High-pressure tank unit

Abstract

This invention provides a method for manufacturing a high-pressure tank with improved adhesion between a first reinforcing layer and a second reinforcing layer. The tank unit (1) comprises a high-pressure tank (10) and a connecting member (30) connected to the high-pressure tank. The connecting member (30) includes an annular sealing member (61, 62) disposed between a liner (11) and an insertion portion (31) and closing a receiving space (S). The high-pressure tank includes a cylindrical body (40A) disposed between the liner (11) and the reinforcing layer (12), positioned opposite the sealing member (61, 62) in a manner surrounding the outer peripheral surface (11a) of the liner (11), and limiting radially expanding deformation of the inner peripheral surface of the neck (15). The longitudinal modulus of elasticity of the material along the circumferential direction of the cylindrical body (40A) is higher than that of the longitudinal modulus of elasticity of the material along the circumferential direction of the liner and the reinforcing layer.

Description

Technical Field

[0001] The present invention relates to a high-pressure tank unit having a high-pressure tank and a connecting component thereto. Background Technology

[0002] For example, high-pressure tanks for storing fuel gases are used in natural gas vehicles or fuel cell vehicles. Such high-pressure tanks have a lining that contains a fluid as a high-pressure gas, and a reinforcing layer made of fiber-reinforced resin that covers the outer periphery of the lining.

[0003] The high-pressure tank includes a tank body having a containment space for high-pressure gas, and a neck continuously formed from the end of the tank body. An opening communicating with the containment space of the tank body is formed in the neck, and this opening is connected by connecting components such as a manifold or bracket. An insertion portion is formed in the connecting component, which is inserted from the opening of the high-pressure tank along the inner circumferential surface of the liner. An annular sealing component is provided between the liner and the insertion portion to close the containment space.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2020-112189

[0005] However, as shown in Patent Document 1, when a high-pressure fluid is filled into the containment space of the high-pressure tank, the tank body tends to expand radially due to the internal pressure of the fluid, and the neck also tends to expand radially. Therefore, the surface pressure of the sealing member provided at the insertion part decreases relative to the lining of the neck, resulting in a decrease in the sealing performance of the neck of the high-pressure tank. Summary of the Invention

[0006] The present invention was made in view of the fact that it provides a high-pressure tank unit capable of ensuring the sealing performance of the sealing component at the neck of the high-pressure tank.

[0007] In view of the above-mentioned problems, the high-pressure tank unit according to the present invention is a tank unit comprising a high-pressure tank and a connecting member. The high-pressure tank has: a liner forming a fluid-containing space, having an opening at least at one end; and a reinforcing layer covering the outer peripheral surface of the liner and made of fiber-reinforced resin. The high-pressure tank also includes: a tank body including the fluid-containing space; and a neck continuous with at least one end of the tank body and having the opening. The connecting member has an insertion portion that extends from the opening along the inner peripheral surface of the liner into the neck, and is connected to the high-pressure tank in a manner that covers the opening. The connection is characterized in that the connecting member has an annular sealing member disposed between the liner and the insertion portion and sealing the receiving space; the high-pressure tank has a cylindrical body disposed between the liner and the reinforcing layer and positioned at least opposite the sealing member in a manner surrounding the outer peripheral surface of the liner, thereby limiting the radially expanding deformation of the inner peripheral surface of the neck; and the longitudinal elastic modulus of the material along the circumferential direction of the cylindrical body is higher than the longitudinal elastic modulus of the material along the circumferential direction of the liner and the longitudinal elastic modulus of the material along the circumferential direction of the reinforcing layer.

[0008] According to the invention, an insertion part with a connecting member is inserted into the neck of the high-pressure tank from the opening, and the receiving space is sealed by contacting the lining of the neck with an annular sealing member. Here, when high-pressure fluid is filled into the receiving space of the high-pressure tank, the tank body and neck tend to expand radially due to the internal pressure of the fluid. However, in this invention, a cylindrical body is positioned opposite the sealing member, surrounding the outer circumferential surface of the lining, between the lining and the reinforcing layer. This cylindrical body restricts the radial expansion deformation of the inner circumferential surface of the neck. That is, as a specific structure to restrict this deformation, according to the invention, the longitudinal elastic modulus of the material along the circumferential direction of the cylindrical body is higher than that of the material along the circumferential direction of the lining and the reinforcing layer. Therefore, compared to the case without a cylindrical body, the radial expansion of the lining caused by the circumferential stress induced by the high-pressure fluid can be suppressed by the cylindrical body. As a result, the sealing performance of the sealing member at the neck of the high-pressure tank can be ensured.

[0009] In a more preferred embodiment, the wall thickness of the portion of the cylindrical body including the end on the tank side decreases towards the end on the tank side. According to this embodiment, since the wall thickness of the portion including the end on the tank side decreases towards the end on the tank side, the end on the tank side is more prone to deformation. Therefore, when high-pressure fluid is filled into the containment space of the high-pressure tank, the end of the cylindrical body follows the deformation of the lining in a radially bulging manner, thus reducing the stress acting on the portion of the lining that contacts that end.

[0010] In a more preferred embodiment, at least one end of the cylindrical body on the tank side is covered by a cushioning member made of a material softer than that of the cylindrical body. According to this embodiment, when high-pressure fluid is filled into the containment space of the high-pressure tank, the lining does not directly contact the end of the cylindrical body but contacts it via the cushioning member. Therefore, the cushioning member can follow the deformation of the lining to reduce the stress acting on the lining.

[0011] Furthermore, as a preferred embodiment, the opposing surface of the cylindrical body on the tank side, which is opposite to the outer peripheral surface of the lining, extends radially away from the outer peripheral surface of the lining.

[0012] According to this configuration, the opposing surfaces on the tank side extend radially away from the outer peripheral surface of the liner, thus preventing the liner from contacting the inner edge of the cylindrical body and thereby avoiding damage to the liner.

[0013] According to the present invention, the sealing performance of the sealing component at the neck of the high-pressure tank can be ensured. Attached Figure Description

[0014] Figure 1 This is a perspective view showing the structure of the tank unit according to the first embodiment of the present invention.

[0015] Figure 2 It is along Figure 1 A cross-sectional view of the tank unit along line AA.

[0016] Figure 3A yes Figure 2 An enlarged sectional view of the main parts of the tank unit on the bracket side is shown.

[0017] Figure 3B yes Figure 2 An enlarged sectional view of the main parts of the tank unit on the manifold side is shown.

[0018] Figure 4 It is related to the second embodiment. Figure 3B Enlarged sectional view of the main parts of the corresponding tank unit.

[0019] Figure 5 This is a variation of the second embodiment involving... Figure 3B Enlarged sectional view of the main parts of the corresponding tank unit.

[0020] Explanation of reference numerals in the attached figures

[0021] 1… Tank unit; 10… High-pressure tank; 13… Opening; 14… Tank body; 15… Neck; 30… Connecting part; 31… Insertion part; 40A, 40B… Cylindrical body; 61, 62… Sealing part; 55… Cover (buffer part); S… Accommodation space. Detailed Implementation

[0022] The following is a reference. Figures 1-5 The embodiments of the tank unit 1 according to the present invention will be described below. For example... Figure 1 As shown, the tank unit 1 involved in this embodiment includes a high-pressure tank 10 and a pair of connecting parts 30, 30 connected to both ends of the high-pressure tank 10.

[0023] The high-pressure tank 10 is a tank filled with high-pressure hydrogen installed in a fuel cell vehicle. The gas that can be filled into the high-pressure tank 10 is not limited to high-pressure hydrogen. It can be filled with various compressed gases such as CNG (compressed natural gas), various liquefied gases such as LNG (liquefied natural gas) and LPG (liquefied petroleum gas), other gases (fluids), or temporarily filled with liquids or other fluids for pressure testing purposes.

[0024] The high-pressure tank 10 includes: a liner 11 forming a space S for containing hydrogen gas and having openings 13 on both sides; and a reinforcing layer 12 laminated on the liner 11 to cover the outer peripheral surface 11a of the liner 11. The liner 11 is made of a gas-barrier material, and the reinforcing layer 12 is made of fiber-reinforced resin.

[0025] The high-pressure tank 10 includes: a tank body 14, including the aforementioned receiving space S; and a pair of necks 15, 15, continuous with the end of the tank body 14, and having an opening 13. In this embodiment, the necks 15, 15 are formed on both sides of the high-pressure tank 10, but the high-pressure tank 10 may also be a bottle-shaped structure with a neck 15 formed only on one side.

[0026] Both the tank body 14 and the neck 15 are constructed by stacking a liner 11 and a reinforcing layer 12. In this embodiment, a cylindrical body 40A, described later, is disposed as an intermediate layer between the liner 11 and the reinforcing layer 12 in the neck 15. Furthermore, the cylindrical body 40A, described later, may also cover the entire outer peripheral surface 11d of the liner 11 forming the neck 15. However, as long as the sealing described later can be ensured, a portion of the outer peripheral surface 11d of the liner 11 may be covered in the neck 15, while the remaining surface (specifically, the outer peripheral surface on the side of the opening 13) may be covered by the reinforcing layer 12.

[0027] In this embodiment, the can body 14 has a cylindrical main body 14a and a shoulder 14b whose inner and outer diameters decrease as it approaches the end of the can body 14 from the main body 14a, as an example of a cylindrical shape. The shoulder 14b is a frustoconical cylindrical portion, and a neck 15 is formed continuously with the shoulder 14b.

[0028] At the neck 15, an annular connector 20 is installed on the outer peripheral surface 12a of the reinforcing layer 12. Multiple protrusions are formed on the inner peripheral surface 22 of the connector 20, and the reinforcing layer 12 is configured to engage with the inner peripheral surface 22 (specifically, with the protrusions interlocking). This allows the connector 20 to be locked to the reinforcing layer 12. An external thread is formed on the outer peripheral surface 21 of the connector 20, which can engage with the internal thread on the inner wall surface 34 of the connecting member 30, described later.

[0029] In this embodiment, the resin constituting the lining 11 is preferably a resin with good gas barrier properties. Examples of such resins include polypropylene resins, nylon resins (e.g., 6-nylon resin or 6,6-nylon resin), polycarbonate resins, acrylic resins, ABS resins, polyamide resins, polyethylene resins, ethylene-vinyl alcohol copolymer resins (EVOH), or polyester resins, etc., which are thermoplastic resins.

[0030] The reinforcing layer 12 is a layer in which reinforcing fibers are impregnated with a thermoplastic resin or a thermosetting resin as the matrix resin. In this embodiment, the reinforcing fibers are fiber bundles. As reinforcing fibers, glass fibers, aramid fibers, boron fibers, and carbon fibers can be used, and carbon fibers are preferred, especially from the viewpoints of lightweight and mechanical strength. As the matrix resin, a thermosetting resin is preferred. The thermosetting resin is a phenolic resin, a melamine resin, a urea resin, or an epoxy resin. From the viewpoints of mechanical strength, an epoxy resin precursor is preferred. The epoxy resin is one that is fluid in its uncured state and forms a strong cross-linked structure after thermosetting.

[0031] The reinforcing layer 12 is a layer in which fiber bundles impregnated with the matrix resin are wound onto the outer peripheral surface 11a of the lining 11 by a filament winding method or a sheet winding method. The reinforcing layer 12 can be a spirally wound layer in which the fiber bundles are wound at an angle relative to the axis CL of the high-pressure tank 10, or it can be a layer woven in which the fiber bundles are wound at an angle relative to the axis CL of the high-pressure tank 10.

[0032] The pair of connecting parts 30, 30 connected to the neck 15 of the high-pressure tank 10 are made of metal such as aluminum or steel, and consist of a bracket 30A and a manifold 30B. The bracket 30A is a component used to secure multiple high-pressure tanks 10, 10 together and install them on a vehicle.

[0033] Manifold 30B is a component that forms a gas flow path for introducing hydrogen into and releasing hydrogen from the containment space S of the high-pressure tank 10. For example... Figure 3A and Figure 3B As shown, the main difference between bracket 30A and manifold 30B is the presence or absence of a gas flow path. Therefore, refer to... Figure 3BThe structure of the manifold 30B, which serves as the connecting component 30, will now be explained.

[0034] The manifold 30B is formed as an opening 13 covering the end of the axial CL of the high-pressure tank 10. The manifold 30B has an insertion part 31 and a cover part 32. The cover part 32 is threaded to the connector 20 and covers the end face of the high-pressure tank 10. The insertion part 31 is formed in the center of the cover part 32.

[0035] The insertion part 31 is a plug-like portion that is inserted into the neck 15 of the high-pressure vessel 10 from the opening 13 along the inner peripheral surface 11b (specifically, the inner peripheral surface 15a of the neck 15) of the liner 11. An annular groove 35 is formed on the outer peripheral surface 31b of the insertion part 31 along its circumference, and annular sealing members 61 and 62 are disposed in the annular groove 35 to close the receiving space S. The sealing members 61 and 62 are made of an elastic material such as a gas-barrier resin material or a rubber material.

[0036] However, when high-pressure hydrogen is filled into the containment space S of the high-pressure tank 10, the tank body 14 of the high-pressure tank 10 tends to expand radially due to the internal pressure of the hydrogen. At the same time, the neck 15 also tends to expand radially, so the surface pressure of the sealing members 61, 52 provided in the insertion part 31 decreases relative to the lining 11 of the neck 15, resulting in a decrease in the sealing performance of the neck 15 of the high-pressure tank 10.

[0037] Therefore, in this embodiment, the high-pressure tank 10 has a cylindrical body 40A positioned opposite the sealing members 61 and 62, between the liner 11 and the reinforcing layer 12, surrounding the outer peripheral surface 11d of the liner 11. The cylindrical body 40A is a component that restricts the radial expansion deformation of the inner peripheral surface 15a of the neck 15.

[0038] Here, "the radial expansion of the inner circumferential surface 15a of the neck 15" refers to the radial expansion of the neck 15 due to the circumferential stress generated by the pressure of hydrogen gas, which is the radial expansion of the lining 11 forming the neck 15 (more specifically, the portion of the lining 11 that abuts against the sealing members 61, 62).

[0039] Furthermore, the inner circumferential surface (opposing surface) 41 of the cylindrical body 40A abuts against the outer circumferential surface 11d of the lining 11 constituting the neck 15. The portion of the cylindrical body 40A including the end 43 on the can body 14 side thins in wall thickness as it approaches the end 43 on the can body 14 side. More specifically, the thinned portion is located on the can body 14 side closer to the front end face of the insertion portion 31, and more preferably, it is the portion that contacts the surface of the shoulder portion 14b of the can body 14.

[0040] In this embodiment, the cylindrical body 40A extends from a position inside the end face of the high-pressure tank 10 (on the tank body 14 side) to a portion of the shoulder 14b of the tank body 14, and the reinforcing layer 12 covers the outer end face of the high-pressure tank 10 within the end face of the cylindrical body 40A. This prevents the cylindrical body 40A from detaching along the axial direction of the high-pressure tank. However, as long as it is positioned opposite the sealing members 61 and 62 and the sealing performance of the sealing members 61 and 62 can be ensured, for example, as in the second embodiment described later, both ends of the cylindrical body 40A can also reach the end face of the high-pressure tank 10.

[0041] As for the material of the cylindrical body 40A, examples include stainless steel, aluminum steel, and other metal materials, as well as fiber-reinforced resins. It is not particularly limited as long as it satisfies the relationship of limiting the radial expansion of the inner circumferential surface 15a of the neck 15. Here, as a specific structure for limiting the radial expansion of the inner circumferential surface 15a of the neck 15, the longitudinal elastic modulus of the material along the circumferential direction of the cylindrical body 40A is higher than the longitudinal elastic modulus of the material along the circumferential direction of the lining 11 and the longitudinal elastic modulus of the material along the circumferential direction of the reinforcing layer 12.

[0042] Specifically, the longitudinal modulus of elasticity is Young's modulus. The lining 11 is made of thermoplastic resin, which is a mechanically isotropic material. Therefore, the longitudinal modulus of elasticity of the lining 11 along the circumferential direction is the longitudinal modulus of elasticity of the thermoplastic resin itself. Similarly, when the cylindrical body 40A is made of a metal material such as stainless steel, since stainless steel and other metal materials are mechanically isotropic, the longitudinal modulus of elasticity of the cylindrical body 40A along the circumferential direction is the longitudinal modulus of elasticity of the metal material itself.

[0043] However, the reinforcing layer 12 is made of fiber-reinforced resin, and in this embodiment, the fiber bundles are oriented in a predetermined direction, thus it is made of anisotropic material. In this case, the longitudinal elastic modulus of the reinforcing layer 12 is the longitudinal elastic modulus of the neck 15 of the reinforcing layer 12 along the circumferential direction.

[0044] Prepare a tensile specimen made of the same material as these components, with the circumferential material suitable for the tensile direction, and stretch the tensile specimen to determine the longitudinal modulus of elasticity of the neck 15 along the circumferential direction.

[0045] For example, when the fiber bundles constituting the reinforcing layer 12 are oriented along the circumference of the neck 15, the longitudinal modulus of elasticity of a tensile specimen of fiber-reinforced resin with the reinforcing fibers oriented along the tensile direction is measured. On the other hand, when the fiber bundles are oriented in a manner parallel to the axis of the neck 15 (i.e., the axis CL of the pressure vessel 10), the longitudinal modulus of elasticity of a tensile specimen of fiber-reinforced resin with the reinforcing fibers oriented in a direction orthogonal to the tensile direction is measured.

[0046] For example, when the lining 11 is made of thermoplastic resin and the reinforcing layer 12 is made of fiber-reinforced resin, it is preferable that the cylindrical body 40A is made of a metal such as stainless steel. Furthermore, when the reinforcing layer 12 includes fiber bundles made of carbon fibers as reinforcing fibers and the fiber bundles are formed at an angle relative to the axis CL of the high-pressure tank 10, the cylindrical body 40A may also be made of annularly wound fiber-reinforced resin.

[0047] In manufacturing such a high-pressure tank 10, a liner 11 is formed from molten thermoplastic resin by extrusion molding, and then cylindrical bodies 40A, 40A are fitted to both ends of the liner 11. Next, a reinforcing layer 12 is formed on the liner 11 together with the cylindrical bodies 40A, 40A, for example by filament winding. If the base resin of the reinforcing layer 12 is a thermosetting resin, a connector 20 is installed at each neck 15 at both ends before thermosetting, and the thermosetting resin is thermoset.

[0048] According to this embodiment, in the neck 15 of the high-pressure tank 10, an insertion part 31 with a connecting member 30 is inserted from the opening 13, and the annular sealing members 61 and 62 contact the inner peripheral surface 15a of the neck 15, thereby sealing the hydrogen containing space S.

[0049] Here, when a high-pressure fluid is filled into the containing space S of the high-pressure tank 10, the tank body 14 and neck 15 tend to expand radially in the high-pressure tank 10 due to the internal pressure of the fluid. However, in this embodiment, a cylindrical body 40A is positioned opposite the sealing members 61 and 62 between the liner 11 and the reinforcing layer 12, in a manner that wraps around the outer peripheral surface 11d of the liner 11. This cylindrical body 40A restricts the deformation of the inner peripheral surface 15a of the neck 15 from expanding radially.

[0050] That is, as a specific structure to limit this deformation, at the neck 15, the longitudinal elastic modulus of the material along the circumferential direction of the cylindrical body 40A is higher than that of the material along the circumferential direction of the lining 11 and the reinforcing layer 12. Therefore, compared to the case without the cylindrical body 40A, the radial expansion of the lining 11 caused by the circumferential stress induced by high-pressure hydrogen can be suppressed by the cylindrical body 40A. As a result, the sealing performance of the sealing components 61 and 62 at the neck 15 of the high-pressure tank 10 can be ensured.

[0051] In addition, the wall thickness of the portion of the cylindrical body 40A including the end on the tank body 14 side thins as it approaches the end on the tank body 14 side, making the end on the tank body 14 side prone to deformation. Therefore, when high-pressure hydrogen is filled into the containment space of the high-pressure tank, the end 43 of the cylindrical body 40A follows the deformation of the lining 11 in a radially bulging manner. Thus, the stress acting on the portion of the lining 11 in contact with this end 43 is reduced, thereby preventing damage to the lining 11.

[0052] The tank unit 1 according to the second embodiment will be described below. Figure 4 It is related to the second embodiment. Figure 3B A cross-sectional view of the main parts of the corresponding tank unit 1. The tank unit 1 in the second embodiment differs from that in the first embodiment in that the cylindrical body 40B has a shape and an annular cover (buffer component) 55 is provided at the end 43 of the cylindrical body 40B.

[0053] In this embodiment, one end of the cylindrical body 40B is exposed relative to the high-pressure tank 40, and the other end 43 of the cylindrical body 40B, i.e., the end 43 on the tank body 14 side, is covered by a cap 55 made of a material softer than that of the cylindrical body 40B. The cap 55 tapers at its end as it approaches the tank body 14 side.

[0054] Specifically, here, as the material of the cover 55, if the material of the cylindrical body 40B is metal, it is made of a resin material or rubber material that is more easily deformed elastically. More preferably, the material of the cover 55 can also be a material that is softer than the material of the lining 11, but for example, it can also be the same material as the lining 11.

[0055] According to this configuration, when high-pressure hydrogen is filled into the containment space S of the high-pressure tank 10, the liner 11 does not directly contact the end 43 of the cylindrical body 40B but contacts it via the cover (buffer member) 55. As a result, the stress on the edge portion 11c of the area in which the cylindrical body 40B contacts the liner 11 can be reduced.

[0056] Starting from such a point, for example, Figure 5 As shown in the modified example, the cylindrical body 40B may also be configured such that the opposing surface 41a on the tank portion 14 side of the opposing surface 41 of the cylindrical body 40B, which is opposite to the outer peripheral surface 11a of the liner 11, extends radially away from the outer peripheral surface 11a of the liner 11. Therefore, since the opposing surface 41a on the tank portion 14 side extends radially away from the outer peripheral surface 11a of the liner 11, contact between the liner 11 and the inner edge of the cylindrical body 40B can be avoided, thereby preventing damage to the liner 11. The aforementioned cushioning material may also be disposed between the opposing surface 41a on the tank portion 14 side and the outer peripheral surface 11a of the liner 11.

[0057] The above describes one embodiment of the present invention in detail, but the present invention is not limited to the above embodiment. Various design changes can be made without departing from the spirit of the present invention as set forth in the claims.

Claims

1. A tank unit comprising a high-pressure tank and connecting components, The high-pressure tank has: a lining forming a fluid-containing space, with an opening at least at one end; and a reinforcing layer covering the outer peripheral surface of the lining and made of fiber-reinforced resin. The high-pressure tank also includes: a tank body including the fluid-containing space; and a neck continuous with at least one end of the tank body, having the opening. The connecting member has an insertion portion that extends from the opening along the inner circumferential surface of the liner into the neck, and is connected to the high-pressure vessel in a manner that covers the opening. Its features are, The connecting component includes an annular sealing member disposed between the liner and the insertion portion, thereby closing the receiving space. The high-pressure tank includes a cylindrical body disposed between the liner and the reinforcing layer, and positioned at least opposite the sealing member in a manner surrounding the outer peripheral surface of the liner, thereby limiting radially expanding deformation of the inner peripheral surface of the neck. The longitudinal elastic modulus of the material along the circumferential direction of the cylindrical body is higher than that of the longitudinal elastic modulus of the material along the circumferential direction of the lining and the longitudinal elastic modulus of the material along the circumferential direction of the reinforcing layer. The opposing surface of the cylindrical body on the tank side, which is opposite to the outer peripheral surface of the liner, extends radially away from the outer peripheral surface of the liner. At least one end of the cylindrical body on the canister side is covered by a cushioning member that is softer than the material of the cylindrical body, so that the lining does not directly contact the end of the cylindrical body on the canister side but contacts it via the cushioning member.

2. The tank unit according to claim 1, characterized in that, The wall thickness of the portion of the cylindrical body, including the end on the tank side, decreases as it approaches the end on the tank side.

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