Large-caliber normally open pneumatic valve for space propulsion system

Abstract

The present invention provides a large-caliber normally-open pneumatic valve for a space propulsion system, comprising: a main valve core assembly, a liquid circuit spring, an inlet joint, a main valve housing, a pilot valve, and a liquid circuit inlet; the main valve core assembly is arranged in the main valve housing, one end of the main valve housing is connected to the pilot valve, and the other end is installed with the inlet joint; the liquid circuit spring is installed between the main valve core assembly and the inlet joint, and the liquid circuit spring pushes the main valve core assembly away from the liquid circuit inlet on the inlet joint and keeps the liquid circuit inlet open; when the pilot valve is energized and opened, the driving air circuit at the pilot valve is ventilated and pushes the main valve core assembly toward the side of the liquid circuit inlet until the liquid circuit inlet is closed.

Description

Technical Field

[0001] The present invention relates to the field of normally open pneumatic valve structures, and in particular to a large-caliber normally open pneumatic valve for a space propulsion system. Background Art

[0002] Large-caliber normally-open pneumatic valves are a critical component of the manned lunar landing orbital control system. The overall propellant flow requirements for manned lunar landings are significantly higher than those of previous missions, and they require valves that operate in a normally-open mode. Previous models of valves rarely utilize this mode. To meet the overall requirements for normally-open valves, a large-caliber normally-open pneumatic valve was designed according to the design brief for propellant control during manned lunar landings.

[0003] The overall requirements for manned lunar landings necessitate valves operating with methylhydrazine (MMH) and green nitrogen tetroxide (MON-1) as the working fluids. These valves must have a high flow rate (5 L / s) and a long operating time (up to six months of contact with the propellant). Traditional pneumatic valves operate in a normally closed mode, with low flow rates and a propellant contact time that cannot meet these stringent requirements, making them unsuitable for manned lunar landings. Therefore, a large-caliber, normally open pneumatic valve was needed to meet these overall requirements. Summary of the Invention

[0004] In view of the defects in the prior art, the purpose of the present invention is to provide a large-caliber normally open pneumatic valve for a space propulsion system.

[0005] According to the present invention, a large-caliber normally open pneumatic valve for a space propulsion system includes: a main valve core assembly, a fluid circuit spring, an inlet connector, a main valve housing, a pilot valve, and a fluid circuit inlet;

[0006] The main valve core assembly is arranged in the main valve housing, one end of the main valve housing is connected to the pilot valve, and the other end is installed with the inlet connector;

[0007] The fluid circuit spring is installed between the main valve core assembly and the inlet joint, and the fluid circuit spring pushes the main valve core assembly away from the fluid circuit inlet on the inlet joint and keeps the fluid circuit inlet in an open state;

[0008] When the pilot valve is powered on and opened, the driving air path at the pilot valve is ventilated and pushes the main valve core assembly toward the liquid path inlet until the liquid path inlet is closed.

[0009] Preferably, a piston shaft assembly is provided inside the main valve core assembly, and the piston shaft assembly is allowed to move axially along the inside of the main valve housing;

[0010] The piston shaft assembly includes: a piston, a piston sleeve and a piston shaft;

[0011] The piston is arranged on the inner wall of the main valve housing at one end facing the pilot valve, the piston sleeve is arranged on the side of the piston facing the inlet joint, and a small spring is installed between the piston and the piston sleeve;

[0012] The piston is connected to the piston shaft on the side facing the inlet joint, a through hole is provided in the piston sleeve, and the piston shaft passes through the through hole. When the pilot valve is energized and opened, the gas in the driving gas circuit pushes the piston and the piston shaft to move toward the inlet joint.

[0013] Preferably, both sides of the piston sleeve are limited by a pressure block and a retaining ring respectively, and the pressure block and the retaining ring are fixedly installed on the inner side of the main valve housing.

[0014] Preferably, a second sealing ring is provided between the piston and the inner side wall of the main valve housing, and a first sealing ring is provided between the piston sleeve and the inner side wall of the main valve housing;

[0015] The piston shaft is sleeved with a bellows on the outside of one end facing the inlet joint, the bellows is connected to the piston sleeve, and the first sealing ring and the second sealing ring are isolated from the propellant flowing from the liquid path inlet through the bellows.

[0016] Preferably, a flood plug is provided between the peripheral side of the piston facing the pilot valve and the inner side wall of the main valve housing.

[0017] Preferably, the main valve core assembly and the pilot valve are connected via flange-matching fasteners.

[0018] Preferably, the pilot valve is connected to the driving air path through a driving air inlet, and the pilot valve is connected to an air path exhaust port.

[0019] Preferably, a liquid outlet is provided at one end of the main valve housing close to the inlet joint, and the liquid outlet is connected to the liquid inlet.

[0020] Preferably, a metal cutting edge is provided on the side of the inlet connector facing the main valve core assembly, and when the pilot valve is energized, the main valve core assembly is pushed and abuts against the metal cutting edge.

[0021] Preferably, the diameter of the large-diameter normally open pneumatic valve is greater than or equal to Φ40mm, which meets the use of a flow rate of 5L / s.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. The present invention drives the main valve to close by opening the pilot valve, presses the main valve core with the liquid circuit spring to realize the main valve is normally open, and the bellows isolates the liquid propellant from the non-metallic seal. The structure realizes the characteristics of normally open, large flow (large diameter), and long contact time with the propellant. If the traditional space propulsion valve is to realize multiple opening and closing of Φ40mm, the weight will reach several kilograms, which will bring a large weight burden to the propulsion system. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Other features, objects and advantages of the present invention will become more apparent upon reading the detailed description of non-limiting embodiments with reference to the following drawings:

[0025] Figure 1 This is a cross-sectional view of a normally open pneumatic valve;

[0026] As shown in the figure:

[0027] DETAILED DESCRIPTION

[0028] The present invention will be described in detail below with reference to specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those skilled in the art, several changes and improvements can be made without departing from the scope of the present invention. These all fall within the scope of protection of the present invention.

[0029] Example 1

[0030] like Figure 1 As shown, this embodiment includes: a main valve core assembly 1, a fluid circuit spring 2, an inlet connector 3, a main valve housing 4, a pilot valve 7, and a fluid circuit inlet 18. The main valve core assembly 1 is mounted within the main valve housing 4. One end of the main valve housing 4 is connected to the pilot valve 7, and the other end is mounted with the inlet connector 3. A fluid circuit outlet 17 is provided on the end of the main valve housing 4 near the inlet connector 3, connecting the fluid circuit outlet 17 to the fluid circuit inlet 18. A fluid circuit spring 2 is mounted between the main valve core assembly 1 and the inlet connector 3. This spring pushes the main valve core assembly 1 away from the fluid circuit inlet 18 on the inlet connector 3, keeping the fluid circuit inlet 18 open. When the pilot valve 7 is energized, the actuating air circuit in the pilot valve 7 is ventilated, pushing the main valve core assembly 1 toward the fluid circuit inlet 18 until it closes. The main valve core assembly 1 and the pilot valve 7 are connected by flanges with fasteners 14. The pilot valve 7 is connected to the actuating air circuit via the actuating air inlet 16, and the pilot valve 7 is also connected to the air circuit exhaust. A metal cutting edge is provided on the side of the inlet connector 3 facing the main valve core assembly 1 . When the pilot valve 7 is energized, the main valve core assembly 1 is pushed and fits onto the metal cutting edge.

[0031] A piston shaft assembly 5 is arranged inside the main valve spool assembly 1, and the piston shaft assembly 5 is allowed to move axially along the inner side of the main valve housing 4; the piston shaft assembly 5 includes: a piston 8, a piston sleeve 19 and a piston shaft; the piston 8 is arranged on the inner wall of the main valve housing 4 facing the pilot valve 7, and a piston sleeve 19 is arranged on the side of the piston 8 facing the inlet joint 3, a small spring 9 is installed between the piston 8 and the piston sleeve 19, and the piston 8 is connected to the piston shaft facing the inlet joint 3. A through hole is arranged in the piston sleeve 19, and the piston shaft passes through the through hole. When the pilot valve 7 is energized and opened, the gas in the driving gas circuit pushes the piston 8 and the piston shaft to move toward the side of the inlet joint 3.

[0032] A flood plug 12 is installed between the side of the piston 8 facing the pilot valve 7 and the inner wall of the main valve housing 4. A pressure block 6 and a retaining ring 10 respectively constrain the piston sleeve 19 on either side, both of which are fixedly mounted on the inner wall of the main valve housing 4. A second sealing ring 13 is installed between the piston 8 and the inner wall of the main valve housing 4, and a first sealing ring 11 is installed between the piston sleeve 19 and the inner wall of the main valve housing 4. A bellows 15 is installed on the outer side of the piston shaft end facing the inlet connector 3 and connected to the piston sleeve 19. The first and second sealing rings 11 and 13, through the bellows 15, isolate the propellant flowing in from the liquid inlet 18.

[0033] Example 2

[0034] Example 2 is a preferred example of Example 1.

[0035] like Figure 1 As shown, this embodiment includes: a pilot valve 7, a main valve core assembly 1, a piston shaft assembly 5, a main valve housing 4, a piston 8, an inlet connector 3, a pressure block 6, a liquid circuit spring 2, a small spring 9, a flooded plug 12, a retaining ring 10, etc. During operation, the pilot valve 7 is initially in a closed state, the main valve core assembly 1 is compressed and limited to an open position by the liquid circuit spring 2, and the liquid circuit main valve (the liquid circuit main valve is on the right side of the pilot valve 7, and the liquid circuit main valve is provided with a main valve core assembly 1) is in an open state. When the liquid circuit main valve needs to be closed, the pilot valve 7 is energized. After the pilot valve 7 is energized and opened, the driving air circuit is connected, and the gas pushes the piston 8 to move, thereby pushing the piston shaft in the piston shaft assembly 5 to move. After the main valve core assembly 1 is subjected to force, it overcomes the preload force of the liquid circuit spring 2 and moves in the closing direction, and the liquid circuit main valve is closed. After closing, the driving air circuit pressure presses the main valve core assembly 1 against the metal cutting edge of the inlet connector 3, achieving a reliable sealing effect. The components of the main valve for the liquid circuit are integrated into the main valve housing 4 , and the main valve for the liquid circuit is connected to the pilot valve 7 via a flange.

[0036] The liquid circuit spring 2 is clamped in the groove on the peripheral side of the main valve core assembly 1 toward the inlet connector 3, which greatly reduces the length of the pneumatic valve and reduces the weight of the pneumatic valve.

[0037] The bellows 15 in the piston shaft assembly 5 is used to effectively isolate the propellant liquid path from the non-metallic seal for a long time, so that the non-metallic seal does not deform and has stable performance during its life cycle, ensuring reliable sealing and providing pre-tightening force.

[0038] When pilot valve 7 is energized and opened, the drive air circuit is connected, pushing the piston shaft in piston shaft assembly 5. The main valve spool assembly 1, under this force, overcomes the preload force of hydraulic circuit spring 2 and moves toward the closed position, closing the main hydraulic valve. Once closed, the non-metallic seal on main valve spool assembly 1 and the cutting edge on inlet connector 3 form a soft-hard seal pair, ensuring a reliable seal after the main hydraulic valve is closed.

[0039] In the description of this application, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0040] The above describes specific embodiments of the present invention. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art may make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. The embodiments of this application and the features in the embodiments may be combined with each other in any manner unless there is a conflict.

Claims

1. A large-caliber normally open pneumatic valve for a space propulsion system, characterized in that: include: A main valve core assembly (1), a fluid circuit spring (2), an inlet connector (3), a main valve housing (4), a pilot valve (7), and a fluid circuit inlet (18); The main valve core assembly (1) is arranged in the main valve housing (4); one end of the main valve housing (4) is connected to the pilot valve (7), and the other end is installed with the inlet connector (3); The liquid circuit spring (2) is installed between the main valve core assembly (1) and the inlet joint (3), and the liquid circuit spring (2) pushes the main valve core assembly (1) away from the liquid circuit inlet (18) on the inlet joint (3) and keeps the liquid circuit inlet (18) in an open state; When the pilot valve (7) is powered on and opened, the driving air path at the pilot valve (7) is ventilated and pushes the main valve core assembly (1) toward the liquid path inlet (18) until the liquid path inlet (18) is closed; A piston shaft assembly (5) is provided inside the main valve core assembly (1), and the piston shaft assembly (5) is allowed to move axially along the inside of the main valve housing (4); The piston shaft assembly (5) comprises: a piston (8), a piston sleeve (19) and a piston shaft; The piston (8) is arranged on the inner wall of the main valve housing (4) at one end facing the pilot valve (7), the piston sleeve (19) is arranged on the side of the piston (8) facing the inlet connector (3), and a small spring (9) is installed between the piston (8) and the piston sleeve (19); The piston (8) is connected to the piston shaft toward the inlet connector (3), a through hole is provided in the piston sleeve (19), and the piston shaft passes through the through hole. When the pilot valve (7) is powered on and opened, the gas in the driving gas circuit pushes the piston (8) and the piston shaft toward the inlet connector (3); The piston sleeve (19) is limited on both sides by a pressure block (6) and a retaining ring (10), respectively. The pressure block (6) and the retaining ring (10) are fixedly mounted on the inner side of the main valve housing (4); A second sealing ring (13) is provided between the piston (8) and the inner side wall of the main valve housing (4), and a first sealing ring (11) is provided between the piston sleeve (19) and the inner side wall of the main valve housing (4); A bellows (15) is sleeved on the outer side of one end of the piston shaft facing the inlet joint (3), and the bellows (15) is connected to the piston sleeve (19). The first sealing ring (11) and the second sealing ring (13) isolate the propellant flowing from the liquid circuit inlet (18) through the bellows (15).

2. The large-caliber normally open pneumatic valve for a space propulsion system according to claim 1, characterized in that: A flood plug (12) is provided between the peripheral side of the piston (8) facing the pilot valve (7) and the inner wall of the main valve housing (4).

3. The large-caliber normally open pneumatic valve for a space propulsion system according to claim 1, characterized in that: The main valve core assembly (1) and the pilot valve (7) are connected via a flange-matching fastener (14).

4. The large-caliber normally open pneumatic valve for a space propulsion system according to claim 1, characterized in that: The pilot valve (7) is connected to the driving air path via the driving air inlet (16), and the pilot valve (7) is connected to the air path exhaust port.

5. The large-caliber normally open pneumatic valve for a space propulsion system according to claim 1, characterized in that: A liquid circuit outlet (17) is provided at one end of the main valve housing (4) close to the inlet joint (3), and the liquid circuit outlet (17) is connected to the liquid circuit inlet (18).

6. The large-caliber normally open pneumatic valve for a space propulsion system according to claim 1, characterized in that: The inlet connector (3) is provided with a metal cutting edge on one side facing the main valve core assembly (1); when the pilot valve (7) is energized, the main valve core assembly (1) is pushed and abuts against the metal cutting edge.

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