High-pressure inflation and deflation tool for liquid rocket engine

Abstract

The utility model provides a high-pressure inflation and deflation tool for a liquid rocket engine. The high-pressure inflation and deflation tool comprises a shell, a straight joint arranged on the shell, a filler neck arranged on the shell and an ejector rod penetrating through the shell and the filler neck. The extension direction of the filler neck is the same as that of the ejector rod; one end of the shell is in threaded connection and welding with the filler neck, and a first jacket nut is arranged at the other end of the shell; the ejector rod and the shell are in threaded connection and sealed, and the shell is welded to the straight joint. The straight-through air inlet pipe is communicated with the filler neck; the back end of the ejector rod protrudes out of the first jacket nut, and the end of the ejector rod protrudes out of the filler neck. The pressure bearing capacity of the inflation and deflation tool is improved by adopting trapezoidal threads, the stress area of a sealing part is reduced, and the rotation resistance of the ejector rod under the high-pressure condition is reduced; a limiting structure is arranged, the extension length of the ejector rod is controlled, and the valve element is prevented from being excessively ejected.

Description

Technical Field

[0001] The utility model relates to the technical field of high-pressure gas charging and discharging devices, in particular to a high-pressure gas charging and discharging tool for a liquid rocket engine. Background Art

[0002] With the development of liquid rocket engine technology, cold gas starting has become a key technology for multiple starts of liquid rocket engines. This requires the engine or rocket to be equipped with a high-pressure gas cylinder, typically at 35MPa. A one-way valve is installed in the pipeline in front of the cylinder. Before starting, the high-pressure gas cylinder is filled and deflated through the one-way valve. Inflation, relying on pressure differential to open the one-way valve, can cause valve core flutter and shorten the service life of the one-way valve. Deflating requires overcoming the force of high pressure on the valve core, so a special tool is required to push the valve core open for inflation and deflation.

[0003] Current inflation and deflation tools have low pressure bearing capacity and low structural safety, and cannot adapt to 35MPa working scenarios; they are prone to safety accidents; and after repeated use under high-pressure conditions, the push rod is easily bent, which can easily cause the valve core to become stuck and unable to reset.

[0004] In summary, the existing technology has the following problems: the existing liquid rocket engine high-pressure filling and deflation tools have low pressure bearing capacity and low structural safety. Utility Model Content

[0005] The utility model provides a liquid rocket engine high-pressure inflation and deflation tool, and solves the technical problem of how to improve the pressure bearing capacity of the liquid rocket engine high-pressure inflation and deflation tool and improve the safety.

[0006] To achieve the above objectives, the present invention provides a liquid rocket engine high-pressure inflation and deflation tool, comprising:

[0007] A housing, a through hole provided on the housing, a filler nozzle provided on the housing, and a push rod passing through the housing and the filler nozzle;

[0008] The extending direction of the nozzle is the same as that of the push rod; the straight bottom is connected to the outer side of the shell;

[0009] One end of the shell is fixedly connected to the mouthpiece; the push rod is threadedly connected to the shell and sealed, and the push rod can move relative to the shell and extend or retract from the mouthpiece; the shell is welded to the straight-through; the straight-through is connected to the mouthpiece; inflation is performed when the one-way valve is opened, and deflation is performed when the external air source is disconnected and the one-way valve is opened.

[0010] The push rod end of the push rod is used to match the valve core of the one-way valve.

[0011] Specifically, the ejector pin includes a first rod portion, a second rod portion, and a third rod portion sequentially distributed along the direction from the shell to the filler nozzle, the outer diameter of the first rod portion is larger than the outer diameter of the second rod portion, and the outer diameter of the second rod portion is larger than the outer diameter of the third rod portion; this reduces the sealing size between the ejector pin and the shell, thereby reducing the force-bearing area.

[0012] The ejector rod is threadably connected to the housing through the first rod portion;

[0013] The outer wall of the third rod portion is sealed with the housing.

[0014] Specifically, the housing is provided with a limit cavity, within which at least a portion of the second rod portion is movable, and the front end surface of the second rod portion is movable until it abuts against the inner wall of the limit cavity, thereby limiting the travel of the ejector rod. This has the advantage of controlling the extension length of the ejector rod, preventing the valve core from being overly pressed, and preventing the valve core spring from being unable to reset.

[0015] Specifically, the shell is further provided with a connecting cavity and a sliding cavity. The limiting cavity, the sliding cavity and the connecting cavity are sequentially distributed along the direction of the shell pointing to the filling nozzle. The third rod portion passes through the connecting cavity and the sliding cavity, and the third rod portion is sealed with the inner wall of the sliding cavity; it can provide sealing protection during straight-through inflation to prevent air leakage.

[0016] The straight-through port and the filling nozzle are both communicated with the communicating cavity.

[0017] Specifically, the side wall of the second rod portion is provided with a first sealing groove, and the sealing ring in the first sealing groove is in sealing cooperation with the inner wall of the limiting cavity;

[0018] The side wall of the third rod portion is provided with a second sealing groove and a third sealing groove distributed at intervals, and the sealing rings of the second sealing groove and the third sealing groove are respectively sealed with the inner wall of the sliding cavity.

[0019] Specifically, a limit structure is provided on the inner wall of the nozzle. The limit structure comprises multiple inwardly projecting protrusions spaced apart around the ejector pin. This prevents the ejector pin from bending under high pressure, which could cause the valve core to become stuck and unable to reset, thereby increasing the reusability of the inflation and deflation tool.

[0020] Specifically, a first outer nut is provided at the end of the housing facing away from the nozzle. The first outer nut is used to limit the rearward movement of the ejector rod. The first outer nut is provided with an outer through hole, and the outer profile of the first rod portion is larger than the outer through hole. This helps to increase the position of the outer nut, prevent the ejector rod from separating from the housing when rotating out, and improve safety.

[0021] Specifically, the first rod portion is connected to the housing via a trapezoidal thread.

[0022] Specifically, a second outer sleeve nut is provided on the pipe connection nozzle, and the pipe connection nozzle is used to connect with the one-way valve.

[0023] Specifically, the nozzle is provided with a fourth sealing groove, the sealing cavity of which is used to seal with the one-way valve. The beneficial technical effects of the above technical solution are as follows: the utility model improves the pressure-bearing capacity of the thread by changing the thread form; adds a limit structure to prevent the ejector rod from separating from the housing when the ejector rod is rotated out; and optimizes the structural design to ensure that the one-way valve can be opened normally after the tool is used repeatedly under high pressure, avoiding the possibility of the valve core being stuck. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic structural diagram of a high-pressure charging and discharging tool for a liquid rocket engine according to an embodiment of the present utility model;

[0025] Figure 2 This is a schematic cross-sectional view of a high-pressure inflation and deflation tool for a liquid rocket engine according to an embodiment of the present utility model;

[0026] Figure 3 A side view of a filler nozzle according to an embodiment of the present invention;

[0027] Figure 4 This is a schematic cross-sectional view of a liquid rocket engine high-pressure charging and discharging tool and a one-way valve when docked in accordance with an embodiment of the present utility model.

[0028] Description of Figure Numbers:

[0029] 1. Push rod; 2. First outer casing nut; 3. Housing; 4. Straight-through; 5. Second outer casing nut; 6. Take-off nozzle; 7. Check valve; 11. Push rod back end; 12. External thread; 13. Push rod end; 21. Outer casing through hole;

[0030] 101, first rod portion; 102, second rod portion; 103, third rod portion;

[0031] 141, first sealing groove; 142, second sealing groove; 143, third sealing groove; 15, ejector stop wall;

[0032] 30. Limiting cavity; 31. Internal thread; 32. Sliding cavity; 33. Housing stop wall; 34. Connecting cavity; 41. Air inlet; 61. Limiting structure; 62. Outer wall of the nozzle; 63. Fourth sealing groove; 71. One-way valve inlet; 72. Valve core; 73. Spring. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0034] The present invention provides a high-pressure gas charging and discharging tool for a liquid rocket engine. Figure 1 As shown, it includes: a shell 3, a straight through 4 arranged on the shell 3, a pipe nozzle 6 arranged on the shell 3, and a push rod 1 passing through the shell 3 and the pipe nozzle 6; the extension direction of the pipe nozzle 6 is the same as the extension direction of the push rod 1; the bottom of the straight through 4 is connected to the outer side surface of the shell 3, and preferably, the extension direction of the straight through 4 is perpendicular to the extension direction of the push rod 1; the air inlet 41 of the straight through 4 is connected to the external gas, and the air inlet 41 is connected to the external gas source. When the one-way valve is opened, it is inflated, and when the external gas source is disconnected and the one-way valve is opened, it is deflated.

[0035] One end of the housing 3 is threadedly connected to and welded to the filler nozzle 6, and the other end of the housing 3 is provided with a first outer sleeve nut 2; a push rod 1 is threadedly connected to the housing 3 and sealed, and the push rod 1 can move relative to the housing 3 and extend or retract from the filler nozzle 6; the housing 3 is welded to the straight-through 4; the intake pipe of the straight-through 4 is connected to the filler nozzle 6;

[0036] The ejector pin 1 includes a first rod portion 101, a second rod portion 102, and a third rod portion 103, which are sequentially distributed along the direction from the housing 3 to the nozzle 6. The outer diameter of the first rod portion 101 is larger than that of the second rod portion 102, and the outer diameter of the second rod portion 102 is larger than that of the third rod portion 103. The first rod portion 101, the second rod portion 102, and the third rod portion 103 are stepped, and the diameter size is gradually reduced through three steps, so that the sealing size between the ejector pin 1 and the housing 3 is reduced, thereby reducing the force-bearing area.

[0037] The ejector pin 1 is threadedly connected to the housing 3 via a first rod portion 101; the first rod portion 101 and the housing 3 are connected by a trapezoidal thread. The outer wall of the third rod portion 103 seals against the housing 3. The housing is provided with a limit cavity 30, within which a portion of the second rod portion 102 is movable. The front end of the second rod portion 102 is movable until it abuts against the inner wall of the limit cavity 30, thereby limiting the travel of the ejector pin 1.

[0038] Controlling the distance between the front end face of the second rod portion 102 and the inner wall of the limiting cavity 30 can prevent the valve core from being over-pressed; rotating the push rod 1 clockwise until the front end face of the second rod portion 102 is in contact with the inner wall of the limiting cavity 30, at which point the push rod 1 cannot move forward any further, thereby preventing the valve core from being over-pressed and damaged. Specifically, a housing stop wall 33 is provided inside the housing 3, and a push rod stop wall 15 is provided on the push rod 1. The housing stop wall 33 corresponds to the push rod stop wall 15, and the maximum distance between the housing stop wall 33 and the push rod stop wall 15 is less than the stroke of the valve core 72 of the one-way valve 7, that is, the movement stroke of the push rod stop wall 15 is less than the stroke of the valve core 72 of the one-way valve 7. It can prevent the valve core from being over-pressed; similarly, the push rod 1 rotates clockwise to the stop point, that is, the push rod stop wall 15 is in contact with the shell stop wall 33, controlling the distance between the push rod end 13 and the outer wall 62 of the nozzle, which can prevent the valve core from being over-pressed.

[0039] The housing is further provided with a connecting cavity 34 and a sliding cavity 32. The limiting cavity 30, sliding cavity 32, and connecting cavity 34 are sequentially arranged along the housing 3 in the direction toward the filler neck 6. The third rod portion 103 passes through the connecting cavity 34 and the sliding cavity 32 and seals against the inner wall of the sliding cavity 32. The through hole 4 and the filler neck 6 are both connected to the connecting cavity 34. Gas enters the connecting cavity 34 through the air inlet 41, then enters the filler neck 6 and enters the one-way valve 7 for inflation.

[0040] The back end 11 of the push rod 1 protrudes from the first outer nut 2, making it easier to screw the back end 11. Figure 2 As shown, a first outer sleeve nut 2 is provided at one end of the shell 3 away from the nozzle 6. The first outer sleeve nut 2 is used to limit the range of backward movement of the push rod 1. The first outer sleeve nut 2 is provided with an outer sleeve through hole 21, and the outer contour of the first rod portion 101 is larger than the outer sleeve through hole 21.

[0041] The first outer nut 2 is threadedly connected to the housing 3, which can limit the position of the push rod 1 when it is rotated out, preventing the push rod 1 from separating from the housing 3 during rotation and improving safety. The push rod end 13 of the push rod 1 protrudes from the nozzle 6 so that the push rod end 13 can press the valve core 72 of the one-way valve 7. The first outer nut 2 is threadedly connected to the housing 3. The first outer sleeve nut 2 is threadedly connected to the shell 3, which can limit the push rod 1 when it is rotated out, preventing the push rod 1 from separating from the shell 3 when it is withdrawn, thereby improving safety; the push rod back end 11 of the push rod 1 is rotated clockwise to the stop point, that is, the push rod stop wall 15 is in contact with the shell stop wall 33, so that the push rod 1 is extended, and the push rod end 13 of the push rod 1 presses the valve core 72 of the one-way valve 7, thereby opening the one-way valve 7 to realize the inflation and deflation function; after the inflation and deflation are completed, the push rod back end 11 of the push rod 1 is rotated counterclockwise, so that the push rod stop wall 15 is separated from the shell stop wall 33, and the one-way valve 7 automatically closes the one-way valve 7 by the valve core 72 spring 73.

[0042] A second outer nut 5 is provided on the take-over nozzle 6, and the take-over nozzle 6 is used to connect with the one-way valve 7. A second outer nut 5 is provided on the take-over nozzle 6 near the end of the ejector rod 13, such as Figure 4 As shown, the nozzle 6 is connected to the one-way valve 7, and the second outer nut 5 is threadedly connected to the nozzle 6 and the one-way valve inlet 71. Figure 2 As shown, the nozzle 6 is provided with a fourth sealing groove 63. The sealing cavity in the fourth sealing groove 63 is used to seal with the one-way valve 7. The fourth sealing groove 63 forms a radial seal with the one-way valve inlet 71. The push rod end 13 corresponds to the valve core 72 of the one-way valve 7.

[0043] The diameter of the ejector pin 1 is stepped and its size decreases step by step, so that the sealing size between the ejector pin 1 and the housing 3 is reduced. The area ratio of the cross-sectional area at the sliding cavity 32 to the cross-sectional area at the ejector pin stop wall 15 is 0.3, which reduces the acting force by 70%, thereby reducing the thread force at the internal thread 31 of the housing 3 and the external thread 12 of the ejector pin 1, which can effectively prevent the thread from being stuck when the ejector pin 1 is rotated under high pressure.

[0044] The ejector pin 1 is provided with a first sealing groove 141, a second sealing groove 142, and a third sealing groove 143. The first sealing groove 141 is provided on the sidewall of the second rod portion 102, and the sealing ring in the first sealing groove 141 seals against the inner wall of the retaining cavity 30. The third rod portion 103 is provided with spaced-apart second sealing grooves 142 and third sealing grooves 143, respectively, and the sealing rings in the second and third sealing grooves 142 and 143 seal against the inner wall of the sliding cavity 32. Specifically, the first, second, and third sealing grooves 141, 142, and 143 are all located on one side of the through-hole 4 intake pipe, that is, between the first outer sleeve nut 2 and the through-hole 4 intake pipe. The three radial seals enhance sealing performance. The diameter of the first sealing groove 141 is larger than that of the second and third sealing grooves 142 and 143. Seal rings of different diameters are used along the diameter of the ejector pin 1 to provide a tight seal and prevent gas leakage during intake. The housing 3 has a sliding cavity 32 therein, the through hole 4 is located on one side of the sliding cavity 32, and the housing stop wall 33 is located on the other side of the sliding cavity 32. The ejector pin 1 passes through the sliding cavity 32, and the second sealing groove 142 and the third sealing groove 143 are located inside the sliding cavity 32.

[0045] A limiting structure 61 is provided on the inner wall of the nozzle 6. The limiting structure 61 is a raised structure. The number of raised structures is N, where N ≥ 1. Preferably, N is 3, N is 4, or N is 5. The addition of the limiting structure 61 helps prevent the ejector rod from bending due to repeated use under high pressure, which can cause the valve core to become stuck and unable to reset, thereby increasing the number of cycles of the inflation and deflation tool.

[0046] The present invention provides a high-pressure gas charging and discharging tool for a liquid rocket engine. Figure 2As shown, the utility model improves the pressure-bearing capacity of the thread by reducing the force-bearing area and changing the thread form; adds a limiting structure to prevent the push rod from separating from the shell when the push rod is rotated out; and optimizes the structural design to ensure that the one-way valve can be opened normally after the tool is used multiple times under high pressure, avoiding the problem of the valve core being stuck.

[0047] like Figure 1 As shown, the take-over nozzle 6 is threadedly connected to the shell 3 and then welded, and the length of the take-over nozzle can be adjusted and the verticality of the two can be ensured; the straight-through 4 is welded to the shell 3, and the air inlet 41 is connected to the external air source. When the one-way valve 7 is opened, it is inflated, and when the external air source is disconnected and the one-way valve 7 is opened, it is deflated; Figure 2 As shown, the push rod 1 is connected to the housing 3 with a trapezoidal thread, which has good centering, high strength of the thread root, and high pressure bearing capacity. Different pitches can be selected according to the pressure bearing size. Three radial seals are provided between the push rod 1 and the housing 3 to improve the sealing performance; they are the first sealing groove 141, the second sealing groove 142, and the third sealing groove 143; all are arranged on one side of the straight-through 4 air intake pipe, among which the second sealing groove 142 and the third sealing groove 143 are arranged inside the sliding cavity 32 to form a seal with the sliding cavity 32.

[0048] like Figure 2 As shown, the diameter of the ejector pin 1 is gradually reduced through three steps, so that the sealing size between the ejector pin 1 and the housing 3 is reduced, thereby reducing the force-bearing area. The area ratio of the cross-sectional area at the sliding cavity 32 to the cross-sectional area at the ejector pin stop wall 15 is 0.3, and the force is reduced by 70%, so that the thread forces at the internal thread 31 of the housing 3 and the external thread 12 of the ejector pin 1 are reduced, which can effectively prevent the threads from being stuck when the ejector pin 1 is rotated under high pressure.

[0049] like Figure 3 As shown, the outlet of the nozzle 6 is provided with a limiting structure 61 to limit the deformation or bending of the push rod in the radial direction, so that the push rod will not be bent after repeated use under high pressure, thereby ensuring the coaxiality of the push rod and the valve core and avoiding the valve core 72 from getting stuck.

[0050] The utility model has the following beneficial effects:

[0051] The use of trapezoidal threads improves the pressure-bearing capacity of the inflation and deflation tools, reduces the stress area of ​​the sealing part, reduces the rotation resistance of the ejector rod under high pressure, and makes operation easier;

[0052] It has a limiting structure to control the extension length of the push rod, prevent the valve core from being over-pressed, and avoid the situation where the valve core spring cannot be reset; the outer nut limit is added to prevent the push rod from separating from the shell when it is rotated out, thereby improving safety; the limiting structure is added to prevent the push rod from being bent due to repeated use under high pressure, and the valve core from being stuck and unable to reset, thereby increasing the number of cycles of the inflation and deflation tool.

[0053] The above description is merely an illustrative embodiment of the present invention and is not intended to limit the scope of the present invention. The various components of the present invention may be combined with each other without conflict, and any equivalent changes and modifications made by a person skilled in the art without departing from the concept and principles of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A liquid rocket engine high-pressure inflation and deflation tool, characterized in that: include: A housing (3), a through-hole (4) provided on the housing (3), a nozzle (6) provided on the housing (3), and a push rod (1) passing through the housing (3) and the nozzle (6); The extending direction of the nozzle (6) is the same as the extending direction of the push rod (1); The bottom of the through hole (4) is connected to the outer side surface of the shell (3); One end of the housing (3) is fixedly connected to the filler nozzle (6); the push rod (1) is threadedly connected to the housing (3) and sealed, and the push rod (1) can move relative to the housing (3) and extend or retract from the filler nozzle (6); the housing (3) is welded to the straight-through (4); the straight-through (4) is in communication with the filler nozzle (6); The push rod end (13) of the push rod (1) is used to match the valve core (72) of the one-way valve (7).

2. A liquid rocket engine high-pressure inflation and deflation tool according to claim 1, characterized in that: The push rod (1) comprises a first rod portion (101), a second rod portion (102) and a third rod portion (103) sequentially distributed along the direction of the housing (3) pointing toward the nozzle (6); the outer diameter of the first rod portion (101) is greater than the outer diameter of the second rod portion (102), and the outer diameter of the second rod portion (102) is greater than the outer diameter of the third rod portion (103); The push rod (1) is threadably connected to the housing (3) via the first rod portion (101); The outer wall of the third rod portion (103) is in sealing cooperation with the housing (3).

3. A liquid rocket engine high-pressure inflation and deflation tool according to claim 2, characterized in that: The housing is provided with a limiting cavity (30), at least a portion of the second rod portion (102) is movable in the limiting cavity (30), and the front end surface of the second rod portion (102) is movable to abut against an inner wall of the limiting cavity (30) to limit the moving stroke of the push rod (1).

4. A liquid rocket engine high-pressure inflation and deflation tool according to claim 3, characterized in that: The housing is further provided with a connecting cavity (34) and a sliding cavity (32). The limiting cavity (30), the sliding cavity (32) and the connecting cavity (34) are sequentially distributed along the direction from the housing (3) to the nozzle (6). The third rod portion (103) passes through the connecting cavity (34) and the sliding cavity (32), and the third rod portion (103) is in sealing engagement with the inner wall of the sliding cavity (32). The straight-through (4) and the nozzle (6) are both connected to the communication cavity (34).

5. A liquid rocket engine high-pressure inflation and deflation tool according to claim 4, characterized in that: A first sealing groove (141) is provided on the side wall of the second rod portion (102), and a sealing ring in the first sealing groove (141) is in sealing cooperation with the inner wall of the limiting cavity (30); The side wall of the third rod portion (103) is provided with a second sealing groove (142) and a third sealing groove (143) that are spaced apart. The sealing rings of the second sealing groove (142) and the third sealing groove (143) are respectively sealed with the inner wall of the sliding cavity (32).

6. A liquid rocket engine high-pressure inflation and deflation tool according to claim 1, characterized in that: The inner wall of the nozzle (6) is provided with a limiting structure (61), and the limiting structure (61) comprises a plurality of inwardly protruding protrusions, and the plurality of protrusions are spaced and distributed around the push rod (1).

7. A liquid rocket engine high-pressure inflation and deflation tool according to claim 2, characterized in that: A first outer sleeve nut (2) is provided at one end of the shell (3) facing away from the nozzle (6), and the first outer sleeve nut (2) is used to limit the range of backward movement of the push rod (1). The first outer sleeve nut (2) is provided with an outer sleeve through hole (21), and the outer contour of the first rod part (101) is larger than the outer sleeve through hole (21).

8. A liquid rocket engine high-pressure inflation and deflation tool according to claim 2, characterized in that: The first rod portion (101) is connected to the housing (3) via a trapezoidal thread.

9. A liquid rocket engine high-pressure inflation and deflation tool according to claim 1, characterized in that: A second outer sleeve nut (5) is provided on the take-over nozzle (6), and the take-over nozzle (6) is used for docking with the one-way valve (7).

10. A liquid rocket engine high-pressure inflation and deflation tool according to claim 1, characterized in that: A fourth sealing groove (63) is provided on the nozzle (6), and a sealing cavity in the fourth sealing groove (63) is used for sealingly cooperating with the one-way valve (7).

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