Rigid constraint structure applied to injection molding inner container connector of high-pressure gas cylinder

Abstract

The invention relates to a rigid constraint structure applied to an injection molding liner interface of a high-pressure gas cylinder, which comprises a valve seat, a radial sealing ring, a first rigid structure and an axial sealing ring, and the valve seat comprises a first connecting part, a flange plate and a second connecting part; a first annular groove is formed in the periphery of the second connecting part around the second connecting part, and the radial sealing ring is arranged in the first annular groove; the first rigid structural part comprises a platform and a protrusion, the protrusion can be inserted into the second connecting part, a through hole communicating with the cavity is formed in the first rigid structural part in the extending direction of the platform and the protrusion, and the platform can abut against the valve seat and the injection molding inner container connector. A second annular groove is formed in the face, abutting against the connector of the valve seat and the injection molding inner container, of the platform, and the axial sealing ring is arranged in the second annular groove. According to the rigid restraining structure, axial and annular bidirectional sealing can be achieved, relative deformation between sealing faces in the high-pressure gas storage environment is reduced, it is guaranteed that the compression ratio of the sealing ring is kept in an ideal state, and therefore the sealing effect is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of high-pressure gas cylinder structures, and in particular to a rigid constraint structure applied to an injection-molded liner interface of a high-pressure gas cylinder. Background Art

[0002] High-pressure gas cylinders made of plastic liner as core mold and fiber-reinforced composite material layer wrapped around its outer surface are also often called IV-type gas cylinders. 70 MPa IV-type hydrogen storage cylinders are an emerging technology and industry currently used in large-scale commercial locomotives (heavy trucks, large passenger vehicles, rail transit, etc.).

[0003] The structural design of the interface of Type IV high-pressure gas cylinders is one of the key technologies, which involves how to control the deformation accuracy between components of different materials (plastic liner, metal valve seat, rubber seal, and composite material winding layer) under high pressure environment, as well as the sealing problem directly related to this. Since the stiffness and strength of the materials between these components vary greatly, and the sealing ring among them has high requirements and is also a vulnerable component, it is necessary to design and set up corresponding rigid constraint components to make the local relative deformation at the sealing point as small as possible, maintain the compression required for sealing, and protect the sealing ring from being damaged or failing under long-term high-pressure load.

[0004] For the injection-molded liner of a high-pressure gas cylinder, a common method at the interface is to use a split valve seat placed in two parts, the upper valve seat component and the lower valve seat component, respectively, where the lower valve seat component and the plastic liner are integrally formed by injection molding, and then the upper valve seat component is screwed and fixed to the lower valve seat component by threading. One of the main disadvantages of this method is that there will be relative movement between the plastic liner and the metal lower valve seat, and between the lower valve seat and the upper valve seat during the loading and unloading process of the high-pressure gas cylinder, causing sealing failure.

[0005] The Chinese invention patent application with the publication number of CN116379334A and the invention name of the invention is a plastic liner sealing structure and its molding process. It adopts an improved split valve seat structure in order to reduce the above problems. The patent application places the interface of the plastic liner between the upper surface of the lower valve seat (referred to as the valve seat inner core in the text) from the flange to the neck and the lower surface of the upper valve seat (referred to as the valve seat outer sleeve in the text) from the flange to the neck, and processes a groove on the valve seat inner core for placing an O-ring for sealing, so as to achieve radial and axial sealing and increase the sealing effect by applying pressure to the metal valve seat inner core through the action of the internal high-pressure gas; however, in this solution, since there is no rigid constraint support inside the liner, the following problems will be caused:

[0006] (1) Due to the low elastic modulus of plastic, the sealing effect of the rubber sealing ring placed on the metal tank liner at the contact point with the plastic liner surface is poor, and the sealing reliability under high pressure conditions is difficult to ensure;

[0007] (2) In a long-term high-pressure hydrogen environment, the contact between the inner tank surface and the sealing ring will form a permanent deformed pit under the combined action of chemical and mechanical effects, causing the seal to fail;

[0008] (3) Under the huge pressure, the rubber sealing ring placed in the groove of the metal inner core flange will be squeezed and damaged. Summary of the invention

[0009] To this end, the technical problem to be solved by the present invention is to overcome the deformation between different materials caused by high-pressure loads in the prior art, which in turn causes the common sealing failure problem at the interface of the high-pressure gas cylinder, and provide a rigid constraint structure applied to the interface of the injection-molded liner of the high-pressure gas cylinder, which can achieve axial and circumferential bidirectional sealing, effectively reduce the relative deformation between the sealing surfaces under the high-pressure gas storage environment, and ensure that the compression rate of the sealing ring is maintained at the ideal state of the initial design, thereby ensuring the sealing effect.

[0010] In order to solve the above technical problems, the present invention provides a rigid constraint structure applied to the interface of the injection-molded liner of a high-pressure gas cylinder, comprising:

[0011] A valve seat, comprising: an integrally formed first connection portion, a flange, and a second connection portion, wherein: the first connection portion can be connected to a valve core, the second connection portion can be inserted into an injection molded liner interface of a high-pressure gas cylinder, and the valve seat has a through cavity along the extending direction of the first connection portion, the flange, and the second connection portion;

[0012] A radial sealing ring, with a first annular groove formed on its outer circumference around the second connecting portion, wherein the radial sealing ring is arranged in the first annular groove;

[0013] A first rigid structural member, comprising a platform and a protrusion disposed on the platform, wherein the protrusion can be inserted into the second connecting portion, a through hole communicating with the cavity is provided in the first rigid structural member along the extending direction of the platform and the protrusion, and the platform can abut against the valve seat and the injection molded liner interface;

[0014] An axial sealing ring is provided with a second annular groove on the abutting surface between the platform, the valve seat and the injection molded liner interface, and the axial sealing ring is arranged in the second annular groove.

[0015] In one embodiment of the present invention, a first connecting thread is provided on the side wall of the cavity at a position of the first connecting portion, and an external thread is provided on the valve core. The valve core can be inserted into the first connecting portion to match the first connecting thread.

[0016] In one embodiment of the present invention, a second connecting thread is provided on the side wall of the cavity at the position of the second connecting portion, and an external thread is provided on the protrusion, and the protrusion can be inserted into the second connecting portion to match the second connecting thread.

[0017] In one embodiment of the present invention, a step is provided in the cavity between the flange and the second connecting portion, and the protrusion abuts against the step.

[0018] In one embodiment of the present invention, two first limit retaining rings are further arranged in the first annular groove, and the radial sealing ring is arranged between the two first limit retaining rings.

[0019] In one embodiment of the present invention, at least two axial sealing rings are further arranged in the second annular groove, wherein one axial sealing ring is arranged between the platform and the valve seat, and the other axial sealing ring is arranged between the platform and the injection molding liner interface.

[0020] In one embodiment of the present invention, a second limit ring is further arranged between the two axial sealing rings.

[0021] In one embodiment of the present invention, the through hole can cooperate with an installation tool, so that the installation tool drives the first rigid structure to rotate.

[0022] In one embodiment of the present invention, it further comprises a second rigid structure member, wherein the second rigid structure member is embedded in the injection-molded liner interface;

[0023] The second rigid structure has a step protruding toward the valve seat;

[0024] Furthermore, the end of the second rigid structural member is flush with the interface of the injection-molded liner, and the end of the second rigid structural member is in contact with the first rigid structural member.

[0025] In one embodiment of the present invention, a plurality of connection holes are formed on the side wall of the second rigid structure.

[0026] The above technical solution of the present invention has the following advantages compared with the prior art:

[0027] The rigid constraint structure applied to the interface of the injection-molded liner of a high-pressure gas cylinder of the present invention is provided with a radial sealing ring and an axial sealing ring, which can perform radial and axial sealing at the same time, thereby enhancing the reliability of the sealing;

[0028] When setting the sealing ring, the sealing ring is placed between the two contact surfaces, and the required component processing accuracy can be easily achieved by machining;

[0029] The introduced first rigid structural member is connected to the valve seat and can limit the first rigid structural member and the valve seat in the axial direction, which can not only ensure the designed compression rate of the sealing ring during the initial installation, but also prevent the damage of the sealing ring caused by deformation caused by high-pressure load under subsequent gas storage conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein:

[0031] Figure 1 It is a schematic diagram of the overall cross-sectional structure of the rigid constraint structure of the injection-molded liner interface of a high-pressure gas cylinder applied by the present invention;

[0032] Figure 2 It is a structural schematic diagram of the valve seat of the present invention;

[0033] Figure 3 is a structural schematic diagram of a first rigid structural member;

[0034] Figure 4 yes Figure 1 A schematic diagram of the enlarged structure at A in the middle;

[0035] Figure 5 It is a schematic structural diagram of the second rigid structural member.

[0036] Description of the accompanying drawings in the specification: 100, injection molding liner interface; 1, valve seat; 11, first connecting part; 12, flange; 13, second connecting part; 14, cavity; 15, first annular groove; 2, first rigid structure; 21, platform; 22, protrusion; 23, second annular groove; 24, through hole; 3, radial sealing ring; 4, axial sealing ring; 5, second rigid structure; 51, step; 52, connecting hole; 6, first limit retaining ring; 7, second limit retaining ring; DETAILED DESCRIPTION

[0037] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0038] Reference Figure 1As shown, the present invention discloses a rigid constraint structure applied to the interface of the injection-molded liner of a high-pressure gas cylinder, comprising: a valve seat 1 and a first rigid structural member 2. The rigid constraint structure of the present invention is suitable for a type IV high-pressure composite gas cylinder with a two-section injection-molded liner as a core mold. The injection-molded liner is welded together by welding after the valve seat 1 and the corresponding sealing member are installed. In addition, the neck of the injection-molded liner has an injection-molded liner interface 100 extending inward, so that the valve seat 1 can be inserted into the injection-molded liner interface 100 and docked with the injection-molded liner.

[0039] Reference Figure 2 As shown, the valve seat 1 includes: an integrally formed first connection part 11, a flange 12 and a second connection part 13, and the valve seat 1 has a through cavity 14 along the extension direction of the first connection part 11, the flange 12 and the second connection part 13, wherein: the first connection part 11 can be connected to the valve core, the valve core can be inserted into the first connection part 11 and block the cavity 14, the high-pressure gas cylinder can be switched on and off through the valve core, the second connection part 13 can be inserted into the injection-molded liner interface 100 of the high-pressure gas cylinder, the outer diameter of the second connection part 13 is the same as the inner diameter of the injection-molded liner interface 100, and the injection-molded liner interface 100 can be blocked by the second connection part 13.

[0040] Reference Figure 3 As shown, the first rigid structural member 2 includes a platform 21 and a protrusion 22 arranged on the platform 21, the protrusion 22 can be inserted into the second connecting portion 13, the outer diameter of the protrusion 22 is the same as the inner diameter of the second connecting portion 13, and a through hole 24 connected to the cavity 14 is opened in the first rigid structural member 2 along the extension direction of the platform 21 and the protrusion 22, and the platform 21 can abut against the valve seat 1 and the injection molded liner interface 100.

[0041] Reference Figure 4 As shown, when the valve seat 1 is actually assembled, due to design errors, there may be a gap between the second connecting portion 13 and the injection molded liner interface 100. Therefore, in order to improve the sealing between the two, a first annular groove 15 is opened around the outer circumference of the second connecting portion 13, and a radial sealing ring 3 is arranged in the first annular groove 15. The sealing between the second connecting portion 13 and the injection molded liner interface 100 is achieved by the radial sealing ring 3.

[0042] When actually assembling the first rigid structural member 2, due to design errors, there may be a gap between the protrusion 22 and the second connecting portion 13. Therefore, in order to improve the sealing between the two, a second annular groove 23 is opened on the abutting surface between the platform 21 and the valve seat 1 and the injection molded liner interface 100, and an axial sealing ring 4 is arranged in the second annular groove 23. The axial sealing ring 4 is used to realize the sealing between the platform 21 and the valve seat 1, and the sealing between the platform 21 and the injection molded liner interface 100.

[0043] The rigid constraint structure used in the injection-molded liner interface 100 of a high-pressure gas cylinder of the present invention is provided with a radial sealing ring 3 and an axial sealing ring 4, which can perform radial and axial sealing at the same time, thereby enhancing the reliability of the sealing;

[0044] When setting the sealing ring, the sealing ring is placed between the two contact surfaces, and the required component processing accuracy can be easily achieved by machining;

[0045] The introduced first rigid structure 2 is connected to the valve seat 1 and can limit the valve seat 1 in the axial direction, which can not only ensure the designed compression rate of the sealing ring during initial installation, but also prevent the sealing ring from being damaged due to deformation caused by high-pressure load under subsequent gas storage conditions.

[0046] Reference Figure 2 and Figure 3 As shown, in order to achieve a detachable connection between the valve core and the valve seat 1, a first connecting thread is opened on the side wall of the cavity 14 at the position of the first connecting part 11, and an external thread is provided on the valve core. The valve core can be inserted into the first connecting part 11 to match the first connecting thread, and the rotational connection between the valve core and the valve seat 1 is achieved by rotating the thread.

[0047] Specifically, in order to achieve a limited connection between the valve seat 1 and the first rigid structural member 2, a second connecting thread is provided on the side wall of the cavity 14 at the position of the second connecting portion 13, and an external thread is provided on the protrusion 22. The protrusion 22 can be inserted into the second connecting portion 13 to match the second connecting thread, and the rotational connection between the valve seat 1 and the first rigid structural member 2 is achieved by rotating the thread.

[0048] Specifically, when actually assembling the first rigid structural member 2, in order to facilitate the installation of the first rigid structural member 2, the through hole 24 is set to cooperate with the installation tool, and the installation tool is inserted into the through hole 24 to drive the first rigid structural member 2 to rotate; for example: when a hexagonal wrench is used as the installation tool, the through hole 24 is set to be a hexagonal structure.

[0049] Specifically, in order to achieve sealing cooperation between the valve seat 1 and the first rigid structure 2 , a step is provided in the cavity 14 between the flange 12 and the second connecting portion 13 , and the protrusion 22 in the first rigid structure 2 can abut against the step.

[0050] Reference Figure 4 As shown, in order to fix the radial sealing ring 3 , two first limit retaining rings 6 are further arranged in the first annular groove 15 , and the radial sealing ring 3 is arranged between the two first limit retaining rings 6 .

[0051] In this embodiment, the platform 21 abuts against both the valve seat 1 and the injection molded liner interface 100. Therefore, when setting the axial seal, it is necessary to set at least two axial sealing rings 4 in the second annular groove 23, wherein one of the axial sealing rings 4 is set between the platform 21 and the valve seat 1, and the other axial sealing ring 4 is set between the platform 21 and the injection molded liner interface 100. Separate sealing is achieved by two axial sealing rings 4 to further improve the sealing effect.

[0052] Specifically, in order to prevent the two axial sealing rings 4 from moving, a second limit ring 7 is provided between the two axial sealing rings 4 .

[0053] It should be noted that, in this embodiment, the depths of the first annular groove 15 and the second annular groove 23 are set according to the compression rates and sizes of the radial sealing ring 3 and the axial sealing ring 4 to ensure that the radial sealing ring 3 and the axial sealing ring 4 can protrude from the first annular groove 15 and the second annular groove 23, and to ensure that the radial sealing ring 3 and the axial sealing ring 4 do not exceed their own compression rates after being squeezed.

[0054] Since the injection molded liner is made of plastic, its rigid constraint strength is relatively low. During long-term use, the position of the injection molded liner interface 100 may be deformed due to the cooperation with the valve seat 1. Figure 1 and Figure 4 As shown, the constraint structure of the present invention further includes a second rigid structure member 5, which is embedded in the injection-molded liner interface 100, the end of the second rigid structure member 5 is flush with the injection-molded liner interface 100, and the end of the second rigid structure member 5 is in contact with the first rigid structure member 2;

[0055] The second rigid structural member 5 can enhance the strength of the injection-molded liner interface 100 , ensuring that it still has a rigid binding force during long-term use.

[0056] Reference Figure 5As shown, the second rigid structure 5 has a step 51 protruding toward the valve seat 1 , and the step 51 can further enhance the rigidity of the contact surface between the injection-molded liner and the first rigid structure 2 .

[0057] Specifically, a plurality of connection holes 52 are provided on the side wall of the second rigid structural member 5, and the second rigid structural member 5 is embedded in the injection molded liner interface 100 when preparing the injection molded liner. By providing a plurality of connection holes 52, the connection strength between the second rigid structural member 5 and the injection molded liner interface 100 can be enhanced during injection molding.

[0058] It should be noted that in the present invention, in order to ensure that the rigid constraint structure has sufficient strength, the valve seat 1 is made of metal material, and the first rigid structural member 2 and the second rigid structural member 5 are made of alloy steel materials that are resistant to hydrogen embrittlement, have high rigidity and high strength, such as austenitic alloy steel.

[0059] Obviously, the above embodiments are merely examples for the purpose of clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the present invention.

Claims

1. A rigid constraint structure used in the injection molding liner interface of a high-pressure gas cylinder, characterized in that: include: A valve seat, comprising: an integrally formed first connection portion, a flange, and a second connection portion, wherein: the first connection portion can be connected to a valve core, the second connection portion can be inserted into an injection molded liner interface of a high-pressure gas cylinder, and the valve seat has a through cavity along the extending direction of the first connection portion, the flange, and the second connection portion; A radial sealing ring, with a first annular groove formed on its outer circumference around the second connecting portion, wherein the radial sealing ring is arranged in the first annular groove; A first rigid structural member, comprising a platform and a protrusion disposed on the platform, wherein the protrusion can be inserted into the second connecting portion, a through hole communicating with the cavity is provided in the first rigid structural member along the extending direction of the platform and the protrusion, and the platform can abut against the valve seat and the injection molded liner interface; An axial sealing ring is provided with a second annular groove on the abutting surface between the platform, the valve seat and the injection molded liner interface, and the axial sealing ring is arranged in the second annular groove.

2. The rigid constraint structure for use in the injection-molded liner interface of a high-pressure gas cylinder according to claim 1, characterized in that: A first connecting thread is provided on the side wall of the cavity at a position of the first connecting portion, and an external thread is provided on the valve core. The valve core can be inserted into the first connecting portion and matched with the first connecting thread.

3. The rigid constraint structure for use in the injection-molded liner interface of a high-pressure gas cylinder according to claim 1, characterized in that: A second connecting thread is provided on the side wall of the cavity at a position of the second connecting portion, and an external thread is provided on the protrusion. The protrusion can be inserted into the second connecting portion and matched with the second connecting thread.

4. The rigid constraint structure for use in the injection-molded liner interface of a high-pressure gas cylinder according to claim 1, characterized in that: A step is provided in the cavity between the flange and the second connecting portion, and the protrusion abuts against the step.

5. The rigid constraint structure for use in the injection-molded liner interface of a high-pressure gas cylinder according to claim 1, characterized in that: Two first limit retaining rings are also arranged in the first annular groove, and the radial sealing ring is arranged between the two first limit retaining rings.

6. The rigid constraint structure for use in the injection-molded liner interface of a high-pressure gas cylinder according to claim 1, characterized in that: At least two axial sealing rings are also arranged in the second annular groove, wherein one of the axial sealing rings is arranged between the platform and the valve seat, and the other axial sealing ring is arranged between the platform and the injection molding liner interface.

7. The rigid constraint structure for use in the injection-molded liner interface of a high-pressure gas cylinder according to claim 6, characterized in that: A second limiting ring is also arranged between the two axial sealing rings.

8. The rigid constraint structure for use in the injection-molded liner interface of a high-pressure gas cylinder according to claim 1, characterized in that: The through hole can cooperate with an installation tool, so that the installation tool drives the first rigid structure to rotate.

9. The rigid constraint structure for use in the injection-molded liner interface of a high-pressure gas cylinder according to claim 1, characterized in that: It also includes a second rigid structure, wherein the second rigid structure is embedded in the injection-molded liner interface; The second rigid structure has a step protruding toward the valve seat; Furthermore, the end of the second rigid structural member is flush with the interface of the injection-molded liner, and the end of the second rigid structural member is in contact with the first rigid structural member.

10. The rigid constraint structure used in the injection molding inner liner interface of a high-pressure gas cylinder according to claim 9, characterized in that: A plurality of connection holes are formed on the side wall of the second rigid structure.

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