A sealing structure of a high-pressure gas cylinder for a launch vehicle

Abstract

The present application provides a high-pressure gas cylinder sealing structure for a launch vehicle, the high-pressure gas cylinder sealing structure comprising: a bottle mouth extension, a sealing plug, a metal sealing ring, a retaining ring and an O-ring, the bottle mouth extension is connected to the gas cylinder shoulder, the bottle mouth extension has a hollow cavity; the outer periphery of the sealing plug is provided with an external thread portion and an O-ring annular groove; the sealing plug extends into the hollow cavity, and is threadedly connected to the bottle mouth extension through the external thread portion; the O-ring and the retaining ring are arranged in the O-ring annular groove, and the retaining ring is arranged on the side of the O-ring away from the gas cylinder shoulder; the O-ring and the metal sealing ring are arranged in the gap between the sealing plug and the bottle mouth extension, respectively realizing the first sealing and the second sealing. The present application has a better sealing effect, a longer service life, and improves the reliability of the gas cylinder sealing.

Description

Technical Field

[0001] The present application relates to the field of launch vehicle technology, and in particular to a sealing structure of a high-pressure gas cylinder for a launch vehicle. Background Art

[0002] Gas cylinders are one of the important stand-alone products in rockets. Their main function is to store high-pressure gas media and pressurize the tank. In addition, they can also provide control gas for pneumatic valves in power systems and control systems, provide a gaseous environment for inertial devices in attitude control systems, and blow off the rocket body compartment.

[0003] Gas cylinders are mainly sealed by sealing structures. Improper design and use of sealing structures can lead to leakage and may cause serious consequences. Therefore, the sealing structure of gas cylinders should be taken seriously.

[0004] At present, the sealing method of composite gas cylinders for launch vehicles mostly adopts O-ring end face sealing method, such as Figure 4 As shown, the plug 7 is threadedly connected to the bottle mouth extension 1, and the O-ring 6 is arranged at the connection between the plug 7 and the bottle mouth extension 1. When the plug 7 is screwed in, this sealing method will rub the sealing surface of the O-ring 6, which may cause scratches on the surface of the O-ring 6, or even squeeze and cut the O-ring 6. Moreover, after the installation is completed, it is impossible to detect whether the surface of the O-ring 6 is damaged, and it can only be confirmed by airtightness inspection. However, such surface damage of the O-ring 6 often causes micro-leakage of the gas cylinder. As the number of uses increases, the leakage will increase. Therefore, the O-ring end face sealing method used in the prior art has the defects of difficult detection and low reliability.

[0005] Therefore, the technical problem that urgently needs to be solved is: how to provide a high-pressure gas cylinder sealing structure for a launch vehicle with better sealing effect, longer service life, and improved reliability of the gas cylinder sealing. Utility Model Content

[0006] The purpose of this application is to provide a high-pressure gas cylinder sealing structure for a launch vehicle, which has better sealing effect, longer service life, and improved reliability of the gas cylinder sealing.

[0007] To achieve the above-mentioned purpose, the present application provides a high-pressure gas cylinder sealing structure for a launch vehicle, the high-pressure gas cylinder sealing structure comprising: a bottle mouth extension, a sealing plug, a metal sealing ring, a retaining ring and an O-ring, the bottle mouth extension is connected to the shoulder of the gas cylinder, and the bottle mouth extension has a hollow cavity; the outer periphery of the sealing plug is provided with an external thread portion and an O-ring annular groove; the sealing plug extends into the hollow cavity and is threadedly connected to the bottle mouth extension through the external thread portion; the O-ring and the retaining ring are arranged in the O-ring annular groove, and the retaining ring is arranged on the side of the O-ring away from the shoulder of the gas cylinder; the O-ring and the metal sealing ring are arranged in the gap where the sealing plug and the bottle mouth extension are connected, respectively realizing the first seal and the second seal.

[0008] As described above, the sealing structure of a high-pressure gas cylinder for a launch vehicle, wherein the hollow cavity of the bottle mouth extension portion has a first shoulder, and the sealing plug has a first boss along its circumferential direction; the sealing plug extends into the hollow cavity, and the metal sealing ring is arranged between the first boss and the first shoulder.

[0009] As described above, the sealing structure of a high-pressure gas cylinder for a launch vehicle is characterized in that a first triangular sealing groove is arranged on a side of the first boss close to the metal sealing ring; a second triangular sealing groove is arranged on a side of the first shoulder close to the metal sealing ring; and the first triangular sealing groove and the second triangular sealing groove are located on both sides of the metal sealing ring.

[0010] As described above, in the sealing structure of a high-pressure gas cylinder for a launch vehicle, the first triangular sealing groove is distributed on the mounting surface of the first boss along the circumferential direction; the second triangular sealing groove is distributed on the mounting surface of the first shoulder along the circumferential direction.

[0011] The sealing structure of a high-pressure gas cylinder for a launch vehicle as described above, wherein a second shoulder is provided in the hollow cavity of the bottle mouth extension portion; the surface of the second shoulder is inclined inwardly along the inner wall of the hollow cavity; the sealing plug is provided with an inclined shoulder corresponding to the second shoulder, and the inclined shoulder has the same inclination angle as the second shoulder.

[0012] As described above, the sealing structure of the high-pressure gas cylinder for a launch vehicle, wherein the inner wall of the hollow cavity of the bottle mouth extension portion is provided with an internal threaded portion; the internal threaded portion of the bottle mouth extension portion is threadedly connected with the external threaded portion of the sealing plug.

[0013] As described above, in the sealing structure of a high-pressure gas cylinder for a launch vehicle, the external threaded portion of the sealing plug is arranged at one end of the sealing plug close to the interior of the gas cylinder.

[0014] As described above, the sealing structure of a high-pressure gas cylinder for a launch vehicle is characterized in that the bottle mouth extension portion is provided with a smooth section, the diameter of the smooth section is smaller than the outer diameter of the O-ring; the O-ring is sleeved in the O-ring annular groove of the sealing plug and is limited on the inner wall of the smooth section to form a first seal.

[0015] In the sealing structure of a high-pressure gas cylinder for a launch vehicle as described above, limiting bosses for limiting the axial movement of the O-ring are provided on both sides of the annular groove of the O-ring.

[0016] In the sealing structure of a high-pressure gas cylinder for a launch vehicle as described above, the second shoulder is in the shape of a truncated cone.

[0017] The beneficial effects achieved by this application are as follows:

[0018] (1) The sealing structure of the present application adopts a double-pass seal of a metal sealing ring and an O-ring. On the basis of the O-ring seal, a metal sealing ring seal is added to improve the sealing effect and sealing reliability of the sealing structure. The double-pass seal form adopted in the present application has the characteristics of high working reliability, good sealing and long service life.

[0019] (2) The present application adds a retaining ring in the annular groove of the O-ring, and the retaining ring is located on the side of the O-ring away from the inner liner of the gas cylinder to prevent the O-ring from being "extruded" under the action of pressure after the gas cylinder is filled with high pressure, causing the O-ring to fail, thereby improving the sealing reliability of the O-ring.

[0020] (3) When installing the sealing plug, the O-ring needs to go over the second shoulder and contact the second shoulder. The inclined surface of the second shoulder guides the movement of the O-ring to avoid damage to the O-ring.

[0021] (4) In the present application, limiting bosses are provided on both sides of the annular groove of the O-ring for limiting the axial movement of the O-ring, thereby preventing the O-ring from moving and preventing the deformed portion of the O-ring from entering the external thread portion and being damaged, thereby improving the sealing effect of the O-ring. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For those skilled in the art, other drawings can also be obtained based on these drawings.

[0023] Figure 1 This is a schematic structural diagram of a high-pressure gas cylinder sealing structure for a launch vehicle according to an embodiment of the present application.

[0024] Figure 2 It is a schematic structural diagram of the bottle mouth extension portion of an embodiment of the present application.

[0025] Figure 3 This is a schematic diagram of the structure of the sealing plug according to an embodiment of the present application.

[0026] Figure 4 It is a schematic diagram of an O-ring end face sealing structure in the prior art.

[0027] Figure markings: 1-bottle mouth extension; 2-gas cylinder shoulder; 3-sealing plug; 4-metal sealing ring; 5-retaining ring; 6-O-ring sealing ring; 7-plug; 11-first shoulder; 12-second shoulder; 13-smooth section; 14-internal threaded portion; 15-hollow cavity; 21-gas cylinder liner; 31-external threaded portion; 32-O-ring annular groove; 33-second boss; 34-first triangular sealing groove; 35-first boss; 36-inclined shoulder; 37-cavity. DETAILED DESCRIPTION

[0028] The following is a clear and complete description of the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0029] like Figure 1-3 As shown, the present application provides a high-pressure gas cylinder sealing structure for a launch vehicle, which includes: a bottle mouth extension portion 1, a sealing plug 3, a metal sealing ring 4, a retaining ring 5 and an O-ring 6, the bottle mouth extension portion 1 is connected to the gas cylinder shoulder 2, and the gas cylinder shoulder 2 is located at the end of the gas cylinder liner 21; the bottle mouth extension portion 1 has a hollow cavity 15; the outer periphery of the sealing plug 3 is provided with an external thread portion 31 and an O-ring annular groove 32; the sealing plug 3 extends into the hollow cavity 15, and is threadedly connected to the bottle mouth extension portion 1 through the external thread portion 31; the O-ring 6 and the retaining ring 5 are arranged in the O-ring annular groove 32, and the retaining ring 5 is arranged on the side of the O-ring 6 away from the gas cylinder shoulder 2; the O-ring 6 and the metal sealing ring 4 are arranged in the gap where the sealing plug 3 and the bottle mouth extension portion 1 are connected, respectively realizing the first sealing and the second sealing, thereby improving the sealing effect and reliability of the sealing structure.

[0030] The sealing structure of the present application adopts a double-pass sealing of a metal sealing ring 4 and an O-ring 6. On the basis of the sealing of the O-ring 6, the sealing of the metal sealing ring 4 is added, thereby improving the sealing effect and sealing reliability of the sealing structure. At the same time, a retaining ring 5 is added to the annular groove 32 of the O-ring, and the retaining ring 5 is blocked on the side of the O-ring 6 away from the gas cylinder liner 21 to avoid the "extrusion phenomenon" of the O-ring 6 under the action of pressure after the gas cylinder is filled with high pressure, resulting in failure of the O-ring 6, thereby improving the sealing reliability of the O-ring 6. The double-pass sealing form adopted by the utility model has the characteristics of high working reliability, good sealing and long service life.

[0031] Preferably, the bottle mouth extension portion 1 is tubular, extending along the opening of the gas cylinder shoulder 2 in a direction away from the gas cylinder liner 21. The hollow cavity 15 of the bottle mouth extension portion 1 is cylindrical as a whole, and the hollow cavity 15 is connected to the opening of the gas cylinder shoulder 2, and the hollow cavity 15 is connected to the gas cylinder liner 21 through the opening.

[0032] like Figure 2 As shown, the bottle mouth extension 1 is provided with a smooth section 13, the diameter of which is smaller than the outer diameter of the O-ring 6; the O-ring 6 is sleeved in the O-ring annular groove 32 of the sealing plug 3 and is limited on the inner wall of the smooth section 13 to form a first seal. When the sealing plug 3 is installed, the smooth section 13 squeezes the O-ring 6 to achieve the effect of the first seal.

[0033] like Figure 2 and 3 As shown, the hollow cavity 15 of the bottle mouth extension 1 has a first shoulder 11, and the sealing plug 3 has a first boss 35 along its circumferential direction; the sealing plug 3 extends into the hollow cavity 15, and a metal sealing ring 4 is arranged between the first boss 35 and the first shoulder 11, and the metal sealing ring 4 is sleeved on the sealing plug 3, and the two sides of the metal sealing ring 4 are limited by the first boss 35 and the first shoulder 11 to prevent the metal sealing ring 4 from moving along the axial direction of the sealing plug 3. The metal sealing ring 4 is sealed and connected between the first boss 35 and the first shoulder 11, realizing the second seal between the bottle mouth extension 1 and the sealing plug 3. The metal sealing ring 4 is usually made of stainless steel, which has the characteristics of high temperature resistance, high pressure resistance and corrosion resistance, and further improves the sealing effect of the sealing structure.

[0034] like Figure 2 and 3As shown, a first triangular sealing groove 34 is provided on the side of the first boss 35 close to the metal sealing ring 4; a second triangular sealing groove is provided on the side of the first shoulder 11 close to the metal sealing ring 4; the first triangular sealing groove 34 and the second triangular sealing groove are located on both sides of the metal sealing ring 4. The cross-sections of the first triangular sealing groove 34 and the second triangular sealing groove are triangular. The first shoulder 11 of the bottle mouth extension portion 1 is used to install the metal sealing ring 4. The second triangular sealing groove provided on the mounting surface of the first shoulder 11 is used in conjunction with the first triangular sealing groove 34 provided on the first boss 35 of the sealing plug 3. Assuming that the metal sealing ring 4 is deformed by high pressure, it can also have a high filling degree in the grooves of the first triangular sealing groove 34 and the second triangular sealing groove. When the pressure changes, the first triangular sealing groove 34 and the second triangular sealing groove can reduce the movement of the metal sealing ring 4, thereby improving the sealing effect.

[0035] As a specific embodiment of the utility model, the first triangular sealing groove 34 is distributed along the circumferential direction on the mounting surface of the first boss 35; the second triangular sealing groove is distributed along the circumferential direction on the mounting surface of the first shoulder 11, so that the two side surfaces of the metal sealing ring 4 are well fitted with the first triangular sealing groove 34 in the circumferential direction of the entire mounting surface of the first boss 35 and the second triangular sealing groove in the circumferential direction of the entire mounting surface of the first shoulder 11, thereby improving the sealing effect.

[0036] like Figure 2 and 3 As shown, the hollow cavity 15 of the bottle mouth extension portion 1 has a second shoulder 12, and the second shoulder 12 is truncated; the second shoulder 12 is distributed along the circumferential direction of the inner wall of the hollow cavity 15. The surface of the second shoulder 12 is inclined inward along the inner wall of the hollow cavity 15; the diameter of the second shoulder 12 at the end close to the gas cylinder liner 21 is smaller than the diameter at the end away from the gas cylinder liner 21. The sealing plug 3 is provided with an inclined shoulder 36 corresponding to the second shoulder 12, and the inclined shoulder 36 has the same inclination angle as the second shoulder 12. The diameter of the second shoulder 12 is larger than the diameter of the sealing plug 3. When installing the sealing plug 3, the O-ring 6 needs to go over the second shoulder 12 and contact the second shoulder 12. The inclined surface of the second shoulder 12 guides the movement of the O-ring 6 to avoid damage to the O-ring 6.

[0037] As a specific embodiment of the utility model, the maximum diameter of the second shoulder 12 is greater than the maximum diameter of the inclined shoulder 36 of the sealing plug 3, and the minimum diameter of the second shoulder 12 is greater than the minimum diameter of the inclined shoulder 36 of the sealing plug 3. During the process of inserting the sealing plug 3 into the hollow cavity 15, the inclined shoulder 36 fits with the inclined surface of the second shoulder 12, and the inclined surface of the second shoulder 12 guides the inclined shoulder 36, thereby making the installation of the sealing plug 3 more accurate.

[0038] like Figure 2 and 3As shown, the inner wall of the hollow cavity 15 of the bottle mouth extension part 1 is provided with an internal thread part 14, which is threadedly connected with the external thread part 31 of the sealing plug 3, thereby improving the reliability of the connection between the sealing plug 3 and the bottle mouth extension part 1.

[0039] As a preferred embodiment of the present utility model, the external threaded portion 31 of the sealing plug 3 is arranged at one end of the sealing plug 3 close to the inside of the gas cylinder.

[0040] As a preferred embodiment of the utility model, the O-ring annular groove 32 is used to install the O-ring 6, and limiting bosses are provided on both sides of the O-ring annular groove 32 for limiting the axial movement of the O-ring 6 to prevent the O-ring 6 from moving and improve the sealing effect of the O-ring 6.

[0041] As a specific embodiment of the utility model, a second boss 33 is provided on the sealing plug 3 between the O-ring 6 and the external threaded portion 31. When the O-ring 6 is installed between the O-ring annular groove 32 and the smooth section 13, the O-ring 6 will be deformed. The provision of the second boss 33 can prevent the deformed portion of the O-ring 6 from entering the external threaded portion 31 and being damaged.

[0042] As a preferred embodiment of the utility model, the internal thread portion 14 of the bottle mouth extension portion 1 is not less than 15 times the thread length. The external thread portion 31 of the sealing plug 3 is not less than 12 times the thread length. The internal thread portion 14 of the bottle mouth extension portion 1 is threadedly connected with the external thread portion 31 of the sealing plug 3, which improves the connection reliability between the sealing plug 3 and the bottle mouth extension portion 1.

[0043] As a specific embodiment of the utility model, since the sealing ring for the gas cylinder is only under pressure at the lower end (close to the side of the gas cylinder liner 21), a retaining ring 5 is added above the O-type sealing ring 6 (away from the side of the gas cylinder liner 21) to improve the installation reliability of the O-type sealing ring 6. The material of the retaining ring 5 is usually polytetrafluoroethylene, and leather and nylon materials can also be used. The material of the retaining ring 5 is not limited here and can be selected according to actual needs.

[0044] like Figure 3 As shown, the sealing plug 3 has a cavity 37, thereby reducing the overall material of the sealing plug 3 and saving costs.

[0045] The beneficial effects achieved by this application are as follows:

[0046] (1) The sealing structure of the present application adopts a double-pass seal of a metal sealing ring and an O-ring. On the basis of the O-ring seal, a metal sealing ring seal is added to improve the sealing effect and sealing reliability of the sealing structure. The double-pass seal form adopted in the present application has the characteristics of high working reliability, good sealing and long service life.

[0047] (2) The present application adds a retaining ring in the annular groove of the O-ring, and the retaining ring is located on the side of the O-ring away from the inner liner of the gas cylinder to prevent the O-ring from being "extruded" under the action of pressure after the gas cylinder is filled with high pressure, causing the O-ring to fail, thereby improving the sealing reliability of the O-ring.

[0048] (3) When installing the sealing plug, the O-ring needs to go over the second shoulder and contact the second shoulder. The inclined surface of the second shoulder guides the movement of the O-ring to avoid damage to the O-ring.

[0049] (4) In the present application, limiting bosses are provided on both sides of the annular groove of the O-ring for limiting the axial movement of the O-ring, thereby preventing the O-ring from moving and preventing the deformed portion of the O-ring from entering the external thread portion and being damaged, thereby improving the sealing effect of the O-ring.

[0050] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "plurality" means two or more, unless otherwise clearly and specifically defined.

[0051] In the description of the present application, the word "for example" is used to mean "used as an example, illustration or explanation". Any embodiment described as "for example" in the present application is not necessarily to be construed as being more preferred or advantageous than other embodiments. In order to enable any technician in the field to implement and use the utility model, the following description is given. In the following description, details are listed for the purpose of explanation. It should be understood that a person of ordinary skill in the art can recognize that the utility model can be implemented without using these specific details. In other examples, well-known structures and processes will not be elaborated in detail to avoid unnecessary details that make the description of the utility model obscure. Therefore, the utility model is not intended to be limited to the embodiments shown, but is consistent with the widest range of principles and features disclosed in the present application.

[0052] The above description is only an embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of the claims of the present invention.

Claims

1. A sealing structure for a high-pressure gas cylinder for a launch vehicle, characterized in that: The sealing structure of the high-pressure gas cylinder comprises: a bottle mouth extension, a sealing plug, a metal sealing ring, a retaining ring and an O-ring. The bottle mouth extension part is connected to the shoulder of the gas cylinder, and the bottle mouth extension part has a hollow cavity; The outer periphery of the sealing plug is provided with an external threaded portion and an O-ring annular groove; The sealing plug extends into the hollow cavity and is threadedly connected to the bottle mouth extension portion through an external thread portion; The O-ring and the retaining ring are arranged in the O-ring annular groove, and the retaining ring is arranged on a side of the O-ring away from the shoulder of the gas cylinder; The O-type sealing ring and the metal sealing ring are arranged in the gap between the sealing plug and the bottle mouth extension part, respectively realizing the first sealing and the second sealing.

2. The sealing structure of a high-pressure gas cylinder for a launch vehicle according to claim 1, characterized in that: The hollow cavity of the bottle mouth extension portion has a first shoulder. The sealing plug has a first boss along its circumferential direction; The sealing plug extends into the hollow cavity, and the metal sealing ring is arranged between the first boss and the first shoulder.

3. The sealing structure of a high-pressure gas cylinder for a launch vehicle according to claim 2, characterized in that: A first triangular sealing groove is provided on one side of the first boss close to the metal sealing ring; A second triangular sealing groove is provided on one side of the first shoulder close to the metal sealing ring; The first triangular sealing groove and the second triangular sealing groove are located on both sides of the metal sealing ring.

4. The sealing structure of a high-pressure gas cylinder for a launch vehicle according to claim 3, characterized in that: The first triangular sealing groove is distributed on the mounting surface of the first boss along the circumferential direction; The second triangular sealing grooves are distributed on the mounting surface of the first shoulder along the circumferential direction.

5. The sealing structure of a high-pressure gas cylinder for a launch vehicle according to claim 2, characterized in that: The hollow cavity of the bottle mouth extension portion is provided with a second shoulder; The surface of the second shoulder is inclined inwardly along the inner wall of the hollow cavity; The sealing plug is provided with an inclined shoulder corresponding to the second shoulder, and the inclined shoulder has the same inclination angle as the second shoulder.

6. The sealing structure of a high-pressure gas cylinder for a launch vehicle according to claim 1, characterized in that: The inner wall of the hollow cavity of the bottle mouth extension portion is provided with an internal thread portion; The internal threaded portion of the bottle mouth extension portion is threadedly connected to the external threaded portion of the sealing plug.

7. The sealing structure of a high-pressure gas cylinder for a launch vehicle according to claim 2, characterized in that: The external threaded portion of the sealing plug is arranged at one end of the sealing plug close to the interior of the gas cylinder.

8. The sealing structure of a high-pressure gas cylinder for a launch vehicle according to claim 1, characterized in that: The bottle mouth extension portion is provided with a smooth section, The diameter of the smooth section is smaller than the outer diameter of the O-ring; The O-ring is sleeved in the O-ring annular groove of the sealing plug and is limited on the inner wall of the smooth section to form a first seal.

9. The sealing structure of a high-pressure gas cylinder for a launch vehicle according to claim 1, characterized in that: Limiting bosses for limiting the axial movement of the O-ring are arranged on both sides of the O-ring annular groove.

10. The sealing structure of a high-pressure gas cylinder for a launch vehicle according to claim 5, characterized in that: The second shoulder is in the shape of a truncated cone.

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