high-pressure tank

Abstract

A high-pressure tank (1) comprises: a liner (2) comprising a body portion (2a) having a tubular shape and lateral end portions (2b, 2c) each having a dome shape, the lateral end portions (2b, 2c) being provided on opposite sides of the body portion (2a); and a reinforcing layer (30) made of fiber-reinforced resin covering an outer surface of the liner (2). The reinforcing layer (30) comprises a tubular member (31) covering the body portion (2a) and dome members (32, 33) connected to opposite sides of the tubular member (31) to cover the lateral end portions (2b, 2c). The liner (2) comprises a first resin layer (24) defining a storage space (5) for storing gas, and a second resin layer (20) provided between the first resin layer (24) and at least the tubular element (31).A modulus of elasticity of a second resin forming the second resin layer (20) is lower than a modulus of elasticity of a first resin forming the first resin layer (24).

Description

Background of the invention 1. Field of the invention

[0001] The present invention relates to a high-pressure tank. 2. Description of the related prior art

[0002] A high-pressure tank for storing fuel gas is used in, for example, a natural gas vehicle, a fuel cell vehicle, and the like. This type of high-pressure tank includes a liner to keep the fuel gas airtight and a reinforcement layer covering the outer surface of the liner.

[0003] As such a high-pressure tank, Japanese Patent Application JP 2017-141947 A, for example, discloses a high-pressure tank with a liner comprising a tubular body portion and dome-shaped lateral end portions provided on opposite sides of the body portion. The high-pressure tank is provided with a reinforcing layer made of fiber-reinforced resin covering the outer surface of the liner.

[0004] Furthermore, US 2009 / 0 263 315 A1 discloses a method for producing an inner polymer shell for a storage tank, in particular for a hydrogen storage tank, the method comprising the steps of: providing a cylindrical body made of a polymer material and having a construction layer and a barrier layer, the cylindrical body having a first open end and a first circumferential connecting tab at the open end; providing a dome-shaped end cap made of the polymer material, the end cap having a bottom with a cross-section substantially corresponding to a cross-section of the first open end of the cylindrical body and having a second circumferential connecting tab at a circumferential end portion of the end cap;Positioning the end cap with its bottom on the first open end of the cylindrical body and with the first and second circumferential tabs in contact with each other; and welding the two connecting tabs together.; Summary of the invention

[0005] However, in the high-pressure tank described in JP 2017-141947 A, the resin liner expands and contracts more easily than the reinforcement layer made of fiber-reinforced resin. When the gas in the tank undergoes adiabatical expansion and compression due to filling or discharging of the gas during use of the high-pressure tank, the liner retained by the reinforcement layer expands and contracts due to thermal changes, and the liner may be damaged.

[0006] The above problems and the resulting object are solved by the subject matter of claim 1. Advantageous developments of the invention are the subject matter of the subsequent dependent claim.

[0007] The present invention provides a high-pressure tank which can suppress damage to a liner when the liner expands and contracts.

[0008] A high-pressure tank according to a first illustrative aspect of the present disclosure includes at least: a liner including a body portion having a tubular shape and side end portions each having a dome shape, the side end portions being provided on opposite sides of the body portion; and a reinforcing layer configured to cover an outer surface of the liner and made of a fiber-reinforced resin. The reinforcing layer includes a tubular member configured to cover the body portion and dome members connected to opposite sides of the tubular member to cover the side end portions.The liner comprises a first resin layer defining a storage space for storing gas, and a second resin layer provided between the first resin layer and at least the tubular member. A modulus of elasticity of a second resin constituting the second resin layer is lower than a modulus of elasticity of a first resin constituting the first resin layer.

[0009] According to the above aspect, the body portion of the liner has a two-layer structure of the first resin layer and the second resin layer. Since the elastic modulus of the second resin constituting the second resin layer is lower than the elastic modulus of the first resin constituting the first resin layer, the second resin is softer and more easily deformed than the first resin. Therefore, the second resin layer provided between the first resin layer and at least the tubular member can function as a buffer layer that buffers thermal stress generated by expansion and contraction of the first resin layer. Consequently, the first resin layer can be restricted or prevented from being damaged by expansion and contraction of the first resin layer, so that the gas can be stably retained in the liner.

[0010] In the above aspect, the second resin layer may also be provided between the first resin layer and the dome elements to cover the first resin layer. Expansion and contraction of the liner are likely to occur at boundary portions between the body portion of the liner and the lateral end portions of the liner. Since the second resin layer, which serves as a buffer layer, is disposed at the lateral end portions including these boundary portions, damage to the first resin layer can be more reliably suppressed.

[0011] According to the present invention, it is possible to prevent damage to the liner upon expansion and contraction of the liner. Short description of the illustrations

[0012] Features, advantages and technical and industrial significance of exemplary embodiments of the invention are described below with reference to the accompanying drawings, in which like characters designate like elements, and wherein: Fig. 1 is a schematic sectional view showing a structure of a high-pressure tank according to an embodiment of the present invention; Fig. 2 is a partial sectional view showing the structure of the Fig. 1 shows the high pressure tanks; Fig. 3 is a flowchart showing a procedure of a manufacturing method of the high-pressure tank according to an embodiment of the present invention; Fig. 4 is a schematic sectional view showing a molding process of a tubular member in a Fig. 3 represents the preparation step shown; Fig. 5 is a partial sectional view showing a molding process of dome elements in the Fig. 3 represents the preparation step shown; Fig. 6 is a schematic sectional view showing the device shown in Fig. 3 shows the dome elements formed in the preparation step shown; Fig. 7 is a schematic sectional view illustrating a tubular member obtained by coating the Fig. 4 shown tubular element with a resin layer in the Fig. 3 shown preparation step; Fig. 8 is a schematic sectional view showing dome elements obtained by coating the Fig. 6 shown dome elements with a resin layer in the Fig. 3 shown preparation step; Fig. 9 is a schematic perspective view showing a Fig. 3 represents the connection step shown; Fig. 10 is a partial sectional view of the dome element and the tubular element, showing the Fig. 3 represents the connection step shown; Fig. 11 is a schematic sectional view showing a first reinforcing layer and a second resin layer according to the method shown in Fig. 3 represents the connection step shown; Fig. 12 is a schematic sectional view showing a step of forming a second reinforcing layer and a step of forming a first resin layer as in Fig. 3; Fig. 13 is a schematic sectional view showing a first modification of the Fig. 1 high-pressure tank; and Fig. 14 is a partial sectional view showing a second modification of the Fig. 2 shows the high pressure tank. Detailed description of embodiments

[0013] Hereinafter, an embodiment of a high pressure tank 1 according to the present invention and a modification thereof will be described with reference to the drawings.

[0014] Below, the high-pressure tank 1 is described as a tank filled with high-pressure hydrogen gas and mounted on a fuel cell vehicle. However, the high-pressure tank 1 can also be used for other purposes. The gas that can be filled into the high-pressure tank 1 is not limited to high-pressure hydrogen gas, and examples include various compressed gases such as compressed natural gas (CNG), various liquefied gases such as liquefied natural gas (LNG) and liquefied petroleum gas (LPG), and other gases. 1. High-pressure tank 1

[0015] As in the Fig. 1 and Fig. As shown in Figure 2, the high-pressure tank 1 is a high-pressure gas storage container having a substantially tubular shape and rounded ends in the form of a dome. The high-pressure tank 1 includes a liner 2 having a gas barrier property and a reinforcing portion 3 made of fiber-reinforced resin and covering an outer surface of the liner 2. The reinforcing portion 3 includes a first reinforcing layer 30 covering the outer surface of the liner 2 and a second reinforcing layer 34 covering an outer surface of the first reinforcing layer 30. An opening is provided at one end of the high-pressure tank 1, and a neck 4 is attached around the opening.

[0016] The liner 2 corresponds to a resin member defining a storage space 5 filled with high-pressure hydrogen gas. The liner 2 has a body portion 2a and lateral end portions 2b, 2c provided on opposite sides of the body portion 2a. The body portion 2a extends along an axial direction X of the high-pressure tank 1 with a predetermined length and has a tubular shape. The lateral end portions 2b, 2c are provided to adjoin the respective sides of the body portion 2a and each has a dome shape. The diameters of the lateral end portions 2b, 2c each decrease with increasing distance from the body portion 2a, and a tubular portion 2d is provided at the portion with the smallest diameter of the lateral end portion 2b. A through hole 2e is provided in the tubular portion 2d.

[0017] A neck 4 is formed by processing a metal material such as aluminum or an aluminum alloy into a predetermined shape. A valve 6 for charging and discharging hydrogen gas into and from the storage space 5 is attached to the neck 4. The valve 6 is provided with a sealing member 6a that contacts an inner surface of the liner 2 (first resin layer 24) at a protrusion portion 32b of a dome member 32 to be described later, sealing the storage space 5 of the high-pressure tank 1.

[0018] The reinforcing portion 3 has a function of improving the mechanical strength of the high-pressure tank 1, such as rigidity and pressure resistance, by reinforcing the liner 2, and is made of a fiber-reinforced resin in which reinforcing fibers (continuous fibers) are impregnated with resin. In the above-described embodiment, the reinforcing portion 3 includes the first reinforcing layer 30 covering the outer surface of the liner 2 and the second reinforcing layer 34 covering the outer surface of the first reinforcing layer 30. The first reinforcing layer 30 has a tubular member 31 having a tubular shape and covering the body portion 2a of the liner 2, and dome members 32, 33 connected to the opposite sides of the tubular member 31 to cover the lateral end portions 2b, 2c, and is integrally formed of these members.The first reinforcing layer 30 of the embodiment can be regarded as the “reinforcing layer” according to the present invention.

[0019] The first reinforcement layer 30 is formed by laminating a plurality of fiber-reinforced resin layers in which the reinforcement fibers are impregnated with resin. The reinforcement fibers of the tubular member 31 are circumferentially aligned at an angle substantially orthogonal to the axial direction X of the tubular member 31; in other words, the reinforcement fibers of the tubular member 31 are aligned in a circumferential direction of the tubular member 31. The reinforcement fibers of the dome members 32, 33 are not aligned in the circumferential direction of the tubular member 31 and extend from the vicinities of the apex points of the dome members 32, 33 toward the circumferential edge portions 32a, 33a in different directions intersecting the circumferential direction.

[0020] In the embodiment, the reinforcing fibers of the tubular member 31 and the reinforcing fibers of the dome members 32, 33 are discontinuous (not connected). This is because, as described later, after the tubular member 31 and the dome members 32, 33 are separately formed, the dome members 32, 33 are attached to the opposite ends of the tubular member 31.

[0021] As the reinforcing fibers constituting the first reinforcing layer 30 (i.e., the tubular member 31 and the dome members 32, 33), glass fibers, aramid fibers, boron fibers, carbon fibers, and the like can be used. From the viewpoint of light weight, mechanical strength, and the like, it is particularly preferable to use carbon fibers.

[0022] The resin (matrix resin) impregnated into the reinforcing fibers of the first reinforcing layer 30 is not particularly limited, and a thermoplastic resin or a thermosetting resin can be used. Examples of the thermoplastic resin include polyetheretherketone, polyphenylene sulfide, polyacrylic acid ester, polyimide, polyamide, nylon 6, and nylon 6,6. Examples of the thermosetting resin include a phenol resin, a melamine resin, a urea resin, an epoxy resin, and the like. From the viewpoint of mechanical strength, etc., it is particularly preferable to use the epoxy resin. The epoxy resin has fluidity in an uncured state and forms a tough, cross-linked structure after thermal curing.

[0023] The second reinforcement layer 34 is formed by laminating a plurality of fiber-reinforced resin layers in which the reinforcement fibers are impregnated with resin. The second reinforcement layer 34 is provided to cover the outer surface of the first reinforcement layer 30. That is, in the embodiment, the second reinforcement layer 34 is a layer covering the outer surface of the tubular member 31 and the outer surfaces of the dome members 32, 33.

[0024] Specifically, the second reinforcement layer 34 corresponds to a layer of fiber-reinforced resin in which fibers are aligned across the two dome elements 32, 33. The reinforcement fibers of the second reinforcement layer 34 are aligned by spirally winding a resin-impregnated fiber bundle so that they are inclined with respect to the axial direction X of the tubular element 31. The dome elements 32, 33 can be held to the tubular element 31 by the reinforcement fibers. Therefore, when using the high-pressure tank 1, it is possible to prevent the dome elements 32, 33 from detaching from the tubular element 31 due to gas pressure along the axial direction X.

[0025] Examples of the reinforcing fibers constituting the second reinforcing layer 34 include the same materials as exemplified for the first reinforcing layer 30, and examples of the resin impregnated into the reinforcing fibers include the same materials as exemplified for the first reinforcing layer 30.

[0026] In the embodiment, the liner 2 has a two-layer structure of the first resin layer 24 made of a first resin and a second resin layer 20 made of a second resin. Specifically, the liner 2 includes the first resin layer 24 defining the storage space 5 for storing gas, and the second resin layer 20 provided between the first resin layer 24 and the first reinforcement layer 30 (reinforcing portion 3). The first resin layer 24 is disposed on the storage space 5 side, while the second resin layer 20 is disposed on the first reinforcement layer 30 side of the reinforcing portion 3.

[0027] The first resin layer 24 defines the storage space 5 for storing gas and corresponds to a layer for holding high-pressure gas in the storage space 5. The first resin constituting the first resin layer 24 is preferably a resin having good performance in retaining the charged or stored gas in the storage space 5, that is, having good gas barrier property.

[0028] The second resin layer 20 is provided between the first resin layer 24 and the first reinforcing layer 30 to cover the first resin layer 24. In the embodiment, the second resin layer 20 includes a body portion 21 provided between the first resin layer 24 and the tubular member 31, and dome-shaped lateral end portions 22, 23 provided between the first resin layer 24 and the dome members 32, 33. The lateral end portions 22, 23 are continuously provided on the opposite sides of the body portion 21, and the second resin layer 20 corresponds to a continuous layer composed of the body portion 21 and the lateral end portions 22, 23.

[0029] Here, in this embodiment, the elastic modulus of the second resin constituting the second resin layer 20 is lower than the elastic modulus of the first resin constituting the first resin layer 24. The elastic modulus here refers to Young's modulus and is a longitudinal elastic modulus. Assuming that the aforementioned elastic modulus condition is satisfied, a thermoplastic resin or a thermosetting resin is exemplified as the first resin constituting the first resin layer 24 and the second resin constituting the second resin layer 20.

[0030] Examples of the thermoplastic resin for the first resin and the second resin include a polypropylene-based resin, a nylon-based resin (for example, nylon 6 or nylon 6,6), a polycarbonate-based resin, an acrylic-based resin, an acrylonitrile-butadiene-styrene (ABS)-based resin, a polyamide-based resin, a polyethylene-based resin, an ethylene-vinyl alcohol copolymer (EVOH) resin, a polyester-based resin, and a liquid crystal polymer.

[0031] Examples of the thermosetting resin for the first resin and the second resin include a phenol resin, a melamine resin, a urea resin, and an epoxy resin. Here, the relationship between the elastic moduli of the first and second resins is satisfied by selecting different resins from the above-mentioned resins, and the relationship can be satisfied, for example, by adjusting additives, etc. (type and amount of a curing agent to be added in the case of the thermosetting resin) to be added to the resins. For example, in the case of an epoxy resin, the elastic modulus can be adjusted in the range of 1000 MPa to 9000 MPa by adjusting the type and amount of the curing agent to be added. Thus, the first resin and the second resin can be selected so that the relationship of the elastic moduli is satisfied.

[0032] Since the elastic modulus of the second resin constituting the second resin layer 20 is lower than the elastic modulus of the first resin constituting the first resin layer 24, the second resin is softer and more easily deformed than the first resin. Therefore, the second resin layer 20, provided between the first resin layer 24 and at least the tubular member 31, can serve as a buffer layer that buffers thermal stress generated by expansion and contraction of the first resin layer 24. Consequently, the first resin layer 24 can be prevented from being damaged by expansion and contraction of the first resin layer 24, so that the gas can be stably retained in the liner 2.

[0033] In particular, expansion and contraction of the liner 2 are likely to occur even at boundary portions between the body portion 2a of the liner 2 and the lateral end portions 2b, 2c of the liner 2. Therefore, the second resin layer 20 is preferably provided between the first resin layer 24 and the tubular member 31, and between the first resin layer 24 and the dome members 32, 33 to cover the first resin layer 24. With such a configuration, the second resin layer 20, which serves as the buffer layer, is disposed at the lateral end portions 2b, 2c including the boundary portions, so that damage to the first resin layer 24 is more reliably suppressed. In particular, the difference between the elastic modulus of the second resin and the elastic modulus of the first resin is preferably in the range of 300 MPa to 500 MPa as a condition under which such an effect is easily observed.

[0034] Furthermore, the linear expansion coefficient of the second resin constituting the second resin layer 20 is preferably lower than the linear expansion coefficient of the first resin constituting the first resin layer 24. Thus, the first reinforcing layer 30 made of the fiber-reinforced resin, the second resin layer 20 made of the second resin, and the first resin layer 24 made of the first resin are not easily expanded and contracted by heat in this order, whereby shear stress due to thermal expansion and contraction is less likely to occur at an interface between the first resin layer 24 and the second resin layer 20. For example, when the second resin is an epoxy resin (linear expansion coefficient of 4.5 to 6.5 × 10 -5 / K), Nylon 6 (linear expansion coefficient of 5.9 to 10 × 10 -5 / K) and nylon 6.6 (linear expansion coefficient from 8.0 to 10 × 10 -5 / K) can be used as the first resin.

[0035] The gas permeability of the first resin is higher than the gas permeability of the second resin. That is, the second resin has a higher gas barrier property than the first resin. Accordingly, when the gas charged into the storage space 5 permeates the first resin layer 24, the passed gas does not accumulate at the interface between the first resin layer 24 and the second resin layer 20 and is discharged from the second resin layer 20 to the outside through the reinforcing portion 3. This makes it possible to prevent the first resin layer 24 and the second resin layer 20 from peeling off due to the gas accumulated at the interface between the first resin layer 24 and the second resin layer 20.

[0036] The degree of gas permeability of the resin can be specified, for example, by measuring the gas permeation amount of the resin according to Japanese Industrial Standard (JIS) K 7126 or the like. The relationship of gas permeability between the first resin and the second resin can be satisfied by appropriately selecting the resins from those mentioned above. Furthermore, in the case of a thermoplastic resin, the gas permeability can be adjusted by adjusting the average molecular weight of the monomer, the degree of polymerization of the resin from monomer to polymer, and the like. On the other hand, in the case of a thermosetting resin, the gas permeability can be adjusted by adjusting the average molecular weight of the uncured thermosetting resin and the type and amount of the curing agent.

[0037] It is preferable that the first resin constituting the first resin layer 24 and the second resin constituting the second resin layer 20 have solubility parameters (SP) that are close to each other. Here, the SP value represents a solubility parameter, and the closer the SP values ​​of the resins are to each other, the higher the compatibility (affinity). In the embodiment, it is even more preferable that the difference (absolute value) in the SP value between the resins of the first resin layer 24 and the second resin layer 20 is 7 or less.

[0038] By setting the difference in SP value to 7 or less, the compatibility between the first resin layer 24 and the second resin layer 20 is increased, and the adhesion between the first resin layer 24 and the second resin layer 20 is improved. With the improved adhesion, it is possible to prevent the first resin layer 24 and the second resin layer 20 from peeling off due to the difference in expansion and contraction between the first resin layer 24 and the second resin layer 20 caused by a temperature change when the high-pressure tank 1 is used. For example, in the case of an epoxy resin, the SP value is in the range of 9.7 to 10.9, in the case of nylon 6, the SP value is about 11.6, and in the case of nylon 6.6, the SP value is 13.6. Thus, by selecting these resins as the first resin and the second resin, the SP values ​​can satisfy the above-mentioned relationship.

[0039] The SP value relationship between the first resin and the second resin can be satisfied by appropriately selecting the first resin and the second resin from the resins exemplified above. For the thermosetting resin, a desired SP value can be adjusted by adjusting the type and amount of the curing agent to be added to the thermosetting resin, and the like. On the other hand, for the thermoplastic resin, a desired SP value can be adjusted by adjusting the average molecular weight and the like.

[0040] For example, if the resin constituting the fiber-reinforced resin of the first reinforcing layer 30 is an epoxy resin, the second resin of the second resin layer 20 is an epoxy resin, and the first resin of the first resin layer 24 is preferably nylon 6 or nylon 6,6. Thus, not only is the above-described relationship of elastic modulus between the first and second resins satisfied, but also the relationships of the linear expansion coefficient, the SP value, and the like between the first and second resins are easily satisfied. Furthermore, if the second resin of the second resin layer 20 is nylon 6,6, the first resin of the first resin layer 24 is preferably nylon 6.

[0041] In the second resin layer 20, the body portion 21 and the side end portions 22, 23 may be made of the same type of second resin, and alternatively, the body portion 21 and the side end portions 22, 23 may be made of different types of second resin. 2. Manufacturing process of the high-pressure tank 1

[0042] Next, a manufacturing method of the high pressure tank 1 according to the embodiment will be described. Fig. 3 is a flowchart showing a process of manufacturing the high pressure tank 1. As shown in Fig. 3, the manufacturing method of the high-pressure tank 1 includes a preparation step S1, a bonding step S2, a second reinforcing layer forming step S3, and a first resin layer forming step S4. 2-1. Preparation step S1

[0043] In the preparation step S1, the tubular member 31 and the dome members 32, 33 coated with the resin layer serving as the second resin layer 20 may be prepared separately. Alternatively, as described below, the tubular member 31 and the dome members 32, 33 may be formed separately and then coated with a resin layer. Formation of the tubular element / dome element

[0044] The formation of the tubular member 31 and the formation of the dome members 32, 33 are performed independently of each other. Therefore, the formation of the tubular member 31 and the formation of the dome members 32, 33 can be performed in parallel, or one of the formations can be performed first. First, a formation method of the tubular member 31 will be described below.

[0045] In the educational process of the Fig. 7, the tubular element 31 is formed, for example, by winding a fiber layer or fiber sheet F1 around the outer surface of a columnar mandrel 100, as shown in Fig. 4. An outer diameter of the mandrel 100 corresponds to an inner diameter of the tubular member 31 and also corresponds to a diameter of an inner periphery of each of the peripheral edge portions 32a, 33a of the dome members 32, 33 at their outermost positions. The material of the mandrel 100 is not particularly limited. However, the material is preferably a metal to ensure sufficient strength to prevent deformation of the mandrel 100 when the fiber sheet F1 is wound.

[0046] In forming the tubular member 31, the prepared fiber sheet F1 is wound multiple times around the mandrel 100 while the mandrel 100 is rotated in a circumferential direction by a rotation mechanism (not shown). The fiber sheet F1 corresponds to a sheet in which reinforcing fibers aligned in one direction are impregnated with resin. The fiber sheet F1 is wound around the mandrel 100 such that the reinforcing fibers are aligned in the circumferential direction of the mandrel 100. Therefore, the tubular member 31 is formed in which the reinforcing fibers are aligned in the circumferential direction.

[0047] For example, a so-called unidirectional (UD) sheet is used as the fiber sheet F1. A UD sheet is a sheet in which a plurality of fiber bundles are aligned in one direction and woven with a retaining thread. However, a fiber sheet in which a plurality of fiber bundles aligned in a single direction and another plurality of fiber bundles intersecting therewith, e.g., orthogonally to the direction, are woven can also be used.

[0048] As the reinforcing fibers of the fiber sheet F1, the same materials as those exemplified for the first reinforcing layer 30 can be used, and examples of the resin impregnated into the reinforcing fiber include the same materials as those exemplified for the first reinforcing layer 30.

[0049] When the resin of the fiber layer F1 is a thermosetting resin, the fiber sheet F1 wound around the mandrel 100 is heated, so that the uncured thermosetting resin enters a fully cured state. Here, the term "fully cured state" refers to a state in which the polymerization reaction of the uncured thermosetting resin is completed, and the thermosetting resin is not further cured by heating. However, if the dimensional stability of the tubular member 31 is ensured, the fiber sheet F1 wound around the mandrel 100 is heated, so that the uncured thermosetting resin enters an incompletely cured state.

[0050] The term "incompletely cured state" here refers to a state in which the fluidity of the thermosetting resin is reduced to ensure dimensional stability in a later step when the polymerization reaction of the uncured thermosetting resin proceeds by heating. In the following description, the fully cured state is referred to as full cure, the incompletely cured state is referred to as pre-cure, and the full cure and pre-cure states are collectively referred to as thermal cure.

[0051] Furthermore, when the resin impregnated into the fiber sheet F1 is a thermoplastic resin, the thermoplastic resin is cooled in a softened state to solidify the resin in the fiber sheet F1. With the above process, an end surface 31d for abutment is formed on each of the peripheral edge portions 31a of the tubular member 31.

[0052] After the resin is thermally cured or solidified, the tubular member 31 is removed from the mandrel 100. The dimensional stability of the tubular member 31 is improved by the thermal curing or solidification of the resin. Therefore, the tubular member 31 can be easily removed from the mandrel 100, and deformation of the tubular member 31 when the tubular member 31 is removed from the mandrel 100 can be suppressed.

[0053] In the embodiment, the example in which the fiber sheet F1 is wound around the outer surface of the mandrel 100 to form the tubular member 31 was described. However, the tubular member 31 may also be formed by hoop winding a resin-impregnated fiber bundle on the outer surface of the mandrel 100 using a filament winding (FW) process. Alternatively, as another method, the tubular member 31 may be formed by a so-called centrifugal winding (CW) process in which a fiber sheet is attached to an inner surface of the rotating mandrel 100.

[0054] In the educational process of the Fig. 6, a resin-impregnated fiber bundle F2 is wound around an outer surface of a mandrel 200, for example by the FW process, as shown in Fig. 5. Specifically, the mandrel 200 includes a main body portion 201 and a shank portion 202 extending outwardly from one end of the main body portion 201.

[0055] The main body portion 201 has a circular shape when viewed from an axial direction of the shaft portion 202. An outer peripheral surface of the main body portion 201 at the center in the axial direction is provided with a groove 201a extending over the entire circumference in the circumferential direction. The outer surface of the mandrel 200 has a shape in which the dome-shaped lateral end portions 2b, 2c of the liner 2 are connected to each other without the body portion 2a, and is provided with the groove 201a at a position corresponding to a seam between the connected lateral end portions 2b, 2c. The shaft portion 202 is rotatably supported by a rotation mechanism (not shown).

[0056] In forming the dome elements 32, 33, the mandrel 200 is first rotated to wind the fiber bundle F2 so that the fiber bundle F2 covers the outer surface of the mandrel 200, thereby forming a wound body 35. During this process, by winding the fiber bundle F2 around the outer surface of the shaft portion 202, the tubular projection portion 32b having a through hole 32c is provided, as shown in Fig. 6. The fiber bundle F2 is wound at an angle to provide an intersection, for example, of 30 to 50 degrees, with respect to the axial direction of the shaft portion 202. The material of the mandrel 200 is not particularly limited. However, the material is preferably a metal to ensure sufficient strength to prevent deformation of the mandrel 200 when the fiber bundle F2 is wound.

[0057] The same materials as those exemplified for the first reinforcing layer 30 can be used as the reinforcing fibers of the fiber bundle F2, and examples of the resin impregnated into the reinforcing fibers include the same materials as those exemplified for the first reinforcing layer 30. When the resin of the fiber bundle F2 is a thermoplastic resin, the fiber bundle F2 is wound around the mandrel 200 while the thermoplastic resin is heated and softened. On the other hand, when the resin of the fiber bundle F2 is a thermosetting resin, the fiber bundle F2 is wound around the mandrel 200 while the thermosetting resin is in an uncured state.

[0058] Next, the winding body 35 wound around the outer surface of the mandrel 200 is divided into two parts using a cutting device or cutting tool 210 (see Fig. 5). After the above process, as in Fig. 5, the split bobbins 35 are removed from the mandrel 200 to form a pair of dome elements 32, 33.

[0059] In particular, the neck 4 is formed on the outer surface of the projection portion 32b in the Fig. 5. When the resin impregnated into the fiber bundle F2 of the wound body 35 is a thermosetting resin, the wound body 35 is thermally cured under the conditions (heating temperature and heating time) of pre-curing or full-curing. When the resin impregnated into the fiber bundle F2 of the wound body 35 is a thermoplastic resin, the thermoplastic resin is cooled in the softened state to solidify the resin in the fiber bundle F2.

[0060] When the resin impregnated into the fiber bundle F2 is thermally cured or solidified as described above, a blade of the cutting tool 210 is inserted into the groove 201a of the mandrel 200 while rotating the mandrel 200. With the above process, the cutting tool 210 cuts the fiber bundle F2, so that the bobbin 35 can be divided into two parts. The two dome members 32, 33 are formed by removing the divided bobbins from the mandrel 200. With the above process, annular end surfaces 32d, 33d for abutment are formed on the peripheral edge portions 32a, 33a of the dome members 32, 33. The cutting tool 210 is not particularly limited.However, the cutting tool 210 may be, for example, a cutting tool having a blade on an outer peripheral surface of a rotating disk, a cutting tool having a blade on a side surface of a thin plate, or a laser cutting device that cuts the fiber bundle F2 using a laser light.

[0061] The resin impregnated into the fiber bundle F2 is cut by the cutting tool 210 in a state where the resin is thermally cured or solidified. Therefore, deformation of the fiber bundle F2 during cutting is suppressed, and at the same time, deformation of the two mandrel elements 32, 33 when they are removed from the mandrel 200 can also be suppressed.

[0062] Furthermore, the example in which the resin of the fiber bundle F2 is cut by the cutting tool 210 in a state where the resin is thermally cured or solidified has been described. However, the resin of the fiber bundle F2 may also be cut by the cutting tool 210 without being thermally cured or solidified. In this case, the fiber bundle F2 may be thermally cured or solidified after being cut by the cutting tool 210.

[0063] In the embodiment, the example in which the resin-impregnated fiber bundle F2 is wound around the outer surface of the mandrel 200 was described. However, the non-resin-impregnated fiber bundle F2 may be wound around the outer surface of the mandrel 200 to form the wound body, and the wound body may then be impregnated with resin.

[0064] Furthermore, in the embodiment, the example in which the neck 4 is attached to the outer surface of the protrusion portion 32b after the fiber bundle F2 is wound around the outer surface of the mandrel 200 was described. However, the neck may be attached in advance to a connecting portion between the main body portion 201 and the shaft portion 202 of the mandrel 200, and the fiber bundle F2 may be wound around a part of the neck together with the outer surface of the mandrel 200 in this state. In this case, the part of the neck is covered and held by the fiber bundle F2. Therefore, the neck can be firmly fixed by the fiber bundle F2. Coating the resin layer

[0065] As in the Fig. 7 and Fig. 8, the inner surfaces of the tubular member 31 and the two dome members 32, 33 formed as described above are coated with resin layers 21A to 23A. The projecting inner surfaces are contact surfaces 31f to 33f that come into contact with the outer surface of the liner 2 and are surfaces located on the inside of the high-pressure tank 1. As shown in Fig. 7, the resin layer 21A coated on the contact surface 31f of the tubular member 31 corresponds to the body portion 21 of the Fig. 1 shown second resin layer 20. As in Fig. 8, the resin layers 22A, 23A coated on the contact surfaces 32f, 33f of the dome elements 32, 33 correspond to the lateral end regions 22, 23 of the Fig. 1 shown second resin layer 20.

[0066] As a forming method of the resin layers 21A to 23A, the resin layer 21A can be formed by applying the liquid or softened second resin to the contact surface 31f, or can be formed, for example, by attaching a sheet made of the second resin. The resin layers 22A, 23A can be formed by applying the liquid or softened second resin to the contact surfaces 32f, 33f, or can be formed, for example, by attaching a sheet made of the second resin.

[0067] Examples of the second resin include the same materials as those for the second resin layer 20. In the embodiment, the resin layers 21A to 23A are formed individually, so that it is easy to use different types of resin for the second resin constituting the resin layers 21A to 23A.

[0068] Further, as the forming method of the resin layers 21A to 23A, a thermosetting two-component mixed resin such as an epoxy resin may be applied to the contact surfaces 31f to 33f and dried to form the resin layers 21A to 23A. In addition, the resin layers 21A to 23A made of a thermoplastic resin such as nylon 6 may be formed by applying a resin containing a thermoplastic resin monomer such as ε-caprolactam and a catalyst to the contact surfaces 31f to 33f and heating the applied resin to a temperature equal to or higher than the temperature at which the polymerization reaction of the thermoplastic resin monomer starts.

[0069] If the second resin is a thermosetting resin, the thermosetting resin may be uncured or precured by heating, so that the thermosetting resin enters an incompletely cured state. Furthermore, the thermosetting resin may be fully cured by heating, so that the thermosetting resin enters a fully cured state. If the second resin is a thermoplastic resin, the thermoplastic resin is in a solidified state.

[0070] In the embodiment, the glass transition temperature (Tg) of the second resin is preferably lower than the Tg of the matrix resin impregnated into the reinforcing fibers of the tubular member 31 and the dome members 32, 33. This allows the resin layers 21A to 23A to be formed at a temperature lower than the Tg of the matrix resin of the tubular member 31 and the dome members 32, 33, so that the dimensional stability of the tubular member 31 and the dome members 32, 33 can be ensured. In the case of the thermosetting resin, a desired Tg can be adjusted by adjusting the type and amount of the curing agent to be added to the thermosetting resin. Furthermore, in the case of the thermoplastic resin, a desired Tg can be adjusted by adjusting the average molecular weight of the monomer, the degree of polymerization of the resin from monomer to polymer, and the like.

[0071] In the embodiment, the formation of the tubular member and the dome elements, and the coating of the resin layer are performed separately. However, the formation of the tubular member and the dome elements, and the coating of the resin layer may, for example, be performed simultaneously. Specifically, the tubular member 31 may be formed on the resin layer after the resin layer is deposited on the surface of the Fig. 4 using the method described above. Similarly, the dome elements 32, 33 can be formed by applying the resin layer to the surface of the mandrel 100 shown in Fig. 5 using the method described above, then the wound body 35 is formed on the resin layer, and then the wound body 35 is cut. 2-2. Connection step S2

[0072] In the connection step S2, as shown in the Fig. 9 and Fig. As shown in Fig. 10, the peripheral edge portions 31a on the opposite sides of the tubular member 31 and the peripheral edge portions 32a, 33a of the dome members 32, 33 are bonded. Furthermore, the resin layer 21A coated on the tubular member 31 and the resin layers 22A, 23A coated on the dome members 32, 33 are bonded.

[0073] During the above joining process, the tubular member 31 and the dome members 32, 33 are joined together, and the resin layer 21A and the resin layers 22A, 23A are joined together by causing the end surfaces 31d of the peripheral edge portions 31a of the tubular member 31 to abut against the end surfaces 32d, 33d of the peripheral edge portions 32a, 33a of the dome members 32, 33.

[0074] Consequently, as in Fig. As shown in Figure 11, the first reinforcing layer 30, which has the tubular member 31 and the two dome members 32, 33, and the second resin layer 20, which has the body portion 21 and the lateral end portions 22, 23, are formed simultaneously. The resin layer 21A serves as the body portion 21 of the second resin layer 20, and the resin layers 22A, 23A serve as the lateral end portions 22, 23 of the second resin layer 20.

[0075] Here, the tubular member 31 and the dome members 32, 33 can be bonded using, for example, an adhesive. The adhesive is preferably an adhesive of the same type as the resin of the fiber-reinforced resin constituting the tubular member 31 and the dome members 32, 33. Furthermore, when the resin of the fiber-reinforced resin constituting the tubular member 31 and the dome members 32, 33 is a thermosetting resin, the tubular member 31 and the dome members 32, 33 can be bonded to each other by causing the tubular member 31 and the dome members 32, 33 to abut each other in a state where the thermosetting resin is pre-cured, and then completely curing the thermosetting resin by heating, as described above.

[0076] When the resin of the fiber-reinforced resin constituting the tubular member 31 and the dome members 32, 33 is a thermoplastic resin, the end surfaces 31d of the peripheral edge portions 31a of the tubular member 31 and the end surfaces 32d, 33d of the peripheral edge portions 32a, 33a of the dome members 32, 33 may be heated and then caused to abut each other in a state where the thermoplastic resin is melted to be thermally bonded (joined).

[0077] The resin layer 21A coated on the tubular member 31 and the resin layers 22A, 23A coated on the dome members 32, 33 can be bonded using the adhesive described above. The adhesive is preferably an adhesive of the same type as the resin of the fiber-reinforced resin constituting the tubular member 31 and the dome members 32, 33. However, the adhesive may be made of, for example, the resin of the same type as the resin of the resin layers 21A to 23A. Furthermore, when the resin of the resin layers 21A to 23A is a thermosetting resin, the resin layers 21A to 23A can be bonded to each other by causing the resin layers 21A to 23A to abut in a state where the thermosetting resin is uncured or precured, and then completely curing the thermosetting resin by heating.When the resin of the resin layers 21A to 23A is a thermoplastic resin, respective end portions of the resin layers 21A to 23A may be heated and abutted in a state where the thermoplastic resin is melted to be thermally bonded (joined). 2-3. Step S3 for forming the second reinforcement layer

[0078] In step S3 for forming the second reinforcing layer, as in Fig. 12, the second reinforcing layer 34 is formed to cover the outer surface of the first reinforcing layer 30.

[0079] In this step, the resin-impregnated fiber bundle serving as the second reinforcing layer 34 is wound in a layered manner around the surface of the first reinforcing layer 30 by spiral winding using the FW process. Spiral winding corresponds to a winding method in which the fiber bundle is wound diagonally (within a range of 10° or more and 60° or less) to the axial direction X of the tubular member 31 over the dome members 32, 33. The number of layers of the wound fiber bundles is not particularly limited as long as the strength of the second reinforcing layer 34 is ensured. However, the number of layers of the wound fiber bundle is, for example, about 2 to 10.

[0080] Examples of the reinforcing fibers of the fiber bundle include the same materials as exemplified for the first reinforcing layer 30, and examples of the resin impregnated into the reinforcing fibers include the same materials as exemplified for the first reinforcing layer 30. 2-4. Step S4 to form the first resin layer

[0081] Next, in step S4, the first resin layer is formed as shown in Fig. 12, the first resin layer 24 is formed to cover the surface of the second resin layer 20, and the second reinforcing layer 34, in which the resin is uncured or softened, is provided to cover the surface of the first reinforcing layer 30. The first resin layer 24 is formed by applying the first resin.

[0082] The method for applying the first resin is not particularly limited as long as the first reinforcing layer 30 can be formed on the surface of the second resin layer 20. For example, as shown in Fig. 12, a nozzle 300 is inserted through the through-hole 32c connecting the inner and outer spaces of the second resin layer 20, and the first resin is ejected from the nozzle 300. At the time of ejection, the nozzle 300 is moved along the axial direction X, and the first reinforcing layer 30 is rotated in the circumferential direction.

[0083] Thereby, the first resin is applied to the entire surface of the second resin layer 20. After coating, the nozzle 300 is withdrawn from the interior through the through-hole 32c. Examples of the first resin include the same resins as those exemplified as the resin constituting the first resin layer 24 described above.

[0084] In the embodiment, the glass transition temperature (Tg) of the first resin is preferably lower than the Tg of the second resin constituting the second resin layer 20. This can limit excessive liquefaction of the second resin of the second resin layer 20, which is fully cured or solidified, when the first resin is applied. As described above, in the thermosetting resin, the desired Tg can be adjusted by adjusting the type and amount of the curing agent to be added to the thermosetting resin. Furthermore, in the case of a thermoplastic resin, the desired Tg can be adjusted by adjusting the average molecular weight of the monomer, the degree of polymerization of the resin from monomer to polymer, and the like.

[0085] When the second resin constituting the second resin layer 20 is an uncured or pre-cured thermosetting resin, the gelling temperature of the first resin is preferably at least 10°C lower than the gelling temperature of the second resin. This allows the shape of the liner 2 to be easily maintained because the first resin is fully cured first when the first resin layer 24 and the second resin layer 20 undergo full curing. From the same point of view, it is preferable to use a resin that is fully cured at the ambient temperature of the second resin layer 20 (particularly at room temperature) for the first resin. When the first resin is applied to the surface of the second resin layer 20, the first resin hardens, so that the shape of the liner 2 can be easily maintained.

[0086] When the resin contained in the second reinforcing layer 34 and the first resin are thermoplastic resins, the resins are cooled to solidify. When the thermoplastic resin comprises a thermoplastic resin monomer and a catalyst that polymerizes the thermoplastic resin monomer, the second reinforcing layer 34 and the first resin layer 24 can be formed by heating to a temperature equal to or higher than the starting temperature of the polymerization reaction. On the other hand, when the resin contained in the second reinforcing layer 34 and the first resin are thermosetting resins, the resins are fully cured by heating. When the resins of the first reinforcing layer 30 and the second resin layer 20 are not fully cured, these resins are also fully cured.When the first reinforcing layer 30 and the second resin layer 20 are fully cured, the full curing of the second reinforcing layer 34 and the first resin is preferably performed under a condition that the resin of the first reinforcing layer 30 is not liquefied, and under a condition that the resin of the second resin layer 20 can be liquefied to some extent but is not excessively liquefied.

[0087] Once the resin has fully cured or solidified, the interior of the storage space 5 can be pressurized. This can improve the adhesion between the first resin layer 24 and the second resin layer 20.

[0088] As in Fig. 1, by forming the first resin layer 24, it is possible to form the liner 2 having the first resin layer 24 and the second resin layer 20. Further, when the first resin layer 24 is formed, the seams between the body portion 21 and the side end portions 22, 23 of the second resin layer 20 are covered with the first resin layer 24. Therefore, the airtightness of the liner 2 can be ensured. On the other hand, by forming the second reinforcing layer 34, it is possible to form the reinforcing portion 3 having the first reinforcing layer 30 and the second reinforcing layer 34. Furthermore, by forming the second reinforcing layer 34, it is possible to adhere the dome members 32, 33 to the tubular member 31.

[0089] After the second reinforcing layer 34 is formed together with the first resin layer 24 as described above, the high pressure tank 1 is assembled by attaching the valve 6 to the neck 4 as shown in Fig. 1 shown, completed.

[0090] In the embodiment, the example in which a fiber bundle is spirally wound around the surface of the first reinforcing layer 30 and then the first resin is applied to the surface of the second resin layer 20 was described. However, a fiber bundle may also be spirally wound around the surface of the first reinforcing layer 30 after the first resin is applied to the surface of the second resin layer 20.

[0091] In the embodiment, the second reinforcing layer 34 and the first resin layer 24 are solidified or fully cured simultaneously. However, either the second reinforcing layer 34 or the first resin layer 24 may be solidified or fully cured first, and then the other may be solidified or fully cured.

[0092] Fig. 13 is a schematic sectional view showing a structure of the high-pressure tank 1 according to a first modification of the embodiment. Fig. The first modification shown in FIG. 13 differs from the embodiment in that the liner 2 has the second resin layer 20 only on the body portion 2a. Therefore, the following mainly describes the differences, and the same elements and portions as in the embodiment are denoted by the same reference numerals, and a detailed description thereof will be omitted.

[0093] In the high-pressure tank 1 of the first modification, the liner 2 has a two-layer structure of the first resin layer 24 and the second resin layer 20, which is provided only between the first resin layer 24 and the tubular member 31. Therefore, the second resin layer 20 is composed only of the body portion 21.

[0094] The body portion 2a of the liner 2 has a larger surface area than the lateral end portions 2b, 2c. Therefore, when the liner 2 expands and contracts, the body portion 2a is more easily restrained by the first reinforcing layer 30 than the lateral end portions 2b, 2c. Accordingly, the body portion 2a is more easily damaged than the lateral end portions 2b, 2c. Therefore, in the first modification, the second resin layer 20 is provided only on the body portion 2a that is easily restrained by the first reinforcing layer 30, so that it is possible to more effectively suppress damage to the first resin layer 24 due to the restraint by the first reinforcing layer 30 when the liner 2 expands and contracts.

[0095] The points in which the manufacturing process of the high-pressure tank 1 of the first modification differs from that in Fig. 3 are described below. In the case of the Fig. 3, the prepared dome elements 32, 33 are not coated with the resin layers 22A, 23A, as in Fig. 6. In particular, the contact surfaces 32f, 33f of the dome elements 32, 33 are not coated with the resin layers 22A, 23A after the dome elements 32, 33 are formed as shown in the Fig. 5 and Fig. 6 were trained. In the Fig. In the joining step S2 shown in Fig. 3, the peripheral edge portions 31a on the opposite sides of the tubular member 31 coated with the resin layer 21A and the peripheral edge portions 32a, 33a of the dome members 32, 33 not coated with the resin layers 22A, 23A are joined. Fig. In the first resin layer forming step S4 shown in Fig. 3, the first resin layer 24 is formed to cover the contact surfaces 32f, 33f of the dome members 32, 33 and the surface of the second resin layer 20 (here, the body portion 21). In this way, the liner 2 can be formed, which has the first resin layer 24 and the second resin layer 20 provided only between the first resin layer 24 and the tubular member 31.

[0096] Fig. 14 is a partial sectional view showing a structure of the high-pressure tank 1 according to a second modification of the embodiment. As in Fig. 14, the second modification differs from the embodiment in that the peripheral edge portions 31a, 31a of the tubular member 31 and the peripheral edge portions 32a, 33a of the dome members 32, 33 are fitted. Therefore, the differences will be mainly described below, and the same elements and portions as those in the embodiment are denoted by the same reference numerals, and a detailed description thereof will be omitted.

[0097] In the second modification, the tubular member 31 and the dome members 32, 33 are configured such that the thicknesses of the peripheral edge portions 31a, 32a, 33a gradually decrease in the axial direction X toward their respective distal ends. With such configurations, a step is less likely to be formed in a connecting portion between the outer surface of the tubular member 31 and the outer surfaces of the dome members 32, 33 when the peripheral edge portions 31a, 31a of the tubular member 31 and the peripheral edge portions 32a, 33a of the dome members 32, 33 are superimposed.

[0098] The points in which the manufacturing method of the high-pressure tank 1 of the second modification differs from that in Fig. 3 are described below. In the Fig. 3, in order to gradually reduce the thickness of the two end portions of the tubular member 31 in the axial direction X, the fiber bundle may be woven so that the thickness of the fiber bundle at the end portions of the tubular member 31 shown in Fig. 4 in the axial direction X (width direction) gradually decreases, or a winding width of the fiber sheet F1 can be gradually reduced. Moreover, the thickness can be gradually reduced by pressing both ends of the tubular member 31 in the axial direction X with a roller, etc. The thickness of the peripheral edge portions 32a, 33a of the dome members 32, 33 can also be reduced compared to the thickness of the other portions by pressing the peripheral edge portions 32a, 33a with a roller, etc.

[0099] Furthermore, in the Fig.In the joining step S2 shown in FIG. 3, the peripheral edge portions 32a, 33a of the dome elements 32, 33 are joined to the peripheral edge portions 31a, 31a of the tubular element 31. Specifically, the peripheral edge portions 31a of the tubular element 31 and the peripheral edge portions 32a, 33a of the dome elements 32, 33 are fitted or assembled with either the peripheral edge portions 31a or the peripheral edge portions 32a, 33a on the inside and the others on the outside. Consequently, the connection between the tubular element 31 and the dome elements 32, 33 can be further strengthened, making it possible to more reliably secure the dome elements 32, 33 and the tubular element 31 against loosening due to gas pressure.

[0100] In the second modification, the second resin layer 20 may be formed only between the first resin layer 24 and the tubular member 31, as in the first modification.

[0101] Furthermore, according to a third modification of the embodiment, although not shown in the drawings, the high-pressure tank 1 may be provided with connecting members between the tubular member 31 and the dome members 32, 33. With such a configuration, the adhesiveness between the tubular member 31 and the dome members 32, 33 can be improved, so that the dome members 32, 33 and the tubular member 31 can be more reliably prevented from being separated by gas pressure. Since the connecting members are also provided between the body portion 21 and the side end portions 22, 23, the connecting members can each serve as a sealing material. With this configuration, the airtightness of the high-pressure gas stored in the liner 2 can be improved.

[0102] The connecting elements are arranged between the peripheral edge portions 31a of the tubular member 31, which comprise the body portion 21, and the peripheral edge portions 32a, 33a of the dome members 32, 33, which comprise the lateral end portions 22, 23. The connecting element may have a ring shape corresponding to the end surfaces 31d to 33d including the second resin layer 20, or may have a shape matching the peripheral edge portions 31a and the peripheral edge portions 32a, 33a. The connecting element is made of resin and is preferably made of the same resin as the fiber-reinforced resin constituting the tubular member 31 and the dome members 32, 33, or may be made of the same resin as that of the second resin layers 20. In the third modification, the second resin layer 20 may be provided only between the first resin layer 24 and the tubular member 31, as in the first modification.

[0103] The embodiment disclosed herein is to be considered in all respects as illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than by the foregoing embodiment, and is intended to include all modifications within the meaning and scope equivalent to those of the claims.

[0104] For example, in the above embodiment, the shape of the body portion of the liner and the tubular member is tubular, but it is not limited to the tubular shape as long as the dome members coated with the resin layer can be connected to the opposite ends of the tubular member coated with the resin layer. For example, the body portion of the liner and the tubular member may have an elongated shape (elliptical shape), a polygonal shape, or the like.

[0105] For example, in the above embodiment, the example in which the through-hole is provided in only one of the dome members and the neck is provided at only one end of the high-pressure tank was described. However, the present invention is not limited to this example, and the through-hole may be provided in both dome members, and the neck may be provided at both ends of the high-pressure tank.

[0106] Furthermore, in the above embodiment, the example in which the first reinforcement layer is constructed of three members (tubular member and dome members) was described. However, the present invention is not limited to this example. For example, the first reinforcement layer may be constructed of four or more members (two or more tubular members and dome members). In this case, after two or more tubular members are connected to each other, the dome members may be connected at the opposite ends of the connected tubular members. Further, after one tubular member is connected to each of the dome members, the tubular members may be connected to each other with dome members.

Claims

[1] High-pressure tank (1), comprising: a liner (2) comprising a body portion (2a) having a tubular shape and lateral end portions (2b, 2c) each having a dome shape, the lateral end portions (2b, 2c) being provided on opposite sides of the body portion (2a); and a reinforcing layer (30) configured to cover an outer surface of the liner (2) and made of a fiber-reinforced resin, wherein: the reinforcing layer (30) comprises a tubular member (31) configured to cover the body portion (2a) and dome members (32, 33) connected to opposite sides of the tubular member (31) to cover the lateral end portions (2b, 2c); the liner (2) comprises a first resin layer (24) defining a storage space (5) for storing gas, and a second resin layer (20) provided between the first resin layer (24) and at least the tubular member (31); a modulus of elasticity of a second resin forming the second resin layer (20) is lower than a modulus of elasticity of a first resin forming the first resin layer (24); the difference between the elastic modulus of the second resin and the elastic modulus of the first resin is in a range of 300 MPa to 500 MPa; and the resin constituting the fiber-reinforced resin of the reinforcing layer (30) is an epoxy resin, the second resin of the second resin layer (20) is nylon 6.6, and the first resin of the first resin layer (24) is nylon 6. [2] The high-pressure tank (1) according to claim 1, wherein the second resin layer (20) is also provided between the first resin layer (24) and the dome members (32, 33) to cover the first resin layer (24).

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