1. A method for manufacturing a high-pressure tank provided with a liner for containing gas and a reinforcing layer made of fiber-reinforced resin for covering the outer surface of the liner, wherein the reinforcing layer is a layer formed by integrating a cylindrical member and two dome members provided at both ends of the cylindrical member, and one of the dome members includes a dome body and a cylindrical protrusion protruding from the dome body and having a gas flow path for filling and discharging gas,

the method of manufacturing a high-pressure tank is characterized in that,

comprising the step of forming at least said one dome member, wherein,

the step of forming at least the one dome member comprises:

a step of arranging a 1 st fiber bundle impregnated with a 1 st resin to form a part of the protruding portion and a part of the dome main body portion; and

a step of disposing a 2 nd fiber bundle impregnated with a 2 nd resin so as to cover the 1 st fiber bundle, wherein,

curing a 1 st resin impregnated into the 1 st fiber bundle while arranging the 1 st fiber bundle in the protruding portion such that the fiber direction of the 1 st fiber bundle is along the axial direction of the protruding portion and continuous from the protruding portion to the dome main body portion,

the 2 nd fiber bundle is disposed so that a fiber direction of the 2 nd fiber bundle intersects with a fiber direction of the 1 st fiber bundle.

2. The method of manufacturing a high-pressure tank according to claim 1,

the 1 st resin is composed of a thermoplastic resin,

the 2 nd resin is composed of a thermosetting resin,

curing the 1 st resin impregnated into the 1 st fiber bundle while arranging the 1 st fiber bundle in a state where the 1 st resin is softened,

after the 2 nd fiber bundle is disposed in a state where the 2 nd resin is not cured, the 2 nd resin is heated and cured.

3. The method of manufacturing a high-pressure tank according to claim 2,

in forming the two dome members, the face of the dome member that is in contact with the gas is formed from the 1 st fiber bundle.

4. A high-pressure tank is characterized by comprising:

a liner configured to contain a gas; and

a reinforcing layer formed of a fiber-reinforced resin so as to cover an outer surface of the liner,

the reinforcing layer is a layer in which a tube member and two dome members provided at both ends of the tube member are integrally formed, one of the dome members includes a dome main body portion and a protruding portion that protrudes from the dome main body portion and has a gas flow path for filling and discharging gas,

the dome main body part and the protruding part are formed by a 1 st fiber bundle impregnated with a 1 st resin and a 2 nd fiber bundle impregnated with a 2 nd resin,

the 1 st fiber bundle constitutes a part of the protrusion and a part of the dome main body, the 1 st fiber bundle is arranged such that a fiber direction of the 1 st fiber bundle is continuous from the protrusion to the dome main body along an axial direction of the protrusion in the protrusion,

the 2 nd fiber bundle is disposed so as to cover the 1 st fiber bundle and to cross the fiber direction of the 2 nd fiber bundle with respect to the fiber direction of the 1 st fiber bundle.

5. The high-pressure tank according to claim 4,

the 1 st resin is composed of a thermoplastic resin,

the 2 nd resin is composed of a thermosetting resin,

the face of the dome member that is in contact with the gas is formed by the 1 st fiber bundle.

6. The method for manufacturing a high-pressure tank according to any one of claims 1 to 3,

the 1 st fiber bundle is arranged on the outer periphery of an insert arranged inside the protruding portion, and the insert has a female screw on the inner peripheral surface.

7. The high-pressure tank according to claim 4 or 5,

a cylindrical insert is disposed inside the protruding portion,

the insert has an internal thread on an inner circumferential surface.

Background

Conventionally, as a high-pressure tank used for storing and supplying hydrogen or the like, a tank including a tank main body and a joint attached to an opening end portion in a longitudinal direction of the tank main body is known. The tank main body includes, for example, a liner for hermetically holding hydrogen gas, and a reinforcing layer reinforced by wrapping an outer surface of the liner with a fiber bundle impregnated with resin.

For example, japanese patent application laid-open No. 2018-179201 discloses a high-pressure tank including a liner, a reinforcing layer covering an outer surface of the liner, and a joint provided at an end of the reinforcing layer. The high-pressure tank disclosed in jp 2018 a-179201 a includes a liner, a reinforcing layer made of fiber-reinforced resin covering the outer surface of the liner, and a joint provided at an end of the reinforcing layer. The joint has a cylindrical projecting portion having a gas flow path for filling and discharging a gas such as hydrogen gas.

However, in order to reduce the weight of the high-pressure tank, from the viewpoint of transportation of the high-pressure tank, improvement in fuel efficiency of a vehicle on which the high-pressure tank is mounted, and the like, it is also conceivable to reduce the weight by forming a portion corresponding to the joint with a fiber-reinforced resin.

In this case, for example, it is conceivable to form the reinforcing layer having a portion corresponding to the joint by winding a fiber bundle impregnated with a resin around the outer surface of a liner or the like provided with a cylindrical protrusion having a gas flow passage by a filament winding method or the like. However, since the inside of the high-pressure tank becomes a very high pressure, a large force toward the axial outside is applied to the valve attached to the tip end of the protrusion, and therefore a large force toward the axial outside is also applied to the protrusion itself. In this case, since the fiber bundle is wound in a spiral shape around the protruding portion, it is difficult to secure the tensile strength in the axial direction of the protruding portion. Therefore, it is considered that the protruding portion is damaged.

Disclosure of Invention

The invention provides a high-pressure tank and a manufacturing method thereof, wherein the high-pressure tank can be lightened, and damage to a protruding part with a gas flow path can be inhibited.

A method of manufacturing a high-pressure tank according to a first aspect of the present invention is a method of manufacturing a high-pressure tank including a liner for accommodating a gas and a reinforcing layer made of a fiber-reinforced resin for covering an outer surface of the liner, the reinforcing layer being a layer formed by integrating a tube member and two dome members provided at both ends of the tube member, one of the dome members including a dome body and a cylindrical protruding portion protruding from the dome body and having a gas flow path for filling and discharging a gas, the method including a step of forming at least one of the dome members, wherein the step of forming at least one of the dome members includes: a step of arranging a 1 st fiber bundle impregnated with a 1 st resin to form a part of the protrusion and a part of the dome main body; and disposing a 2 nd fiber bundle containing a 2 nd resin so as to cover the 1 st fiber bundle, wherein the 1 st fiber bundle impregnated with the 1 st fiber bundle is cured while the 1 st fiber bundle is disposed so that a fiber direction of the 1 st fiber bundle is along an axial direction of the protrusion and is continuous from the protrusion to the dome main body portion, and the 2 nd fiber bundle is disposed so that a fiber direction of the 2 nd fiber bundle intersects with a fiber direction of the 1 st fiber bundle.

According to the method of manufacturing the high-pressure tank of the present invention, the 1 st fiber bundle is arranged so that the fiber direction of the protrusion portion is along the axial direction of the protrusion portion. This ensures the axial tensile strength of the protruding portion. Further, the 1 st fiber bundle is disposed so as to be continuous from the protruding portion to the dome main body portion, and the 2 nd fiber bundle is disposed so as to cover the 1 st fiber bundle. Thus, the 2 nd fiber bundle can restrain the 1 st fiber bundle from moving, and the protrusion can be prevented from falling off from the dome main body. Further, since the 2 nd fiber bundle is provided so that the fiber direction of the 2 nd fiber bundle intersects with the fiber direction of the 1 st fiber bundle, not only the tensile strength in the axial direction but also the tensile strength in other directions such as the radial direction can be ensured. Therefore, even when the inside of the high-pressure tank becomes high-pressure and a large force toward the outside in the axial direction is applied to the protruding portion, the protruding portion can be suppressed from being damaged. Therefore, it is not necessary to provide a joint, and the high-pressure tank can be made lightweight.

The following may be configured: in the method of manufacturing a high-pressure tank according to the first aspect, the 1 st resin is made of a thermoplastic resin, the 2 nd resin is made of a thermosetting resin, the 1 st resin impregnated into the 1 st fiber bundle is cured while the 1 st fiber bundle is disposed in a state where the 1 st resin is softened, and after the 2 nd fiber bundle is disposed in a state where the 2 nd resin is not cured, the 2 nd resin is heated and cured. In this way, by using the thermoplastic resin as the 1 st resin impregnated into the 1 st fiber bundle, the 1 st fiber bundle is arranged on the surface of the core member or the liner, for example, in a state where the 1 st resin is softened, whereby the heat of the 1 st fiber bundle is taken away by the core member or the liner, and the resin impregnated into the 1 st fiber bundle is cured. Thereby, the 2 nd fiber bundle is arranged on the 1 st fiber bundle in the 1 st resin cured state. Therefore, the 1 st fiber bundle is not bent or displaced when the 2 nd fiber bundle is arranged, and therefore, the tensile strength in the axial direction of the protruding portion can be suppressed from being lowered. Further, by using the thermosetting resin as the 2 nd resin impregnated into the 2 nd fiber bundle, the mechanical strength of the projection after curing the 2 nd resin can be easily improved.

The following may be configured: in the method of manufacturing the high-pressure tank according to the first aspect, when the two dome members are formed, the surface of the dome member that contacts the gas is formed by the 1 st fiber bundle. Since the thermoplastic resin has gas barrier properties, the surface of the dome member that contacts the gas is formed of the 1 st fiber bundle impregnated with the thermoplastic resin, so that it is not necessary to provide (both dome-shaped end portions of) the liner along the inner surface of the dome member. This makes it possible to further reduce the weight of the high-pressure tank.

A high-pressure tank according to a second aspect of the present invention includes: a liner configured to contain a gas; and a reinforcing layer configured to cover an outer surface of the liner and made of a fiber-reinforced resin, wherein the reinforcing layer is a layer that integrates a cylindrical member and two dome members provided at both ends of the cylindrical member, and one of the dome members includes a dome main body portion and a protrusion portion that protrudes from the dome main body portion and has a gas flow path for filling and discharging gas, wherein the dome main body portion and the protrusion portion are formed of a 1 st fiber bundle impregnated with a 1 st resin and a 2 nd fiber bundle impregnated with a 2 nd resin, wherein the 1 st fiber bundle constitutes a part of the protrusion portion and a part of the dome main body portion, and the 1 st fiber bundle is arranged so that a fiber direction of the 1 st fiber bundle is continuous from the protrusion portion to the dome main body portion along an axial direction of the protrusion portion at the protrusion portion, the 2 nd fiber bundle is arranged so as to cover the 1 st fiber bundle and to cross the fiber direction of the 2 nd fiber bundle with respect to the fiber direction of the 1 st fiber bundle.

According to the high-pressure tank relating to the second aspect of the present invention, the 1 st fiber bundle is arranged so that the fiber direction is along the axial direction of the protrusion in the protrusion. This ensures the axial tensile strength of the protruding portion. The 1 st fiber bundle is arranged to be continuous from the protrusion portion to the dome main body portion, and the 2 nd fiber bundle is arranged to cover the 1 st fiber bundle. Thus, the 2 nd fiber bundle restricts the movement of the 1 st fiber bundle, and the protrusion can be prevented from falling off from the dome main body. Further, since the 2 nd fiber bundle is provided so that the fiber direction of the 2 nd fiber bundle intersects with the fiber direction of the 1 st fiber bundle, not only the tensile strength in the axial direction but also the tensile strength in other directions such as the radial direction can be ensured. Therefore, even when the inside of the high-pressure tank becomes high-pressure and a large force toward the outside in the axial direction is applied to the protruding portion, damage to the protruding portion can be suppressed. Therefore, it is not necessary to provide a joint, and the high-pressure tank can be made lightweight.

The following may be configured: in the high-pressure tank according to the second aspect, the 1 st resin is made of a thermoplastic resin, the 2 nd resin is made of a thermosetting resin, and the surface of the dome member that contacts the gas is formed of the 1 st fiber bundle. Since the thermoplastic resin has gas barrier properties, the surface of the dome member that contacts the gas is formed of the 1 st fiber bundle impregnated with the thermoplastic resin, so that it is not necessary to provide (the dome portion of) the liner along the inner surface of the dome member. This makes it possible to further reduce the weight of the high-pressure tank. Further, by using the 2 nd resin impregnated in the 2 nd fiber bundle as a thermosetting resin, the mechanical strength of the protruding portion can be easily improved.

The following may be configured: in the method of manufacturing the high-pressure tank according to the first aspect, the 1 st fiber bundle is arranged on the outer periphery of the insert arranged inside the protruding portion, and the insert has a female screw on the inner peripheral surface. Thus, the insert can be disposed inside the protruding portion of the dome member, and the valve having the male screw on the outer peripheral surface can be attached to the protruding portion by screwing the female screw on the inner peripheral surface of the insert. With this configuration, even if the internal pressure of the high-pressure tank acts on the valve and a tensile force acting toward the outside of the high-pressure tank in the axial direction acts on the protruding portion, stress concentration on a specific portion can be avoided, and damage to the liner can be prevented. Further, the following may be configured: the 1 st fiber bundle is disposed on the outer periphery of the 2 nd fiber bundle disposed on the outer periphery of the insert, and the 2 nd fiber bundle is further disposed on the outer periphery thereof, whereby the 1 st fiber bundle is disposed in the intermediate layer between the 2 nd fiber bundles. In this case, both surfaces of the 1 st fiber bundle can be bonded to the 2 nd fiber bundle.

The following may be configured: in the high-pressure tank according to the second aspect, a cylindrical insert having a female screw on an inner peripheral surface is disposed inside the protruding portion. Thus, the valve having the male screw on the outer peripheral surface thereof can be attached to the protruding portion by screwing the female screw on the inner peripheral surface of the insert. With this configuration, even when the internal pressure of the high-pressure tank acts on the valve and a tensile force acting on the protrusion in the axial direction outward of the high-pressure tank acts on the protrusion, stress concentration on a specific portion can be avoided, and damage to the liner can be prevented.

According to the present invention, it is possible to provide a high-pressure tank and a method of manufacturing the same, in which the weight of the high-pressure tank is reduced and damage to a protruding portion having a gas flow path can be suppressed.

Drawings

Features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which like reference numerals represent like elements, and wherein,

fig. 1 is a sectional view showing the structure of a high-pressure tank according to embodiment 1 of the present invention.

Fig. 2 is a flowchart illustrating a method of manufacturing a high-pressure tank according to embodiment 1 of the present invention.

Fig. 3 is a flowchart showing a dome member forming step of the method for manufacturing a high-pressure tank according to embodiment 1 of the present invention.

Fig. 4 is a perspective view for explaining a dome member forming step in the method for manufacturing a high-pressure tank according to embodiment 1 of the present invention.

Fig. 5 is a cross-sectional view for explaining a dome member forming step in the method for manufacturing a high-pressure tank according to embodiment 1 of the present invention.

Fig. 6 is a perspective view for explaining a modification of the dome member forming step in the method for manufacturing a high-pressure tank according to embodiment 1 of the present invention.

Fig. 7 is a perspective view for explaining a modification of the dome member forming step in the method for manufacturing a high-pressure tank according to embodiment 1 of the present invention.

Fig. 8 is a perspective view for explaining a tube member forming step in the method for manufacturing a high-pressure tank according to embodiment 1 of the present invention.

Fig. 9 is a perspective view for explaining a joining step in the method for manufacturing a high-pressure tank according to embodiment 1 of the present invention.

Fig. 10 is a cross-sectional view for explaining a joining step in the method for manufacturing a high-pressure tank according to embodiment 1 of the present invention.

Fig. 11 is a diagram for explaining the relationship between the fiber direction in the protruding portion and the tensile strength in the axial direction.

Fig. 12 is a sectional view showing the structure of the high-pressure tank according to embodiment 2 of the present invention.

Fig. 13 is a perspective view for explaining a dome member forming step in the method for manufacturing a high-pressure tank according to embodiment 2 of the present invention.

Fig. 14 is a perspective view for explaining a dome member forming step in the method for manufacturing a high-pressure tank according to the modification of the present invention.

Fig. 15 is a sectional view showing the structure of the high-pressure tank according to embodiment 3 of the present invention.

Fig. 16 is a perspective view for explaining a dome member forming step in the method for manufacturing a high-pressure tank according to embodiment 3 of the present invention.

Fig. 17 is a sectional view showing an example of the structure of a conventional high-pressure tank.

Fig. 18 is a top view showing an example of stress distribution of a conventional high-pressure tank.

Detailed Description

Embodiment 1

Hereinafter, a method of manufacturing the high-pressure tank 10 according to embodiment 1 of the present invention will be described with reference to the drawings, but the structure of the high-pressure tank 10 will be described in a simple manner. Hereinafter, the high-pressure tank 10 will be described as a tank filled with high-pressure hydrogen gas to be mounted on a fuel cell vehicle, but may be used for other applications. The gas that can be filled in the high-pressure tank 10 is not limited to high-pressure hydrogen gas.

As shown in fig. 1, the high-pressure tank 10 is a high-pressure gas storage container having a substantially cylindrical shape with dome-shaped ends. The high-pressure tank 10 includes: an inner liner 11 having gas barrier properties; and a fiber-reinforced resin layer 12 made of a fiber-reinforced resin covering the outer surface of the liner 11. The fiber-reinforced resin layer 12 includes a reinforcement body 20 as a reinforcing layer covering the outer surface of the liner 11, and an outer reinforcing layer 13 covering the outer surface of the reinforcement body 20. An opening is formed at one end of the high-pressure tank 10. In addition, the high-pressure tank 10 of the present embodiment is not provided with a joint. Further, the other end of the high-pressure tank 10 is not formed with an opening.

The liner 11 is formed along the inner surface of the reinforcement body 20. The liner 11 is a resin-made member forming a housing space 17 filled with high-pressure hydrogen gas. The resin constituting the liner 11 is preferably a resin having good performance of holding the filled gas (here, hydrogen gas) in the accommodation space 17, that is, good gas barrier properties. Examples of such resins include thermoplastic resins such as polyamide, polyethylene, ethylene-vinyl alcohol copolymer resin (EVOH), and polyester, and thermosetting resins such as epoxy resins. The storage space 17 defined by the liner 11 may be filled with, for example, various compressed gases such as CNG (compressed natural gas), various liquefied gases such as LNG (liquefied natural gas) and LPG (liquefied petroleum gas), and other gases, in addition to hydrogen gas, as fuel gas.

The reinforcement body 20 covers the outer surface of the liner 11 and has a function of improving the mechanical strength such as rigidity and pressure resistance of the high-pressure tank 10 by reinforcing the liner 11. As will be described later, the reinforcing body 20 is a layer having a cylindrical tubular member 21 and two dome members 22 and 23 connected to both ends of the tubular member 21 and integrally formed therewith. In the present embodiment, the dome member 22 is composed of the 1 st resin layer 121 and the 2 nd resin layer 122 formed to cover the 1 st resin layer 121, and the dome member 23 is composed of the 3 rd resin layer 125.

Here, in the present embodiment, the dome member 22 includes a dome main body portion 22a and a cylindrical protruding portion 22b protruding from the dome main body portion 22 a. The protrusion 22b has a gas passage 22c for filling and discharging a gas such as hydrogen gas. A metal valve holder 14 is fixed to the outer peripheral surface of the projection 22b, and a metal valve 15 for filling and discharging hydrogen gas into and from the housing space 17 is attached to the outer peripheral surface of the valve holder 14. A retaining protrusion 14a is formed on the inner surface of the valve fixing member 14, and a screw thread 14b to which the valve 15 is attached is formed on the outer surface of the valve fixing member 14. The valve fixing member 14 is fixed to the outer peripheral surface of the protrusion 22b by caulking. A thread 15a that engages with the thread 14b of the valve fixing 14 is formed on the inner surface of the valve 15, and the valve 15 is fixed to the end of the protrusion 22b via the valve fixing 14. Further, the valve 15 is formed with an insertion portion 15b inserted into the protrusion portion 22 b. The insertion portion 15b is provided with a seal member 15c that seals the housing space 17, and a passage 15d through which hydrogen gas passes is formed.

The 1 st resin layer 121 is formed of a fiber bundle F1 (1 st fiber bundle), and the fiber bundle F1 is impregnated with the 1 st resin made of a thermoplastic resin. The 1 st resin layer 121 forms a part of the dome main body portion 22a and a part of the protrusion portion 22b, and is disposed such that fibers are continuous from the protrusion portion 22b to the dome main body portion 22 a. Here, the 1 st resin layer 121 is disposed such that the fibers are continuous from the protruding portion 22b to the peripheral portion of the dome main body portion 22 a. The 1 st resin layer 121 is formed so that the fiber direction of the protrusion 22b is along the axial direction X of the protrusion 22b (here, parallel to the axial direction X). The detailed fiber direction in the protrusion 22b of the 1 st resin layer 121 will be described later.

The 2 nd resin layer 122 is formed of a fiber bundle F2 (2 nd fiber bundle), and the fiber bundle F2 is impregnated with a 2 nd resin made of a thermosetting resin. The 2 nd resin layer 122 is formed to cover the 1 st resin layer 121. In addition, the 2 nd resin layer 122 is formed such that the fiber direction of the 2 nd resin layer 122 intersects with the fiber direction of the 1 st resin layer 121.

The outer reinforcing layer 13 is formed to cover the outer surface of the reinforcing body 20. The outer reinforcing layer 13 covers the entirety of the dome members 22 and 23. The outer reinforcing layer 13 is made of resin and fibers (continuous fibers). In the outer reinforcing layer 13, the fibers are aligned in parallel or inclined at 45 degrees or less with respect to the axial direction X of the barrel member 21, and are aligned across the two dome members 22 and 23 via the barrel member 21. The fibers prevent the movement of the dome members 22 and 23 outward in the axial direction X, and prevent the dome members 22 and 23 from falling off from the tubular member 21 outward in the axial direction X due to the air pressure.

Next, a method for manufacturing the high-pressure tank 10 according to embodiment 1 of the present invention will be described. Fig. 2 is a flowchart illustrating a method of manufacturing the high-pressure tank 10. As shown in fig. 2, the method of manufacturing the high-pressure tank 10 includes a liner preparation step S1, a dome member forming step S2, a tube member forming step S3, a joining step S4, and an outer reinforcing layer forming step S5. In fig. 2, the liner preparation step S1, the dome member forming step S2, and the tubular member forming step S3 are described as being performed in this order, but the liner preparation step S1, the dome member forming step S2, and the tubular member forming step S3 are independent steps, and therefore, may be performed in parallel or may be performed first.

As shown in fig. 1, in the liner preparation step S1, a liner 11 is prepared, in which the liner 11 has a cylindrical tube portion, dome portions are provided at both ends of the tube portion, and a cylindrical protruding portion having a gas flow passage connecting the inside and the outside is formed at one dome portion. The method for producing the liner 11 is not particularly limited, and it can be produced by a known technique.

As shown in fig. 3, the dome member forming step S2 includes a 1 st resin layer forming step S21, a 2 nd resin layer forming step S22, and a removing step S23. The 1 st resin layer forming step S21, the 2 nd resin layer forming step S22, and the removing step S23 are steps for forming the dome sheet 22, but the dome sheet 23 may be formed at the same time. Further, the dome member 23 may be formed in a step separate from the step of forming the dome member 22. Here, after the description of the method of forming the dome member 22 and the dome member 23 separately in separate steps, the description will be given of the method of forming the dome member 22 and the dome member 23 simultaneously.

As shown in fig. 4, in the 1 st resin layer forming step S21, the 1 st resin layer 121 is formed on the outer surface of the core member 200. Specifically, the core member 200 includes a dome-shaped body portion 201 and a shaft portion 202 extending outward from the body portion 201. As shown in fig. 5, for example, the fiber bundle F1 impregnated with the thermoplastic resin is bonded to the outer surface of the core member 200 by pressing with a pressure roller 210 using a tape laying method. At this time, the resin impregnated in the fiber bundle F1 is heated and softened by a laser device (not shown), and the fiber bundle F1 is attached (disposed) to the core member 200 in this state. The resin impregnated in the bonded fiber bundle F1 is immediately cured by the heat removed from the core member 200. By using the fiber bundle F1 impregnated with the thermoplastic resin in this manner, the resin impregnated in the bonded fiber bundle F1 can be immediately cured, and therefore the fiber bundle F1 can be bonded while applying tension thereto. Therefore, the fiber direction of the fiber bundle F1 is uniform, and thus a decrease in the tensile strength of the 1 st resin layer 121 can be suppressed. Further, the cooling air may be blown to the fiber bundle F1 to cure the thermoplastic resin impregnated in the fiber bundle F1 more quickly. The material of the core 200 is not particularly limited, but is preferably metal in order to ensure strength that does not deform when the fiber bundle F1 and the fiber bundle F2 described later are arranged.

Here, the fiber bundle F1 is arranged to be continuous from the main body portion 201 to the shaft portion 202 of the core member 200. In the present embodiment, the fiber bundle F1 is arranged to be continuous from the peripheral portion of the body 201 to the shaft portion 202. The fiber bundle F1 is arranged such that the fiber direction is along the axial direction X of the shaft 202 (here, parallel to the axial direction X) at the shaft 202. The fiber bundles F1 are arranged at predetermined angular intervals in the circumferential direction of the core 200. In this way, the 1 st resin layer 121 of the dome member 22 is formed so as to radially (in the radial direction) spread from the shaft portion 202 of the core member 200.

In the 2 nd resin layer forming step S22, the 2 nd resin layer 122 is formed on the outer surface of the core member 200 so as to cover the 1 st resin layer 121 (i.e., the fiber bundle F1 impregnated with the 1 st resin) from the state shown in fig. 4 (see fig. 7). Note that the state in which the 2 nd resin layer 122 is formed so as to cover the 1 st resin layer 121 from the state shown in fig. 4 is the same as a part of fig. 7 described later, and therefore, the drawings are omitted here. In forming the 2 nd resin layer 122, for example, the fiber bundle F2 impregnated with the uncured 2 nd resin made of a thermosetting resin may be bonded by pressing with the pressing roller 210 so as to cover the outer surface of the core member 200 by using a tape laying method as in the 1 st resin layer 121. At this time, the fiber bundle F2 is arranged such that the fiber direction of the fiber bundle F2 intersects with the fiber direction of the fiber bundle F1.

Then, the 2 nd resin layer 122 (i.e., the uncured thermosetting resin impregnated with the fiber bundle F2) is heated and cured. At this time, the curing temperature of the thermosetting resin of the 2 nd resin layer 122 is preferably set lower than the softening temperature of the thermoplastic resin of the 1 st resin layer 121. For example, the curing temperature of the thermosetting resin of the 2 nd resin layer 122 is changed by adjusting the amount and type of the curing agent contained in the thermosetting resin of the 2 nd resin layer 122, and therefore, the curing temperature of the thermosetting resin of the 2 nd resin layer 122 can be easily set to be lower than the softening temperature of the thermoplastic resin of the 1 st resin layer 121. With this configuration, softening of the 1 st resin layer 121 can be suppressed when the 2 nd resin layer 122 is cured, and deflection or positional displacement of fibers included in the 1 st resin layer 121 can be suppressed.

In the removing step S23, the 1 st resin layer 121 and the 2 nd resin layer 122 are removed from the core member 200. Thereby, the dome member 22 is formed. In this way, after the 2 nd resin layer 122 is heated and cured, the 2 nd resin layer 122 is removed from the core member 200, whereby deformation of the 2 nd resin layer 122 can be suppressed.

In the case where the dome member 23 is formed in a process separate from the process of forming the dome member 22, for example, the 3 rd resin layer 125 is formed on the outer surface of the body portion 201 of the core member 200 having no shaft portion 202. In this case, the 3 rd resin layer 125 can be formed by sticking fiber bundles impregnated with the 3 rd resin made of thermosetting resin by a tape laying method, similarly to the 2 nd resin layer 122. Then, the 3 rd resin layer 125 is heated to be hardened. Thereafter, dome piece 23 is formed by removing 3 rd resin layer 125 from core member 200.

The thermoplastic resin contained in the 1 st resin layer 121 is not particularly limited, and polyether ether ketone, polyphenylene sulfide, polyacrylate, polyimide, polyamide, or the like can be used.

The thermosetting resin contained in the 2 nd resin layer 122 and the 3 rd resin layer 125 is not particularly limited, but thermosetting resins such as phenol resin, melamine resin, urea resin, and epoxy resin are preferably used, and particularly, epoxy resin is preferably used from the viewpoint of mechanical strength and the like. In general, an epoxy resin refers to a resin obtained by mixing and thermally curing a prepolymer such as a copolymer of bisphenol a and epichlorohydrin and a curing agent such as polyamine. The epoxy resin has fluidity in an uncured state, and forms a strong crosslinked structure after thermal curing.

As the fibers contained in the 1 st resin layer 121, the 2 nd resin layer 122, and the 3 rd resin layer 125, glass fibers, aramid fibers, boron fibers, carbon fibers, and the like can be used, and carbon fibers are particularly preferably used from the viewpoint of lightweight, mechanical strength, and the like.

Next, a case where the dome member 23 is formed at the same time (in the same process) as the formation of the dome member 22 will be described. Further, in this method, the 3 rd resin layer 125 is formed from the fiber bundle F2.

In the 1 st resin layer forming step S21, the core 200 as shown in fig. 6 is used. The body 201 of the core member 200 is formed into a substantially spherical shape. Further, the 1 st resin layer 121 is formed on the outer surface of the core member 200 in the same manner as described above.

As shown in fig. 7, in the 2 nd resin layer forming step S22, the 2 nd resin layer 122 is formed on the outer surface of the core member 200 so as to cover the 1 st resin layer 121. At this time, the 2 nd resin layer 122 can be formed by adhering the fiber bundle F2 by using the tape laying method described above, but the 2 nd resin layer 122 can be formed by winding the fiber bundle F2 by using, for example, a filament winding method (FW method). Specifically, the shaft 202 of the core 200 is attached to a rotation mechanism (not shown). Then, the fiber bundle F2 is wound so as to cover the 1 st resin layer 121 and the outer surface of the core 200 by rotating the core 200. At this time, the fiber bundle F2 is wound at an angle of, for example, 40 degrees or more with respect to the axial direction X of the shaft 202. Then, the thermosetting resin impregnated into the fiber bundle F2 is heated and cured.

In the removal step S23, the wound body (fiber bundle F2) wound around the outer surface of the core member 200 is divided into two parts along the two-dot chain line L in fig. 7 by a cutter (not shown). Thereafter, the two dome pieces 22 and 23 are formed by separating the divided roll from the core member 200.

In the present embodiment, after the removal step S23, the valve fixing member 14 is caulked and fixed to the protruding portion 22 b. In addition, the valve retainer 14 may also be secured prior to removal of the dome 22 from the core piece 200. In addition, the valve fixing member 14 may be fixed before the 2 nd resin layer 122 is heat-cured, in which case the valve fixing member 14 can be firmly fixed to the protruding portion 22 b.

In the tubular member forming step S3, as shown in fig. 8, for example, the tubular member 21 is formed by a so-called CW (Centrifugal Winding) method in which a fiber sheet F3 is stuck to the inner surface of a rotating cylindrical mold 300. Specifically, the cylindrical mold 300 is rotated at a predetermined rotational speed by a rotation mechanism (not shown).

The cylindrical die 300 is provided with an unwinding roller 310 of an unwinding device (not shown) for unwinding a rolled fiber sheet F3. The cylindrical mold 300 is rotated to unwind the fiber sheet F3, and the fiber sheet F3 is stuck to the inner surface of the cylindrical mold 300, thereby forming the cylindrical member 21.

The fiber sheet F3 has at least fibers aligned in the circumferential direction of the unwinding roller 310. Thereby, the tubular member 21 in which the fibers are aligned in the circumferential direction can be obtained.

As the fiber sheet F3, for example, a so-called UD (Uni-Direction: unidirectional) sheet in which a plurality of fiber bundles aligned in a single Direction are woven with a binding thread, a fiber sheet in which a plurality of fiber bundles aligned in a single Direction and a plurality of fiber bundles intersecting with, for example, orthogonal to, the plurality of fiber bundles are woven, or the like is used, which is impregnated with a resin in advance.

The 3 rd resin impregnated in the fiber sheet F3 is not particularly limited, but for example, a thermosetting resin can be used. As the thermosetting resin, as in the case of the fiber bundle F2, thermosetting resins such as phenol resin, melamine resin, urea resin, and epoxy resin are preferably used, and particularly, epoxy resin is preferably used from the viewpoint of mechanical strength and the like.

As the fibers constituting the fiber sheet F3, glass fibers, aramid fibers, boron fibers, carbon fibers, and the like can be used as in the fiber bundles F1 and F2, and carbon fibers are particularly preferably used from the viewpoint of lightweight, mechanical strength, and the like.

As shown in fig. 1, the cylindrical member 21 formed on the inner surface of the cylindrical mold 300 is formed so as to be gradually thinner toward both ends in the axial direction X. In addition, the dome members 22 and 23 are also similarly formed such that the thickness of the peripheral portion becomes gradually thinner. Thus, in a state where the cylindrical member 21 and the two dome members 22 and 23 are combined, a step is not easily formed at a connecting portion between the outer surface of the cylindrical member 21 and the outer surfaces of the two dome members 22 and 23.

In order to gradually reduce the thickness of both ends of the cylindrical member 21 in the axial direction X, the fiber bundle is preferably woven into the end portion of the fiber sheet F3 in the axial direction X (width direction) so that the thickness of the fiber bundle is gradually reduced. Further, the thickness may be gradually reduced by pressing both ends of the cylindrical member 21 in the axial direction X with rollers or the like. In order to gradually reduce the thickness of the peripheral portions of the dome members 22 and 23, the number and direction of winding of the fiber bundle F2 may be adjusted, or the peripheral portions may be pressed by a roller or the like.

Then, after the cylindrical member 21 is heated and hardened, the cylindrical member 21 is removed from the inside of the cylindrical mold 300. This can suppress deformation of the cylindrical member 21 when the cylindrical member 21 is removed from the cylindrical mold 300.

Here, although an example of forming the cylindrical member 21 on the inner surface of the cylindrical mold 300 is described, the cylindrical member 21 may be formed by another method. For example, the cylindrical member 21 may be formed by attaching a fiber sheet F3 to the outer surface of a cylindrical mold, or by annularly winding a fiber bundle impregnated with the 3 rd resin around the outer surface of the cylindrical mold by the FW method.

Further, since the dome members 22 and 23 are formed using the core member 200 and the tube member 21 is formed using the cylindrical mold 300, the tube member 21 and the dome members 22 and 23 can be formed without directly winding the fiber bundle or the like around the liner 11. Thus, the rolling force by the hoop winding, the spiral winding, or the like does not act on the liner 11, and therefore, it is not necessary to increase the strength of the liner 11 so that the liner 11 is not deformed by the rolling force. Therefore, the thickness (wall thickness) of the liner 11 can be reduced, so that the volume of the liner 11 can be increased and the weight of the liner 11 can be reduced.

In the joining step S4, as shown in fig. 9 and 10, the reinforcing body 20 as a reinforcing layer is formed by joining the peripheral portions 21a at both ends of the tubular member 21 and the peripheral portions 22d and 23a of the two dome members 22 and 23.

Specifically, the liner 11 prepared in the liner preparation step S1 is inserted into the tubular member 21, and the dome members 22 and 23 cover both ends of the liner 11. In this case, in the present embodiment, the peripheral portions 22d and 23a of the dome members 22 and 23 are made inner, and the peripheral portions 21a at both ends of the cylindrical member 21 are made outer to be fitted. Since the 1 st resin layer 121 of the dome 22 is exposed inward (liner 11 side) and the 1 st resin layer 121 contains a thermoplastic resin, the adhesion to the liner 11 is higher than that in the case where the 1 st resin layer 121 is formed of a thermosetting resin. Here, an example is shown in which the dome member 23 is formed of the 3 rd resin layer 125 containing a thermosetting resin, but the dome member 23 may be formed of a resin layer containing a thermoplastic resin and a resin layer containing a thermosetting resin, similarly to the dome member 22. In this case, the dome member 23 can be made to have high adhesion to the liner 11.

The peripheral portions 22d and 23a of the dome members 22 and 23 may be outside and the peripheral portions 21a at both ends of the tubular member 21 may be inside to be fitted, or the peripheral portions 22d and 23a of the dome members 22 and 23 may be butted against and joined to the peripheral portions 21a at both ends of the tubular member 21. Further, an adhesive (not shown) may be disposed between the cylindrical member 21 and the dome members 22 and 23.

In the outer reinforcing layer forming step S5, the outer reinforcing layer 13 in which fibers are arranged over the two dome members 22 and 23 is formed of fiber-reinforced resin so as to cover the outer surface of the reinforcement body 20. Thereby, the fiber-reinforced resin layer 12 having the reinforcement body 20 and the outer reinforcing layer 13 is formed. For example, the outer reinforcing layer 13 may be formed by spirally winding fiber bundles impregnated with a thermosetting resin around the outer surface of the reinforcement 20. The outer reinforcing layer 13 may be formed by bonding a plurality of fiber bundles impregnated with a thermosetting resin to the outer surface of the reinforcement body 20 in a state of extending in the axial direction X of the reinforcement body 20, or the outer reinforcing layer 13 may be formed by using a so-called sheet winding method in which a fiber sheet impregnated with a thermosetting resin is wound around the outer surface of the reinforcement body 20. Then, the thermosetting resin contained in the outer reinforcing layer 13 is heated to be hardened. As the thermosetting resin and the fiber bundles included in the outer reinforcing layer 13, for example, the same materials as those of the thermosetting resin and the fiber bundles forming the dome members 22 and 23 can be used.

Then, the valve 15 is mounted to the valve fixing member 14, whereby the high-pressure tank 10 is completed. Here, although an example in which the valve 15 is attached to the protruding portion 22b via the valve fixing member 14 is shown, the present invention is not limited to this. For example, the valve 15 may be directly attached to the outer peripheral surface of the protrusion 22b without the valve fixing member 14. In this case, the valve 15 may be caulked and fixed to the outer peripheral surface of the projection 22 b.

Next, the relationship between the fiber direction in the protruding portion 22b of the 1 st resin layer 121 and the tensile strength in the axial direction X will be described. As shown in fig. 11, when the tensile strength in the axial direction X is normalized to 100 when the fiber direction of the 1 st resin layer 121 in the protrusion 22b is parallel to the axial direction X (90 degrees in fig. 11), the tensile strength is reduced to about 90, 65, and 33 when the fiber direction is inclined by 10 degrees, 20 degrees, and 30 degrees (80 degrees, 70 degrees, and 60 degrees in fig. 11, respectively) with respect to the axial direction X. In addition, since the angle that can be formed by the FW method is usually 0 to 30 degrees in fig. 11, when the protrusion 22b is formed by the FW method, the tensile strength becomes about 8.

In the present embodiment, the 1 st resin layer 121 is formed so that the fiber direction is along the axial direction X of the protruding portion 22b in the protruding portion 22b, specifically, so that the inclination angle of the fiber direction with respect to the axial direction X is 20 degrees or less, preferably 10 degrees or less, and more preferably 0 degree (70 degrees or more, 80 degrees or more, and 90 degrees in fig. 11, respectively). This can sufficiently ensure the tensile strength of the protruding portion 22 b.

In the present embodiment, as described above, the fiber bundle F1 is disposed in the protruding portion 22b such that the fiber direction is along the axial direction X of the protruding portion 22 b. This ensures the axial tensile strength of the protruding portion 22 b. Further, the fiber bundle F1 is disposed so as to be continuous from the protrusion 22b to the dome main body portion 22a, and the fiber bundle F2 is disposed so as to cover the fiber bundle F1. Thus, the fiber bundle F2 restricts the movement of the fiber bundle F1, and the protrusion 22b can be prevented from falling off the dome main body 22 a. Further, since the fiber bundle F2 is provided so that the fiber direction of the fiber bundle F2 intersects with the fiber direction of the fiber bundle F1, it is possible to ensure not only the tensile strength in the axial direction X but also the tensile strength in other directions such as the radial direction. Therefore, even when the inside of the high-pressure tank 10 becomes high pressure and a large force toward the outside in the axial direction X is applied to the valve 15 attached to the tip end of the protruding portion 22b, and a large force toward the outside in the axial direction X is applied to the protruding portion 22b, damage to the protruding portion 22b can be suppressed. Therefore, it is not necessary to provide a joint, and the high-pressure tank 10 can be made lightweight.

As described above, the 1 st resin impregnated into the fiber bundle F1 is made of a thermoplastic resin, and the 2 nd resin impregnated into the fiber bundle F2 is made of a thermosetting resin. By using the thermoplastic resin as the 1 st resin impregnated into the fiber bundle F1 in this way, the fiber bundle F1 is disposed on the surface of the core 200 or the liner 11, for example, in a state where the 1 st resin is softened, and thereby the heat of the fiber bundle F1 is taken away by the core 200 or the liner 11, and the resin impregnated into the fiber bundle F1 is cured. Thus, the fiber bundle F2 was arranged on the fiber bundle F1 in the state where the 1 st resin was cured. Therefore, the fiber bundle F1 is not bent or displaced when the fiber bundle F2 is arranged, and therefore, a decrease in the tensile strength of the protruding portion 22b in the axial direction X can be suppressed. Further, by using the thermosetting resin as the 2 nd resin impregnated into the fiber bundle F2, the mechanical strength of the protruding portion 22b after curing the 2 nd resin can be easily improved.

Embodiment 2

In embodiment 2, an example in which the inner surfaces (surfaces that come into contact with hydrogen gas as described later) of the dome members 22 and 23 are formed by fiber bundles F1 impregnated with a thermoplastic resin, unlike embodiment 1, will be described.

In the high-pressure tank 10 of the present embodiment, as shown in fig. 12, the liner 11 is formed only by a cylindrical tube portion.

In the present embodiment, the dome member 22 is composed of the 1 st resin layer 121 and the 2 nd resin layer 122 formed so as to cover the 1 st resin layer 121. Unlike the above-described embodiment 1, the 1 st resin layer 121 is formed over the entire inner surface (the surface in contact with the hydrogen gas, that is, the inner surface of the dome main body 22a and the inner surface of the protrusion 22 b).

The dome member 23 is different from the above embodiment 1 in that it is composed of a 4 th resin layer 126 and a 3 rd resin layer 125 covering the 4 th resin layer 126. The 4 th resin layer 126 is formed of a fiber bundle impregnated with a thermoplastic resin and is formed over the entire inner surface (surface in contact with hydrogen gas).

That is, the dome members 22 and 23 have gas barrier properties over the entire inner surfaces thereof, and have the same functions as those of both dome-shaped end portions of the liner 11 of embodiment 1 described above, and therefore, in the present embodiment, the liner 11 is formed in a cylindrical shape with both end portions open. Further, the hydrogen gas-filled storage space 17 is formed by the cylindrical liner 11, the 1 st resin layer 121, and the 4 th resin layer 126.

The other structure of embodiment 2 is the same as embodiment 1 described above.

Next, a method for manufacturing the high-pressure tank 10 according to embodiment 2 of the present invention will be described. In the present embodiment, in the liner preparation step S1, a cylindrical liner 11 having both ends open is prepared. The method for producing the liner 11 is not particularly limited, and the liner can be produced by a known technique.

As in the above-described embodiment 1, the dome member forming step S2 includes a 1 st resin layer forming step S21, a 2 nd resin layer forming step S22, and a removing step S23, as shown in fig. 3.

In the 1 st resin layer forming step S21, as shown in fig. 13, the 1 st resin layer 121 is formed so as to cover the entire outer surface of the core member 200. At this time, as shown in fig. 13, all the fiber bundles F1 may be bonded so as to spread radially (in the radial direction) from the shaft portion 202 of the core member 200, and for example, the fiber bundles F1 may be further bonded so as to intersect with each other at various angles from the state shown in fig. 4 and 6. Thereby forming the 1 st resin layer 121 of the dome member 22.

In the case of forming the 4 th resin layer 126 of the dome member 23, the formation can be performed in the same manner as the formation method of the 1 st resin layer 121, but since the dome member 23 does not have the protruding portion 22b, the 4 th resin layer 126 may not be provided so as to radially spread from the shaft portion 202 of the core member 200. In addition, as in the above-described embodiment 1, the dome member 23 may be formed at the same time (in the same step) as the dome member 22.

The other manufacturing method of embodiment 2 is the same as embodiment 1.

In the present embodiment, as described above, when the dome members 22 and 23 are formed, the surfaces of the dome members 22 and 23 that come into contact with hydrogen gas are formed by the fiber bundle F1. Since the thermoplastic resin has gas barrier properties, the surfaces of the dome members 22 and 23 that come into contact with hydrogen gas are formed by the fiber bundles F1 impregnated with the thermoplastic resin, and thus it is not necessary to provide (both dome-shaped end portions of) the liners 11 along the inner surfaces of the dome members 22 and 23. This makes it possible to further reduce the weight of the high-pressure tank 10.

Other effects of embodiment 2 are similar to those of embodiment 1.

Embodiment 3

In embodiment 3, an example will be described in which an insert 16 for attaching a metal valve 18 is disposed inside a protruding portion 22b of a dome member 22, unlike embodiment 1.

In the high-pressure tank 10 of the present embodiment, as shown in fig. 15, a metal cylindrical insert 16, for example, is disposed inside the protruding portion 22b of the dome member 22. In the present embodiment, the dome member 22 is composed of the liner 11, the insert 16, the 1 st resin layer 121 formed so as to cover the liner 11 and the insert 16, and the 2 nd resin layer 122 formed so as to cover the 1 st resin layer 121.

The insert 16 has an internal thread 16a on the inner peripheral surface. The insert 16 is disposed adjacent to the axial tip of the cylindrical projecting portion of the liner 11 on the inner side of the 1 st resin layer 121 of the dome member 22. The insert 16 has, for example, a cylindrical shape in which the inner end portion in the axial direction of the high-pressure tank 10 is reduced in diameter to a tapered shape.

The valve 18 is formed with an insertion portion 18a inserted into the protrusion portion 22 b. A male screw 18b screwed into the female screw 16a of the insert 16 and a seal member 18c for sealing the accommodation space 17 are provided on the outer peripheral surface of the insertion portion 18 a. Although not shown, a passage for passing hydrogen gas is formed in the valve 18, similarly to the passage 15d of the valve 15 of embodiment 1 shown in fig. 1.

The other structure of embodiment 3 is the same as embodiment 1 described above.

Next, a method for manufacturing the high-pressure tank 10 according to embodiment 3 of the present invention will be described. In the present embodiment, in the 1 st resin layer forming step S21 in which the fiber bundle F1 (the 1 st fiber bundle) is arranged, for example, the insert 16 having the female screw 16a on the inner peripheral surface is supported on the outer periphery of the distal end portion of the shaft portion 202 of the core 200 shown in fig. 4. Then, the fiber bundle F1 is arranged on the outer periphery of the insert 16 and the outer periphery of the core member 200.

The other manufacturing method of embodiment 3 is the same as embodiment 1. More specifically, in the 1 st resin layer forming step S21 similar to that of the above-described embodiment 1, the 1 st resin layer 121 is formed on the outer surface of the insert 16 and the outer surface of the core member 200, similar to fig. 4 or 14. Here, the fiber bundle F1 constituting the 1 st resin layer 121 is arranged in the insert 16 and the shaft 202 such that the fiber direction is along the axial direction X of the shaft 202 (here, parallel to the axial direction X), as in the above-described embodiment 1. Thus, the 1 st resin layer 121 of the protrusion 22b shown in fig. 15 is disposed such that the fiber bundle F1 is along the axial direction of the protrusion 22b (here, parallel to the axial direction of the protrusion 22 b).

In addition, in the 2 nd resin layer forming step S22 similar to that of the above-described 1 st embodiment, as shown in fig. 16, the 2 nd resin layer 122 is formed on the outer surface of the core member 200 so as to cover the 1 st resin layer 121 (i.e., the fiber bundle F1 impregnated with the 1 st resin). At this time, the fiber bundle F2 constituting the 2 nd resin layer 122 is arranged at least on the outer periphery of the insert 16 and the outer periphery of the shaft portion 202 such that the fiber direction of the fiber bundle F2 intersects with the fiber direction of the fiber bundle F1 (here, orthogonally intersects at an angle of 80 degrees or more).

The fiber bundle F2 wound around the outer periphery of the insert 16 and the outer periphery of the shaft 202 is continuously wound from the outer periphery of the insert 16 and the outer periphery of the shaft 202 to the outer periphery of the dome-shaped core member 200. Thereby, the 2 nd resin layer 122 continuing from the protrusion 22b of the dome member 22 to the dome-shaped portion shown in fig. 15 is integrally formed by winding the fiber bundle F2 integrally wound from the insert 16 and the shaft portion 202 to the core member 200 in a coherent manner.

As shown in fig. 17, a conventional high-pressure tank 90 includes a tank main body 91 and a joint 92 attached to an opening end portion in a longitudinal direction of the tank main body 91. The tank main body 91 includes, for example, a liner 911 for gas-tight holding of hydrogen gas and a reinforcing layer 912 reinforced by wrapping the outer surface of the liner with a fiber bundle impregnated with resin. The joint 92 has a flange 921 whose diameter is larger than that of the other portion on the inner side in the axial direction of the high-pressure tank 900. The joint 92 has an internal thread or an external thread, and is screwed to attach a valve, not shown.

In the conventional high-pressure tank 90, a thrust force TF directed outward in the axial direction of the high-pressure tank 90 acts on the reinforcing layer 912 from the flange portion 921 of the joint 92 that receives the internal pressure of the high-pressure tank 90. As shown in fig. 18, such a thrust force TF increases the stress acting on the fibers at the outer edge 921a of the flange 921 of the joint 92, the intersection 921x of the fibers in the flange 921 of the joint 92, and the like, thereby generating a stress concentration portion SC in the high-pressure tank 900. Further, during low-temperature filling of the high-pressure tank 900, due to the difference in the linear expansion coefficient between the reinforcing layer 912 and the joint 92, as shown in fig. 17, a tensile force PF acts on the reinforcing layer 912 at the outer peripheral portion of the flange 921 of the joint 92, and the liner 911 may be pulled out and damaged.

In contrast, in the method of manufacturing the high-pressure tank 10 according to the present embodiment, in the step of disposing the fiber bundle F1 (the 1 st fiber bundle), the fiber bundle F1 is disposed on the outer periphery of the insert 16 having the female screw 16a on the inner peripheral surface. Thus, the cylindrical insert 16 can be disposed inside the protruding portion 22b of the dome member 22, and the high-pressure tank 10 in which the insert 16 has the female screw 16a on the inner peripheral surface can be manufactured.

Thus, the male screw 18b on the outer peripheral surface of the valve 18 is screwed into the female screw 16a on the inner peripheral surface of the insert 16, and the valve 18 can be attached to the tubular insert 16 disposed inside the protrusion 22 b. With this configuration, a tensile force caused by the internal pressure P of the high-pressure tank 10 acts on the entire periphery of the connection portion between the dome main body portion 22a and the protrusion portion 22b of the dome member 22, thereby preventing stress from concentrating on a specific portion such as the intersection of the fiber bundles F1 and F2.

Therefore, even when the internal pressure P of the high-pressure tank 10 acts on the valve 18 and a tensile force acting toward the outside in the axial direction of the high-pressure tank 10 acts on the protrusion 22b, stress concentration on a specific portion can be avoided, and the strength utilization efficiency of the fiber bundles F1 and F2 can be improved. Therefore, the amount of the fiber bundles F1 and F2 used can be reduced to reduce the weight of the high-pressure tank 10. Further, by preventing stress concentration, damage to the liner 11 can be prevented.

The fiber bundle F1 (1 st fiber bundle) may be disposed on the outer periphery of the fiber bundle F2 (2 nd fiber bundle) disposed on the outer periphery of the insert 16, and the fiber bundle F2 may be further disposed on the outer periphery thereof, so that the fiber bundle F1 may be disposed in an intermediate layer between the fiber bundles F2. In this case, both surfaces of the fiber bundle F1 can be bonded to the fiber bundle F2.

Other effects of embodiment 3 are similar to those of embodiment 1.

It should be noted that all the embodiments disclosed herein are to be considered as examples, and the present invention is not limited thereto. The scope of the present invention is defined by the claims, not by the description of the above embodiments, and includes meanings equivalent to the claims and all modifications within the scope thereof.

For example, in the above-described embodiment, an example has been described in which the reinforcing body as the reinforcing layer is formed by forming two dome members and the tubular member separately and then joining the dome members and the tubular member, but the present invention is not limited to this. For example, the tubular member and the two dome members of the reinforcing layer may be formed simultaneously by arranging the 1 st fiber bundle and the 2 nd fiber bundle on the surface of the resin liner formed by a known manufacturing method. In this case, the process of joining the cylindrical member and the two dome members is not required.

In the above embodiment, the example in which the 1 st fiber bundle is impregnated with the thermoplastic resin has been described, but the present invention is not limited to this, and the 1 st fiber bundle may be impregnated with the thermosetting resin. In this case, in the step of arranging the 1 st fiber bundle, while arranging the 1 st fiber bundle, hot air may be sprayed to the arranged 1 st fiber bundle, for example, to cure and cure the thermosetting resin impregnated into the 1 st fiber bundle. However, since the thermoplastic resin can be easily cured, it is preferable that the resin impregnated into the 1 st fiber bundle is a thermoplastic resin.

In the above embodiment, the example in which the 2 nd fiber bundle is impregnated with the thermosetting resin has been described, but the present invention is not limited to this, and the 2 nd fiber bundle may be impregnated with the thermoplastic resin. However, from the viewpoint of mechanical strength, it is preferable that the resin impregnated in the 2 nd fiber bundle is a thermosetting resin.

In the above embodiment, the example in which the 1 st resin layer 121 is disposed from the protrusion 22b to the peripheral portion of the dome main body 22a has been described, but the present invention is not limited to this, and the 1 st resin layer 121 may not be disposed from the protrusion 22b to the dome main body 22 a. That is, for example, as shown in fig. 14, when the fiber bundle F1 is arranged from the shaft portion 202 to the main body portion 201 of the core member 200, the fiber bundle F1 may not be arranged in the peripheral portion of the main body portion 201.

In the above-described embodiment, an example in which the tubular member is formed of one member has been described, but the present invention is not limited to this. For example, the tubular member may be formed of two or more members. In this case, the dome member may be joined to both ends of two or more tube members after joining them to each other. Further, the cylindrical member and the dome member may be joined one by one and then joined together.

In the above-described embodiment, an example in which the tube member and the dome member are disposed so as to cover the liner after the liner is prepared, and are joined, has been described, but the present invention is not limited to this. For example, after the cylindrical member and the dome member are joined to form the reinforcement body, a liner may be formed inside the reinforcement body. In this case, for example, two or more types of low-molecular-weight, low-viscosity liquid materials having fluidity at room temperature may be used as the resin material to form the liner by a Reaction injection molding (Reaction injection molding) method. In addition, as in the blow molding, a liner may be formed by extruding a resin material softened by heating into a cylindrical shape inside a reinforcing body and feeding compressed air into the cylindrical resin material. Further, the liner may be formed by spraying a liquid or softened resin material onto the inner surface of the reinforcement body, as in thermal spraying.