Sealing structure for type iv cylinder liner and type iv cylinder having same

Abstract

The present application relates to the technical field of pressure vessels, and discloses a sealing structure for a Type IV cylinder liner and a Type IV cylinder having same, said sealing structure comprising: a valve seat; an inner plug, mounted in an inner cavity of the valve seat, wherein the inner plug is sealingly engaged with the valve seat, a mounting space is provided between one end of the inner plug facing the inner side of the valve seat and the valve seat, the mounting space comprises a mounting gap and a wedging gap, and the wedging gap is arranged obliquely towards the valve seat relative to the mounting gap; and a plastic liner, mounted in the mounting space, wherein the plastic liner completely fills the mounting space.

Description

A four-type bottle inner liner sealing structure and a four-type bottle having the same structure. Technical Field

[0001] This application relates to the field of pressure vessel technology, and mainly to a sealing structure for the inner liner of a type 4 bottle and a type 4 bottle having the same structure. Background Technology

[0002] Type IV hydrogen fuel cell cylinders, also known as plastic-lined fiber-wound cylinders, typically use non-metallic materials for their inner liner, such as high-density polyethylene or polyethylene terephthalate (PET), while the outer layer is made of composite materials such as carbon fiber and epoxy resin. Due to their lightweight, good fatigue resistance, and high hydrogen storage density, Type IV cylinders are the primary type of cylinder used in hydrogen fuel cell vehicles. During manufacturing, the hollow inner liner is usually produced using rotational molding. Plastic powder is injected into a rotational molding mold, with valve seats installed at both ends. The mold is heated and tumbled to achieve a one-piece molding of the molten plastic and valve seats. The valve seats are used to connect valves and plugs, among other cylinder accessories. Because hydrogen storage cylinders require high energy density storage, the internal pressure is relatively high. Furthermore, the cylinder temperature changes rapidly during filling and discharging. The strong internal pressure and rapid temperature changes during filling place significant stress on the plastic inner liner and sealing rings. Under extreme temperature and pressure conditions, the plastic inner liner is prone to collapse and seal failure.

[0003] Application content

[0004] In view of this, this application provides a sealing structure for the inner liner of a Type 4 bottle and a Type 4 bottle having the same, in order to solve the problem in the prior art that the inner liner of a Type 4 bottle is prone to sealing failure such as plastic inner liner collapse and shrinkage under extreme temperature environment and ultra-high pressure.

[0005] In a first aspect, this application provides a four-type bottle inner liner sealing structure, comprising: a valve seat; an inner plug installed in the inner cavity of the valve seat, the inner plug sealingly engaging with the valve seat, an installation space reserved between the inner end of the inner plug facing the inner side of the valve seat and the valve seat, the installation space including an installation gap and a tightening gap, the tightening gap being inclined relative to the installation gap toward the valve seat; and a plastic inner liner installed within the installation space, the plastic inner liner completely filling the installation space.

[0006] Secondly, this application also provides a type four bottle having the type four bottle inner liner sealing structure described in this application. Attached Figure Description

[0007] To more clearly illustrate the technical solutions in this application 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 this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0008] Figure 1 is a schematic diagram of the internal structure of the four-type bottle inner liner sealing structure provided in the embodiment of this application.

[0009] Figure 2 is a schematic diagram of the external structure of the four-type bottle inner liner sealing structure provided in the embodiments of this application.

[0010] Figure 3 is a magnified view of part A in Figure 1;

[0011] The components are: 1. Valve seat; 2. Inner plug; 3. Plastic inner liner; 4. First seal; 5. Second seal; 6. Retaining ring. Detailed Implementation

[0012] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. The embodiments of this application are described below with reference to Figures 1 to 3.

[0013] According to an embodiment of this application, a four-type bottle inner liner sealing structure is provided, including a valve seat 1, an inner plug 2, and a plastic inner liner 3. The inner plug 2 is installed in the inner cavity of the valve seat 1, and the inner plug 2 and the valve seat 1 are in a sealing fit. An installation space is reserved between the inner end of the inner plug 2 facing the inside of the valve seat 1 and the valve seat 1. The installation space includes an installation gap and a tightening gap, and the tightening gap is inclined towards the valve seat 1 relative to the installation gap. The plastic inner liner 3 is installed within the installation space, completely filling the installation space. In this embodiment, the inner plug 2 and the valve seat 1 are sealed together by a sealing ring.

[0014] In the installation of the plastic inner liner, the end of the plastic inner liner 3 is pre-melted, and then the plastic inner liner 3 is fixed to the inner wall of the valve seat 1 by rotational molding. Then, the inner plug 2 is installed. The installation space between the inner plug 2 and the valve seat 1 is annular, with the installation gap portion being a cylindrical annular shape and the tightening gap portion being a frustum-shaped annular shape. The installation space is inclined towards the valve seat 1, so that the portions of the valve seat 1 and the inner plug 2 corresponding to the tightening gap are all inclined surfaces.

[0015] In the four-type bottle inner liner sealing structure, the plastic inner liner 3 is formed inside the valve seat 1. When installing the inner plug 2, the inner plug 2 is installed into the valve seat 1 from the open end of the valve seat 1. Since the plastic inner liner 3 completely fills the installation space, the shape of the plastic inner liner 3 is adapted to the installation space, and the tightening gap is inclined relative to the installation gap, so that the end of the plastic inner liner 3 is formed into an inclined surface adapted to the shape of the tightening gap. When installing the inner plug 2, the inclined surface of the inner side of the inner plug 2 forming the tightening gap cooperates with the inclined surface of the end of the plastic inner liner 3 to tighten and seal. By adopting the inclined surface structure of the valve seat 1, the inner plug 2, in conjunction with the inclined surface inside the valve seat 1, can resist the plastic inner liner 3 for pre-tightening during the installation process into the valve seat 1, so as to prevent the plastic inner liner 3 from collapsing and deforming. Thus, by limiting and pre-tightening, the anti-creep effect of the plastic inner liner 3 is strengthened, and the sealing effect is ultimately enhanced.

[0016] In one embodiment, to ensure a proper seal between the inner plug 2 and the plastic inner liner 3, a first sealing element 4 is installed between the inner plug 2 and the plastic inner liner 3. The first sealing element 4 seals the inner plug 2 and the plastic inner liner 3. Under the pressure of the plastic inner liner 3, the first sealing element 4 adheres to the side of the plastic inner liner 3 facing the inner plug 2 to achieve a seal.

[0017] To prevent significant movement of the first sealing element 4 during the installation of the inner plug 2, which could lead to a deterioration or failure of the sealing effect, a first sealing groove is provided at the position of the inner plug 2 facing the installation gap. The first sealing element 4 is installed in the first sealing groove and extends from the first sealing groove into the installation space. By setting the first sealing groove, the installation position of the first sealing element 4 is limited, thereby preventing displacement of the first sealing element 4 during the installation of the inner plug 2 and thus avoiding a weakening of the sealing effect. Specifically, the first sealing element 4 is a soft sealing ring made of materials such as rubber or silicone. The soft sealing ring will adhere to the plastic surface under the compression of the plastic inner liner 3 to achieve a seal.

[0018] Furthermore, in order to ensure the sealing effect of the inner liner sealing structure of the Type IV bottle in the event that the first seal deforms and fails under extreme temperature and ultra-high pressure, a second sealing element 5 is installed in the tightening gap. The second sealing element 5 is pressed between the plastic inner liner 3 and the inner plug 2. By setting the second sealing element 5 in the inclined tightening gap, a second sealing surface is formed at the tightening gap between the inner plug 2 and the valve seat 1 when the first sealing element 4 deforms under extreme temperature and ultra-high pressure, which greatly compensates for the defect of gas cylinder leakage after the plastic inner liner 3 collapses.

[0019] To prevent the second seal 5 from shifting and becoming misaligned during the installation of the inner plug 2, a second sealing groove is provided at the position of the inner plug 2 facing the tightening gap. The second seal 5 is fixedly installed in the second sealing groove, extending into the tightening gap. By providing the second sealing groove, the installation position of the second seal 5 is defined, ensuring the stability of the position of the second seal 5, thereby ensuring the stability of the sealing effect of the second seal 5.

[0020] In this embodiment, the second sealing element 5 is a star-shaped sealing ring or other shaped sealing ring made of high-strength plastic material, and the side of the second sealing element 5 that mates with the plastic inner liner 3 is an arc surface. To prevent excessive deformation of the first sealing element 4 and the second sealing element 5, a retaining ring 6 is installed between the plastic inner liner 3 and the inner plug 2 within the tightening gap. After the plastic inner liner 3 is roll-molded on the valve seat 1, a forming tool is used to cut the plastic inner liner 3 into the shape shown in the figure. Then, the triangular retaining ring and the star-shaped sealing ring are fitted onto the inner plug 2 and screwed into the valve seat 1. The force generated by the deformation and rebound of the star-shaped sealing ring compresses the plastic surface, simultaneously achieving a seal on the metal surface. In some other embodiments, the cross-section of the second sealing element 5 is circular.

[0021] In one embodiment, the installation gap is parallel to the axial direction of the inner plug 2, and the angle between the tightening gap and the installation gap is 120°-150°. Specifically, in this embodiment, the angle between the tightening gap and the installation gap is 135°, and the angle between the inclined surface on the inner side of the valve seat 1 and the axial direction of the valve seat 1, as well as the angle between the inclined surface on the inner plug 2 and the axial direction of the inner plug 2, are both 135°. In some other embodiments, the angle between the tightening gap and the installation gap can be adjusted according to actual needs.

[0022] The four-type bottle liner sealing structure provided in this embodiment achieves the effect of preventing liner collapse through the special structure of the inner plug 2, valve seat 1, and plastic inner liner 3. The external thread on the inner plug 2 connects to the internal thread on the valve seat 1. The inner plug 2 and the plastic inner liner 3 are sealed by a soft sealing ring and a retaining ring 6. The soft sealing ring adheres to the plastic surface under the pressure of the plastic inner liner 3, achieving a seal. The retaining ring 6 prevents excessive deformation of the soft sealing ring. The soft sealing ring and the retaining ring 6 form the first seal between the inner plug 2 and the plastic inner liner 3. Under high pressure and high temperature environments, the bottle opening of the plastic inner liner 3 may be squeezed outwards, leading to seal failure. To compensate for this and considering the feasibility of rotational molding, the valve seat 1 adopts a 135° inclined surface structure. The plastic inner liner 3 is bonded to the inclined step on the valve seat 1. During installation, the inner plug 2, in conjunction with the 135° inclined surface, presses against the plastic inner liner 3, thereby enhancing the creep resistance of the plastic inner liner 3 through limiting and pre-tightening, ultimately achieving a stronger sealing effect. To reduce the contact stress between the plastic inner liner 3 and the inclined surface of the inner plug 2, a soft retaining ring 6 made of engineering plastic is used in contact with a soft sealing ring. A predetermined compression amount of the sealing ring is used, and the rebound force generated by compressing the soft sealing ring pushes against the inclined surface, thus achieving soft contact between the inclined surface of the inner plug 2 and the plastic inner liner 3. Simultaneously, a metal sealing ring, acting as a second sealing element 5, forms a second metal sealing surface between the metal inner plug 2 and the metal valve seat 1 when the sealing ring deforms, significantly compensating for the gas cylinder leakage defect caused by the collapse of the plastic inner liner 3. By creating an inclined surface in the inner cavity of the valve seat 1, the plastic inner liner 3 is pre-tightened by the inner plug 2 pressing against the inclined surface of the inner cavity of the valve seat 1 during installation, thus preventing the collapse and deformation of the plastic inner liner 3. Furthermore, by forming two additional sealing surfaces with different properties between the valve seat 1 and the inner plug 2, the sealing performance of the gas cylinder is enhanced after the plastic inner liner 3 collapses. The soft contact pre-tightening force generated by the deformation of the soft sealing ring can effectively prevent the plastic inner liner 3 from deforming prematurely due to excessive compression.

[0023] Secondly, this application also provides a Type IV bottle with the Type IV bottle inner liner sealing structure provided in this embodiment. By setting the bottle mouth end of the Type IV bottle as the Type IV bottle inner liner sealing structure, the inclined structure enables the inner plug 2 to apply a pre-tightening force to the plastic inner liner 3, thereby ensuring a stronger anti-creep effect at the end of the plastic inner liner 3. After the plastic inner liner 3 collapses, it can also provide an effective metal sealing surface, greatly improving the sealing performance of the gas cylinder; the compression of the inclined surface is achieved by the reaction force generated by the deformation of the metal sealing ring, which greatly reduces the stress concentration at the contact point. This pre-tightening force can be adjusted according to the actual process parameters, thereby achieving a stable and consistent pre-tightening force.

[0024] Although embodiments of this application have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of this application, and all such modifications and variations fall within the scope defined by the appended claims.

Claims

1. A four-type bottle inner liner sealing structure, characterized in that, include: Valve seat (1); An inner plug (2) is installed in the inner cavity of the valve seat (1). The inner plug (2) is sealed to the valve seat (1). An installation space is reserved between the inner end of the inner plug (2) facing the inner side of the valve seat (1) and the valve seat (1). The installation space includes an installation gap and a tightening gap. The tightening gap is inclined relative to the installation gap towards the valve seat (1). A plastic inner liner (3) is installed in the installation space, and the plastic inner liner (3) completely fills the installation space.

2. The four-type bottle inner liner sealing structure according to claim 1, characterized in that, The installation space is annular between the inner plug (2) and the valve seat (1), wherein the installation gap portion is cylindrical and the tightening gap portion is frustum-shaped.

3. The four-type bottle inner liner sealing structure according to claim 1, characterized in that, A first sealing element (4) is installed between the inner plug (2) and the plastic inner liner (3).

4. The four-type bottle inner liner sealing structure according to claim 3, characterized in that, The first sealing element (4) is a soft sealing ring made of rubber or silicone.

5. The four-type bottle inner liner sealing structure according to claim 3, characterized in that, The inner plug (2) is provided with a first sealing groove at the position facing the installation gap, and the first sealing member (4) is installed in the first sealing groove and extends from the first sealing groove into the installation space.

6. The four-type bottle inner liner sealing structure according to any one of claims 1 to 5, characterized in that, A second seal (5) is installed in the top-tightening gap, and the second seal (5) is pressed between the plastic inner liner (3) and the inner plug (2).

7. The four-type bottle inner liner sealing structure according to claim 6, characterized in that, The second sealing element (5) is a star-shaped sealing ring made of plastic.

8. The four-type bottle inner liner sealing structure according to claim 6, characterized in that, The inner plug (2) is provided with a second sealing groove at the position facing the tightening gap, and the second sealing member (5) is fixedly installed in the second sealing groove and extends into the tightening gap.

9. The four-type bottle inner liner sealing structure according to claim 6, characterized in that, The side of the second sealing element (5) that mates with the plastic inner liner (3) is an arc surface.

10. The four-type bottle inner liner sealing structure according to any one of claims 1 to 5, characterized in that, The installation gap is parallel to the axial direction of the inner plug (2), and the angle between the tightening gap and the installation gap is from 120° to 150°.

11. The four-type bottle inner liner sealing structure according to any one of claims 1 to 5, characterized in that, Within the clamping gap, a retaining ring (6) is installed between the plastic inner liner (3) and the inner plug (2).

12. The four-type bottle inner liner sealing structure according to any one of claims 1 to 5, characterized in that, The plastic inner liner (3) is fixedly fitted with the valve seat (1).

13. A type four bottle, characterized in that, It has the four-type bottle inner liner sealing structure as described in any one of claims 1 to 12.

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