Bottle opening structure of high-pressure IV type hydrogen storage bottle

Abstract

The invention belongs to the field of processing of pressure containers and high polymer materials, and particularly relates to a bottle opening structure of a high-pressure IV type hydrogen storage bottle. The invention provides a bottle opening structure design scheme of the high-pressure IV type hydrogen storage bottle, designs a sealing ring with a special section and a sealing mode, and improves the sealing performance of the hydrogen storage bottle under a high-pressure condition through a method of guiding a gas sealing direction. In order to solve the sealing installation problem and the like, various BOSS and inner plug combined installation modes are designed. And meanwhile, by reducing the metal thickness of the BOSS edge, the deformation coordination of the plastic-metal-carbon fiber composite material is improved, the stress concentration problem of the inner container under the high-pressure condition is weakened, and the service life of the hydrogen storage bottle is prolonged.

Description

Technical Field

[0001] The invention relates to the field of pressure vessels and polymer material processing, in particular to a bottle mouth structure of a high-pressure IV type hydrogen storage bottle. Background Art

[0002] Type IV hydrogen storage bottles are researched and developed due to their advantages such as high hydrogen storage density, resistance to hydrogen embrittlement, and low cost. As one of the core components of Type IV hydrogen storage bottles, the service performance of the plastic liner is the key to affecting the overall service life of the hydrogen storage bottle. At present, Type IV hydrogen storage bottles range from a few liters for drones to thousands of liters for tube bundle container storage. The volume span is large and the size effect is very obvious. In addition, the large deformation caused by high pressure also poses challenges to the stress-strain behavior of the hydrogen storage bottle liner, especially at structural mutation locations such as the head and at the intersection of structures of different materials. Therefore, it is necessary to design a structure that reduces stress concentration.

[0003] More importantly, high-pressure hydrogen storage is the key to improving the hydrogen storage density and efficiency of hydrogen storage bottles during gaseous hydrogen storage. However, the higher the pressure, the greater the challenge of sealing the bottle mouth. This is mainly because the plastic liner will deform due to high-pressure compression, long-term aging, creep, etc. within the operating temperature range and high-pressure conditions of the hydrogen storage bottle, which will lead to seal failure. The higher the operating temperature and the higher the pressure level, the greater the risk of seal failure. Therefore, it is necessary to design a bottle mouth sealing structure. Summary of the invention

[0004] In response to the above needs, the present invention innovatively proposes a bottle mouth structure design scheme for high-pressure type IV hydrogen storage bottles, which improves the sealing performance of hydrogen storage bottles under high-pressure conditions by limiting plastic deformation, special structural sealing ring sealing, cone sealing, metal-plastic interference fit, etc. At the same time, by reducing the metal thickness at the edge of the bottle mouth BOSS, the deformation coordination of the plastic-metal-carbon fiber composite is improved, the stress concentration problem of the liner under high-pressure conditions is reduced, and the service life of the hydrogen storage bottle is increased.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] The bottle mouth structure of the high-pressure IV type hydrogen storage bottle of the present invention comprises a metal BOSS, a plastic part of an inner liner, an inner plug and a sealing ring.

[0007] The metal BOSS of the present invention includes, starting from the inner thread of the bottle mouth, the following parts:

[0008] A. An internal fixing groove is used to fix the plastic to prevent the shrinkage of the plastic during cooling, which may lead to metal-plastic peeling. The cross section of the internal fixing groove is preferably a trapezoidal structure with a wide bottom and a narrow mouth. As an alternative structure, it can be designed as a parallelogram structure, and the hypotenuse forms an obtuse angle with the inner direction of the inner liner axis.

[0009] B. A straight tube structure used for radial sealing, and the height of the straight tube is at least greater than the maximum cross-sectional width of the inner sealing ring or the sealing groove corresponding to the inner sealing ring.

[0010] C. The sealing cone surface structure used for cone surface sealing has a larger outer surface and a smaller inner surface relative to the inner shell.

[0011] D. A radial-axial conical surface structure for radial and axial double sealing, wherein the radial-axial conical surface structure is smaller on the outside and larger on the inside relative to the inner shell.

[0012] E. After the transition to the inner surface of the BOSS web, an internal stress-reducing groove is designed, which is mainly used to reduce the excessive internal stress of the plastic on the inner surface of the web after molding shrinkage, which causes the plastic to crack. Then, through an external cone structure, the metal thickness at the edge of the BOSS web is reduced, so that it can deform more easily, resulting in more coordinated deformation of the liner plastic, the metal BOSS web edge, and the carbon fiber composite material. In the thinner position of the web, an external stress-reducing groove can be selectively designed. In addition, on the inner surface of the web, a rotation-stop groove is designed at a suitable position to prevent the plastic liner and the metal BOSS from rotating.

[0013] F. An external fixing groove is designed on the outer side of the edge of the BOSS web. The external fixing groove is designed as a rectangular groove. After the inner liner is formed, the plastic and metal can be prevented from peeling off because of the material limit filled into the external fixing groove. Alternatively, the external fixing groove can be designed as a triangle or other cross-section. Preferably, the smaller the external fixing groove is designed, the better. If the metal and plastic can be controlled not to be separated by the process during the inner liner molding, it is preferred not to design an external fixing groove.

[0014] The plastic liner of the bottle mouth structure of the high-pressure IV type hydrogen storage bottle of the present invention is preferably directly molded on the metal BOSS. Alternatively, a plastic liner compatible with the metal BOSS can be first molded, and then the BOSS can be installed on the plastic liner by gluing, threading or forced installation.

[0015] The sealing ring of the present invention is preferably a sealing ring of a special-shaped structure, and the cross section of the sealing ring is custom-molded. The preferred sealing ring includes the following cross-section types.

[0016] A. The inner sealing ring is a conical sealing ring with a "7"-shaped cross section. The smaller diameter position of the conical surface of the inner sealing ring is preferably designed as a larger rectangular cross section, or it can be designed as a rectangle closer to the outside and a semicircle closer to the inside. The cross section of the transition section from the small diameter to the large diameter of the inner sealing ring is preferably designed as a rectangle, and the radial thickness of the rectangular cross section at this position must be smaller than the radial thickness of the rectangle at the position of the small diameter conical surface. At the bottom of the cone, where the diameter is the largest, the cross section is designed as a triangular cross section, and the top of the triangular cross section adopts a rounded transition. The outer conical surface of the inner sealing ring cannot have a gradient and must be smooth. When installing the inner sealing ring, it must be ensured that the cone angle of the inner sealing ring is facing outward along the axis of the inner liner; and after the inner sealing ring is installed, the outer surface of the inner sealing ring must be in close contact with the inner liner, and the outer conical surface tends to be compressed into a straight cylindrical surface.

[0017] B. The outer sealing ring is also a conical sealing ring. Its cross-sectional structure and sealing principle are basically similar to those of the inner sealing ring. Figure 2 As shown, the original dotted line position is extruded into the shape after installation.

[0018] As an alternative, the sealing ring of the present invention can be replaced by a sealing ring with a conventional circular cross-section, T-section, X-section, U-section, V-section, etc.

[0019] The inner plug of the present invention is designed to be used in testing. When the hydrogen storage bottle is in service, the sealing structure of the inner plug position remains unchanged and is replaced by various valves. Preferably, the inner plug is manufactured as a medium for connecting various bottle valves with BOSS, so that various valves are sealed with the metal part of the inner plug, and the inner plug ensures the sealing of the plastic part of the inner liner.

[0020] The specific installation and sealing method of BOSS and the inner plug described in the present invention is as follows: after the inner liner is formed, the sealing surface is first processed according to the design size. The inner sealing ring and the outer sealing ring are sequentially installed in the sealing ring groove of the inner plug from the thread of the inner plug to the inside. The inner plug is fixed to the BOSS through the thread. After the inner plug is fixed to the BOSS, the inner sealing ring is located at the straight tube structure of the BOSS radial seal. The inner plug-inner liner contact surface between the inner sealing ring and the inner plug-BOSS connecting thread is preferably designed as a transition fit or an interference fit. As a further preferred embodiment, the inner plug-inner liner contact surface between the inner sealing ring and the inner plug-BOSS connecting thread can be closely matched with a conical surface. As a preferred embodiment, the sealing groove of the inner sealing ring is designed to match the shape of the inner sealing ring, and after the inner plug is fixed, the smaller thickness of the inner sealing ring is designed to be a clearance fit with the inner plug, guiding the high-pressure gas into the "7"-shaped cross section, and pressing the sealing ring and the plastic liner. At the corresponding position of the BOSS sealing cone structure between the inner sealing ring and the outer sealing ring, a metal-plastic-metal cone compression matching method is adopted, which can form a certain cone sealing effect and control the plastic deformation to prevent the plastic from rapid axial deformation or large stress during rapid hydrogen charging and discharging.

[0021] Based on the above sealing structure solution, as an alternative, the positions of the inner sealing ring and the outer sealing ring are replaced with sealing rings with circular cross-section, T-section, X-section, U-section or V-section, and straight face sealing or conical face sealing is used at the corresponding position. Single replacement or full replacement is within the design scope of the present invention. The metal-plastic at other positions adopts transition fit.

[0022] As an optimized sealing solution, the contact position of the BOSS with the plastic liner is coated to make the plastic and metal firmly bonded, or the surface of the metal BOSS is pickled or ionized to create more micro-nano-scale micropores, which promotes the stable connection between plastic and metal and prevents large metal-plastic relative slip. At this time, even if the plastic creeps, a part of the plastic will remain bonded to the metal, improving the sealing performance.

[0023] As a further optimized sealing solution, a sealing groove is machined at the plastic terminal position on the BOSS, and the terminal plastic at the connection between the inner liner and the BOSS is used as a retaining ring. The terminal plastic is located at the bottom of the sealing groove, the plastic terminal sealing ring is installed in the middle of the sealing groove, and a sintered ceramic block for the sealing groove is installed on the upper part of the sealing groove. A sintered ceramic block for the inner plug is embedded in the inner plug corresponding to the sealing groove.

[0024] The above-mentioned sintered ceramic blocks all adopt a petal structure for easy installation. The sintered ceramic blocks are required to have a porous and breathable structure and have higher deformation resistance and strength than plastics, so as to guide the gas to squeeze the sealing ring in the direction of the terminal plastic and limit the displacement of the sealing ring in other directions. The sintered ceramic can also be replaced by other metal powder sintered blocks, such as aluminum alloy powder sintered blocks, as long as they have the above-mentioned capabilities.

[0025] As an alternative solution, the corresponding position of the BOSS sealing cone structure between the original inner sealing ring and the outer sealing ring still maintains the metal-plastic-metal cone pressing matching mode, and removes the outer sealing ring and its inner plug corresponding structure, and is modified so that the tail end of the inner plug directly presses the plastic at the sealing cone structure to form an inner plug metal-plastic-BOSS metal sealing structure. In the inner plug metal-plastic-BOSS metal sealing structure, the inner plug metal and plastic can be sealed in the inner plug arc-plastic cone or inner plug cone-plastic cone.

[0026] As an alternative solution, the BOSS sealing cone structure between the original inner sealing ring and the outer sealing ring is removed, and the inner sealing ring and the outer sealing ring are directly used as two sealing methods.

[0027] In order to optimize sealing and installation, three connection schemes between the inner plug and the BOSS are designed. The following content is only an explanation of the structural changes of the inner plug and the BOSS. Among the relevant sealing schemes, the above-mentioned inner sealing ring, outer sealing ring sealing scheme, and conical metal-plastic-metal sealing scheme are still applicable.

[0028] As a deformed structural design scheme, BOSS is changed to an assembled structure, including a BOSS base and a BOSS extension. After the BOSS base and the BOSS extension are assembled, their internal structural shape is consistent with the main structural shape of the original BOSS. When the inner tank is formed, the BOSS base is first installed in the mold, and the plastic is molded on the BOSS base. Preferably, the top plastic covers the BOSS base at the top position of the BOSS base. After molding, the top plastic shrinks due to cooling and hugs the BOSS base; and during the hydrogen storage service process, the top plastic coated at the top position of the BOSS base can form a self-tightening seal because the deformation direction is inconsistent with the plastic deformation direction of the inner surface of the BOSS base. After the inner tank is cooled, the sealing surface is cut out according to the requirements of sealing and installation. The extension sealing ring is installed on the BOSS extension, and then the BOSS base and the BOSS extension are fixed by threaded connection. After the BOSS base and the BOSS extension are fixed, the extension sealing ring is pressed against the plastic to improve the sealing effect. At this time, the inner plug is fixedly connected to the BOSS extension piece by a thread, and the inner plug and the plastic are preferably sealed by an outer sealing ring substitute with a circular cross section. The outer sealing ring substitute is also a rubber sealing ring. Alternatively, the sealing relationship between the outer sealing ring substitute and the plastic is changed to a sealing relationship between the outer sealing ring and the plastic, and the outer sealing ring is used for sealing. If necessary, a BOSS sealing ring is used to seal between the BOSS base and the BOSS extension piece.

[0029] As a modified structural design, the BOSS extension piece and the inner plug are combined into a special-shaped inner plug. The inner liner is formed and sealed in the same way as above.

[0030] As a deformed structural design scheme, the special-section inner plug is designed as a split inner plug, including an inner plug seal and an inner plug fixing. The inner liner 3 in this scheme is formed and processed in the same way as above. During installation, the inner plug seal is first inserted axially into the plastic inner liner, and the sealing ring is in contact with the plastic; further, the inner plug seal is fixed by threading the inner plug fixing and the BOSS base to form a stable sealing structure to prevent the seal from shifting due to rotation during installation or large-area scratching between the seal and the plastic of the inner liner.

[0031] The present invention proposes a bottle mouth structure design scheme for a high-pressure type IV hydrogen storage bottle, designs a sealing ring with a special cross-section and a sealing method, and improves the sealing performance of the hydrogen storage bottle under high-pressure conditions by guiding the gas sealing direction. In view of the installation problem of the seal, a variety of combined installation methods of BOSS and inner plugs are designed. At the same time, by reducing the metal thickness of the BOSS edge, the deformation coordination of the plastic-metal-carbon fiber composite is improved, the stress concentration problem of the inner liner under high-pressure conditions is reduced, and the service life of the hydrogen storage bottle is increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a schematic diagram of the main structure design of the connection between the bottle mouth structure and the inner liner of the high-pressure IV type hydrogen storage bottle of the present invention.

[0033] Figure 2 It is a schematic diagram of the preferred sealing structure of the bottle mouth structure and the BOSS edge structure details of the high-pressure type IV hydrogen storage bottle of the present invention.

[0034] Figure 3 It is a schematic diagram of an alternative solution after replacing the sealing ring of the preferred sealing structure of the bottle mouth structure of the high-pressure IV type hydrogen storage bottle of the present invention.

[0035] Figure 4 A schematic diagram of a further preferred detailed sealing structure of the plastic terminal of the bottle mouth structure of the high-pressure IV type hydrogen storage bottle of the present invention.

[0036] Figure 5 It is an alternative solution after simplifying the preferred sealing structure of the bottle mouth structure of the high-pressure IV type hydrogen storage bottle of the present invention.

[0037] Figure 6 This is another alternative solution after simplifying the preferred sealing structure of the bottle mouth structure of the high-pressure IV type hydrogen storage bottle of the present invention.

[0038] Figure 7 This is the first alternative connection scheme between the inner plug of the bottle mouth structure of the high-pressure IV type hydrogen storage bottle of the present invention and the BOSS.

[0039] Figure 8 This is a second alternative connection scheme between the inner plug of the bottle mouth structure of the high-pressure IV type hydrogen storage bottle of the present invention and the BOSS.

[0040] Fig. 9 This is a third alternative connection scheme between the inner plug of the bottle mouth structure of the high-pressure IV type hydrogen storage bottle of the present invention and BOSS.

[0041] 1-Metal BOSS; 101-BOSS extension; 102-BOSS base; 10201-Top plastic; 2-Inner plug; 3-Plastic liner; 301-Sealing cone structure; 302-Inner plug-liner contact surface; 303-External fixing groove; 304-External stress relief groove; 305-Internal stress relief groove; 306-Stop groove; 307-External cone structure; 308-BOSS plate edge; 309-Internal fixing Groove; 3010-straight cylinder structure; 3011-radial-axial cone structure; 4-inner sealing ring; 5-outer sealing ring; 501-outer sealing ring replacement; 6-plastic terminal sealing ring; 601-terminal plastic; 602-sintered ceramic block for sealing groove; 603-sintered ceramic block for inner plug; 7-extension sealing ring; 8-BOSS sealing ring; 9-special-section inner plug; 901-inner plug seal; 902-inner plug fixing. DETAILED DESCRIPTION

[0042] like Figure 1 As shown, the bottle mouth structure of the high-pressure IV type hydrogen storage bottle of the present invention includes a metal BOSS 1, an inner plug 2, a plastic part 3 of the inner liner and a sealing ring.

[0043] like Figure 2 As shown, the metal BOSS1 of the present invention includes, starting from the inner thread of the bottle mouth, the following:

[0044] A. An internal fixing groove 309 used to fix the plastic to prevent the plastic from shrinking during cooling and causing metal-plastic peeling. The cross-section of the internal fixing groove 309 is preferably a trapezoidal structure with a wide bottom and a narrow mouth.

[0045] B. A straight tube structure 3010 for radial sealing, wherein the height of the straight tube 3010 is at least greater than the maximum cross-sectional width of the inner sealing ring 4 or the sealing groove corresponding to the inner sealing ring 4.

[0046] C. A sealing cone surface structure 301 for cone surface sealing. The sealing cone surface structure 301 is larger on the outside and smaller on the inside relative to the inner shell.

[0047] D. A radial-axial conical surface structure 3011 for radial and axial double sealing, wherein the radial-axial conical surface structure 3011 is smaller on the outside and larger on the inside relative to the inner shell.

[0048] E. After transitioning to the inner surface of the BOSS web, an internal stress relief groove 305 is designed. The internal stress relief groove 305 is preferably an inverted trapezoidal structural section, and can also be designed as a rectangular structure or a parallelogram structural section. When the metal BOSS1 is applied to rotational molding, the width of the narrow side of the internal stress relief groove 305 is preferably greater than the groove depth, and the groove depth is further preferably less than 5mm, and the narrow side width of the trapezoidal section is greater than 8mm; when the metal BOSS1 is applied to injection molding, the internal stress relief groove 305 is preferably deeper than 3 times the narrow side width, providing a sealing effect while providing a stress relief effect. Then the inner surface of the BOSS web is reduced through an outer conical structure 307 to reduce the metal thickness of the BOSS web edge 308, so that it can be deformed more easily, resulting in more coordinated deformation of the plastic liner 3, the metal BOSS web edge 308 and the carbon fiber composite material. The outer conical structure 307 is preferably designed at an angle less than 40°. At the thinner position of the metal BOSS web, an external stress relief groove 304 can be selectively designed. The cross-sectional structure of the outer stress-reducing groove 304 and the cross-sectional structure of the inner stress-reducing groove 305 can be designed to be the same structure or different structures. Figure 1 As shown, on the inner surface of the metal BOSS web, a stop groove 306 is designed at a suitable position to prevent the plastic liner and the metal BOSS1 from rotating. The stop groove 306 is preferably designed as a rectangular cross-section structure, and is rotated on the inner surface of the metal BOSS web with the central axis of the insert as the axis. All the stop grooves 306 cannot be connected to form a complete annular groove. The stop groove 306 can be processed axially symmetrically on a circle with the central axis of the insert as the axis, or it can be processed on multiple circles with the central axis of the insert as the axis, and the occupied angle can be designed to be axially symmetrical.

[0049] F. An external fixing groove 303 is designed on the outside of the BOSS web edge 308. The external fixing groove 303 is designed as a rectangular groove. After the plastic liner 3 is formed, the plastic and metal can be prevented from peeling off because of the material limit filled into the external fixing groove 303. Alternatively, the external fixing groove 303 can be designed as a triangle or other cross-section. Preferably, the smaller the external fixing groove 303 is designed, the better. If the metal and plastic can be controlled not to be separated by the process during the molding of the liner, it is preferred not to design the external fixing groove 303.

[0050] The plastic liner 3 of the bottle mouth structure of the high-pressure type IV hydrogen storage bottle of the present invention is preferably directly molded on the metal BOSS1. Alternatively, it is also possible to first mold a plastic liner 3 that is compatible with the metal BOSS1, and then install the metal BOSS1 on the plastic liner 3 by gluing, threading or forced installation.

[0051] The sealing ring of the present invention is preferably a sealing ring of a special-shaped structure, and the cross section of the sealing ring is custom-molded. The preferred sealing ring includes the following cross-section types.

[0052] A. The inner sealing ring 4 is a conical sealing ring with a "7"-shaped cross section. The smaller diameter position of the conical surface of the inner sealing ring 4 is preferably designed as a larger rectangular cross section, and can also be designed as a rectangle closer to the outside and a semicircle closer to the inside. The cross section of the transition section from the small diameter to the large diameter of the inner sealing ring 4 is preferably designed as a rectangle, and the radial thickness of the rectangular cross section at this position must be smaller than the radial thickness of the rectangle at the position of the small diameter conical surface. At the bottom of the cone, that is, the position with the largest diameter, the cross section is designed as a triangular cross section, and the top of the triangular cross section adopts a rounded transition. The outer conical surface of the inner sealing ring 4 must not have a gradient and must be smooth. When installing the inner sealing ring 4, it must be ensured that the cone angle of the inner sealing ring 4 is outward along the axis of the inner liner; and after the inner sealing ring 4 is installed, the outer surface of the inner sealing ring 4 must be in close contact with the inner liner, and the outer conical surface tends to be compressed into a straight cylindrical surface.

[0053] B. The outer sealing ring 5 is also a conical sealing ring, and its cross-sectional structure and sealing principle are basically similar to those of the inner sealing ring 4. Figure 2 As shown, the original dotted line position is extruded into the shape after installation.

[0054] As an alternative, the sealing ring of the present invention can be replaced by a sealing ring with a conventional circular cross-section, T-section, X-section, U-section, V-section, etc.

[0055] The specific installation and sealing method of the metal BOSS1 and the inner plug 2 described in the present invention is: after the inner liner 3 is formed, the sealing surface is first processed according to the design size. The inner sealing ring 4 and the outer sealing ring 5 are installed in the sealing ring groove of the inner plug 2 inward from the thread of the inner plug 2. The inner plug 2 is fixed to the metal BOSS1 through threads. After the inner plug 2 is fixed to the metal BOSS1, the inner sealing ring 4 is located at the straight cylinder structure 3010 of the BOSS radial seal. The inner plug-inner liner contact surface 302 between the inner sealing ring 4 and the inner plug-BOSS connecting thread is preferably designed as a transition fit or an interference fit. As a further preferred embodiment, the inner plug-inner liner contact surface 302 between the inner sealing ring 4 and the inner plug-BOSS connecting thread can use a conical surface for a tight fit. Preferably, the sealing groove of the inner sealing ring 4 is designed to match the shape of the inner sealing ring 4, and after the inner plug 2 is fixed, the smaller thickness of the inner sealing ring 4 is designed to be clearance-matched with the inner plug 2, guiding the high-pressure gas into the "7"-shaped cross section, and pressing the sealing ring 4 and the plastic liner 3. At the corresponding position of the BOSS sealing cone structure 301 between the inner sealing ring 4 and the outer sealing ring 5, a metal-plastic-metal cone surface pressing matching mode is adopted, which can form a certain cone surface sealing effect and control the deformation of the plastic, preventing the plastic from rapidly deforming in the axial direction or generating large stress during rapid hydrogen charging and discharging.

[0056] Based on the above sealing structure solution, as an alternative, Figure 3As shown, the positions of the inner seal ring 4 and the outer seal ring 5 are replaced with seal rings with circular cross-section, T-section, X-section, U-section or V-section, and straight face seals or conical face seals are used at the corresponding positions. Single replacement or full replacement is within the design scope of the present invention. The metal-plastic at other positions adopts transition fit.

[0057] As an optimized sealing solution, the contact position of the metal BOSS1 with the plastic liner 3 is coated to make the plastic and metal firmly bonded, or a large number of micro-nano-scale micropores are created on the surface of the metal BOSS1 by pickling or ionization, so as to promote the stable connection between the plastic and the metal and prevent the generation of large metal-plastic relative slip. At this time, even if the plastic creeps, a part of the plastic will remain bonded to the metal, thereby improving the sealing performance.

[0058] As a further optimized sealing solution, Figure 4 As shown, a sealing groove is machined at the plastic terminal position on the metal BOSS1, and the terminal plastic 601 at the connection between the inner liner 3 and the metal BOSS1 is used as a retaining ring. The terminal plastic 601 is located at the bottom of the sealing groove, the plastic terminal sealing ring 6 is installed in the middle of the sealing groove, and a sintered ceramic block 602 for the sealing groove is installed on the upper part of the sealing groove. A sintered ceramic block 603 for the inner plug 2 is embedded in the inner plug 2 corresponding to the sealing groove.

[0059] As an alternative, Figure 5 As shown, the corresponding position of the BOSS sealing cone structure 301 between the original inner sealing ring 4 and the outer sealing ring 5 still maintains the metal-plastic-metal cone pressing matching mode, and the outer sealing ring 5 and its inner plug corresponding structure are removed, and the tail end of the inner plug 2 is modified to directly press the plastic at the sealing cone structure 301 to form an inner plug metal-plastic-BOSS metal sealing structure. In the inner plug metal-plastic-BOSS metal sealing structure, the inner plug metal and plastic can be sealed in the inner plug arc-plastic cone or inner plug cone-plastic cone.

[0060] As an alternative, Figure 6 As shown, the BOSS sealing cone structure 301 between the original inner sealing ring 4 and the outer sealing ring 5 is removed, and the two sealing modes of the inner sealing ring 4 and the outer sealing ring 5 are directly used.

[0061] Preferably, the rubber ring pressing positions of the inner sealing ring 4 and the outer sealing ring 5 should avoid the position of the groove and other structures, and the distance between the inner sealing ring 4 and the outer sealing ring 5 and the edge of the groove structure is preferably greater than 2 mm. The distance between the inner sealing ring 4 and the outer sealing ring 5 is preferably greater than 5 mm.

[0062] In order to optimize sealing and installation, three connection schemes between the inner plug 2 and BOSS1 are designed. The following content is only used as an explanation of the structural changes of the inner plug 2 and BOSS1. Among the relevant sealing schemes, the above-mentioned inner sealing ring 4, outer sealing ring 5 sealing scheme, and conical metal-plastic-metal sealing scheme are still applicable.

[0063] As a modified structural design, Figure 7 As shown, BOSS is changed into an assembled structure, including a BOSS base 102 and a BOSS extension 101. After the BOSS base 102 and the BOSS extension 101 are assembled, their internal structural shape is consistent with the main structural shape of the original metal BOSS1. When the inner liner is formed, the BOSS base 102 is first installed in the mold, and the plastic is molded on the BOSS base 102. Preferably, the top plastic 10201 covers the BOSS base 102 at the top position of the BOSS base 102. After molding, the top plastic 10201 hugs the BOSS base 102 due to cooling and shrinkage; and during the hydrogen storage service process, the top plastic 10201 coated at the top position of the BOSS base 102 can form a self-tight seal because the deformation direction is inconsistent with the deformation direction of the plastic on the inner surface of the BOSS base 102. After the inner liner 2 is cooled, the sealing surface is cut out according to the requirements of sealing and installation. The extension piece sealing ring 7 is installed on the BOSS extension piece 101, and then the BOSS base 102 and the BOSS extension piece 101 are fixed by threaded connection. After the BOSS base 102 and the BOSS extension piece 101 are fixed, the extension piece sealing ring 7 is pressed against the plastic to improve the sealing effect. At this time, the inner plug 2 is fixedly connected to the BOSS extension piece 101 by threads, and the inner plug 2 and the plastic are preferably sealed with an outer sealing ring substitute 501 with a circular cross-section. The outer sealing ring substitute 501 is also a rubber sealing ring. Alternatively, the sealing relationship between the outer sealing ring substitute 501 and the plastic is changed to a sealing relationship between the outer sealing ring 5 and the plastic, and the outer sealing ring 5 is used for sealing. If necessary, the BOSS base 102 and the BOSS extension piece 101 are sealed with a BOSS sealing ring 8.

[0064] As a modified structural design, Figure 8 As shown, the BOSS extension piece 101 and the inner plug 2 are combined and designed as an integral special-section inner plug 9. The molding method and sealing method of the inner liner 3 are consistent with the above.

[0065] As a modified structural design, Fig. 9As shown, the special-shaped cross-section inner plug 9 is designed as a split inner plug, including an inner plug seal 901 and an inner plug fixing 902. The inner liner 3 is formed and processed in the present solution in the same manner as described above. During installation, the inner plug seal 901 is first axially inserted into the plastic inner liner 3, and the sealing ring is brought into contact with the plastic; further, the inner plug seal 901 is fixed by threading the inner plug fixing 902 with the BOSS base 102 to form a stable sealing structure, thereby preventing the seal from shifting due to rotation during installation or large-area scratching between the seal and the plastic of the inner liner 3.

[0066] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. The mouth structure of the high-pressure IV type hydrogen storage bottle is characterized by: The bottle mouth structure includes a metal BOSS, a plastic part of an inner liner, an inner plug, and a sealing ring; the metal BOSS, starting from the inner thread of the bottle mouth, includes: an internal fixing groove for fixing the plastic to prevent the shrinkage of the plastic during cooling and causing metal-plastic peeling; a straight cylinder structure for radial sealing; a sealing cone structure for conical sealing, the sealing cone structure is larger on the outside and smaller on the inside relative to the inner liner; a radial-axial cone structure for radial and axial double sealing, the radial-axial cone structure is smaller on the outside and larger on the inside relative to the inner liner; after the transition to the inner surface of the BOSS web, an internal stress relief groove is designed, and then an outer cone structure is used to reduce the metal thickness of the BOSS web edge so that it can be deformed more easily; at the thinner position of the web, An external stress-reducing groove is selectively designed; a rotation-stop groove is designed on the inner surface of the web to prevent the plastic liner and the metal BOSS from rotating; an external fixing groove is designed on the outer side of the web edge of the BOSS; the installation and sealing method of the bottle mouth structure is as follows: after the liner is formed, a sealing surface is first processed according to the designed size; the inner sealing ring and the outer sealing ring are sequentially installed in the sealing ring groove of the inner plug from the thread of the inner plug inward; the inner plug is fixedly connected to the BOSS through the thread; after the inner plug is fixedly connected to the BOSS, the inner sealing ring is located at the straight cylinder structure of the BOSS radial seal; the inner plug-inner liner contact surface between the inner sealing ring and the inner plug-BOSS connecting thread is preferably designed as a transition fit or an interference fit; as a further preferred embodiment, the inner sealing ring and the inner plug-BOSS connecting thread are preferably designed as a transition fit or an interference fit. The inner plug-inner liner contact surface between the connecting threads can be closely matched with a conical surface; preferably, the sealing groove of the inner sealing ring is designed to match the shape of the inner sealing ring, and after the inner plug is fixed, the smaller thickness of the inner sealing ring is designed to be a clearance fit with the inner plug to guide the high-pressure gas into the "7"-shaped cross-section and compress the sealing ring and the plastic liner; the corresponding position of the BOSS sealing cone structure between the inner sealing ring and the outer sealing ring adopts a metal-plastic-metal cone-surface compression matching method, which can form a certain cone-surface sealing effect and control the deformation of the plastic to prevent the plastic from rapidly deforming in the axial direction or generating large stress during rapid hydrogen charging and discharging; the inner stress-reducing groove is preferably an inverted trapezoidal structural cross-section, and can also be designed as a rectangular structure or a parallelogram. Structural cross section; and when the BOSS is applied to rotational molding, the width of the narrow side of the internal stress-reducing groove is preferably greater than the groove depth, and the groove depth is further preferably less than 5mm, and the narrow side width of the trapezoidal cross section is greater than 8mm; when the BOSS is applied to injection molding, the groove depth is preferably greater than 3 times the narrow side width, providing a sealing effect while providing stress relief; the outer cone structure is preferably designed at an angle less than 40°; the cross-sectional structure of the external stress-reducing groove and the cross-sectional structure of the internal stress-reducing groove can be designed to be the same structure or different structures; the anti-rotation groove is preferably designed to be a rectangular cross-sectional structure, and is rotated on the inner surface of the BOSS plate with the central axis of the insert as the axis; all anti-rotation grooves cannot be connected to form a complete annular groove;The anti-rotation groove can be processed axially symmetrically on a circle with the central axis of the insert as the axis, or can be processed on multiple circles with the central axis of the insert as the axis, and the occupied angle can be designed to be axially symmetrical. ; 2. The bottle mouth structure of the high-pressure IV type hydrogen storage bottle according to claim 1 is characterized in that: A sealing groove is processed at the plastic terminal position on the BOSS, and the terminal plastic at the connection between the inner liner and the BOSS is used as a retaining ring; the terminal plastic is located at the bottom of the sealing groove, the plastic terminal sealing ring is installed in the middle of the sealing groove, and a sintered ceramic block for the sealing groove is installed on the upper part of the sealing groove; a sintered ceramic block for the inner plug is embedded in the inner plug corresponding to the sealing groove; the sintered ceramic blocks all adopt a petal structure for easy installation; the sintered ceramic blocks are required to have a porous and breathable structure, and have higher deformation resistance and strength than plastics; the sintered ceramics can also be replaced by other metal powder sintered blocks, such as aluminum alloy powder sintered blocks, as long as they have the above-mentioned capabilities.

3. The bottle mouth structure of the high-pressure IV type hydrogen storage bottle according to claim 1 is characterized in that: The sealing ring is preferably a sealing ring of a special-shaped structure, and the cross-section of the sealing ring is custom-molded, including an inner sealing ring and an outer sealing ring; the inner sealing ring is a conical sealing ring with a "7"-shaped cross-section; the smaller diameter position of the conical surface of the inner sealing ring is preferably designed as a larger rectangular cross-section, and can also be designed as a rectangle close to the outside and a semicircle close to the inside; the cross-section of the transition section from the small diameter to the large diameter of the inner sealing ring is preferably designed as a rectangle, and the radial thickness of the rectangular cross-section at this position must be less than the radial thickness of the rectangle at the position of the small diameter conical surface; at the bottom of the conical surface, that is, the position with the largest diameter, its cross-section is designed as a triangular cross-section, and the top of the triangular cross-section adopts a rounded transition; the outer conical surface of the inner sealing ring cannot have a gradient and must be smooth; when installing the inner sealing ring, it must be ensured that the cone angle of the inner sealing ring is outward along the axis of the inner liner; and after the inner sealing ring is installed, the outer surface of the inner sealing ring must be in close contact with the inner liner, and the outer conical surface tends to be compressed into a straight cylindrical surface; the outer sealing ring is also a conical sealing ring, and its cross-sectional structural shape and sealing principle are basically similar to those of the inner sealing ring.

4. The bottle mouth structure of the high-pressure IV type hydrogen storage bottle according to claim 1 is characterized in that: The positions of the inner sealing ring and the outer sealing ring are replaced with sealing rings with circular cross-section, T-section, X-section, U-section or V-section, and straight face seals or conical face seals are used at the corresponding positions; single replacement or full replacement is within the design scope of the present invention; metal-plastic at other positions adopts transition fit.

5. The bottle mouth structure of the high-pressure IV type hydrogen storage bottle according to claim 1 is characterized in that: One or more sealing methods can be selected for use at different locations.

6. The bottle mouth structure of the high-pressure IV type hydrogen storage bottle according to claim 1 is characterized in that: The contact position of the BOSS with the plastic liner is coated to make the plastic and metal firmly bonded, or by pickling or ionizing the surface of the metal BOSS to create more micro-nano-scale micropores, thereby promoting a stable connection between the plastic and the metal.

7. The bottle mouth structure of the high-pressure IV type hydrogen storage bottle according to claim 1 is characterized in that: The inner plug is designed to be used during testing; when the hydrogen storage bottle is in service, the sealing structure of the inner plug position remains unchanged and is replaced by various valve components; preferably, the inner plug is manufactured as a medium for connecting various bottle valves with BOSS, so that the various valve components are sealed with the metal part of the inner plug, and the inner plug ensures the sealing of the plastic part of the inner liner.

8. The bottle mouth structure of the high-pressure IV type hydrogen storage bottle according to claim 1 is characterized in that: The cross section of the internal fixing groove is preferably a trapezoidal structure with a wide bottom and a narrow mouth; as an alternative structure, it can be designed as a parallelogram structure, and the hypotenuse forms an obtuse angle with the inward direction of the axis of the inner liner.

9. The bottle mouth structure of the high-pressure IV type hydrogen storage bottle according to claim 1 is characterized in that: The external fixing groove is designed as a rectangular groove; alternatively, the external fixing groove can be designed as a triangular or other shaped cross-section; preferably, the external fixing groove is designed to be as small as possible. If the metal-plastic can be controlled not to come apart during the molding of the inner liner through the process, it is preferred not to design an external fixing groove.

10. The bottle mouth structure of the high-pressure IV type hydrogen storage bottle according to claim 1 is characterized in that: Either the inner plug or the BOSS is changed into an assembled structure; the inner sealing ring, outer sealing ring sealing scheme, and the conical metal-plastic-metal sealing scheme in the original claim 1 are still applicable; in the alternative scheme, the BOSS can be changed into an assembled structure, including a BOSS base and a BOSS extension; after the BOSS base and the BOSS extension are assembled, their internal structural shape is consistent with the main structural shape of the original BOSS; when the inner tank is formed, the BOSS base is first installed in the mold, and the plastic is molded on the BOSS base; preferably, the top plastic covers the BOSS base at the top position of the BOSS base; after molding, the top plastic holds the BOSS base tightly due to cooling and shrinkage; and during the hydrogen storage service process, the top plastic coated at the top position of the BOSS base can form a self-tightening seal because the deformation direction of the top plastic is inconsistent with the deformation direction of the plastic on the inner surface of the BOSS base.

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