (703) are installed in one of the annular grooves, and a second guide ring (704) is installed in the other annular groove.

8. The overpressure rapid shut-off valve according to claim 1 or 2, characterized in that: The lower cavity of the pilot valve has a lower exhaust port (25).

9. The overpressure quick shut-off valve according to claim 8, characterized in that: The lower cavity of the pilot valve is connected to the spring seat (5), and the pilot valve spring (6) is clamped between the spring seat (5) and the pilot valve piston assembly (7).

10. The overpressure quick shut-off valve according to claim 1 or 2, characterized in that: The upper part of the vacuum bellows (13) has a bolt, which passes through the bellows cover (12) and is fixed by a nut (14).

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