A sealing reinforcing structure and reinforcing method between a cylinder valve seat and a plastic liner of a type IV cylinder

Abstract

This invention relates to a sealing reinforcement structure and method for a valve seat and plastic inner liner of a Type IV gas cylinder. The invention includes a valve seat; a plastic inner liner with an annular groove at its end cap, the valve seat being fitted into the annular groove; a sealing ring disposed between the valve seat and the plastic inner liner to form a radial seal; and a reinforcing ring embedded in the annular groove and located near the sealing ring, to improve the local structural rigidity of the connection area between the valve seat and the plastic inner liner, suppress creep deformation of the plastic inner liner under high pressure, and maintain the sealing stability of the sealing ring. This invention solves the problems of decreased sealing performance and insufficient local rigidity caused by plastic creep, improving the sealing reliability and long-term durability of the gas cylinder under high-pressure conditions.

Description

Technical Field

[0001] This invention relates to the field of pressure vessel technology, and in particular to a sealing reinforcement structure and reinforcement method for the valve seat and plastic inner liner of a Type IV gas cylinder. Background Technology

[0002] The main structure of a Type IV gas cylinder typically includes a valve seat, a plastic inner liner, and a fiber winding layer. The valve seat is generally made of metal to meet the requirements for connection strength and pressure resistance under high-pressure conditions. The plastic inner liner is usually made of materials such as nylon PA6 or high-density polyethylene (HDPE) to balance lightweight requirements and molding process needs.

[0003] The valve seat is used to connect the external valve to the plastic inner liner. The valve seat and the plastic inner liner also work together to seal the gas cylinder, typically achieved by pressing a sealing ring together. Existing sealing methods mainly include axial sealing and radial sealing.

[0004] In addition, the end cap of the plastic liner is usually designed with a groove structure, and an assembly interface adapted to the bottle valve seat is reserved at the end of the end cap to realize the assembly connection between the bottle valve seat and the end cap, while ensuring assembly accuracy and connection stability. In order to improve the structural strength of local areas, some existing products also have a reinforcing ring inside the plastic liner to enhance the support capacity of the plastic liner near the bottle mouth or sealing area.

[0005] However, existing technologies still have the following shortcomings: First, plastic inner liner is prone to creep under long-term high-pressure conditions, which causes the initial preload of the sealing ring to gradually decrease, thus affecting the sealing stability and potentially causing leakage problems in severe cases.

[0006] Secondly, the existing reinforcement structure between the bottle valve seat and the plastic inner liner, especially the external reinforcement structure, while improving local strength, may create additional potential leakage paths, which is not conducive to improving the overall sealing reliability.

[0007] Third, during the high-pressure injection molding process of the plastic inner liner, the reinforcing ring is prone to displacement or deformation, making it difficult to maintain it stably in the predetermined position, which in turn affects the reinforcing effect and the consistency and reliability of the subsequent sealing structure. Summary of the Invention

[0008] To address this, the present invention provides a sealing reinforcement structure and method for the valve seat and plastic inner liner of a Type IV gas cylinder. An annular groove is formed on the end cap of the plastic inner liner, and a sealing ring adapted to the groove is configured. Simultaneously, a reinforcing ring structure is added around the sealing ring to solve the problems of decreased sealing performance and insufficient local stiffness caused by plastic creep, thereby improving the sealing reliability and long-term durability of the gas cylinder under high-pressure conditions. By designing multiple fixing structures for the reinforcing rings and restricting their degrees of freedom, the displacement and deformation problems of the reinforcing rings in the high-pressure injection mold are solved, ensuring that the reinforcing rings are always in the designed position, playing their role in enhancing the stiffness of the sealing area, and further improving the sealing performance of the sealing structure and the product's service life.

[0009] To solve the above-mentioned technical problems, the present invention provides a sealing reinforcement structure between the valve seat and the plastic inner liner of a Type IV gas cylinder, comprising: Bottle valve seat; The plastic inner liner has an annular groove at its end cap, and the bottle valve seat is assembled in the annular groove. A sealing ring is disposed between the bottle valve seat and the plastic inner liner to form a radial seal; A reinforcing ring is embedded in the annular groove and located on the side close to the sealing ring to improve the local structural rigidity of the connection area between the bottle valve seat and the plastic inner liner, and to suppress the creep deformation of the plastic inner liner under high pressure and maintain the sealing stability of the sealing ring.

[0010] In one embodiment of the present invention, the reinforcing ring is a circular metal component, and the circular main structure of the reinforcing ring is completely covered by the material of the plastic inner liner.

[0011] In one embodiment of the present invention, the cross-section of the annular groove is Ω-shaped, and the groove wall of the annular groove can elastically deform toward the valve seat under the action of the internal pressure of the gas cylinder to increase the clamping force on the sealing ring and form a self-tightening seal.

[0012] In one embodiment of the invention, the contour of the reinforcing ring is adapted to the contour of the annular groove.

[0013] In one embodiment of the present invention, the reinforcing ring has a trumpet-shaped cross-section, with its large-diameter end facing outward from the plastic liner and its small-diameter end facing inward from the inner cavity of the plastic liner.

[0014] In one embodiment of the present invention, the large-diameter end of the reinforcing ring is provided with a plurality of positioning protrusions that are spaced apart circumferentially and protrude axially. The positioning protrusions are used to position and cooperate with the mold during the molding process of the plastic inner liner to limit the axial and radial displacement of the reinforcing ring during the molding process.

[0015] In one embodiment of the present invention, a plurality of elongated holes distributed circumferentially are provided in the transition area between the large-diameter end and the small-diameter end of the reinforcing ring, so as to increase the contact area and interfacial bonding force between the reinforcing ring and the plastic inner liner, and reduce the impact of the plastic melt on the reinforcing ring during the molding process.

[0016] In one embodiment of the present invention, the side of the reinforcing ring is provided with a plurality of reinforcing ribs spaced apart in the circumferential direction, and the reinforcing ribs are provided with grooves for forming an interlocking interface with the plastic liner. The side of the reinforcing ring facing the inside of the plastic liner is integrally provided with a plurality of positioning pins spaced apart in the circumferential direction, so as to limit the circumferential rotational displacement, axial displacement and radial deformation of the reinforcing ring during the molding process of the plastic liner.

[0017] In one embodiment of the present invention, the cross-section of the reinforcing rib is trapezoidal or rectangular; the cross-section of the groove is semi-circular or rectangular.

[0018] The present invention also provides a method for strengthening the seal between the valve seat and the plastic inner liner of a type IV gas cylinder, comprising: S1. Provide bottle valve seat, sealing ring and reinforcing ring, and provide reinforcing ring with a trumpet-shaped cross section according to structural design requirements, or provide reinforcing ring with reinforcing ribs on the side and a positioning pin on the side facing the inside of the plastic liner; S2. Arrange the reinforcing ring in the sealing reinforcement area corresponding to the plastic inner liner end cap, so that the reinforcing ring is located inside the subsequently formed annular groove and close to the location of the sealing ring; wherein, when a reinforcing ring with a trumpet-shaped cross-section is used, the positioning protrusion provided at the large diameter end of the reinforcing ring cooperates with the molding mold to position the reinforcing ring, thereby limiting the axial, radial, and circumferential rotational displacement of the reinforcing ring during the molding process; when a reinforcing ring with reinforcing ribs is used, the positioning pin cooperates with the molding mold to position the reinforcing ring, thereby limiting the circumferential rotational displacement, axial displacement, and radial deformation of the reinforcing ring during the molding process; S3. The plastic inner liner is formed by injection molding, rotational molding or blow molding process, so that the reinforcing ring is covered by the material of the plastic inner liner and embedded in the sealing area of ​​the end cap of the plastic inner liner; S4. An annular groove is formed at the end cap of the plastic inner liner; S5. Place the sealing ring between the bottle valve seat and the plastic inner liner, and assemble the bottle valve seat into the annular groove to form a radial seal; S6. By using the reinforcing ring embedded in the inner side of the annular groove and close to the sealing ring, the local structural rigidity of the connection area between the bottle valve seat and the plastic inner liner is improved, the influence of the creep of the plastic inner liner on the seal is reduced, and the sealing stability of the sealing ring is maintained.

[0019] The technical solution of the present invention has the following advantages compared with the prior art: This invention discloses a sealing reinforcement structure and method for the valve seat and plastic inner liner of a Type IV gas cylinder. The structure offers high sealing durability. By embedding a reinforcing ring into the plastic inner liner, the rigidity of the sealing area near the valve seat is enhanced, reducing the impact of plastic creep under high pressure on the cylinder's sealing performance. This means the structure used to compress the sealing ring is less prone to deformation, ensuring the compression and filling rates of the sealing ring meet design requirements, thereby improving sealing stability.

[0020] The reinforcing ring of this invention is encased in a plastic liner, completely isolating its main body from the hydrogen medium and preventing potential leakage paths. This embedded design improves both structural rigidity and the sealing performance of the gas cylinder.

[0021] The present invention designs the annular groove of the plastic inner liner end cap as "Ω" shape. This structure can work together with the reinforcing ring. The reinforcing ring improves the rigidity of the plastic inner liner in the sealing area, while the "Ω" shaped groove can produce slight deformation under the pressure inside the gas cylinder, pressing more tightly against the valve seat and ensuring the structural stability of the sealing area.

[0022] This invention improves the stability of high-pressure injection molding. By designing multiple methods for fixing the reinforcing ring, it achieves full-degree-of-freedom positioning of the reinforcing ring in the axial, radial, and circumferential directions, limiting the displacement of the reinforcing ring and reducing its deformation under high-pressure injection molding conditions, thereby increasing the rigidity of the plastic inner liner sealing area near the bottle valve seat.

[0023] This invention offers strong process adaptability and minimal impact on production efficiency. The newly added fixing methods comprehensively cover mainstream molding processes for Type IV gas cylinder plastic liners, such as injection molding, rotational molding, and blow molding. The fixing structure requires no additional complex production steps and can be directly adapted to existing production lines. Attached Figure Description

[0024] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0025] Figure 1 This is a schematic diagram of the sealing reinforcement structure between the valve seat and the plastic inner liner of a type IV gas cylinder according to Embodiment 1 of the present invention.

[0026] Figure 2 This is a schematic diagram of the sealing reinforcement structure between the valve seat and the plastic inner liner of a type IV gas cylinder according to Embodiment 2 of the present invention.

[0027] Figure 3 This is a schematic diagram of the sealing reinforcement structure between the valve seat and the plastic inner liner of a type IV gas cylinder according to Embodiment 3 of the present invention.

[0028] Explanation of reference numerals in the instruction manual: 1. Bottle valve seat; 2. Plastic inner liner; 3. Reinforcing ring; 4. Sealing ring; 5. Fiber winding layer; 6. Annular groove; 7. Positioning protrusion; 8. Injection channel; 9. Oblong hole; 10. Positioning pin; 11. Reinforcing rib. Detailed Implementation

[0029] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0030] In this invention, when directions (up, down, left, right, front, and back) are described, it is only for the convenience of describing the technical solution of this invention, and does not indicate or imply that the technical features referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0031] In this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," "exceeding," etc., are understood to exclude the stated number; "above," "below," "within," etc., are understood to include the stated number. In the description of this invention, the terms "first" and "second" are used only to distinguish technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0032] In this invention, unless otherwise explicitly defined, the terms "setting," "installing," and "connecting" should be interpreted broadly. For example, they can refer to a direct connection or an indirect connection through an intermediate medium; a fixed connection, a detachable connection, or an integrally formed connection; a mechanical connection, an electrical connection, or a connection capable of mutual communication; or the internal connection of two components or the interaction between two components. Those skilled in the art can reasonably determine the specific meaning of the above terms in this invention based on the specific content of the technical solution.

[0033] Example 1 like Figure 1 As shown, this embodiment provides a sealing reinforcement structure between the valve seat and the plastic inner liner for a type IV gas cylinder, including a valve seat 1, a plastic inner liner 2, a reinforcing ring 3, a sealing ring 4, and a fiber winding layer 5.

[0034] The cylinder valve seat 1 is a metal component, preferably a high-strength, pressure-resistant metal part. It has a through hole inside to connect the cylinder valve with the internal space of the plastic inner liner 2, so as to complete the filling and release of hydrogen. At the same time, the cylinder valve seat 1 also bears the local pressure-bearing and connection function of the cylinder opening area to ensure the structural stability of the vehicle-mounted hydrogen storage cylinder under high-pressure conditions.

[0035] The plastic inner liner 2 is preferably made of nylon PA6, high-density polyethylene HDPE, or other plastic materials suitable for high-pressure gas cylinder molding. The overall structure is preferably an integral molding of the end cap and cylindrical body, used to store hydrogen and provide an installation base for the cylinder valve seat 1. A fiber winding layer 5 is wound around the outside of the plastic inner liner 2, serving as the main pressure-bearing component of the gas cylinder. It is preferably formed of a carbon fiber and resin composite to balance high strength and lightweight requirements.

[0036] The end cap of the plastic inner liner 2 is provided with an annular groove 6, and the bottle valve seat 1 is assembled in the annular groove 6. A sealing ring 4 is provided between the bottle valve seat 1 and the plastic inner liner 2. The sealing ring 4 is preferably an O-ring rubber ring, which is used to form a radial seal between the bottle valve seat 1 and the plastic inner liner 2. Through this radial sealing method, a reliable high-pressure sealing interface can be formed between the bottle valve seat 1 and the plastic inner liner 2.

[0037] In this embodiment, the reinforcing ring 3 is embedded inside the annular groove 6 and located on the side close to the sealing ring 4. The reinforcing ring 3 is preferably a circular metal component, and its annular main structure is completely covered by the material of the plastic inner liner 2.

[0038] It should be noted that the reinforcing ring 3 is located in the sealed reinforcement area inside the plastic inner liner 2, rather than being exposed to the hydrogen storage medium, thereby isolating the main body of the reinforcing ring 3 from the hydrogen medium and avoiding the formation of new potential leakage paths due to the exposure of the reinforcement structure.

[0039] In this embodiment, the reinforcing ring 3 is disposed around the sealing ring 4 in the area where the valve seat 1 and the plastic inner liner 2 connect. Its main function is not simply as a connector, but to improve the local structural rigidity of this area. Because Type IV gas cylinders are subjected to high-pressure environments for extended periods, the plastic inner liner 2 is prone to creep in the sealing area at the bottle mouth, leading to a decrease in the preload of the sealing ring 4. By embedding the reinforcing ring 3 on the side close to the sealing ring 4, the deformation resistance of the plastic inner liner 2 in the sealing area can be significantly enhanced, thereby suppressing plastic creep under high pressure, maintaining the compression ratio and filling rate of the sealing ring 4 at the designed state, and ultimately improving sealing stability and durability.

[0040] Furthermore, such as Figure 1 As shown, the cross-section of the annular groove 6 is preferably Ω-shaped. Under the pressure inside the gas cylinder, the groove walls on both sides of the opening of the Ω-shaped annular groove 6 can undergo elastic deformation toward the valve seat 1, forming an additional pressing effect on the sealing ring 4, thereby forming a self-tightening seal.

[0041] It should be noted that in this embodiment, on the one hand, the sealing ring 4 forms the main seal, and on the other hand, the Ω-shaped annular groove 6 generates a small centripetal deformation under the action of internal pressure, which continuously compensates and presses the sealing ring 4; at the same time, the reinforcing ring 3 also provides rigidity support for the plastic area near the annular groove 6, so that the deformation of the annular groove 6 is kept within a reasonable range that is conducive to sealing, and the sealing failure is avoided due to material creep or local collapse.

[0042] Therefore, this embodiment uses a composite sealing enhancement mechanism through the coordinated operation of the reinforcing ring 3 and the Ω-shaped annular groove 6. The reinforcing ring 3 is responsible for maintaining local stiffness, while the Ω-shaped annular groove 6 is responsible for achieving auxiliary self-tightening under internal pressure. When the two work together, they can simultaneously take into account the initial assembly sealing performance and the sealing stability under long-term high-pressure conditions.

[0043] Preferably, the contour of the reinforcing ring 3 is adapted to the contour of the annular groove 6. This adaptation allows the reinforcing ring 3 to be more closely distributed in the sealing reinforcement area, which not only helps to improve the uniformity of local load bearing, but also helps to maintain the geometric stability and stress rationality of the annular groove 6, thereby further improving the long-term sealing performance and product service life between the bottle valve seat 1 and the plastic inner liner 2.

[0044] Therefore, this embodiment has at least the following beneficial effects: First, by embedding the reinforcing ring 3 and arranging it close to the sealing ring 4, the effect of creep 2 of the plastic inner liner on the seal can be effectively reduced, and the pre-tightening force of the sealing ring 4 can be prevented from weakening; Second, the annular main structure of the reinforcing ring 3 is completely covered by the plastic inner liner 2, and the main body is isolated from the hydrogen medium, reducing the risk of leakage from the source; Third, the Ω-shaped annular groove 6 and the reinforcing ring 3 work together to achieve a more stable self-tightening sealing effect under internal pressure, thereby improving the sealing reliability and long-term durability of the Type IV gas cylinder.

[0045] Example 2 like Figure 2 As shown, based on Example 1, this embodiment further provides a reinforcing ring 3 fixing structure suitable for high-pressure molding process. Unlike Example 1, the reinforcing ring 3 in this embodiment preferably has a trumpet-shaped cross-section, with its larger diameter end facing outwards from the plastic inner liner 2 and its smaller diameter end facing inwards from the inner cavity of the plastic inner liner 2.

[0046] The purpose of adopting the above-mentioned flared structure is twofold: firstly, by forming a gradual contour between the large-diameter end and the small-diameter end, the reinforcing ring 3 can better conform to the geometric transition shape of the end cap of the plastic inner liner 2, making it easier to adapt and arrange with the surrounding area of ​​the annular groove 6; secondly, the flared contour helps to expand the support range of the reinforcing ring 3 for the sealing area, so that the plastic area near the sealing ring 4 can obtain more stable rigidity support, thereby further reducing the impact of plastic creep on the sealing structure.

[0047] To address the potential displacement of the reinforcing ring 3 during high-pressure injection molding, rotational molding, or blow molding of the plastic inner liner 2, this embodiment provides several circumferentially spaced and axially protruding positioning protrusions 7 at the large-diameter end of the reinforcing ring 3. These positioning protrusions 7 engage with the mold during the molding process of the plastic inner liner 2 to limit the axial, radial, and circumferential rotational displacement of the reinforcing ring 3. In other words, before molding, the reinforcing ring 3 can be pre-fixed or supported at the corresponding position in the mold via the positioning protrusions 7, ensuring that the reinforcing ring 3 remains within the predetermined sealing and reinforcing area, preventing displacement under the impact of the flowing molten plastic.

[0048] Furthermore, several elongated holes 9 are provided in the transition area between the large-diameter end and the small-diameter end of the reinforcing ring 3, distributed circumferentially. The elongated holes 9 serve multiple functions. First, they increase the contact area between the reinforcing ring 3 and the plastic inner liner 2, thereby improving the interfacial bonding force and creating a more reliable mechanical bond between them. Second, molten plastic can enter the elongated holes 9 during molding, resulting in a more stable coating and anchoring effect. Third, the elongated holes 9 can also reduce the direct impact of the molten plastic on the reinforcing ring 3 during injection molding, allowing for smoother melt flow and reducing the risk of displacement or stress concentration of the reinforcing ring 3 due to localized fluid impact.

[0049] like Figure 2 As shown, the arrow indicates the injection direction. After the molten plastic enters the mold cavity through the injection channel 8, it flows along the cavity of the end cap of the plastic inner liner 2 and covers the reinforcing ring 3. During this process, the cooperation between the positioning protrusion 7 and the mold effectively restricts the axial and radial movement and circumferential rotation of the reinforcing ring 3, while the elongated hole 9 facilitates the passage and filling of the plastic fluid and promotes the formation of a strong interfacial bond. Therefore, the position retention capability and molding consistency of the reinforcing ring 3 under high-pressure injection molding conditions can be significantly improved.

[0050] In this embodiment, the annular main structure of the reinforcing ring 3 is completely covered by the material of the plastic inner liner 2. For the axially protruding positioning protrusion 7, in the specific process, it can be set as a temporary positioning structure located on the outside of the plastic inner liner 2 after molding, as needed. After the plastic inner liner 2 is molded and before the bottle valve seat 1 is installed, the exposed part can be processed to avoid affecting the subsequent assembly accuracy and sealing performance. It can also be understood that the positioning protrusion 7 is mainly used for positioning and limiting during the molding stage, and after its function is completed, its adverse effects on the appearance or assembly of the finished product can be eliminated through post-processing.

[0051] The beneficial effects of this embodiment are as follows: the cooperation of the trumpet-shaped reinforcing ring 3, the positioning protrusion 7, and the elongated hole 9 not only further improves the local rigidity of the sealing area, but also effectively solves the problems of axial displacement, radial and circumferential rotational displacement, and instability due to molten impact that easily occur in the reinforcing ring 3 during high-pressure molding. This allows the reinforcing ring 3 to be more accurately and stably embedded in the predetermined sealing reinforcement area. This ensures both the subsequent support effect of the reinforcing ring 3 on the surrounding area of ​​the sealing ring 4 and the structural and sealing consistency during mass production. At the same time, a good contour fit can still be formed between the trumpet-shaped reinforcing ring 3 and the Ω-shaped annular groove 6, thereby further improving the sealing performance and service life.

[0052] Example 3 like Figure 3 As shown, based on Embodiment 1, this embodiment further provides another fixing structure for the reinforcing ring 3. Unlike Embodiment 2, the reinforcing ring 3 (which is annular) in this embodiment has several reinforcing ribs 11 distributed circumferentially on its side, and several positioning pins 10 distributed circumferentially are integrally provided on the side of the reinforcing ring 3 facing the inside of the plastic inner liner 2.

[0053] The reinforcing ribs 11 are preferably evenly distributed along the circumference of the reinforcing ring 3, and their cross-section can be trapezoidal or rectangular. To further enhance the bonding relationship between the reinforcing ribs 11 and the plastic inner liner 2, grooves are provided on the reinforcing ribs 11, preferably grooves with a semi-circular or rectangular cross-section. When the molten plastic covers the reinforcing ring 3 during the molding process, the plastic material can fill into the grooves, thereby forming an interlocking interface between the reinforcing ribs 11 and the plastic inner liner 2. Through this interlocking interface, on the one hand, the contact area and interfacial bonding force between the reinforcing ring 3 and the plastic inner liner 2 can be increased, and on the other hand, the fixing ability of the reinforcing ring 3 to the mold can be significantly improved, thereby reducing the radial deformation and axial displacement of the reinforcing ring 3 in the high-pressure injection molding environment.

[0054] Furthermore, the positioning pin 10 is preferably located on the side of the reinforcing ring 3 facing the inside of the plastic inner liner 2, and is integrally formed with the reinforcing ring 3. The positioning pin 10 is used to position and engage with the mold during the molding process of the plastic inner liner 2, thereby limiting the circumferential rotational displacement and axial displacement of the reinforcing ring 3 during the molding process. Unlike Embodiment 2, which mainly limits axial and radial displacement, the positioning pin 10 in this embodiment focuses more on limiting the circumferential degree of freedom of the reinforcing ring 3, thereby preventing the reinforcing ring 3 from rotating and shifting during the molding process, and ensuring that the reinforcing rib 11 and each groove always remain in the predetermined position.

[0055] Combination Figure 3As can be seen, after the molten plastic enters through the injection channel 8, it flows along the cavity of the plastic inner liner 2 and covers the reinforcing ring 3, the reinforcing rib 11, and the positioning pin 10. Because the reinforcing rib 11 has a semi-circular groove, the molten plastic can form a stable mechanical engagement with it; simultaneously, the positioning pin 10 cooperates with the mold for positioning, effectively constraining the position of the reinforcing ring 3 in both the circumferential and axial directions. Through the combined action of the reinforcing rib 11 and the positioning pin 10, comprehensive constraints can be achieved on the reinforcing ring 3 in multiple degrees of freedom (circumferential, axial, and radial) during the molding process, thereby significantly improving the stability of the reinforcing ring 3 in high-pressure molding.

[0056] In this embodiment, the reinforcing rib 11 is preferably completely covered by the plastic inner liner 2 and does not come into direct contact with the hydrogen medium, thus avoiding the introduction of new leakage paths. Furthermore, since the reinforcing rib 11 is part of the embedded covering structure, it can be directly adapted to the mainstream molding process of existing Type IV gas cylinder plastic inner liners without adding complex manufacturing processes.

[0057] The beneficial effects of this embodiment are as follows: by setting the reinforcing rib 11, the semi-circular groove, and the positioning pin 10, not only can the interfacial bonding force between the reinforcing ring 3 and the plastic inner liner 2 be further increased, but the circumferential rotational displacement, axial displacement, and radial deformation of the reinforcing ring 3 during the molding process can also be comprehensively restricted, thereby ensuring that the reinforcing ring 3 is more stably positioned within the sealing reinforcement area. At the same time, the interlocking interface formed by the reinforcing rib 11 can also improve the uniformity of local force transmission, making the support of the reinforcing ring 3 for the surrounding area of ​​the sealing ring 4 more reliable. Therefore, this embodiment is particularly suitable for Type IV gas cylinder products with higher requirements for molding precision and long-life sealing performance.

[0058] Example 4 This embodiment provides a method for strengthening the seal between the valve seat and the plastic inner liner of a Type IV gas cylinder, corresponding to the sealing strengthening structure described in any of the preceding embodiments. The method includes the following steps: S1. Provide a bottle valve seat 1, a sealing ring 4, and a reinforcing ring 3, and select a suitable type of reinforcing ring 3 according to the structural design requirements. Specifically, a reinforcing ring 3 with a trumpet-shaped cross-section can be selected, or a reinforcing ring 3 with reinforcing ribs 11 on the side and a positioning pin 10 on the side facing the inside of the plastic inner liner 2 can be selected.

[0059] S2. Arrange the reinforcing ring 3 in the sealing reinforcement area corresponding to the end cap of the plastic inner liner 2, so that the reinforcing ring 3 is located inside the subsequently formed annular groove 6 and close to the location of the sealing ring 4. Specifically, when using a trumpet-shaped reinforcing ring 3, the positioning protrusion 7 at the large-diameter end of the reinforcing ring 3 cooperates with the molding mold for positioning, thereby limiting the axial, radial, and circumferential rotational displacement of the reinforcing ring 3 during the molding process; when using a reinforcing ring 3 with reinforcing ribs 11, the positioning pin 10 cooperates with the molding mold for positioning, thereby limiting the circumferential rotational displacement, axial displacement, and radial deformation of the reinforcing ring 3 during the molding process.

[0060] S3. The plastic inner liner 2 is formed using injection molding, rotational molding, or blow molding processes, so that the reinforcing ring 3 is covered by the material of the plastic inner liner 2 and embedded in the sealing area of ​​the end cap of the plastic inner liner 2. For different process routes, the embedding and covering of the reinforcing ring 3 can be completed without significantly changing the configuration of the existing mainstream production line, thus having good process adaptability.

[0061] S4. An annular groove 6 is formed at the end cap of the plastic inner liner 2. Preferably, the annular groove 6 is formed with an Ω-shaped cross-section so as to produce a self-tightening sealing effect during subsequent high-pressure use.

[0062] S5. Place the sealing ring 4 between the bottle valve seat 1 and the plastic inner liner 2, and assemble the bottle valve seat 1 into the annular groove 6 to form a radial sealing structure.

[0063] S6. By using the reinforcing ring 3 embedded in the inner side of the annular groove 6 and close to the sealing ring 4, the local structural rigidity of the connection area between the bottle valve seat 1 and the plastic inner liner 2 is improved, the creep of the plastic inner liner 2 is reduced to reduce the impact on the seal, and the sealing stability of the sealing ring 4 is maintained.

[0064] Using the above method, the reinforcing ring 3 can be stably positioned within the target sealing reinforcement area during the molding stage of the plastic inner liner 2. This solves both the problem of leakage paths potentially introduced by conventional external reinforcement structures and the problem of displacement and deformation of the reinforcing ring 3 during high-pressure molding. In particular, when the annular groove 6 adopts an Ω-shaped structure, the effect of the reinforcing ring 3 in improving local stiffness and the self-tightening effect of the annular groove 6 under internal pressure can form a stable fit, ultimately enabling the Type IV gas cylinder to possess excellent initial sealing performance, long-term high-pressure durability, and batch manufacturing consistency.

[0065] Example 5 In other alternative embodiments, the plastic inner liner 2 can be made of different plastic material systems, as long as it can meet the requirements of media resistance, formability, and strength under high-pressure hydrogen storage environment; the reinforcing ring 3 can be made of stainless steel, high-strength steel, aluminum alloy, or other metal materials that meet the strength requirements; the sealing ring 4, in addition to O-rings, can also be selected according to the groove shape of the valve seat 1 and the working conditions, and other sealing structures suitable for high-pressure hydrogen environment can be selected. In addition to preferably adopting an Ω shape, the annular groove 6 can also be adapted by adjusting the local rounded corners, groove depth, and groove width without departing from the core concept of the present invention, as long as it can still work together with the reinforcing ring 3 to improve sealing stability.

[0066] Furthermore, in Embodiments 2 and 3, the number and circumferential distribution of the positioning protrusions 7 and positioning pins 10, as well as the number and size of the reinforcing ribs 11, can be adjusted according to the bottle opening size, molding process parameters, and mold structure. For example, the positioning protrusions 7 and positioning pins 10 can be arranged in multiple equal parts along the circumference to achieve a more uniform positioning effect; the cross-sectional dimensions of the reinforcing ribs 11 can be optimized according to the required anchoring strength and plastic flow characteristics; the length direction, number of holes, and hole spacing of the elongated holes 9 can also be matched and set according to the plastic flow direction and local stress distribution. All of the above changes do not alter the basic principle of this invention: to improve the rigidity of the sealing area, reduce the creep effect of the plastic inner liner 2 on the sealing, and enhance long-term sealing performance through the embedded reinforcing ring 3.

[0067] In summary, this invention, by embedding a reinforcing ring 3 within the sealing area of ​​the plastic inner liner 2, and combining it with a sealing ring 4 and an annular groove 6, especially the self-tightening sealing characteristics of the Ω-shaped annular groove 6, forms a comprehensive technical solution that balances main sealing, auxiliary sealing, local reinforcement, and molding stability. This solution not only effectively improves the long-term sealing reliability between the bottle valve seat 1 and the plastic inner liner 2, but also avoids the leakage risks that may arise from traditional external reinforcement structures. Furthermore, it is well-suited for mainstream plastic inner liner molding processes such as injection molding, rotational molding, and blow molding, and has high engineering application value.

[0068] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A sealing reinforcing structure between a cylinder valve seat and a plastic liner for a type IV cylinder, characterized in that, include: Bottle valve seat (1); The plastic inner liner (2) has an annular groove (6) at its end cap, and the bottle valve seat (1) is assembled in the annular groove (6); A sealing ring (4) is disposed between the bottle valve seat (1) and the plastic inner liner (2) to form a radial seal; A reinforcing ring (3) is embedded in the annular groove (6) and located on the side close to the sealing ring (4) to improve the local structural rigidity of the connection area between the bottle valve seat (1) and the plastic inner liner (2), and to suppress the creep deformation of the plastic inner liner (2) under high pressure and maintain the sealing stability of the sealing ring (4).

2. The sealing reinforcement structure between the valve seat and the plastic inner liner of a Type IV gas cylinder according to claim 1, characterized in that, The reinforcing ring (3) is a circular metal component, and the circular main structure of the reinforcing ring (3) is completely covered by the material of the plastic inner liner (2).

3. The sealing reinforcement structure between the valve seat and the plastic inner liner of a Type IV gas cylinder according to claim 1, characterized in that, The cross-section of the annular groove (6) is Ω-shaped. The groove wall of the annular groove (6) can elastically deform towards the valve seat (1) under the action of the internal pressure of the gas cylinder, so as to increase the clamping force on the sealing ring (4) and form a self-tightening seal.

4. The sealing reinforcement structure between the valve seat and the plastic inner liner of a Type IV gas cylinder according to claim 1, characterized in that, The outline of the reinforcing ring (3) is adapted to the outline of the annular groove (6).

5. The sealing reinforcement structure between the valve seat and the plastic inner liner of a Type IV gas cylinder according to claim 1, characterized in that, The reinforcing ring (3) has a trumpet-shaped cross-section, with its large-diameter end facing outward from the plastic inner liner (2) and its small-diameter end facing inward from the inner cavity of the plastic inner liner (2).

6. The sealing reinforcement structure between the valve seat and the plastic inner liner of a type IV gas cylinder according to claim 5, characterized in that, The large-diameter end of the reinforcing ring (3) is provided with a number of positioning protrusions (7) that are spaced apart circumferentially and protrude axially. The positioning protrusions (7) are used to position and cooperate with the mold during the molding process of the plastic inner liner (2) to limit the axial and radial displacement of the reinforcing ring (3) during the molding process.

7. The sealing reinforcement structure between the valve seat and the plastic inner liner of a type IV gas cylinder according to claim 6, characterized in that, The transition area between the large-diameter end and the small-diameter end of the reinforcing ring (3) is provided with several elongated holes (9) distributed circumferentially to increase the contact area and interfacial bonding force between the reinforcing ring (3) and the plastic inner liner (2), and to reduce the impact of the plastic melt on the reinforcing ring (3) during the molding process.

8. The sealing reinforcement structure between the valve seat and the plastic inner liner of a type IV gas cylinder according to claim 2, characterized in that, The reinforcing ring (3) has several reinforcing ribs (11) spaced apart along the circumference on its side. The reinforcing ribs (11) have grooves for forming an interlocking interface with the plastic inner liner (2). The reinforcing ring (3) has several locating pins (10) spaced apart along the circumference on its side facing the inside of the plastic inner liner (2) to limit the circumferential rotational displacement, axial displacement and radial deformation of the reinforcing ring (3) during the molding process of the plastic inner liner (2).

9. The sealing reinforcement structure between the valve seat and the plastic inner liner of a type IV gas cylinder according to claim 8, characterized in that, The cross-section of the reinforcing rib (11) is trapezoidal or rectangular; the cross-section of the groove is semi-circular or rectangular.

10. A method for strengthening the seal between the valve seat (1) and the plastic inner liner (2) of a type IV gas cylinder, characterized in that, include: S1. Provide a bottle valve seat (1), a sealing ring (4) and a reinforcing ring (3), and provide a reinforcing ring (3) with a trumpet-shaped cross-section according to the structural design requirements, or provide a reinforcing ring (3) with reinforcing ribs (11) on the side and a positioning pin (10) on the side facing the inside of the plastic liner (2). S2. Arrange the reinforcing ring (3) in the sealing reinforcement area corresponding to the end cap of the plastic inner liner (2), so that the reinforcing ring (3) is located inside the subsequently formed annular groove (6) and close to the side where the sealing ring (4) is located; wherein, when a reinforcing ring (3) with a trumpet-shaped cross-section is used, the positioning protrusion (7) provided at the large diameter end of the reinforcing ring (3) is used to cooperate with the molding mold to position the reinforcing ring (3) to limit the axial displacement, radial displacement and circumferential rotation displacement of the reinforcing ring (3) during the molding process; when a reinforcing ring (3) with reinforcing ribs (11) is used, the positioning pin (10) is used to cooperate with the molding mold to position the reinforcing ring (3) to limit the circumferential rotation displacement, axial displacement and radial deformation of the reinforcing ring (3) during the molding process; S3. The plastic inner liner (2) is formed by injection molding, rotational molding or blow molding process, so that the annular main structure of the reinforcing ring (3) is covered by the material of the plastic inner liner (2) and embedded in the sealing area of ​​the head of the plastic inner liner (2); S4. An annular groove (6) is formed at the end cap of the plastic inner liner (2). S5. Place the sealing ring (4) between the bottle valve seat (1) and the plastic inner liner (2), and assemble the bottle valve seat (1) into the annular groove (6) to form a radial seal; S6. By using the reinforcing ring (3) embedded in the inner side of the annular groove (6) and close to the sealing ring (4), the local structural rigidity of the connection area between the bottle valve seat (1) and the plastic inner liner (2) is improved, the effect of the creep of the plastic inner liner (2) on the seal is reduced, and the sealing stability of the sealing ring (4) is maintained.

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