Double-thread IV-type hydrogen storage bottle opening structure

Abstract

The invention relates to the technical field of hydrogen storage bottles, and discloses a double-thread IV-type hydrogen storage bottle opening structure which comprises an inner container, the inner container is divided into a head, a shoulder and a bottle body, the shoulder is connected with the head and the bottle body, the head, the shoulder and the bottle body are of an integrally-formed structure, the head of the inner container is of an annular structure, and the bottle body is of an annular structure. Inner container internal threads are arranged on the inner side of the head portion, inner external threads are arranged on the outer side of the head portion, and the inner container internal threads and the inner container external threads are the same in thread pitch and rotation direction. The bottle opening comprises a bottle opening body, an annular threaded groove is formed in the bottle opening body, a lap joint piece is integrally formed on the bottle opening body, when the bottle opening body and the head of the inner container are installed in a matched mode, the annular threaded groove is in threaded connection through the inner threads of the inner container and the outer threads of the inner container, and the lap joint piece is matched with the shoulder of the inner container in a shape-following mode. Inner container internal threads and inner container external threads in the inner container are in threaded connection with the inner side and the outer side of the annular threaded groove in the bottle opening correspondingly, and double-thread meshing sealing is achieved.

Description

Technical Field

[0001] This invention relates to the field of hydrogen storage cylinder technology, and more specifically, to a double-threaded Type IV hydrogen storage cylinder mouth structure. Background Technology

[0002] Hydrogen-powered vehicles rely on hydrogen as their energy source. The chemical energy released through the hydrogen reaction is converted into mechanical energy, which then powers the vehicle. Although hydrogen's energy density is far greater than gasoline's, reaching three times that of gasoline, its low density means that the energy provided per unit volume of hydrogen is not significant at room temperature and pressure. To increase hydrogen's energy density at room temperature, high-pressure hydrogen storage technology is currently the primary method. Hydrogen storage cylinders have undergone four generations of innovation, from the initial steel cylinders (Type I), to carbon fiber-wound steel liners (Type II), then to carbon fiber-wound aluminum liners (Type III), and finally to the latest Type IV cylinders with carbon fiber-wound plastic liners. Besides automobiles, hydrogen storage cylinders can also be used in emergency power supplies and other scenarios requiring energy storage.

[0003] Fiber winding is a unique continuous molding technology. Resin-impregnated continuous fibers are wound onto an inner liner according to a specific pattern, and then cured to form the finished product. This process is particularly suitable for rotationally symmetrical structures such as circular pipes or storage tanks. Its advantage lies in its ability to be molded in one step, ensuring the product's accuracy in size and shape. Because inflation and deflation operations are involved, carbon fiber composite materials cannot cover the bottle neck area, so the neck needs to be reinforced with metal (commonly known as BOSS) and connected to the inner liner made of polymer material.

[0004] Currently, numerous inventions have emerged regarding the connection structure between the metal BOSS and the plastic inner liner of Type IV hydrogen storage cylinders. For example, Chinese patent ZL201510440522.8 employs an interference fit and conical surface structure design to achieve an expansion-tight sealing connection; Chinese patent ZL202010437023.4 uses a combination of threaded connection and sealing ring for sealing; Chinese patents ZL201910446895.4, ZL201820469616.7, and ZL202021451880.1 all adopt an inward-folding plastic inner liner structure design; and Chinese patent CN 215174104U demonstrates a BOSS structure suitable for fiber-wound hydrogen storage cylinders with plastic inner liners. Although existing BOSS structure designs for hydrogen storage cylinders are diverse, their sealing effect and bonding strength still require further improvement and refinement. Summary of the Invention

[0005] The purpose of this invention is to provide a double-threaded Type IV hydrogen storage cylinder mouth structure to solve the problems existing in the prior art. The double-threaded interlocking seal is achieved by connecting the inner thread and outer thread of the inner liner to the inner and outer threads of the annular thread groove in the bottle mouth.

[0006] To achieve the above objectives, the present invention provides the following solution: The present invention provides a double-threaded Type IV hydrogen storage cylinder mouth structure, comprising: an inner liner, the inner liner being divided into a head, a shoulder, and a body, the shoulder connecting the head and the body, the head, shoulder, and body being an integrally formed structure, the head of the inner liner being an annular structure, and the inner side of the head having an inner thread, and the outer side of the head having an inner external thread, the pitch and direction of the inner thread and the inner external thread being the same; and a bottle mouth, comprising a bottle mouth body, the bottle mouth body having an annular threaded groove, the bottle mouth body being integrally formed with an overlapping member, when the bottle mouth body is fitted and installed with the head of the inner liner, the annular threaded groove being threadedly connected through the inner thread and the inner external thread, and the overlapping member being conformally fitted to the shoulder of the inner liner.

[0007] Furthermore, the inner side of the annular threaded groove is provided with an internal thread for the bottle mouth, and the outer side is provided with an external thread for the bottle mouth. When the head is connected to the bottle mouth, the internal thread for the bottle mouth is adapted to the internal thread for the inner liner, and the external thread for the bottle mouth is adapted to the external thread for the inner liner.

[0008] Furthermore, the shoulder edge is provided with a snap-fit, and the edge of the overlapping piece is provided with an outer edge, which is interference-fitted with the snap-fit.

[0009] Furthermore, a sealing material is filled between the top of the head and the top of the annular threaded groove.

[0010] Furthermore, the top of the bottle mouth body is an upper end face, and a discharge hole is also provided on the upper end face. The bottom of the discharge hole is connected to the top of the annular threaded groove.

[0011] Furthermore, a blind hole is provided on the annular wall of the head, and a positioning hole is provided on the upper end face.

[0012] Furthermore, a positioning pin is provided between the head of the inner liner and the annular threaded groove, and the positioning pin passes through the positioning hole and the blind hole.

[0013] Furthermore, the top is provided with an external hydrogen refueling nozzle, which is threadedly connected to an external hydrogen refueling gun.

[0014] Furthermore, the inner liner and the outer side of the bottle opening are wrapped with carbon fiber composite material.

[0015] The present invention discloses the following technical effects:

[0016] The inner liner has an inner thread and an outer thread on its inner and outer sides respectively. The inner thread and the outer thread are connected to the inner and outer sides of the annular thread groove at the top of the bottle mouth. The inner liner and the bottle mouth are connected by a double thread structure, which enhances the sealing between the inner liner and the bottle mouth. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0019] Figure 2 This is a schematic diagram of the inner liner structure in this invention;

[0020] Figure 3 This is a cross-sectional view of the inner liner in this invention;

[0021] Figure 4 This is a schematic diagram of the bottle opening structure in this invention;

[0022] Among them, 1. Inner liner; 2. Bottle mouth; 3. Sealing material; 4. Positioning pin; 5. Carbon fiber composite material; 6. Outer edge; 11. Inner liner internal thread; 12. Inner liner external thread; 13. Blind hole; 14. Bayonet; 15. Shoulder; 16. Head; 17. Bottle body; 21. Bottle mouth external thread; 22. Discharge hole; 23. External hydrogen refueling nozzle; 24. Bottle mouth internal thread; 25. Positioning hole; 26. Upper end face; 27. Lower end face; 28. Overlapping piece. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] like Figures 1-4As shown, the present invention provides a double-threaded Type IV hydrogen storage cylinder mouth structure, comprising: an inner liner 1, the inner liner 1 being divided into a head 16, a shoulder 15, and a body 17, the shoulder 15 connecting the head 16 and the body 17, the head 16, shoulder 15, and body 17 being an integrally formed structure, the head 16 being an annular structure, the inner side of the head 16 being provided with an inner liner inner thread 11, and the outer side of the head 16 being provided with an inner liner outer thread 12; the pitch and direction of the inner liner inner thread 11 and the inner liner outer thread 12 are the same; and a bottle mouth 2, comprising a bottle mouth body, the bottle mouth body having an annular threaded groove inside, and an integrally formed overlapping member 28 outside the bottle mouth body, when the bottle mouth body is fitted and installed with the head 16, the annular threaded groove is threadedly connected through the inner liner inner thread 11 and the inner liner outer thread 12, and the overlapping member 28 is conformally fitted to the shoulder 15 of the inner liner 1.

[0026] The inner liner 1 is made of high molecular polymer and serves to isolate gas. The inner thread 11 and the outer thread 12 of the inner liner are threads with the same pitch and direction.

[0027] like Figure 4 As shown, the inner side of the annular threaded groove is provided with an internal thread 24 for the bottle mouth, and the outer side is provided with an external thread 21 for the bottle mouth. When the bottle mouth 2 and the head 16 are installed, the internal thread 24 of the bottle mouth is adapted to the internal thread 11 of the inner liner, and the external thread 21 of the bottle mouth is adapted to the external thread 12 of the inner liner.

[0028] The bottle neck 2 is a metal neck, preferably made of 6061 aluminum, 7060 steel, or 316 stainless steel. The bottle neck 2 has an annular threaded groove, and the head 16 is connected to the top of the annular threaded groove. The internal thread 24 and external thread 21 of the bottle neck are aligned with the pitch and direction of the internal thread 11 and external thread 12 of the inner liner. The inner liner 1 and the bottle neck 2 are connected by a double-threaded connection formed by the internal thread 11 and external thread 12 of the inner liner and the internal thread 24 and external thread 21 of the bottle neck, achieving a seal between the inner liner 1 and the bottle neck 2 through thread engagement. When hydrogen leaks from the bottle neck 2, it will first penetrate the inside of the head 16 and then escape through the outside. When hydrogen enters the inside, the high pressure difference between the inside and outside of the bottle causes it to squeeze the inner liner 1 outwards, thereby strengthening the fit between the external thread 12 of the inner liner and the external thread 21 of the bottle neck, thus enhancing the seal.

[0029] like Figure 3 As shown, the inner liner 1 has a snap 14 on the edge of the shoulder 15, and the bottle mouth 2 has an outer edge 6 on the edge of the overlapping part. When the bottle mouth 2 is connected to the inner liner 1, the outer edge 6 and the snap 14 are interference fit, so that the overlapping part 28 and the shoulder 15 can be smoothly transitioned on the surface.

[0030] During installation, the head 16 is threaded into the annular threaded groove in the bottle mouth 2, and the outer edge 6 of the bottle mouth 2 lap joint 28 is snapped into the snap 14 of the shoulder 15 of the inner liner 1.

[0031] A sealing material 3 is filled between the top of the head 16 and the top of the annular thread groove. In this embodiment, the sealing material 3 is a thermosetting resin, silicone or other curing sealing material 3. Since hydrogen has the characteristics of small molecules and strong diffusion ability, and the pressure difference between the inside and outside of the hydrogen storage bottle is large, hydrogen molecules can easily escape from the threaded meshing gap. The sealing material 3 is filled between the metal bottle mouth 2 and the polymer material inner liner 1 to strengthen the seal.

[0032] The upper end face 26 is provided with positioning holes 25 and discharge holes 22. There are several positioning holes 25 and discharge holes 22. In this embodiment, the number is set to 2-6, which are evenly distributed on the upper end face 26. The specific number is determined according to the pitch and the size of the bottle mouth 2. The positioning holes 25 and discharge holes 22 penetrate the upper end face 26 and are connected to the annular thread groove. The diameter of the positioning holes 25 and discharge holes 22 is the same. Before the positioning pin 4 is inserted, the positioning holes 25 and discharge holes 22 are used to discharge air and excess glue.

[0033] Because of the small thread engagement gap and the good airtightness of the filling sealant 3, the internal air cannot be discharged during the tightening process of the double thread structure, which easily forms air bubbles in the sealant 3, thereby affecting the mechanical strength, fatigue resistance and airtightness of the sealant 3 after curing. Therefore, a positioning hole 25 and a discharge hole 22 are provided on the upper end face 26 to facilitate the timely discharge of air and excess uncured sealant 3.

[0034] A blind hole 13 is provided on the annular wall of the head 16, which corresponds to the positioning hole 25. A positioning pin 4 is driven into the positioning hole 25 and the blind hole 13 to prevent the inner liner 1 from moving with the bottle mouth 2. For vehicle hydrogen storage cylinders, it is also necessary to prevent the relative sliding between the inner liner 1 and the bottle mouth 2 caused by long-term bumps to avoid affecting the strength and sealing of the bottle mouth 2. Therefore, in this embodiment, the positioning pin 4 is used to position the inner liner 1 and the bottle mouth 2 to prevent relative sliding between the inner liner 1 and the bottle mouth 2.

[0035] An external hydrogen refueling nozzle 23 is provided at the center of the top of the bottle mouth 2. The external hydrogen refueling nozzle 23 penetrates the top of the bottle mouth 2. The inner wall of the external hydrogen refueling nozzle 23 is provided with threads for connecting to an external hydrogen refueling gun or hydrogen refueling tube.

[0036] The inner liner 1 and the outer side of the bottle mouth 2 are wrapped with carbon fiber composite material 5, and the carbon fiber composite material 5 is wrapped around the outer side of the bottle mouth 2 and the inner liner 1 and then thermoset.

[0037] In this embodiment, before installation, the upper end face 26 of the bottle mouth 2 faces downward and the lower end face 27 faces upward. The discharge hole 22 and the positioning hole 25 are externally sealed. Uncured sealing material 3 is poured into the annular threaded groove. Air in the sealing material is removed by methods such as standing, vibration, and ultrasound. Preferably, the sealing material 3 is a thermosetting expansion material. After the wall product is formed, air bubbles are avoided at the discharge hole 22 and other positions filled with sealing material 3. Keeping the bottle mouth 2 still, the inner liner 1 is screwed into the bottle mouth 2. During the screwing process, the discharge hole 22 is opened to allow excess adhesive to flow out. The overlapping part 28 of the bottle mouth 2 and the inner liner are connected. After the shoulder 15 of the inner liner 1 contacts, continue screwing the inner liner 1 in so that the positioning hole 25 is aligned with the blind hole 13. At this time, the shoulder 15 of the inner liner 1 and the overlapping part 28 of the bottle mouth 2 are interference-fitted. The positioning pin 4 is driven into the positioning hole 25 and the blind hole 13 to complete the fixation between the inner liner 1 and the bottle mouth 2. The positioning hole 25 and the discharge hole 22 are sealed at the upper end face 26 of the bottle mouth 2. Preferredly, the thermosetting temperature of the filling sealing material 3 should be higher than the thermosetting temperature of the carbon fiber composite material 5 used for winding. The heat setting of the bottle mouth 2 is carried out first to ensure the connection between the inner liner 1 and the bottle mouth 2. Then the carbon fiber composite material 5 is wound and heat-set.

[0038] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0039] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A double-threaded type IV hydrogen storage cylinder mouth structure, comprising an inner liner (1), characterized in that, include: The inner liner (1) is divided into a shoulder (15), a head (16), and a bottle body (17). The shoulder (15) connects the head (16) and the bottle body (17). The head (16), shoulder (15), and bottle body (17) are integrally formed. The head (16) is a ring structure. The inner side of the head (16) is provided with an inner thread (11), and the outer side of the head (16) is provided with an inner thread (12). The pitch and direction of the inner thread (11) and the inner thread (12) are the same. The bottle mouth (2) includes a bottle mouth body, an annular threaded groove is provided in the bottle mouth body, and an overlapping part (28) is integrally formed on the outside of the bottle mouth body. When the bottle mouth body is fitted and installed with the head (16), the annular threaded groove is threadedly connected by the inner thread (11) and the outer thread (12) of the inner liner, and the overlapping part (28) is fitted to the shoulder (15) according to its shape.

2. The double-threaded type IV hydrogen storage cylinder neck structure according to claim 1, characterized in that: The inner side of the annular threaded groove is provided with an internal thread (24) for the bottle mouth, and the outer side is provided with an external thread (21) for the bottle mouth. When the head (16) is connected to the bottle mouth (2), the internal thread (24) for the bottle mouth is adapted to the internal thread (11) of the inner liner, and the external thread (21) for the bottle mouth is adapted to the external thread (12) of the inner liner.

3. The double-threaded type IV hydrogen storage cylinder neck structure according to claim 2, characterized in that: The shoulder (15) has a snap-fit ​​(14) at its edge, and the overlapping part (28) has an outer edge (6) at its edge, with the outer edge (6) and the snap-fit ​​(14) being interference fit.

4. The type IV hydrogen storage cylinder neck structure with double threads according to claim 1, characterized in that: The top of the head (16) and the top of the annular threaded groove are filled with sealing material (3).

5. The double-threaded type IV hydrogen storage cylinder neck structure according to claim 1, characterized in that: The top of the bottle mouth body is an upper end face (26), and an outlet hole (22) is also provided on the upper end face (26). The bottom of the outlet hole (22) is connected to the top of the annular threaded groove.

6. The type IV hydrogen storage cylinder neck structure with double threads according to claim 1, characterized in that: A blind hole (13) is provided on the annular wall of the head (16), and a positioning hole (25) is provided on the upper end face (26).

7. The type IV hydrogen storage cylinder neck structure with double threads according to claim 6, characterized in that: A positioning pin (4) is provided between the head (16) and the annular threaded groove, and the positioning pin (4) passes through the positioning hole (25) and the blind hole (13).

8. The double-threaded type IV hydrogen storage cylinder neck structure according to claim 1, characterized in that: The top is provided with an external hydrogen refueling nozzle (23), which is threadedly connected to an external hydrogen refueling gun.

9. The double-threaded type IV hydrogen storage cylinder neck structure according to claim 1, characterized in that: The inner liner (1) and the bottle mouth (2) are wrapped with carbon fiber composite material (5).

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