IV-type hydrogen storage cylinder BOSS structure bottle opening sealing assembly good in sealing performance and easy to form

Abstract

The invention discloses an IV-type hydrogen storage cylinder BOSS structure bottle opening sealing assembly which is good in sealing performance and easy to form, and belongs to the technical field of high-pressure hydrogen storage cylinders. The water heater comprises an end cover, a BOSS structure and a plastic inner container. The end cover and the BOSS structure are fastened and connected through threads, and the BOSS structure and the plastic inner container are integrally formed through rotational molding; sealing structures are arranged on the contact surface between the end cover and the BOSS structure and the contact surface between the BOSS structure and the plastic liner; the bottom of the BOSS structure is provided with a set of rotation stopping grooves and a clamping groove used for improving the bonding strength of the BOSS structure and the plastic inner container, and the bottom of the BOSS structure is further provided with a bonding part used for reducing rotational molding defects and further improving the stability of the molding structure. Compared with an existing BOSS structure bottle opening sealing design, the bottle opening sealing structure has the advantages of being simple in structure, good in sealing performance, capable of easily forming the inner container, stable in forming structure and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of high-pressure hydrogen storage cylinders, and in particular relates to a BOSS structure bottle mouth sealing component of a type IV hydrogen storage cylinder with good sealing performance and easy molding. Background Art

[0002] In order to cope with the energy crisis and environmental pollution, hydrogen energy as a clean energy has attracted much attention, and hydrogen storage technology is a key link in the utilization of hydrogen energy. The demand for on-board hydrogen storage bottles in the domestic market is growing rapidly. According to statistics, the demand will reach 69,000 in 2022, a year-on-year increase of 127.7%; it will reach 230,000 in 2025, with an annual compound growth rate of about 66%. Type IV hydrogen storage cylinders have gradually become a research hotspot due to their lighter weight, higher mass hydrogen storage density, and better fatigue performance.

[0003] Type IV hydrogen storage cylinders are usually composed of a plastic liner and a carbon fiber layer. Among them, the BOSS structure, as a key component connecting the plastic liner and the metal bottle mouth valve, needs to ensure sealing performance to ensure that hydrogen does not leak. At present, the injection molding process is the main way to connect the plastic liner and the BOSS structure, but the injection molding process can easily lead to a loose connection between plastic and metal, stratification and leakage. In addition, although the existing bottle mouth sealing structure design is diverse, it is often unable to adapt to different types of bottle mouth valves on the market, and there are problems such as insufficient adaptability and poor sealing performance. Summary of the invention

[0004] In view of the above problems existing in the prior art, the purpose of the present invention is to provide a BOSS structure bottle mouth sealing assembly for type IV hydrogen storage cylinders. Compared with the existing BOSS structure bottle mouth sealing design, the BOSS structure bottle mouth sealing assembly designed by the present invention has the advantages of simple structure, good sealing performance, easy inner liner molding, stable molding structure, etc.

[0005] The present invention provides the following technical solutions: a BOSS structure bottle mouth sealing assembly of a type IV hydrogen storage gas cylinder with good sealing performance and easy molding, comprising an end cap, a BOSS structure and a plastic liner; the end cap and the BOSS structure are fastened and connected by threads, and the BOSS structure and the plastic liner are integrally molded by rotational molding; a sealing structure is provided on the contact surface between the end cap and the BOSS structure and the contact surface between the BOSS structure and the plastic liner;

[0006] The bottom of the BOSS structure is provided with a group of anti-rotation grooves and a slot for improving the bonding strength between the BOSS structure and the plastic liner. The bottom of the BOSS structure is also provided with a joint for reducing rotational molding defects and further improving the stability of the molding structure.

[0007] Furthermore, the anti-rotation groove and the locking groove are both located on the bottom end surface of the BOSS structure; and the coupling portion is located on the outer side of the bottom of the BOSS structure.

[0008] Furthermore, the anti-rotation groove is an annular groove structure, and a group of anti-rotation grooves are coaxially arranged along the central axis of the BOSS structure.

[0009] Furthermore, the card slots are arc-shaped waist-shaped slot structures, and a group of card slots are arranged at intervals in a circle along the central axis of the BOSS structure.

[0010] Furthermore, the joint portion is in a step-like structure with the bottom extending outward.

[0011] Furthermore, the BOSS structure is provided with a through hole structure along the axial direction, and an annular groove is provided on the inner side of the through hole; its outer side is provided with an external thread connected to the trailer tube plate thread and a rotation-stopping platform for stopping the BOSS structure and the plastic liner from rotating.

[0012] Furthermore, the plastic liner is located at the lower part of the BOSS structure, and the upper part of the plastic liner is located in the through hole of the BOSS structure; the upper part of the plastic liner is a tapered structure, and the inner wall of the through hole of the BOSS structure is provided with a tapered structure that is interference fit with the tapered structure of the upper part of the plastic liner; the upper part of the plastic liner is provided with a rubber protrusion that matches the annular groove in the BOSS structure.

[0013] Furthermore, the main body of the end cover is arranged in the through-hole structure in the BOSS structure by screwing, and its lower part is tightly inserted into the upper part of the plastic liner; a limiting structure is provided at the upper end of the main body, and the limiting structure is abutted against the upper end surface of the BOSS structure; an external thread structure matching the internal thread is provided on the outer side of the main body, and a through hole and an internal thread structure coaxial with the main body are provided inside the main body.

[0014] Furthermore, a sealing structure is provided between the contact surface between the limiting structure of the end cover and the upper end surface of the BOSS structure, and between the contact surface between the end cover body and the upper part of the plastic liner.

[0015] By adopting the above technology, compared with the prior art, the beneficial effects of the present invention are as follows:

[0016] 1) In the present invention, the bottle mouth sealing assembly is provided with a sealing structure on the contact surface, which ensures the connection stability and airtightness of the entire BOSS structure bottle mouth sealing assembly during the hydrogen filling and discharging process;

[0017] 2) In the present invention, end caps of different sizes can be designed to be compatible with bottle mouth valves of different designs on the market;

[0018] 3) In the present invention, the end cap and the tapered structure of the plastic liner are designed to achieve an interference fit between the end cap and the plastic liner, thereby ensuring the sealing of the bottle mouth assembly under high pressure;

[0019] 4) In the present invention, the inner and outer axial surfaces of the end cap and the inner and outer surfaces of the BOSS structure are both arranged with thread designs to achieve a fastening connection between metal connectors such as the end cap, the BOSS structure, the bottle mouth valve and the external tube sheet;

[0020] 5) In the present invention, an inwardly sunken annular groove is provided on the inner surface of the BOSS structure to have an interference fit with the plastic liner, and rotational molding is used to ensure the connection stability between the BOSS structure and the plastic liner;

[0021] 6) In the present invention, the BOSS structure is provided with a rotation-stopping platform and a rotation-stopping groove, which can prevent the BOSS structure from being separated from the carbon fiber layer and the plastic liner during the winding and transportation of the hydrogen storage cylinder;

[0022] 7) In the present invention, the structural design based on the stepped joint can improve the fluidity of the molten plastic during the rotational molding process and improve the molding quality of the liner compared with the existing concave structural design, and further improve the stability of the one-piece molding by using the embedded connection between the joint and the liner after molding;

[0023] 8) In the present invention, the BOSS structure is integrally formed without welding or other connection methods, and has high structural strength and sealing reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0025] Figure 2 for Figure 1 A schematic diagram of the enlarged structure at A in the middle;

[0026] Figure 3 3a is a schematic diagram of the structure of the end cover of the present invention, wherein 3a is a schematic diagram of the structure in a top view, and 3b is a schematic diagram of the structure in a cross-section;

[0027] Figure 4 4a is a schematic diagram of the structure of the BOSS structure of the present invention, wherein 4b is a schematic diagram of the test structure, and 4c is a schematic diagram of the cross-sectional structure;

[0028] Figure 5 It is a schematic diagram of the structure of the plastic liner of the present invention;

[0029] Figure 6 A schematic diagram of pressure testing results of a hydrogen storage cylinder using the sealing assembly of the present invention. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments of the specification. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0031] On the contrary, the present invention covers any substitution, modification, equivalent method and scheme made on the essence and scope of the present invention as defined by the claims. Further, in order to make the public have a better understanding of the present invention, some specific details are described in detail in the detailed description of the present invention below. Those skilled in the art can fully understand the present invention without the description of these details.

[0032] See also Figure 1-6 This embodiment provides a BOSS structure bottle mouth sealing assembly for a type IV hydrogen storage cylinder, including an end cap 101, a BOSS structure 111, and a plastic liner 121. The end cap 101 and the BOSS structure 111 are fastened by threads, and the BOSS structure 111 and the plastic liner 121 are integrally formed by rotational molding.

[0033] Specifically, Figure 3 As shown, the end cover 101 of this embodiment includes a main body and a limiting structure located at the top of the main body; a through hole and an internal thread 102 are arranged along the axis in the main body, and an external thread 103 is arranged on the outside of the main body; a sealing groove 104 is arranged on the outside of the main body and the lower end surface of the limiting structure.

[0034] Specifically, Figure 4 As shown, the interior of the BOSS structure 111 of this embodiment is provided with a through hole along the axial direction, the upper part of the through hole is provided with an internal thread 112, the middle part is provided with two annular grooves 114, the outer side is provided with an external thread 113 and a stop platform 115, the bottom is provided with two grooves 117, a stop groove 116 located between the two grooves 117 and a joint portion 118 located around the bottom edge, and the joint portion 118 is a step-like structure.

[0035] Specifically, Figure 1 As shown, the plastic liner 121 is located at the lower part of the BOSS structure 111, and the upper part of the plastic liner 121 is located in the through hole of the BOSS structure 111; the upper part of the plastic liner 121 is a tapered structure (a 2° tapered design in this embodiment), and the inner wall of the through hole of the BOSS structure 111 is provided with a tapered structure that is interference-fitted with the tapered structure of the upper part of the plastic liner 121; the upper part of the plastic liner 121 is provided with a rubber protrusion that is matched with the annular groove 114 in the BOSS structure 111. Based on the design of the tapered structure, the sealing ring 105 in the sealing groove 104 on the side of the end cover 101 is interference-fitted to assume the sealing function, and the rubber protrusion is matched with the annular groove 114 on the axial inner surface of the BOSS structure 111 to achieve sealing.

[0036] Specifically, Figure 2 As shown, the sealing structure of this embodiment includes a sealing ring 105 and a retaining ring 106, and the sealing ring 105 and the retaining ring 106 are embedded in the corresponding sealing groove 104 to prevent hydrogen leakage from the hydrogen storage cylinder during high-pressure filling and discharge.

[0037] Specifically, the internal thread 112 is fastened to the external thread 103 of the end cover, the external thread 113 is fastened to the thread of the long tube trailer tube sheet, the annular groove 114 opened inside the BOSS structure 111 and the rubber protrusion of the plastic liner 121 are interference fit to achieve connection and sealing functions, the axially arranged anti-rotation platform 115, through an irregular structural design, assumes the anti-rotation function between the BOSS structure and the carbon fiber layer arranged on the outside of the BOSS structure, and the anti-rotation groove 116 arranged at the lower part assumes the anti-rotation function between the BOSS structure and the plastic liner 121 through a circumferential distribution design.

[0038] Specifically, the internal thread 102 is fastened to the external bottle mouth valve thread, the external thread 103 is fastened to the BOSS structure internal thread 112, the lower end outer surface of the end cap 101 is designed with a 2° taper, and a sealing ring 105 is placed in the sealing groove 104 to achieve a sealed connection with the BOSS structure 111, the plastic liner 121 and the external bottle mouth valve, the retaining ring 106 is located in the sealing groove 104 on the contact surface of the end cap and the plastic liner, and the end cap 101 provides different sizes of inner diameters to adapt to bottle mouth valves on the market.

[0039] In summary, the present invention can adapt to bottle mouth valves of different sizes, and realize the BOSS structure bottle mouth sealing assembly to achieve stable connection and good sealing at the bottle mouth position of the IV type hydrogen storage cylinder.

[0040] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A BOSS-structured bottle mouth sealing assembly for a type IV hydrogen storage cylinder with good sealing performance and easy molding, characterized in that: The invention comprises an end cover (101), a BOSS structure (111) and a plastic liner (121); the end cover (101) and the BOSS structure (111) are fastened by threads, and the BOSS structure (111) and the plastic liner (121) are integrally formed by rotational molding; a sealing structure is provided on the contact surface between the end cover (101) and the BOSS structure (111), and on the contact surface between the BOSS structure (111) and the plastic liner (121); The bottom of the BOSS structure (111) is provided with a group of anti-rotation grooves (116) and a clamping groove (117) for improving the bonding strength between the BOSS structure (111) and the plastic liner (121). The bottom of the BOSS structure (111) is also provided with a bonding portion (118) for reducing rotational molding defects and further improving the stability of the molding structure.

2. The BOSS structure bottle mouth sealing assembly of type IV hydrogen storage cylinder with good sealing performance and easy molding according to claim 1 is characterized in that: The anti-rotation groove (116) and the locking groove (117) are both located on the bottom end surface of the BOSS structure (111); and the connecting portion (118) is located on the outer side of the bottom of the BOSS structure (111).

3. The BOSS structure bottle mouth sealing assembly of type IV hydrogen storage cylinder with good sealing performance and easy molding according to claim 2 is characterized in that: The anti-rotation groove (116) is an annular groove structure, and a group of anti-rotation grooves (116) are coaxially arranged along the central axis of the BOSS structure (111).

4. The BOSS structure bottle mouth sealing assembly of type IV hydrogen storage cylinder with good sealing performance and easy molding according to claim 2 is characterized in that: The card slots (117) are arc-shaped waist-shaped slot structures, and a group of card slots (117) are arranged at intervals along the central axis of the BOSS structure (111) in a circumferential manner.

5. The BOSS structure bottle mouth sealing assembly of type IV hydrogen storage cylinder with good sealing performance and easy molding according to claim 2 is characterized in that: The connecting portion (118) is in a step-like structure with a bottom extending outward.

6. The BOSS structure bottle mouth sealing assembly of type IV hydrogen storage cylinder with good sealing performance and easy molding according to any one of claims 1 to 5, characterized in that: The BOSS structure (111) is provided with a through hole structure along the axial direction, and the inner side of the through hole is provided with an annular groove (114); the outer side thereof is provided with an external thread (113) threadedly connected to the trailer tube plate and a rotation-stopping platform (115) for stopping the BOSS structure (111) and the plastic liner (121) from rotating.

7. The BOSS structure bottle mouth sealing assembly of type IV hydrogen storage cylinder with good sealing performance and easy molding according to claim 6 is characterized in that: The plastic liner (121) is located at the lower part of the BOSS structure (111), and the upper part of the plastic liner (121) is located in the through hole of the BOSS structure (111); the upper part of the plastic liner (121) is a tapered structure, and the inner wall of the through hole of the BOSS structure (111) is provided with a tapered structure that is interference-fitted with the tapered structure of the upper part of the plastic liner (121); the upper part of the plastic liner (121) is provided with a rubber protrusion that matches with an annular groove (114) in the BOSS structure (111).

8. The BOSS structure bottle mouth sealing assembly of type IV hydrogen storage cylinder with good sealing performance and easy molding according to claim 7 is characterized in that: The main body of the end cover (101) is arranged in a through-hole structure in the BOSS structure (111) by screwing, and its lower part is tightly fitted and inserted into the upper part of the plastic liner (121); a limiting structure is provided at the upper end of the main body, and the limiting structure is abutted against the upper end surface of the BOSS structure (111); an external thread structure (103) matching with the internal thread (112) is provided on the outer side of the main body, and a through-hole and an internal thread structure (102) coaxial with the main body are provided inside the main body.

9. The BOSS structure bottle mouth sealing assembly of type IV hydrogen storage cylinder with good sealing performance and easy molding according to claim 8 is characterized in that: A sealing structure is provided between the contact surface between the limiting structure of the end cover (101) and the upper end surface of the BOSS structure (111), and between the contact surface between the main body of the end cover (101) and the upper part of the plastic liner (121).

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