A pressure reducing valve with a rechargeable airbag

Abstract

The present application provides a pressure reducing valve with a pressurizable airbag. The pressure reducing valve includes a one-way pressurizing nozzle, an airbag, sealing grease, an upper valve body, an upper valve core, a middle valve body, a pressure regulating nut, a pressure regulating spring, a sealing ring, a lower valve core, and a lower valve body. Among them: The lower valve body is a hollow structure with a circular cavity inside, and has an oil circuit interface, an oil inlet, an oil outlet, and an air vent communicating with the atmosphere on the outside; A feedback pipe connected to the back pressure chamber is provided at the oil outlet; The middle valve body is a hollow structure with a circular cavity inside, is connected to the lower valve body by a thread, and has threads for installing a pressure regulating nut and a set screw respectively; The upper valve body is a hollow structure with a circular cavity inside and is connected to the middle valve body by a thread; The upper valve core is installed in the middle valve body and is connected to the lower valve core by a thread. The diameter of the upper valve core is equal to the diameter of the piston (2) on the lower valve core; The airbag is installed in the upper valve body and the middle valve body, is pressed on the upper valve core, and is filled with sealing grease in the middle.

Description

Technical Field

[0001] The present invention belongs to the field of hydraulic technology, and particularly relates to a pressure reducing valve with a pressurizable airbag. Background Art

[0002] For some helicopter engines, the required variation range of the fuel inlet pressure is smaller than the variation range of the system pressure caused by helicopter overload, atmospheric pressure, etc., resulting in the fuel supply pressure of the fuel system not meeting the engine requirements during the flight profile. Therefore, a pressure reducing valve solution can be adopted to solve this problem.

[0003] However, in the prior art, the pressure reducing valve has the problem of unstable outlet pressure during flight. Summary of the Invention

[0004] The present application provides a pressure reducing valve with a pressurizable airbag, which can eliminate the problem of unstable outlet pressure existing during flight.

[0005] Technical Solution: A pressure reducing valve with a pressurizable airbag, the pressure reducing valve includes a one-way pressurizing nozzle, an airbag, sealing grease, an upper valve body, an upper valve core, a middle valve body, a pressure regulating nut, a pressure regulating spring, a sealing ring, a lower valve core, and a lower valve body, wherein:

[0006] The lower valve body is a hollow structure with a circular cavity inside, and is provided with an oil circuit interface, an oil inlet, an oil outlet and an air vent communicating with the atmosphere on the outside; a feedback pipe connected to the back pressure cavity is provided at the oil outlet;

[0007] The middle valve body is a hollow structure with a circular cavity inside, is connected to the lower valve body by a thread, and has threads for installing a pressure regulating nut and a set screw respectively;

[0008] The upper valve body is a hollow structure with a circular cavity inside, and is connected to the middle valve body by a thread;

[0009] The upper valve core is installed in the middle valve body and is connected to the lower valve core by a thread. The diameter of the upper valve core is equal to the diameter of the piston (2) on the lower valve core;

[0010] The airbag is installed in the upper valve body and the middle valve body, is pressed on the upper valve core, and is filled with sealing grease in the middle; the inflation pressure in the airbag and the pre-tightening force of the spring determine the pressure at the oil outlet;

[0011] The one-way pressurizing nozzle is installed on the airbag, leads to the outside through the opening of the upper valve body, and the airbag can be pressurized through the one-way pressurizing nozzle.

[0012] Specifically, the lower valve core is a circular structure, including a piston (1), a piston (2) and a lower valve core rod, and is installed in the lower valve body. The piston (1) and the piston (2) divide the lower valve body into three parts: one part is the back pressure cavity, one part is the pressure oil cavity that connects the oil inlet and the oil outlet, and one part is the air cavity that communicates with the atmosphere.

[0013] Specifically, the pressure regulating spring is installed on the lower spool valve.

[0014] Specifically, when the outlet pressure of the pressure reducing valve is P o , then the pressure to be filled in the airbag is P c = k(z0 + x0) / S - P o , where S is the annular area of the end face of the piston (2) of the lower spool valve, k is the stiffness of the pressure regulating spring, z0 is the pre-compression of the pressure regulating spring, and x0 is the piston displacement of the lower spool valve.

[0015] Specifically, a throttle orifice is formed between the piston (1) of the lower spool valve and the lower valve body; an annular groove for installing a sealing ring is formed on the piston (2) of the lower spool valve.

[0016] Specifically, the sealing ring is installed on the piston (2) of the lower spool valve to play a sealing role and prevent oil from flowing from the pressure oil chamber into the air chamber.

[0017] Specifically, the pressure regulating nut is installed on the middle valve body through threads and presses on the pressure regulating spring to adjust the spring pre-tightening force and has a large gap with the lower spool valve rod.

[0018] Specifically, the set screw is installed on the middle valve body to press the pressure regulating nut to prevent it from loosening.

[0019] In summary, the present application provides a pressure reducing valve with a pressurizable airbag, which can reduce the fluctuation of the outlet pressure of the pressure reducing valve caused by the change of the atmospheric pressure when the helicopter changes its flight altitude. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 FIG. is a schematic structural diagram of a pressure reducing valve with a pressurizable airbag provided by the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] For a general pressure reducing valve, since the pressure regulating spring chamber is open to the atmosphere, when the helicopter flies from the ground to a high altitude or descends, due to the change of the atmosphere, the change of the outlet pressure of the pressure reducing valve is superimposed on the change of the atmosphere, resulting in an expansion of the change of the outlet pressure of the pressure reducing valve (~60 kPa). For a low-pressure system (~200 kPa) such as the helicopter fuel supply system, this pressure change still accounts for a relatively large proportion. Therefore, a pressure reducing valve with a pressurizable airbag is proposed to eliminate the influence caused by the change of the atmospheric pressure during flight.

[0022] Key points of the present invention: Since the pressure regulating spring chamber is open to the atmosphere, the change in atmospheric pressure is introduced into the outlet pressure of the pressure reducing valve. Therefore, a corresponding upper valve core of the same size needs to be designed. One side is communicated with the pressure regulating spring chamber, and the other side is in contact with the airbag. The contact area is equal to the area of the upper valve core. The airbag is connected to the one-way charging nozzle. When the airbag is filled to the specified pressure, during the entire flight of the helicopter, the outlet pressure of the pressure reducing valve is determined by the airbag pressure, ambient temperature, and spring, thereby eliminating the influence of atmospheric pressure.

[0023] As Figure 1 shown, a pressure reducing valve with a chargeable airbag provided by the present application includes a one-way charging nozzle, an airbag, sealing grease, an upper valve body, an upper valve core, a middle valve body, a pressure regulating nut, a pressure regulating spring, a sealing ring, a lower valve core, and a lower valve body, where:

[0024] The lower valve body is a hollow structure with a circular cavity inside, and has an oil circuit interface, an oil inlet, an oil outlet, and an air vent communicating with the atmosphere on the outside; a feedback pipe connected to the back pressure chamber is provided at the oil outlet;

[0025] The middle valve body is a hollow structure with a circular cavity inside, is connected to the lower valve body by a thread, and has threads for installing a pressure regulating nut and a set screw respectively;

[0026] The upper valve body is a hollow structure with a circular cavity inside and is connected to the middle valve body by a thread;

[0027] The upper valve core is installed inside the middle valve body and is connected to the lower valve core by a thread. The diameter of the upper valve core is equal to the diameter of the piston 2 on the lower valve core;

[0028] The airbag is installed inside the upper valve body and the middle valve body, is pressed on the upper valve core, and sealing grease is filled in the middle; the inflation pressure in the airbag and the pre-tightening force of the spring determine the pressure at the oil outlet;

[0029] The one-way charging nozzle is installed on the airbag, leads to the outside through an opening in the upper valve body, and the airbag can be charged through the one-way charging nozzle.

[0030] Specifically, the lower valve core is a circular structure, including piston 1, piston 2, and a lower valve core rod, and is installed inside the lower valve body. Piston 1 and piston 2 divide the lower valve body into three parts: one part is the back pressure chamber, one part is the pressure oil chamber that connects the oil inlet and the oil outlet, and one part is the air chamber that communicates with the atmosphere.

[0031] Specifically, the pressure regulating spring is installed on the lower valve core.

[0032] More specifically, when the outlet pressure of the pressure reducing valve is P o , then the pressure to be filled in the airbag is P c = k(z0 + x0) / S - P o, where S is the annular area of the end face of the piston 2 of the lower spool, k is the stiffness of the pressure regulating spring, z0 is the pre-compression of the pressure regulating spring, and x0 is the piston displacement of the lower spool.

[0033] It should be noted that the piston displacement of the lower spool is equal to the displacements of the lower spool and the upper spool.

[0034] Specifically, a throttle orifice is formed between the piston 1 of the lower spool and the lower valve body; an annular groove for installing a sealing ring is provided on the piston 2 of the lower spool.

[0035] Specifically, the sealing ring is installed on the piston 2 of the lower spool to play a sealing role and prevent oil from flowing from the pressure oil chamber into the air chamber.

[0036] Specifically, the pressure regulating nut is installed on the middle valve body through threads, presses on the pressure regulating spring, is used to adjust the spring pre-tightening force, and has a large gap with the lower spool rod.

[0037] Specifically, the set screw is installed on the middle valve body to press the pressure regulating nut to prevent it from loosening.

[0038] The inlet pressure at the oil inlet is high-pressure oil P i , which is introduced into the pressure oil chamber. After passing through the throttle orifice, the pressure drops to P o , and at the same time P o enters the back pressure chamber through the feedback pipe of the lower valve body, and the pressure is P b (P b ≈P o ). The back pressure chamber acts on the lower spool with an upward hydraulic pressure, which is equal to the sum of the force of the pressure regulating spring on the lower spool and the force of the pressure P c in the airbag acting on the upper spool downward. As Figure 1 shown, assuming the spool displacement is x0, the force balance equation on the spool is:

[0039] SP o = k(z0 + x0) + SP c (1)

[0040] In the formula: S is the annular area of the end face of the piston 2 of the lower spool, k is the stiffness of the pressure regulating spring, z0 is the pre-compression of the pressure regulating spring, x0 is the piston displacement of the lower spool, and P c is the pressure in the airbag.

[0041] Then the outlet pressure of the pressure reducing valve is: P o = k(z0 + x0) / S + P c .

[0042] Conversely, when the specified outlet pressure of the pressure reducing valve is P o , then the pressure to be filled in the airbag is:

[0043] P c= k(z0 + x0) / S - P o

[0044] As described above, it is only a specific embodiment of the present invention. The present invention has been described in detail, and the parts not described in detail are conventional technologies. However, the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. The protection scope of the present invention shall be subject to the protection scope of the claims described above.

[0045] The present application provides a capsule pressure reducing valve with a pressurizable function. When the flight altitude of a helicopter changes, the present invention can be used to reduce the fluctuation of the pressure at the outlet of the pressure reducing valve caused by the change of the pressure in the pressure regulating spring chamber with the atmospheric pressure.

Claims

1. A pressure reducing valve with a pressurizable airbag, characterized in that, The pressure reducing valve includes a one-way charging nozzle, an airbag, sealing grease, an upper valve body, an upper valve core, a middle valve body, a pressure regulating nut, a pressure regulating spring, a sealing ring, a lower valve core, and a lower valve body, where: The lower valve body is a hollow structure with a circular cavity inside, and has an oil circuit interface, an oil inlet, an oil outlet, and an air vent communicating with the atmosphere on the outside; a feedback pipe connected to the back pressure cavity is provided at the oil outlet. The middle valve body is a hollow structure with a circular cavity inside, is connected to the lower valve body by threads, and has threads for installing a pressure regulating nut and a set screw respectively. The upper valve body is a hollow structure with a circular cavity inside, and is connected to the middle valve body by threads. The upper valve core is installed inside the middle valve body and is connected to the lower valve core by threads. The diameter of the upper valve core is equal to the diameter of the piston (2) on the lower valve core. The airbag is installed inside the upper valve body and the middle valve body, is pressed on the upper valve core, and is filled with sealing grease in the middle; the inflation pressure in the airbag and the pre-tightening force of the spring determine the pressure at the oil outlet. The one-way charging nozzle is installed on the airbag, leads to the outside through an opening in the upper valve body, and the airbag can be pressurized through the one-way charging nozzle.

2. The pressure reducing valve with a rechargeable airbag according to claim 1, characterized in that, The lower valve core is a circular structure, including a piston (1), a piston (2), and a lower valve core rod, and is installed inside the lower valve body. The piston (1) and the piston (2) divide the lower valve body into three parts: one part is the back pressure cavity, one part is the pressure oil cavity that connects the oil inlet and the oil outlet, and one part is the air cavity that communicates with the atmosphere.

3. The pressure reducing valve with a rechargeable airbag according to claim 1, characterized in that, The pressure regulating spring is installed on the lower valve core.

4. The pressure reducing valve with a rechargeable airbag according to claim 1, characterized in that, When the outlet pressure of the pressure reducing valve is P o , the pressure to be filled in the airbag is P c = k(z0 + x0) / S - P o ; Among them, S is the annular area of the end face of the piston (2) of the lower valve core, k is the stiffness of the pressure regulating spring, z0 is the pre-compression amount of the pressure regulating spring, and x0 is the piston displacement of the lower valve core.

5. The pressure reducing valve with a rechargeable airbag according to claim 1, characterized in that, A throttle orifice is formed between the piston (1) of the lower valve core and the lower valve body; an annular groove for installing a sealing ring is provided on the piston (2) of the lower valve core.

6. The pressure reducing valve with a pressurizable airbag according to claim 1, characterized in that, The sealing ring is installed on the piston (2) of the lower valve core to play a sealing role and prevent oil from flowing from the pressure oil cavity into the air cavity.

7. The pressure reducing valve with a chargeable airbag according to claim 1, characterized in that The pressure regulating nut is installed on the middle valve body by threads, presses on the pressure regulating spring, is used to adjust the spring pre-tightening force, and has a large gap with the lower valve core rod.

8. The pressure reducing valve with a chargeable airbag according to claim 1, characterized in that, The set screw is installed on the middle valve body to press the pressure regulating nut to prevent it from loosening.

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