Sealing structure for pneumatic electromagnetic valve and injector of liquid rocket engine

Abstract

The invention provides a pneumatic electromagnetic valve and injector sealing structure of a liquid rocket engine. The pneumatic electromagnetic valve and injector sealing structure comprises a pneumatic electromagnetic valve shell (1) and an injector (2). An oxygen path and a combustion path of the pneumatic electromagnetic valve shell (1) are respectively connected with an oxygen path and a combustion path of the injector (2) in a sealing manner; the sealing structure of the sealing connection adopts an end face sealing structure and a radial sealing structure at the same time. The sealing cavity and the end face sealing groove are formed in the pneumatic electromagnetic valve shell, meanwhile, the sealing column and the radial sealing groove are arranged on the injector, O-shaped ring double sealing of propellant is achieved, and the on-orbit working reliability of a liquid rocket engine can be improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of spacecraft propulsion systems, and in particular, relates to a pneumatic solenoid valve and an injector sealing structure of a liquid rocket engine. Background Art

[0002] Liquid rocket engines are the power units of missiles, launch vehicles and spacecraft, providing power for attitude control, orbit transfer, space docking, propellant sinking, etc. Pneumatic solenoid valves are devices that control the entry of propellants into the engine. They are composed of pneumatic valve parts and solenoid valve parts. The oxidizer and fuel valve core movements can be controlled simultaneously by the controller, and they have the characteristics of compact space structure and light weight.

[0003] Before the pneumatic solenoid valve is powered on, both the gas circuit and the liquid circuit are in a closed state; after power is turned on, the armature in the solenoid valve is forced to move, the gas circuit is opened, and the gas source enters the air cavity of the pneumatic valve through the gas circuit inlet, pushing the oxidizer circuit valve core and the fuel circuit valve core to move left and right respectively, thereby achieving liquid circuit conduction. The injector is the core component of the engine. Its function is to inject the propellant into the combustion chamber at a certain pressure and organize the atomization and mixing of the propellant, ultimately achieving efficient and stable combustion.

[0004] Looking at the current state of technology at home and abroad, the oxygen and fuel flow channel outlets of the commonly used pneumatic solenoid valves are set on the same plane, and the propellant inlet of the injector is set on the top plane of the oxidizer support and the fuel support. When assembling a liquid rocket engine, a plurality of screws are usually used to connect the pneumatic solenoid valve and the injector, and O-ring sealing grooves are processed at the oxidizer and fuel flow channel outlets of the two joint surfaces, respectively, and sealing is achieved by the end face O-ring to prevent the propellant from leaking from the joint surface. If the seal of the joint surface between the pneumatic solenoid valve and the injector fails, it will cause propellant escape, working pressure drop, insufficient thrust, abnormal combustion and other faults.

[0005] According to the need to improve the reliability of aerospace products, the requirement for long-term on-orbit use, and the concept of redundant design, the joint surface of the valve and the injector should at least adopt a double sealing structure to improve the reliability of engine operation. Therefore, it is necessary to design a sealing structure for the pneumatic solenoid valve and the injector to achieve a double sealing function.

[0006] Patent document CN113790109A discloses a strut injector connection and sealing structure applicable to a composite material engine, which is used to solve the problem that the existing engine strut injector cannot adapt to complex environments and different structural body materials. The strut injector sequentially passes through a positioning groove, a through hole, a sealing groove and a limiting platform; the positioning platform is located in the positioning groove; the cylindrical section passes through the through hole and the sealing groove, and the main body of a pressure ring is arranged in the limiting platform, the sealing end of the pressure ring is arranged in the sealing groove, and a gasket is also arranged in the sealing groove, and the gasket contacts the sealing end of the pressure ring. However, the patent document CN113790109A does not solve the sealing problem between the pneumatic solenoid valve and the injector. Summary of the Invention

[0007] Aiming at the defects in the prior art, the purpose of the present invention is to provide a sealing structure for a pneumatic solenoid valve and an injector of a liquid rocket engine.

[0008] A sealing structure for a pneumatic solenoid valve and an injector of a liquid rocket engine according to the present invention includes: a pneumatic solenoid valve housing 1 and an injector 2;

[0009] The oxygen path and the fuel path of the pneumatic solenoid valve housing 1 are respectively and sealingly connected to the oxygen path and the fuel path of the injector 2;

[0010] The sealing structure of the sealing connection simultaneously adopts an end face sealing structure and a radial sealing structure;

[0011] The end face sealing structure includes an oxygen path end face O-ring 3 and a fuel path end face O-ring 4;

[0012] The radial sealing structure includes an oxygen path radial O-ring 5 and a fuel path radial O-ring 6.

[0013] Preferably, the pneumatic solenoid valve housing 1 is provided with a housing oxygen path flow channel 15, a housing fuel path flow channel 16, an oxygen path end face sealing groove 17, a fuel path end face sealing groove 18, a housing oxygen path sealing cavity 19 and a housing fuel path sealing cavity 20;

[0014] Both the housing oxygen path sealing cavity 19 and the housing fuel path sealing cavity 20 are divided into an upper cylindrical section and a lower frustum section.

[0015] Preferably, a fillet is used for smooth transition between the cylindrical section and the frustum section to prevent the oxygen path radial O-ring 5 and the fuel path radial O-ring 6 from being cut when being installed.

[0016] Preferably, the upper surface of the cylindrical section is subjected to root clearing treatment, and the fillet of the root clearing tool is not greater than R0.2.

[0017] Preferably, the upper cylindrical section of the housing oxygen path sealing cavity 19 is communicated with the housing oxygen path flow channel 15;

[0018] The upper cylindrical section of the combustion path sealing cavity 20 of the housing communicates with the combustion path flow channel 16 of the housing;

[0019] The central axes of the oxygen path flow channel 15 and the combustion path flow channel 16 of the housing both form an angle with the vertical direction.

[0020] Preferably, an oxygen path end face sealing groove 17 is provided above the cylindrical section of the oxygen path sealing cavity 19 of the housing;

[0021] A combustion path end face sealing groove 18 is provided above the cylindrical section of the combustion path sealing cavity 20 of the housing.

[0022] Preferably, a fillet is provided at the inlet edge of the lower surface of the sealing grooves of the oxygen path end face sealing groove 17 and the combustion path end face sealing groove 18.

[0023] Preferably, an oxygen path support 7 and a combustion path support 8 are provided on the injector 2;

[0024] The oxygen path support 7 includes a support oxygen path sealing column 9, an oxygen path radial sealing groove 11, and a support oxygen path flow channel 13;

[0025] The combustion path support 8 includes a support combustion path sealing column 10, a combustion path radial sealing groove 12, and a support combustion path flow channel 14;

[0026] The depth of the oxygen path sealing cavity 19 of the housing is greater than the height of the support oxygen path sealing column 9 with which it is in clearance fit;

[0027] The depth of the combustion path sealing cavity 20 of the housing is greater than the height of the support combustion path sealing column 10 with which it is in clearance fit.

[0028] Preferably, a chamfer is provided at the inlet of the flow channels of the support oxygen path flow channel 13 and the support combustion path flow channel 14;

[0029] A chamfer is provided at the upper surface edge of the support oxygen path sealing column 9 and the support combustion path sealing column 10;

[0030] The inlet edge of the sealing grooves of the oxygen path radial sealing groove 11 and the combustion path radial sealing groove 12 is a fillet.

[0031] An assembly method for a pneumatic solenoid valve and an injector sealing structure of a liquid rocket engine according to the present invention includes:

[0032] First, place the sealing cavity of the pneumatic solenoid valve housing 1 facing upward on the assembly table, place the oxygen path end face O-ring 3 into the oxygen path end face sealing groove 17, and place the combustion path end face O-ring 4 into the combustion path end face sealing groove 18;

[0033] Second, the oxygen path loads the O-ring 5 into the oxygen path sealing groove 11, and the fuel path loads the O-ring 6 into the fuel path sealing groove 12;

[0034] Third, place the sealing column of the injector 2 downward, and at the same time, fit the support oxygen path sealing column 9 and the support fuel path sealing column 10 into the housing oxygen path sealing cavity 19 and the housing fuel path sealing cavity 20 in a clearance fit manner, with a clearance of 0.1 - 0.2 mm, and then fixedly connect the pneumatic solenoid valve housing 1 and the injector 2.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] 1. By providing a sealing cavity and an end face sealing groove on the pneumatic solenoid valve housing, and at the same time providing a sealing column and a radial sealing groove on the injector, the present invention realizes double O-ring sealing of the propellant, which helps to improve the on-orbit working reliability of the liquid rocket engine;

[0037] 2. Without changing the height of the injector and the pneumatic solenoid valve, the present invention adds O-ring radial sealing, which is beneficial to meeting the overall design requirements for the envelope size of the rocket engine;

[0038] 3. When designing the housing sealing cavity and the support sealing column, the present invention adopts reasonable clearance fit dimensions, which can meet double sealing without affecting the assemblability between products; BRIEF DESCRIPTION OF THE DRAWINGS

[0039] By reading the following detailed description of the non-restrictive embodiments with reference to the accompanying drawings, other features, objects, and advantages of the present invention will become more apparent:

[0040] Figure 1 is a schematic diagram of the sealing structure of the embodiment of the present invention;

[0041] Figure 2 is a front view cross-sectional view of the injector;

[0042] Figure 3 is a front view cross-sectional view of the pneumatic solenoid valve housing;

[0043] The figures show:

[0044] DETAILED DESCRIPTION OF THE INVENTION

[0045] The present invention will be described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several changes and improvements can still be made. These all fall within the protection scope of the present invention.

[0046] The present invention provides a pneumatic solenoid valve and injector sealing structure for a liquid rocket engine, as Figures 1 to 3 shown, which includes a pneumatic solenoid valve housing 1 and an injector 2.

[0047] As Figure 3 shown, the pneumatic solenoid valve housing 1 is provided with a housing oxygen flow channel 15, a housing fuel flow channel 16, an oxygen path end face sealing groove 17, a fuel path end face sealing groove 18, a housing oxygen path sealing cavity 19, and a housing fuel path sealing cavity 20. Both the housing oxygen path sealing cavity 19 and the housing fuel path sealing cavity 20 can be divided into an upper cylindrical section and a lower conical section. The total depth of the cylindrical section and the conical section is 5 mm, the diameter of the cylindrical section is 19 mm, the diameter of the upper surface of the conical section is 19 mm, and the angle between the generatrix and the vertical direction is 35°. A fillet with a radius of R3 is used for smooth transition between the cylindrical section and the conical section to prevent the oxygen path O-ring 5 and the fuel path O-ring 6 from being cut when installed, and to reduce the installation resistance of the radial O-ring. The upper surface of the cylindrical section is subjected to root clearing treatment, and the fillet of the root clearing tool is not greater than R0.2 to avoid interference after the support oxygen path sealing column 9 and the support fuel path sealing column 10 are installed.

[0048] Affected by the flow channel design of the pneumatic solenoid valve and the structure design of the injector, the central axes of the housing oxygen flow channel 15 and the housing fuel flow channel 16 form an angle of 45° with the vertical direction. For the aperture design of the housing oxygen flow channel 15 and the housing fuel flow channel 16, the fluid resistance and the feasibility of drilling processing should be comprehensively considered. If the aperture is too small, the fluid resistance will be large; if the aperture is too large, the drill bit will interfere with the inner wall of the conical section. Therefore, the preferred aperture in this embodiment is 5.5 mm.

[0049] The outer diameters of both the oxygen path end face sealing groove 17 and the fuel path end face sealing groove 18 are 17.3 mm, the groove width is 2.6 mm, and the groove depth is 1.28 mm. An R0.2 fillet is provided at the entrance edge of the lower surface of the sealing groove to prevent the oxygen path end face O-ring 3 and the fuel path end face O-ring 4 from being scratched when installed.

[0050] As Figure 2As shown, an oxygen path support 7 and a fuel path support 8 are provided on the injector 2. The oxygen path support 7 includes a support oxygen path sealing column 9, an oxygen path radial sealing groove 11, and a support oxygen path flow channel 13. The fuel path support 8 includes a support fuel path sealing column 10, a fuel path radial sealing groove 12, and a support fuel path flow channel 14. The depth of the housing oxygen path sealing cavity 19 is greater than the height of the support oxygen path sealing column 9, and the depth of the housing fuel path sealing cavity 20 is greater than the height of the support fuel path sealing column 10.

[0051] Affected by the flow channel structure design of the injector, the oxygen path support 7 and the fuel path support 8 are not symmetric about the center line of the injector 2. The diameters of the support oxygen path flow channel 13 and the support fuel path flow channel 14 are 8 mm, and a C1 chamfer is provided at the inlet of the flow channel, which is beneficial to reducing the flow resistance of the docking surface between the pneumatic solenoid valve housing 1 and the injector 2.

[0052] The heights of the support oxygen path sealing column 9 and the support fuel path sealing column 10 are 4.6 mm and the diameters are 19 mm, and a C0.3 chamfer is provided at the edge of the upper surface to avoid interference when being installed into the housing oxygen path sealing cavity 19 and the housing fuel path sealing cavity 20.

[0053] The widths of the oxygen path radial sealing groove 11 and the fuel path radial sealing groove 12 are 2.8 mm and the depths are 1.4 mm. The edges at the inlets of the radial sealing grooves are R0.2 rounded corners to prevent the oxygen path O-ring 5 and the fuel path O-ring 6 from being scratched when being installed.

[0054] The inner diameters of the oxygen path end face O-ring 3 and the fuel path end face O-ring 4 are 13.7 mm and the cross-sectional diameters are 1.8 mm. The inner diameters of the oxygen path radial O-ring 5 and the fuel path radial O-ring 6 are 15.7 mm and the cross-sectional diameters are 2.0 mm.

[0055] The assembly method of the pneumatic solenoid valve housing 1 and the injector 2 includes:

[0056] First, place the pneumatic solenoid valve housing 1 with the sealing cavity facing up on the assembly table, put the oxygen path end face O-ring 3 into the oxygen path end face sealing groove 17, and put the fuel path end face O-ring 4 into the fuel path end face sealing groove 18;

[0057] Second, install the oxygen path radial O-ring 5 into the oxygen path radial sealing groove 11, and install the fuel path radial O-ring 6 into the fuel path radial sealing groove 12;

[0058] Thirdly, turn the sealing column of the injector 2 downward, and at the same time, insert the support oxygen path sealing column 9 and the support fuel path sealing column 10 into the housing oxygen path sealing cavity 19 and the housing fuel path sealing cavity 20 respectively in a clearance fit manner, where the preferred fit clearance is 0.1 - 0.2 mm. Then, fixedly connect the pneumatic solenoid valve housing 1 and the injector 2 with 4 M6 bolts.

[0059] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.

[0060] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. Without conflict, the embodiments of the present application and the features in the embodiments can be arbitrarily combined with each other.

Claims

1. A liquid rocket engine pneumatic solenoid valve and injector sealing structure, characterized in that: include: Pneumatic solenoid valve housing (1), injector (2); The oxygen path and the fuel path of the pneumatic solenoid valve housing (1) are respectively sealedly connected to the oxygen path and the fuel path of the injector (2); The sealing structure of the sealed connection adopts both an end face sealing structure and a radial sealing structure; The end face sealing structure comprises an oxygen path end face O-ring (3) and a combustion path end face O-ring (4); The radial sealing structure comprises an O-ring (5) in the oxygen path direction and an O-ring (6) in the combustion path direction.

2. The liquid rocket engine pneumatic solenoid valve and injector sealing structure according to claim 1, characterized in that: The pneumatic solenoid valve housing (1) is provided with a housing oxygen path flow channel (15), a housing fuel path flow channel (16), an oxygen path end face sealing groove (17), a fuel path end face sealing groove (18), a housing oxygen path sealing cavity (19), and a housing fuel path sealing cavity (20); The shell oxygen path sealing chamber (19) and the shell combustion path sealing chamber (20) are both divided into an upper cylindrical section and a lower frustum section.

3. The liquid rocket engine pneumatic solenoid valve and injector sealing structure according to claim 2, characterized in that: A rounded and smooth transition is adopted between the cylindrical section and the truncated cone section to prevent edge cutting when the oxygen path is installed into the O-ring (5) and the combustion path is installed into the O-ring (6).

4. The liquid rocket engine pneumatic solenoid valve and injector sealing structure according to claim 2, characterized in that: The upper surface of the cylindrical segment is subjected to root cleaning, and the radius of the root cleaning tool is not greater than R0.

2.

5. The liquid rocket engine pneumatic solenoid valve and injector sealing structure according to claim 2, characterized in that: The upper cylindrical section of the shell oxygen path sealing cavity (19) is in communication with the shell oxygen path flow channel (15); The upper cylindrical section of the shell combustion path sealing cavity (20) is in communication with the shell combustion path flow channel (16); The central axes of the shell oxygen path flow channel (15) and the shell combustion path flow channel (16) both form an angle with the vertical direction.

6. The liquid rocket engine pneumatic solenoid valve and injector sealing structure according to claim 2, characterized in that: An oxygen path end face sealing groove (17) is provided above the cylindrical section of the oxygen path sealing cavity (19) of the housing; A combustion path end face sealing groove (18) is provided above the cylindrical section of the combustion path sealing cavity (20) of the shell.

7. The liquid rocket engine pneumatic solenoid valve and injector sealing structure according to claim 6, characterized in that: Rounded corners are provided at the inlet edges of the lower surfaces of the sealing grooves of the oxygen path end face sealing groove (17) and the combustion path end face sealing groove (18).

8. The liquid rocket engine pneumatic solenoid valve and injector sealing structure according to claim 2, characterized in that: The injector (2) is provided with an oxygen path support (7) and a combustion path support (8); The oxygen path support (7) comprises a support oxygen path sealing column (9), an oxygen path directional sealing groove (11), and a support oxygen path flow channel (13); The combustion path support (8) comprises a support combustion path sealing column (10), a combustion path directional sealing groove (12), and a support combustion path flow channel (14); The depth of the housing oxygen path sealing cavity (19) is greater than the height of the support oxygen path sealing column (9) which is gap-matched; The depth of the combustion path sealing cavity (20) of the housing is greater than the height of the combustion path sealing column (10) of the support that is clearance-matched.

9. The liquid rocket engine pneumatic solenoid valve and injector sealing structure according to claim 8, characterized in that: Chamfers are provided at the flow channel entrances of the support oxygen path flow channel (13) and the support combustion path flow channel (14); The upper surface edges of the support oxygen path sealing column (9) and the support combustion path sealing column (10) are chamfered; The sealing groove entrance edges of the oxygen path sealing groove (11) and the combustion path sealing groove (12) are rounded.

10. A method for assembling a liquid rocket engine pneumatic solenoid valve and an injector sealing structure according to any one of claims 1 to 9, characterized in that: include: First, the pneumatic solenoid valve housing (1) is placed on an assembly table with the sealed cavity facing upward, the oxygen path end face O-ring (3) is placed in the oxygen path end face sealing groove (17), and the fuel path end face O-ring (4) is placed in the fuel path end face sealing groove (18); Second, the oxygen path O-ring (5) is installed in the oxygen path sealing groove (11), and the fuel path O-ring (6) is installed in the fuel path sealing groove (12); Third, the sealing column of the injector (2) is facing downward, and the support oxygen path sealing column (9) and the support fuel path sealing column (10) are respectively installed into the shell oxygen path sealing cavity (19) and the shell fuel path sealing cavity (20) in a clearance fit manner, with the fitting clearance being 0.1 to 0.2 mm, and then the pneumatic solenoid valve shell (1) and the injector (2) are fixedly connected.

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