high-pressure tank

Abstract

High-pressure tank (10), comprising: a liner (20) having a space in which a gas is hermetically sealed, the liner (20) comprising a cylinder portion (21) in a cylindrical shape and a pair of dome portions (22, 23) arranged at both ends of the cylinder portion (21) in an axial direction of the cylinder portion (21); and a reinforcing layer (30) adapted to cover a periphery of the liner (20), wherein a curved surface shape of each of the dome sections (22, 23) is a uniformly stressed curved surface shape when an internal pressure of the lining (20) reaches a set pressure set higher than an atmospheric pressure, an inclination of the dome section (22, 23) relative to the cylinder section (21) at a connecting section (CN) between the cylinder section (21) and the dome section (22, 23) is 0 degrees and a radius of curvature of the connecting section (CN) is in a range of 6 mm to 30 mm, or the inclination is 7 degrees and the radius of curvature of the connecting section (CN) is in a range of 10 mm to 20 mm.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention

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

[0002] Some liners included in high-pressure tanks for storing fuel gas for use in natural gas vehicles, fuel cell automobiles, and elsewhere may each have a cylinder portion in a cylindrical shape and a pair of dome portions at both ends in the axial direction of the cylinder portion (see Japanese Patent Application Publication No. 2018-099828 (JP 2018-099828 A)). SUMMARY OF THE INVENTION

[0003] JP 2018-99828 A describes that a curved surface shape of each dome portion is designed to be a uniformly stressed curved surface shape in a state where gas is introduced into the high-pressure tank. However, since the high-pressure tank is deformed by its internal pressure, there is room for the idea that the curved surface of each dome portion should become a uniformly stressed curved surface in accordance with the amount of gas introduced into the high-pressure tank.

[0004] Furthermore, US 2009 / 0 314 785 A1 discloses a linerless tank structure with a body defining a closed internal volume. The body has a cylindrical section with an axis of symmetry and a dome section connected to the cylindrical section. The construction of the pressure vessel shown comprises multiple fiber layers. At least one of the fiber layers is a spiral layer with fibers traversing the dome in a helical manner around the axis of symmetry. At least a second of the fiber layers is a braided or woven layer.

[0005] The above object is achieved by the subject matter of claim 1. Advantageous developments of the invention are the subject matter of the subsequent dependent claims.

[0006] The present invention can be realized as the following aspect.

[0007] According to one aspect of the present invention, a high-pressure tank is provided. This high-pressure tank includes: a liner having a space in which a gas is hermetically sealed, the liner having a cylinder portion in a cylindrical shape and a pair of dome portions arranged at both ends of the cylinder portion in an axial direction of the cylinder portion; and a reinforcing layer configured to cover a periphery of the liner, wherein a curved surface shape of each of the dome portions is a uniformly stressed curved surface shape when an internal pressure of the liner reaches a set pressure set higher than an atmospheric pressure.

[0008] According to the above aspect, it is possible to reduce the strain generated in the reinforcement layer when the internal pressure of the liner reaches the set pressure, compared to the high-pressure tank whose dome portions each have the uniformly stressed curved surface shape when the internal pressure of the liner is at atmospheric pressure. Therefore, since the reinforcement layer in such a high-pressure tank can be made thinner than that of the high-pressure tank whose dome portions each have the uniformly stressed curved surface shape when the internal pressure of the liner is at atmospheric pressure, it is possible to reduce the mass of the high-pressure tank and reduce the manufacturing cost of the high-pressure tank.

[0009] In the above aspect, the set pressure may be a pressure that causes the liner to burst.

[0010] According to the above aspect, it is possible to reduce the strain generated in the reinforcement layer when the internal pressure of the liner reaches a pressure that causes the liner to burst, unlike the high-pressure tank whose dome portions each have the uniformly stressed curved surface shape when the internal pressure of the liner is the atmospheric pressure.

[0011] In the above aspect, the set pressure may be a maximum boost pressure of the high-pressure tank.

[0012] According to the above aspect, the reinforcement layer can be made thinner than in the high-pressure tank whose dome portions each have the uniformly stressed curved surface shape when the internal pressure of the liner reaches a pressure that causes the liner to burst; thus, it is possible to reduce the mass of the high-pressure tank and reduce the cost of manufacturing the high-pressure tank.

[0013] In the above aspect, an inclination of the dome portion relative to the cylinder portion at a connecting portion between the cylinder portion and the dome portion is 0 degrees, and a radius of curvature of the connecting portion is in a range of 6 mm to 30 mm, or the inclination is 7 degrees, and the radius curvature of the connecting portion is in a range of 10 mm to 20 mm.

[0014] According to the above aspect, it is possible to reduce the strain generated in the reinforcing layer covering the joint portion.

[0015] The present invention is not limited to a high-pressure tank and can be applied to various forms, such as a method for manufacturing a high-pressure tank, a manufacturing apparatus for a high-pressure tank, and the like. The present invention is by no means limited to the aspect described above, and it should be understood that the present invention can be implemented in various forms without departing from the spirit of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] 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 reference numerals designate like elements, and in which: Fig. 1 is a sectional view showing a schematic configuration of a high-pressure tank of the first embodiment; Fig. 2 is an explanatory view explaining a dome section shape; Fig. 3 is an enlarged view showing the vicinity of a connecting portion between a cylinder portion and a dome portion; Fig. 4 is an explanatory view comparing strains in reinforcement layers of high-pressure tanks of respective embodiments; and Fig. 5 is an explanatory view showing numerical values of shapes and strains in reinforcing layers of the respective embodiments. DETAILED DESCRIPTION OF EMBODIMENTS A. First Embodiment

[0017] Fig. Fig. 1 is a sectional view showing a schematic configuration of a high-pressure tank 10 of the first embodiment; XYZ axes orthogonal to each other are shown in Fig. 1. The XYZ axes in Fig. 1 correspond to XYZ axes in the other drawings. The high-pressure tank 10 of the present embodiment stores a high-pressure hydrogen gas at, for example, about 70 MPa. The high-pressure tank 10 includes a liner 20 and a reinforcement layer 30.

[0018] The liner 20 is a hollow liner made of resin and forms a space in which a gas is hermetically sealed. The liner 20 is made of, for example, a thermoplastic resin such as polyethylene, nylon, polypropylene, and polyester. The liner 20 has an axis common to an axis AX of the high-pressure tank 10. The liner 20 includes a cylinder portion 21 and dome portions 22, 23.

[0019] The cylinder portion 21 has a cylindrical shape. Dome portions 22, 23 are arranged at both ends of the cylinder portion 21 in the axial direction of the cylinder portion 21 and are each formed into a curved surface shape that is convex outward of the liner 20. On the highest ends of the dome portions 22, 23, fittings 13 and 14 made of metal such as aluminum and stainless steel are arranged, respectively. The fitting 13 on one side has a through hole 15 and serves to extract the gas from the high-pressure tank 10 or to fill the high-pressure tank 10 with the gas. The fitting 14 on the other side serves to rotate the liner 20 at the time of reinforcing the liner 20 or forming the reinforcing layer of the liner 20. The fitting 14 may be omitted.

[0020] The curved surface shape of each of the dome portions 22, 23 is a uniformly stressed curved surface shape when the internal pressure of the liner 20 reaches a set pressure set higher than atmospheric pressure. In the present embodiment, the set pressure is a burst pressure, which is a pressure that causes the liner 20 to burst. The burst pressure referred to herein is a pressure that falls within a range of -5% to +5% of the pressure when a crack is confirmed in a part of the liner 20 after the liner 20 is filled with a hydrogen gas in a state where it is not covered by the reinforcing layer 30. A pressure value of such a burst pressure is previously determined by experimental measurement or simulation.The burst pressure in the liner 20 of the present embodiment is a pressure within a range of 171 MPa to 189 MPa, based on the pressure of 180 MPa. A uniformly stressed curved surface shape refers to a curved surface shape in which a stress on a curved surface of interest becomes the same at any position and in any orientation of that curved surface when an internal pressure is applied. Since the curved surface shape of each of the dome portions 22, 23 is a uniformly stressed curved surface shape, when the internal pressure of the liner 20 reaches the burst pressure, in the present embodiment, theoretically, no crack occurs, but fracture occurs over the entire curved surface of each of the dome portions 22, 23 at the time of the burst pressure.Through a CAE (Computer Aided Engineering) simulation used in the design of the liner 20, it is confirmed that the dome sections 22, 23 each have a uniformly stressed curved surface shape when the internal pressure of the liner 20 reaches the set pressure. As the curved surface shape of each dome section 22, 23, a shape formed when the internal pressure of the liner 20 is returned to atmospheric pressure is practically used after the curved surface shape of the dome section is adjusted by the simulation so that it becomes a uniformly stressed curved surface shape when the internal pressure of the liner 20 reaches the set pressure.

[0021] The reinforcement layer 30 is a layer that covers the periphery of the liner 20 to reinforce the liner 20. The reinforcement layer 30 includes a strapping layer 32 and a helical layer 34.

[0022] The strapping layer 32 is formed by strap-winding a fiber bundle around the cylinder portion 21. The fiber bundle used for the strapping winding is formed by impregnating a fiber bundle of carbon fibers with a thermosetting resin such as an epoxy resin.

[0023] The helical layer 34 is formed by helically winding a fiber bundle around the strapping layer 32 and the dome portions 22, 23. The fiber bundle used for the helical winding is formed by impregnating a fiber bundle of carbon fibers with a thermosetting resin such as epoxy resin, as in the case of the fiber bundle used for the strapping winding.

[0024] The thickness of the strapping layer 32 and the thickness of the helical layer 34 are appropriately adjusted depending on the pressure resistance and strength required for the high-pressure tank 10.

[0025] Fig. 2 is an explanatory view explaining a dome portion shape of the liner 20 of the present embodiment and a dome portion shape of a liner of a comparative example. The configuration of the liner of the comparative example is the same as the liner 20 of the present embodiment, except that they have different pressures when the curved surface shape of each dome portion becomes a uniformly stressed curved surface shape.

[0026] In the Fig. In the diagram illustrated in Figure 2, a vertical axis indicates an axial position in the high-pressure tank. An axial position indicates a distance from a central position in an AX-axis direction of the high-pressure tank. A horizontal axis indicates a radial position in the high-pressure tank. A radial position indicates a distance in the Z-axis direction from the AX axis of the high-pressure tank.

[0027] In dem in Fig. In the diagram illustrated in FIG. 2, a dash-dot-dash line Dm indicates a dome section shape when the internal pressure of the liner 20 of the present embodiment is at atmospheric pressure. A dash-dot-dot-dash line dm indicates a dome section shape when the internal pressure of the liner of the comparative example is at atmospheric pressure. A solid line DM indicates a dome section shape when the internal pressure of the liner 20 of the present embodiment is 180 MPa. A solid line dM indicates a dome section shape when the internal pressure of the liner of the comparative example is 180 MPa. 180 MPa is a pressure that falls within the range of the burst pressure in the liner 20.Furthermore, the respective dome section shapes indicated by the dash-dot-dash line Dm, the dash-dot-dot-dash line dm, the solid line DM and the solid line dM indicate the dome section shapes of the respective liners without being covered by the reinforcement layers.

[0028] When the internal pressure of the liner is at atmospheric pressure, the dome section shape of the liner of the comparative example is a uniformly stressed curved surface shape. That is, the liner of the comparative example has the dome sections each having the uniformly stressed curved surface shape in a state where the liner is not filled with hydrogen gas and no stress caused by the internal pressure is applied to the dome sections. When the internal pressure of the liner is at atmospheric pressure, each dome section shape of the liner becomes the uniformly stressed curved surface shape. This means that when the internal pressure increases by a change amount as close to zero as possible from the atmospheric pressure, each dome section shape becomes the uniformly stressed curved surface shape.The dome section shape of the liner of the comparative example at this time is indicated by the dash-dot-dot-dash line dm. When the liner of the comparative example is pressurized with hydrogen gas in an amount that allows the internal pressure of the liner to reach 180 MPa in the state indicated by the dash-dot-dot-dash line dm, the liner of the comparative example assumes the state indicated by the solid line dM.

[0029] In contrast, when the internal pressure of the liner 20 of the present embodiment is at atmospheric pressure, the liner 20 does not have a uniformly stressed curved surface shape. The domed portion shape of the liner 20 of the present embodiment at this time is indicated by the dash-dot-dash line Dm. When the liner 20 of the present embodiment, in the state indicated by the dash-dot-dash line Dm, is filled with the hydrogen gas in an amount that allows the internal pressure of the liner 20 to reach 180 MPa, which is the burst pressure, the liner 20 of the present embodiment assumes the state indicated by the solid line DM. Since the internal pressure of the liner 20 is 180 MPa, the domed portion shape of the liner 20 of the present embodiment at this time is the uniformly stressed curved surface shape.The curved surface shape of each dome portion of the liner of the comparative example is the uniformly stressed curved surface when the internal pressure of the liner is at atmospheric pressure. In contrast, the curved surface shape of each dome portion 22, 23 of the liner 20 of the present embodiment is the uniformly stressed curved surface shape when the internal pressure of the liner 20 is at the burst pressure.

[0030] Based on the comparison between the dash-dot-dot-dash line dm and the dash-dot-dash line Dm, the dome portion shapes of the liner 20 of the present embodiment are closer inward to each other than those of the liner of the comparative example in the state where the internal pressure of the liner is at atmospheric pressure. Based on the comparison between the solid line dM and the solid line DM, the dome portion shapes of the liner 20 of the present embodiment are closer inward to each other than those of the liner of the comparative example even in the state where the internal pressure of the liner is 180 MPa. That is, the liner 20 of the present embodiment can reduce the strain generated in the reinforcing layer by the expansion of the dome portions when the internal pressure of the liner increases above atmospheric pressure, compared to the liner of the comparative example."Strain" as used herein means any displacement, extension, contraction, torsion, linear or surface strain, or any other deformation in any portion of the reinforcement layer. It should be noted that the strain induced in the reinforcement layer is calculated through CAE simulation.

[0031] Furthermore, the dome section shape of the liner of the comparative example is the uniformly stressed curved surface shape when the internal pressure of the liner is at atmospheric pressure. Therefore, when the internal pressure of the liner increases above atmospheric pressure, each dome section shape deforms into a shape that is more expanded than the uniformly stressed curved surface shape. The dome section shape is different from a hemispherical shape because of the presence of the connecting piece and its thickness is not uniform. Therefore, when the dome section shape is in a shape that expands from the uniformly stressed curved surface shape, the amount of deformation between the respective parts differs compared to the state where the dome section shape is the uniformly stressed curved surface shape.Therefore, since the stress on the curved surface of each dome portion becomes irregular at the positions and orientations of the curved surface of the dome portion, a large strain of the reinforcing layer may occur depending on the positions and orientations. To counteract this strain, the thickness of the reinforcing layer can be increased, but in the high-pressure tank provided with such a reinforcing layer, an increase in the mass of the tank is caused, resulting in an increase in the cost of the tank. In contrast, the dome portion shape of the liner 20 of the present embodiment is the uniformly stressed curved surface shape when the internal pressure of the liner 20 is at the burst pressure.Therefore, when the internal pressure of the liner 20 is at the burst pressure and the dome portions 22, 23 each have the uniformly stressed curved surface shape, the stress on the curved surface of each of the dome portions 22, 23 becomes the same at any position and in any orientation of the curved surface; therefore, compared to the liner of the comparative example, a large strain is less likely to occur in the reinforcing layer 30. Accordingly, in the high-pressure tank 10 of the present embodiment, compared to the high-pressure tank of the comparative example, it is possible to reduce mass increase and cost increase due to the increase in the thickness of the reinforcing layer.

[0032] According to the first embodiment described above, it is possible to reduce the strain generated in the reinforcement layer 30 when the internal pressure of the liner 20 reaches the pressure that causes the liner 20 to burst, compared to the high-pressure tank whose dome portions each have the uniformly stressed curved surface shape when the internal pressure of the liner is atmospheric pressure. Accordingly, with such a high-pressure tank 10, it is possible to realize a mass reduction of the high-pressure tank 10 and a cost reduction in the manufacturing of the high-pressure tank 10 because the reinforcement layer 30 can be made thinner.

[0033] Since the dome portion shapes of the liner 20 of the present embodiment are closer to each other inward of the high-pressure tank than those of the liner of the comparative example, the following effects can be achieved when, for example, defining the dimension of an installation space for the high-pressure tank in a vehicle in which the high-pressure tank is mounted. That is, when the high-pressure tank 10 of the present embodiment and the high-pressure tank of the comparative example, both of which have the same length in the AX direction, are designed to dispose the high-pressure tanks in the respective installation spaces, the high-pressure tank 10 of the present embodiment can be formed so that the length of the cylinder portion 21 can be longer than that of the high-pressure tank of the comparative example; thus, it is possible to increase the storage amount of the gas.

[0034] Fig. 3 is an enlarged view illustrating the vicinity of a connecting portion CN between the cylinder portion 21 and the dome portion 23 in the configuration of the high-pressure tank 10 according to the first embodiment. In the high-pressure tank 10, when the internal pressure of the liner 20 is atmospheric pressure, an inclination α of each dome portion 22, 23 relative to the cylinder portion 21 at the connecting portion CN between the cylinder portion 21 and each dome portion 22, 23 (hereinafter referred to as an inclination of the connecting portion CN) is 0 degrees. The inclination α of the connecting portion CN mentioned herein is measured as follows.Namely, assuming that an end point of the dome portion 23 on the -X-axis direction side and an end point of the cylinder portion 21 on the +X-axis direction side overlap each other at the connecting portion CN, an inclination having an angle smaller than 90 degrees in the inclination of an extension line EL relative to the cylinder portion 21 is measured as an inclination α of the connecting portion CN, where the extension line EL is defined by extending a tangent at the end point of the dome portion 23 on the -X-axis direction side toward the -X-axis direction side. Note that the inclination α of the connecting portion CN is zero degrees in the high-pressure tank 10; in . Fig. However, for better understanding, Figure 3 illustrates the inclination α with an angle greater than 0 degrees.

[0035] Furthermore, the connecting portion CN has a curved surface with a radius of curvature of 6 mm when the internal pressure of the liner 20 is equal to atmospheric pressure. Hereinafter, the connecting portion CN is described as being formed into a curved surface shape defined by a radius of curvature. In the above description of the inclination α, for convenience of explanation, it was stated that the end point of the dome portion 23 on the -X-axis direction side overlaps the end point of the cylinder portion 21 on the +X-axis direction side; however, the connecting portion of the actual liner is formed in the following shape.Namely, the connecting portion CN, before being processed into a curved surface, is a portion where the end point of the dome portion 23 on the -X-axis direction side and the end point of the cylinder portion 21 on the +X-axis direction side overlap each other. This connecting portion CN has a corner because this portion corresponds to a part where the straight shape of the cylinder portion 21 shifts along the X-axis direction to the curved dome portion shape 23. This corner is formed into a round shape defined by a radius of curvature by processing this corner into a curved surface, and this finished corner is the actual connecting portion CN. In other words, the cylinder portion 21 and the dome portion 23 are actually connected to each other by the connecting portion CN, which is formed into a curved surface shape defined by the radius of curvature.In the design process of the liner 20, during CAE simulation, the inclination α of each dome portion 22, 23 relative to the cylinder portion 21 is determined at the connecting portion CN between the cylinder portion 21 and each dome portion 22, 23 (at this time, the connecting portion CN has a corner shape). Thereafter, the radius of curvature in machining the connecting portion CN (to round this portion) is determined so that the shape of the connecting portion CN is changed from a corner shape to a round shape. Furthermore, in the manufacturing process of the actual liner 20, the corner is machined into a curved surface in the same manner as in the design process, thereby making the connecting portion CN round.

[0036] Fig. 4 and Fig. 5 are explanatory views comparing strains in the reinforcement layers of the high-pressure tanks with respective embodiments. The vertical axis in Fig. 4 shows a maximum value of strain generated in the reinforcing layer 30 covering the joint portion CN when the high-pressure tank of each embodiment is filled with the hydrogen gas in an amount that allows the internal pressure of the liner to reach 180 MPa. Fig. 5 is an explanatory view showing numerical values of the radius of curvature defining the curved surface shape of the connecting portion CN and the inclination of the connecting portion CN of each embodiment, as well as the strain (the maximum value of the strain) in the reinforcing layer in the high-pressure tank of each embodiment. The portion of the reinforcing layer 30 used for the measurement is a portion of the first layer of the helical layer 34, the portion first wound around the liner 20. Assuming that a state in which no strain is generated in the reinforcing layer 30 is defined as 0%, among the strains generated by increasing the internal pressure of the liner 20 from this state, a ratio of a strain generated in a portion experiencing the largest strain is defined as the maximum value of the strain.

[0037] The first embodiment is the high-pressure tank 10 of the first embodiment. The inclination α of the connecting portion CN in the first embodiment is 0 degrees, and the connecting portion CN has a curved surface with a radius of curvature of 6 mm. The inclination α of the connecting portion CN in the second embodiment is 0 degrees, and the connecting portion CN has a curved surface with a radius of curvature of 10 mm. The inclination α of the connecting portion CN in the third embodiment is 0 degrees, and the connecting portion CN has a curved surface with a radius of curvature of 20 mm. The inclination α of the connecting portion CN in the fourth embodiment is 0 degrees, and the connecting portion CN has a curved surface with a radius of curvature of 30 mm.

[0038] The inclination α of the connecting portion CN in the fifth embodiment is 7 degrees, and the connecting portion CN has a curved surface with a radius of curvature of 10 mm. The inclination α of the connecting portion CN in the sixth embodiment is 7 degrees, and the connecting portion CN has a curved surface with a radius of curvature of 20 mm. The inclination α of the connecting portion CN in the seventh embodiment is 15 degrees, and the connecting portion CN has a curved surface with a radius of curvature of 10 mm. The inclination α of the connecting portion CN in the eighth embodiment is 15 degrees, and the connecting portion CN has a curved surface with a radius of curvature of 20 mm.The dome portions 22, 23 of the high-pressure tank according to each of the first to eighth embodiments each have the uniformly stressed curved surface shape when the internal pressure of the liner 20 reaches the burst pressure. The radius of curvature defining the curved surface of the connecting portion CN and the inclination α of the connecting portion CN in the high-pressure tank of each of the above-described first to eighth embodiments are represented by values when the internal pressure of the liner 20 is atmospheric pressure.

[0039] Based on the results in Fig.4, in the first embodiment, a strain of 1.92% is generated in the reinforcement layer 30 when the internal pressure of the liner 20 reaches the burst pressure. On the other hand, in the seventh embodiment and the eighth embodiment, strains of 2.47% and 2.48% are generated in the reinforcement layers 30 when the internal pressure of the liner 20 reaches the burst pressure, respectively. In the second embodiment to the sixth embodiment, on the other hand, among the strains generated in the respective reinforcement layers 30 when the internal pressure of each liner 20 reaches the burst pressure, the minimum strain corresponds to 1.65% in the high-pressure tank of the third embodiment, and the maximum strain corresponds to 2.17% in the fifth embodiment.

[0040] The high-pressure tank of each of the second to sixth embodiments described above can reduce the strain generated in the reinforcing layer 30 covering the connecting portion CN as smoothly as in the high-pressure tank 10 of the first embodiment (first embodiment). Thus, since the reinforcing layer 30 can be set to have a thinner thickness than in the case of the high-pressure tank of each of the seventh and eighth embodiments, it is possible to achieve a reduction in the mass of the high-pressure tank and a reduction in the manufacturing cost of the high-pressure tank in the high-pressure tank of each of the second to sixth embodiments. B. Further embodiments

[0041] In the embodiment described above, the state in which the curved surface shapes of the dome portions 22, 23 are the uniformly stressed curved surfaces is determined by the internal pressure of the liner 20, but the present invention is not limited thereto. For example, the state in which the curved surface shapes of the dome portions 22, 23 are the uniformly stressed curved surfaces may be determined by the stresses of the curved surfaces in the dome portions 22, 23 or the volumes of the dome portions 22, 23. The curved surface stress and the volume in this case denote a curved surface stress and a volume that lead to the rupture of the liner 20.

[0042] In the embodiment described above, the set pressure is set as a burst pressure that causes the liner 20 to burst, but the present invention is not limited thereto. For example, the set pressure may be a maximum filling pressure of the high-pressure tank. The maximum filling pressure mentioned in this case is stipulated by Article 2(25) of the Pressure Vessel Safety Regulations and corresponds to a numerical value of the highest pressure among gas pressures with which a given vessel can be filled at a temperature of 35 degrees. For example, if the maximum filling pressure of the high-pressure tank is 160 MPa, the set pressure is 160 MPa. With this configuration, the reinforcement layer can be made thinner than that of the high-pressure tank whose set pressure is at the burst pressure, thereby achieving a mass reduction of the high-pressure tank and a reduction in the manufacturing cost of the high-pressure tank.

[0043] The present invention is not limited to the above-described embodiments, working examples, and modifications, and can be implemented in various forms without departing from the scope of the invention. For example, the technical features in the embodiments, working examples, and modifications that correspond to the technical features in the respective aspects described in the SUMMARY OF THE INVENTION section can be replaced or combined as needed to realize part or all of the above-mentioned effects. Furthermore, if the technical features are not described as essential in this specification, they may be omitted as appropriate.

Claims

[1] High-pressure tank (10), comprising: a liner (20) having a space in which a gas is hermetically sealed, the liner (20) comprising a cylinder portion (21) in a cylindrical shape and a pair of dome portions (22, 23) arranged at both ends of the cylinder portion (21) in an axial direction of the cylinder portion (21); and a reinforcing layer (30) adapted to cover a periphery of the liner (20), wherein a curved surface shape of each of the dome sections (22, 23) is a uniformly stressed curved surface shape when an internal pressure of the lining (20) reaches a set pressure set higher than an atmospheric pressure, an inclination of the dome section (22, 23) relative to the cylinder section (21) at a connecting section (CN) between the cylinder section (21) and the dome section (22, 23) is 0 degrees and a radius of curvature of the connecting section (CN) is in a range of 6 mm to 30 mm, or the inclination is 7 degrees and the radius of curvature of the connecting section (CN) is in a range of 10 mm to 20 mm. [2] High pressure tank (10) according to claim 1, wherein the set pressure is a pressure that causes the liner (20) to burst. [3] High-pressure tank (10) according to claim 1, wherein the set pressure is a maximum filling pressure of the high-pressure tank (10).

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