Method for manufacturing high pressure tank

Abstract

The present invention provides a method for manufacturing a high-pressure tank. In the method, a plurality of fiber-reinforced resin plates are stacked crosswise on a guide recess while rotating around an axis of a fixture, thereby forming a circular plate-shaped dome reinforcement layer intermediate, and a first dome reinforcement layer is manufactured by stamping the formed dome reinforcement layer intermediate into a dome shape.

Description

Technical Field

[0001] The invention relates to a method for manufacturing a high-pressure tank. Background Art

[0002] As a high-pressure tank mounted on a fuel cell vehicle or the like, there is known a structure having a liner and a reinforcement layer, the liner having a cylindrical tube portion and a pair of dome portions provided at both ends of the tube portion in the axial direction, and the reinforcement layer being composed of a fiber reinforced resin covering the outer peripheral surface of the liner. The high-pressure tank having such a structure is manufactured by first forming a liner, and using the formed liner as a winding core to wind a fiber bundle impregnated with a resin around the outer peripheral surface of the liner by a wire winding method (FW method) to form a reinforcement layer (for example, see Japanese Patent Application Laid-Open No. 2012-149739 below). Summary of the invention

[0003] Recently, as a method to replace the above-mentioned manufacturing method, a method of using a mold to separately manufacture a tube reinforcement layer covering the tube portion of the liner and a dome reinforcement layer covering the dome portion, and assembling the manufactured tube reinforcement layer and dome reinforcement layer has been studied. However, in this manufacturing method, a method for efficiently manufacturing the dome reinforcement layer has not yet been established, and there is a problem that it is difficult to achieve an improvement in the productivity of the high-pressure tank.

[0004] The present invention has been made to solve such technical problems, and an object of the present invention is to provide a method for manufacturing a high-pressure tank capable of efficiently manufacturing a dome reinforcement layer and improving the productivity of the high-pressure tank.

[0005] In the manufacturing method of the high-pressure tank of the present invention, the high-pressure tank comprises a lining and a reinforcement portion, the lining comprises a cylindrical tube portion and a pair of dome portions arranged at both ends of the tube portion in an axial direction, the reinforcement portion comprises a tube reinforcement layer covering the outer peripheral surface of the tube portion and a dome reinforcement layer covering the outer peripheral surface of the dome portion, and the manufacturing method of the high-pressure tank is characterized in that the manufacturing method of the high-pressure tank includes the following dome reinforcement layer manufacturing process: a circular plate-shaped dome reinforcement layer intermediate is formed by cross-stacking a plurality of fiber-reinforced resin sheets, and the dome reinforcement layer is manufactured by stamping the formed dome reinforcement layer intermediate into a dome shape.

[0006] According to the manufacturing method of the high-pressure tank of the present invention, a dome reinforcement layer intermediate body in the shape of a disk is formed by stacking a plurality of fiber-reinforced resin sheets crosswise with each other, and a dome reinforcement layer is manufactured by stamping the formed dome reinforcement layer intermediate body into a dome shape. Therefore, the dome reinforcement layer can be manufactured efficiently, and the productivity of the high-pressure tank can be improved. Moreover, since a plurality of fiber-reinforced resin sheets are stacked crosswise with each other, the strength of the manufactured dome reinforcement layer can be improved compared with the case where the fiber-reinforced resin sheets are stacked in parallel.

[0007] In the method for manufacturing a high-pressure tank of the present invention, it is preferred that, in the dome reinforcement layer manufacturing step, a jig having a cylindrical guide recess and a shaft erected at a central position of the guide recess is used to stack the plurality of fiber-reinforced resin sheets on the guide recess in a manner of rotating around the shaft, thereby forming the dome reinforcement layer intermediate. In this way, the dome reinforcement layer intermediate can be manufactured efficiently, and the strength of the manufactured dome reinforcement layer can be ensured.

[0008] In the method for manufacturing a high-pressure tank of the present invention, it is preferred that, in the dome reinforcement layer manufacturing step, a jig having a cylindrical guide recess is used to stack the plurality of fiber-reinforced resin sheets on the guide recess in a manner of rotating about the center of the guide recess, thereby forming the dome reinforcement layer intermediate. In this way, the dome reinforcement layer intermediate can be manufactured efficiently, and the strength of the manufactured dome reinforcement layer can be ensured.

[0009] According to the present invention, the dome reinforcement layer can be efficiently manufactured, and the productivity of the high-pressure tank can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] 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 symbols represent like elements, and in which:

[0011] Figure 1 It is a schematic cross-sectional view showing the structure of a high-pressure tank.

[0012] Figure 2 It is a process diagram showing a method for manufacturing a high-pressure tank according to an embodiment.

[0013] Figure 3A It is a schematic diagram explaining the production of the first dome reinforcement layer.

[0014] Figure 3B It is a schematic diagram explaining the production of the first dome reinforcement layer.

[0015] Figure 3C It is a schematic diagram explaining the production of the first dome reinforcement layer.

[0016] Figure 3D It is a schematic diagram explaining the production of the first dome reinforcement layer.

[0017] Figure 4 It is a cross-sectional view showing a state where a pipe head is mounted on the first dome reinforcement layer.

[0018] Figure 5 It is a cross-sectional view explaining the formation of the first dome segment body.

[0019] Figure 6It is a cross-sectional view explaining the formation of the second dome segment.

[0020] Figure 7 It is a cross-sectional view explaining the production of the pipe reinforcement layer.

[0021] Figure 8 It is a cross-sectional view explaining the formation of the pipe segment body.

[0022] Fig. 9 It is a cross-sectional view explaining the assembly of the first dome segment body, the pipe segment body, and the second dome segment body.

[0023] Fig.10 It is a cross-sectional view explaining the formation of a high helical layer. DETAILED DESCRIPTION

[0024] Hereinafter, an embodiment of the method for manufacturing a high-pressure tank of the present invention will be described with reference to the accompanying drawings. Figure 1 The structure of the high-pressure tank will be described below.

[0025] [About high pressure tanks]

[0026] Figure 1 1 is a schematic cross-sectional view showing the structure of a high-pressure tank. The high-pressure tank 1 is mounted on, for example, a fuel cell vehicle, and is filled with high-pressure hydrogen. It should be noted that the gas filled into the high-pressure tank 1 is not limited to high-pressure hydrogen, and may be various compressed gases such as CNG (compressed natural gas), various liquefied gases such as LNG (liquefied natural gas), LPG (liquefied petroleum gas), and other gases.

[0027] like Figure 1 As shown, the high-pressure tank 1 is a high-pressure gas storage container with a roughly cylindrical shape and rounded corners at both ends, and comprises: a liner 2 with gas barrier properties; a reinforcement portion 3 covering the outer peripheral surface of the liner 2 and having multiple reinforcement layers; and a pipe head 4 installed at one end of the high-pressure tank 1.

[0028] The liner 2 is a hollow container having a storage space 5 for storing high-pressure hydrogen, and is formed of a resin material having gas barrier properties for hydrogen. The liner 2 is composed of a cylindrical tube 21 and a pair of dome portions (a first dome portion 22 and a second dome portion 23) provided on both sides of the axial direction of the tube 21 (i.e., the axis L direction of the high-pressure tank 1). The tube 21 extends along the axis L direction of the high-pressure tank 1 by a predetermined length. The first dome portion 22 and the second dome portion 23 are continuously formed on both sides of the tube 21, and the diameters thereof are respectively reduced as they are away from the tube 21.

[0029] The end 221 of the first dome portion 22 is connected to the pipe head 4. The end 222 of the first dome portion 22 opposite to the end 221 is formed to bend toward the outside of the high-pressure tank 1. The end 231 of the second dome portion 23 is also formed to bend toward the outside of the high-pressure tank 1.

[0030] The resin material forming the liner 2 is preferably a material having a performance of retaining the filled gas in the storage space 5, that is, having excellent gas barrier properties. Examples of such a resin material include thermoplastic resins and thermosetting resins described below.

[0031] The pipe head 4 is a structure formed by processing a metal material such as aluminum or aluminum alloy into a predetermined shape. The pipe head 4 has a substantially cylindrical pipe head body 41 and a flange 42 embedded between the liner 2 and the reinforcement 3. The pipe head 4 is provided with a valve (not shown) for filling and discharging hydrogen gas into the storage space 5.

[0032] The reinforcement part 3 has the function of reinforcing the liner 2 to improve the mechanical strength of the high-pressure tank 1, such as rigidity and pressure resistance, and has a plurality of reinforcement layers formed of a fiber-reinforced resin in which a resin is impregnated in a reinforcing fiber (continuous fiber). Specifically, the reinforcement part 3 has: a tube reinforcement layer 31 covering the outer peripheral surface of the tube part 21; a first dome reinforcement layer 32 covering the outer peripheral surface of the first dome part 22; a second dome reinforcement layer 33 covering the outer peripheral surface of the second dome part 23; a high helical layer 34 covering the entire tube reinforcement layer 31, a part of the first dome reinforcement layer 32, and a part of the second dome reinforcement layer 33; and an outer helical layer 35 covering the entire high helical layer 34, a part of the first dome reinforcement layer 32, and a part of the second dome reinforcement layer 33.

[0033] The tube reinforcement layer 31 is a reinforcement layer corresponding to the tube portion 21, and is cylindrical in shape following the shape of the tube portion 21. The tube reinforcement layer 31 is formed of a fiber-reinforced resin in which a resin is impregnated in a reinforcement fiber. The reinforcement fibers of the tube reinforcement layer 31 are circumferentially arranged at an angle substantially orthogonal to the axial L direction of the high-pressure tank 1. In other words, the reinforcement fibers of the tube reinforcement layer 31 are arranged along the circumferential direction of the high-pressure tank 1.

[0034] The first dome reinforcement layer 32 is a reinforcement layer corresponding to the first dome portion 22, and is dome-shaped in accordance with the shape of the first dome portion 22. The first dome reinforcement layer 32 is formed of a fiber-reinforced resin in which a resin is impregnated in reinforcing fibers. The reinforcing fibers of the first dome reinforcement layer 32 are not oriented along the circumferential direction of the high-pressure tank 1 but extend in various directions intersecting the circumferential direction of the high-pressure tank 1.

[0035] The second dome reinforcement layer 33 is a reinforcement layer corresponding to the second dome portion 23, and is dome-shaped in accordance with the shape of the second dome portion 23. The second dome reinforcement layer 33 is formed of a fiber-reinforced resin in which a resin is impregnated in a reinforcing fiber. The reinforcing fibers of the second dome reinforcement layer 33 are not oriented along the circumferential direction of the high-pressure tank 1 but extend in various directions intersecting the circumferential direction of the high-pressure tank 1.

[0036] It should be noted that the reinforcing fibers of the tube reinforcement layer 31 are not continuous (not connected) with the reinforcing fibers of the first dome reinforcement layer 32 or the second dome reinforcement layer 33. This is because, as described later, the tube reinforcement layer 31, the first dome reinforcement layer 32, and the second dome reinforcement layer 33 are separately manufactured structures.

[0037] In this embodiment, the tube portion 21 and the tube reinforcement layer 31 covering the outer peripheral surface of the tube portion 21 constitute the tube segmentation body 11, the first dome portion 22 and the first dome reinforcement layer 32 covering the outer peripheral surface of the first dome portion 22 constitute the first dome segmentation body 12, and the second dome portion 23 and the second dome reinforcement layer 33 covering the outer peripheral surface of the second dome portion 23 constitute the second dome segmentation body 13.

[0038] In the axial L direction of the high-pressure tank 1, the pipe segment 11, the first dome segment 12, and the second dome segment 13 form an assembly 10 by assembling one end of the pipe segment 11 with the first dome segment 12 and assembling the other end of the pipe segment 11 with the second dome segment 13. Furthermore, the pipe segment 11 and the first dome segment 12 are assembled in such a manner that the first dome portion 22 is arranged at the outer side of the high-pressure tank 1 than the pipe portion 21. Similarly, the pipe segment 11 and the second dome segment 13 are assembled in such a manner that the second dome portion 23 is arranged at the outer side of the high-pressure tank 1 than the pipe portion 21.

[0039] Both ends of the tube portion 21 in the axial L direction of the high-pressure tank 1 are folded back ends 211 folded back to the outside of the high-pressure tank 1. Specifically, the folded back ends 211 are folded back to the outside of the high-pressure tank 1 in a manner to surround the ends of the tube reinforcement layer 31 disposed outside thereof, and are formed to extend to about half the thickness of the tube reinforcement layer 31. In addition, at the assembly portion of the tube segment 11 and the first dome segment 12 or the second dome segment 13, the folded back ends 211 of the tube portion 21 abut against the first dome portion 22 or the second dome portion 23.

[0040] Specifically, at the assembly position of the pipe segment 11 and the first dome segment 12, the folded end 211 of the pipe portion 21 abuts against the end 222 of the first dome portion 22. At the assembly position of the pipe segment 11 and the second dome segment 13, the folded end 211 of the pipe portion 21 abuts against the end 231 of the second dome portion 23. It should be noted that the "assembly position" here refers to the portion where the pipe segment 11 overlaps with the first dome segment 12 or the second dome segment 13.

[0041] In addition, the thickness of the first dome portion 22 and the second dome portion 23 is preferably greater than the thickness of the tube portion 21. In this way, the unevenness of the contact position between the tube portion 21 and the first dome portion 22 or the second dome portion 23 can be absorbed, so that the sealing performance of the liner 2 formed by the tube portion 21, the first dome portion 22 and the second dome portion 23 can be reliably ensured.

[0042] The high helical layer 34 is a reinforcement layer formed by high-angle spiral winding of a fiber bundle impregnated with a resin in a reinforcing fiber on the outside of the assembly 10. Spiral winding is a form of winding a fiber bundle at a winding angle greater than 0° and less than 90° relative to the axis L direction of the high-pressure tank 1. The spiral winding is divided into low-angle spiral winding and high-angle spiral winding according to the size of the winding angle. Low-angle spiral winding is spiral winding when the winding angle is small (for example, greater than 0° and less than 30°), and high-angle spiral winding is spiral winding when the winding angle is large (for example, greater than 30° and less than 90°).

[0043] The high helical layer 34 is formed by high-angle helical winding of a fiber bundle obtained by impregnating a resin in reinforcing fibers, so the reinforcing fibers of the high helical layer 34 are oriented obliquely with respect to the axis L direction of the high-pressure tank 1. Figure 1 As shown, the high spiral layer 34 is not only formed on the whole tube reinforcement layer 31, but also one end thereof passes over the assembly position of the tube segment 11 and the first dome segment 12 and extends to a part of the first dome segment 12, and the other end passes over the assembly position of the tube segment 11 and the second dome segment 13 and extends to a part of the second dome segment 13.

[0044] The outer helical layer 35 is a reinforcement layer arranged on the outermost side of the high-pressure tank 1, and is formed by spirally winding a fiber bundle formed by impregnating a resin in a reinforcing fiber at a low angle on the outer side of the assembly 10 and the high helical layer 34. In addition, the reinforcing fibers of the outer helical layer 35 are also oriented obliquely with respect to the axis L direction of the high-pressure tank 1.

[0045] [Regarding the manufacturing method of the high pressure tank]

[0046] Next, a method for manufacturing the high-pressure tank 1 will be described. Figure 2The process diagram of the manufacturing method of the high-pressure tank 1 shows an embodiment. The manufacturing method of the high-pressure tank 1 includes a first dome reinforcement layer manufacturing process S1, a first dome segmentation body forming process S2, a second dome reinforcement layer manufacturing process S3, a second dome segmentation body forming process S4, a tube reinforcement layer manufacturing process S5, a tube segmentation body forming process S6, an assembly process S7, a sealing inspection process S8, a high helical layer forming process S9, and an outer helical layer forming process S10.

[0047] It should be noted that the first dome reinforcement layer manufacturing step S1, the second dome reinforcement layer manufacturing step S3, and the tube reinforcement layer manufacturing step S5 are independent of each other, and thus can be performed in parallel, or any one of them can be performed first. Furthermore, the first dome segmentation body forming step S2, the second dome segmentation body forming step S4, and the tube segmentation body forming step S6 are independent of each other, and thus can be performed in parallel, or any one of them can be performed first. Here, the first dome reinforcement layer manufacturing step S1 to the tube segmentation body forming step S6 are described in order.

[0048] [First dome reinforcement layer manufacturing step S1]

[0049] In the first dome reinforcement layer manufacturing step S1, a plurality of fiber reinforced resin sheets are cross-laminated to form a disk-shaped dome reinforcement layer intermediate, and the formed dome reinforcement layer intermediate is press-formed into a dome shape to manufacture the first dome reinforcement layer 32. Specifically, first, as Figure 3A As shown in the figure, a jig 100 having a cylindrical guide recess 101 and a cylindrical shaft 102 erected at the center of the guide recess 101 is prepared. The shaft 102 has the same diameter as the outer diameter of the ferrule 4.

[0050] Next, if Figure 3B and Figure 3C As shown, a fiber-reinforced resin sheet F1 in which reinforcing fibers are impregnated with resin is stacked on the guide recess 101 while rotating around the axis 102, thereby forming a disk-shaped dome reinforcement layer intermediate body 30. In this way, the dome reinforcement layer intermediate body 30 can be efficiently manufactured, and the strength of the manufactured first dome reinforcement layer 32 can be ensured.

[0051] The fiber reinforced resin sheet F1 is processed into a thin sheet shape. When the fiber reinforced resin sheet F1 is stacked, the difference in thickness between the center and the edge of the dome reinforcing layer intermediate body 30 is achieved by adjusting the number of stacked layers, for example.

[0052] Next, the formed dome reinforcement layer intermediate body 30 is removed from the jig 100 and placed in a die (not shown) to press-form the dome reinforcement layer intermediate body 30 into the same shape as the first dome portion 22. Figure 3DAs shown, a first dome reinforcing layer 32 having an opening into which the pipe head 4 can be inserted is produced.

[0053] The resin impregnated in the fiber-reinforced resin sheet F1 is not particularly limited, and for example, a thermosetting resin can be used. As the thermosetting resin, a thermosetting resin such as a phenolic resin, a melamine resin, a urea resin, and an epoxy resin is preferably used. In this case, the fiber-reinforced resin sheet F1 is laminated on the guide recess 101 of the fixture 100 in an uncured state of the thermosetting resin. In particular, epoxy resin is preferably used from the viewpoint of mechanical strength. Epoxy resin has fluidity in an uncured state and forms a tough bridging structure after thermal curing.

[0054] When using a thermosetting resin, the uncured thermosetting resin can be thermally cured by heating the dome reinforcing layer intermediate body 30 simultaneously with the press forming, or the dome reinforcing layer intermediate body 30 can be thermally cured by placing it in a thermal curing device after the press forming.

[0055] It should be noted that a thermoplastic resin can be used as the resin impregnated in the fiber-reinforced resin sheet F1. As the thermoplastic resin, polyetheretherketone, polyphenylene sulfide, polyacrylate, polyimide, polyamide, nylon 6, nylon 6,6, polyethylene terephthalate, etc. can be used. In this case, the fiber-reinforced resin sheet F1 is laminated to the guide recess 101 of the jig 100 while the thermoplastic resin is heated and softened, and the formed dome reinforcement layer intermediate 30 is press-formed. And after the press-forming, the softened thermoplastic resin of the first dome reinforcement layer 32 is cooled and solidified.

[0056] As the fiber constituting the fiber-reinforced resin sheet F1, glass fiber, aramid fiber, boron fiber, carbon fiber, etc. can be used. In particular, carbon fiber is preferably used from the viewpoint of lightness, mechanical strength, etc.

[0057] In the present embodiment, a carbon fiber reinforced resin (CFRP) sheet is used as the fiber reinforced resin sheet F1, but a so-called UD (Uni-Direction) sheet or the like in which a plurality of fiber bundles aligned in one direction are knitted with restraining threads may be used.

[0058] [First Dome Segment Forming Step S2]

[0059] In the first dome segment forming step S2, the first dome portion 22 is formed on the inner surface of the first dome reinforcement layer 32 formed in the first dome reinforcement layer forming step S1, thereby forming the first dome segment. Figure 4As shown, the pre-prepared pipe head 4 is installed to the opening of the first dome reinforcement layer 32. Next, as shown in FIG. Figure 5 As shown, the first dome portion 22 is formed by applying a liquid or softened resin material to the inner surface of the first dome reinforcing layer 32, or by attaching a sheet made of a resin material. At this time, the end portion 222 of the first dome portion 22 is formed to be warped outward.

[0060] The resin material here is preferably a material with excellent gas barrier properties as described above, and examples thereof include thermoplastic resins or thermosetting resins. As thermoplastic resins, for example, polypropylene resins, nylon resins (e.g., 6-nylon resins or 6,6-nylon resins), polycarbonate resins, acrylic resins, ABS resins, polyamide resins, polyethylene resins, ethylene-vinyl alcohol copolymer resins (EVOH), and polyester resins (e.g., polyethylene terephthalate) can be cited. As thermosetting resins, for example, epoxy resins, modified epoxy resins represented by vinyl ester resins, phenolic resins, melamine resins, urea resins, unsaturated polyester resins, alkyd resins, polyurethane resins, and thermosetting polyimide resins can be cited.

[0061] Alternatively, a two-liquid mixed thermosetting resin such as epoxy resin may be applied to the inner surface of the first dome reinforcing layer 32 and dried to form the first dome portion 22. Alternatively, a resin containing a thermoplastic resin monomer such as ε-caprolactam and a catalyst may be applied to the inner surface of the first dome reinforcing layer 32 and heated to a temperature above the polymerization reaction start temperature of the thermoplastic resin monomer to form the first dome portion 22 made of a thermoplastic resin such as nylon 6.

[0062] Furthermore, when the resin material of the first dome portion 22 is a thermosetting resin, the thermosetting resin may be uncured, the resin may be preliminarily cured by heating so that the thermosetting resin is completely uncured, or the resin may be fully cured by heating so that the thermosetting resin is completely cured. It should be noted that when the resin material of the first dome portion 22 is a thermoplastic resin, the thermoplastic resin is cured by cooling.

[0063] When such a resin material is thermally cured or solidified, the first dome segment body 12 including the first dome portion 22 and the first dome reinforcing layer 32 covering the outer peripheral surface of the first dome portion 22 is formed.

[0064] [Second dome reinforcement layer manufacturing step S3]

[0065] In the second dome reinforcement layer manufacturing step S3, a plurality of fiber reinforced resin sheets are cross-stacked to form a disk-shaped dome reinforcement layer intermediate, and the formed dome reinforcement layer intermediate is punched into a dome shape to manufacture the second dome reinforcement layer 33. The manufacturing method of the first dome reinforcement layer 32 is the same as that of the first dome reinforcement layer 32 described above, so the description thereof is omitted, but the second dome reinforcement layer 33 is not provided with an opening for inserting the pipe head 4, so a jig 100 without a shaft 102 is used. In this case, the fiber reinforced resin sheet F1 is stacked toward the guide recess 101 while rotating around the center of the guide recess 101 of the jig 100, thereby manufacturing the second dome reinforcement layer intermediate. In this way, the second dome reinforcement layer intermediate can be manufactured efficiently, and the strength of the manufactured second dome reinforcement layer 33 can be ensured.

[0066] [Second Dome Segment Forming Step S4]

[0067] In the second dome segment forming step S4, the second dome portion 23 is formed on the inner surface of the second dome reinforcing layer 33 produced in the second dome reinforcing layer producing step S3, thereby forming the second dome segment 13 (see FIG. Figure 6 ). This forming method is the same as the first dome segment 12. It should be noted that when the second dome portion 23 is formed on the inner surface of the second dome reinforcement layer 33, the second dome portion 23 is formed in such a manner that its end portion 231 is warped outward.

[0068] [Tube reinforcement layer manufacturing step S5]

[0069] On the other hand, in the tube reinforcement layer manufacturing step S5, if Figure 7 As shown, for example, the fiber sheet F2 is wound around the outer surface of a cylindrical mandrel 200 to produce the tube reinforcement layer 31. The outer diameter of the mandrel 200 is equivalent to the inner diameter of the tube reinforcement layer 31. The material of the mandrel 200 is not particularly limited, but is preferably metal in order to ensure strength that does not deform when the fiber sheet F2 is attached.

[0070] When manufacturing the tube reinforcement layer 31, the mandrel 200 is rotated in the circumferential direction by a rotating mechanism (not shown) while the rolled fiber sheet F2 is wound (in other words, wound) a plurality of times around the mandrel 200. The fiber sheet F2 is a sheet in which a resin is impregnated in reinforcing fibers aligned in one direction, and the fiber sheet F2 is wound around the mandrel 200 in such a manner that the reinforcing fibers are oriented in the circumferential direction of the mandrel 200. In this way, the tube reinforcement layer 31 in which the reinforcing fibers are oriented in the circumferential direction is manufactured.

[0071] As the fiber sheet F2, for example, a so-called UD (Uni-Direction) sheet is used in which a plurality of fiber bundles aligned in one direction are woven through limiting lines, but a fiber sheet in which a plurality of fiber bundles aligned in a single direction and a plurality of fiber bundles intersecting with the plurality of fiber bundles, for example, orthogonal to the plurality of fiber bundles, are woven may also be used.

[0072] The reinforcing fibers of the fiber sheet F2 may be the same materials as those exemplified in the fiber-reinforced resin sheet F1, and the resin impregnated in the reinforcing fibers may be the same resins as those exemplified in the fiber-reinforced resin sheet F1.

[0073] When the resin of the fiber sheet F2 is composed of a thermosetting resin, the fiber sheet F2 wound on the mandrel 200 is thermally cured. On the other hand, when the resin of the fiber sheet F2 is composed of a thermoplastic resin, the fiber sheet F2 wound on the mandrel 200 is cured by cooling.

[0074] After the resin is thermally cured or solidified, the tube reinforcement layer 31 is removed from the mandrel 200. The shape retention of the tube reinforcement layer 31 is improved by thermally curing or solidifying the resin. Therefore, the tube reinforcement layer 31 can be easily demolded from the mandrel 200, and deformation of the tube reinforcement layer 31 when the tube reinforcement layer 31 is removed from the mandrel 200 can be suppressed.

[0075] It should be noted that, here, an example in which the tube reinforcing layer 31 is produced by winding the fiber sheet F2 on the outer surface of the mandrel 200 is described, but the tube reinforcing layer 31 may be produced by spirally winding a fiber bundle impregnated with a resin on the outer surface of the mandrel 200 by the FW method. Alternatively, as another method, the tube reinforcing layer 31 may be formed by a so-called CW (Centrifugal Winding) method in which a fiber sheet is attached to the inner surface of the rotating mandrel 200.

[0076] [Tube segment forming step S6]

[0077] In the tube segment forming step S6, the tube portion 21 is formed on the inner surface of the tube reinforcement layer 31 produced in the tube reinforcement layer producing step S5, thereby producing the tube segment 11 (see Figure 8 The method of forming the tube segment 11 is the same as that of the first dome segment 12. When forming the tube portion 21, both ends thereof are formed into folded end portions 211 folded outward.

[0078] It should be noted that when the first dome portion 22 is formed on the inner surface of the first dome reinforcement layer 32, the second dome portion 23 is formed on the inner surface of the second dome reinforcement layer 33, and the tube portion 21 is formed on the inner surface of the tube reinforcement layer 31, it is preferably performed in a manner that the thickness of the first dome portion 22 and the second dome portion 23 are greater than the thickness of the tube portion 21. In this way, when the assembly 10 is formed in the subsequent assembly step S7, the unevenness of the contact position between the tube portion 21 and the first dome portion 22 or the second dome portion 23 can be absorbed, so that the sealing performance of the liner 2 formed by the tube portion 21, the first dome portion 22, and the second dome portion 23 can be reliably ensured.

[0079] [Assembly process S7]

[0080] In the assembly step S7, the first dome segment 12 formed in the first dome segment forming step S2, the second dome segment 13 formed in the second dome segment forming step S4, and the tube segment 11 formed in the tube segment forming step S6 are assembled to form the assembly 10. Specifically, Fig. 9 As shown, for example, one end of the pipe segment 11 is assembled to the first dome segment 12, and the other end of the pipe segment 11 is assembled to the second dome segment 13. At this time, the first dome segment 12 and the pipe segment 11 are assembled in such a manner that the first dome portion 22 is arranged at the outer side of the high-pressure tank 1 than the pipe portion 21, and the second dome segment 13 and the pipe segment 11 are assembled in such a manner that the second dome portion 23 is arranged at the outer side of the high-pressure tank 1 than the pipe portion 21.

[0081] More specifically, first, the pipe segment 11 is pressed into the first dome segment 12 with a predetermined pressing force so that the first dome portion 22 does not abut against the pipe portion 21 but abuts against the pipe reinforcement layer 31. Similarly, the pipe segment 11 is pressed into the second dome segment 13 with a predetermined pressing force so that the second dome portion 23 does not abut against the pipe portion 21 but abuts against the pipe reinforcement layer 31. In this case, compared with the case where the above-mentioned segment is pressed in such a way that the first dome portion 22 or the second dome portion 23 directly abuts against the pipe portion 21, there is no friction between the liners during the pressing, so it is possible to prevent the formed seal from being damaged. As a result, the sealing performance of the liner 2 can be ensured.

[0082] When the pressing force is released, the pipe segment 11 expands due to the restoring force. As a result, a force that expands the first dome segment 12 or the second dome segment 13 from the pipe segment 11 disposed inside to the outside is exerted. Therefore, both the first dome portion 22 and the pipe portion 21 are deformed, and the end 222 of the first dome portion 22 abuts against the folded end 211 of the pipe portion 21 (see Figure 1). In addition, the sealing portion of the liner 2 is formed at the abutting position of the end 222 of the first dome portion 22 and the folded end 211 of the tube portion 21. Similarly, the second dome portion 23 and the tube portion 21 are also deformed, and the end 231 of the second dome portion 23 abuts against the folded end 211 of the tube portion 21 (see Figure 1 A sealing portion of the liner 2 is formed at abutment between the end portion 231 of the second dome portion 23 and the folded-back end portion 211 of the tube portion 21 .

[0083] Thus, the assembled body 10 is formed.

[0084] It should be noted that, when assembling the pipe segment 11 with the first dome segment 12 or the second dome segment 13, in order to make the pipe portion 21, the first dome portion 22 and the second dome portion 23 easy to deform, the respective assembly operations can be performed after the linings thereof are heated. In this way, the unevenness of the abutting position of the pipe portion 21 and the first dome portion 22 and the unevenness of the abutting position of the pipe portion 21 and the second dome portion 23 can be easily absorbed, respectively, so that it is easier to ensure the abutting state of the pipe portion 21 and the first dome portion 22 or the second dome portion 23. Moreover, among the pipe portion 21 and the first dome portion 22 and the second dome portion 23, only the pipe portion 21 or only the first dome portion 22 and the second dome portion 23 can be heated. On the other hand, when the first dome portion 22 and the second dome portion 23 are formed thicker than the pipe portion 21, it is preferred to heat the first dome portion 22 and the second dome portion 23.

[0085] [Sealing performance inspection step S8]

[0086] In the sealing inspection step S8, negative pressure is applied to the inside of the assembly 10 formed in the assembly step S7 to inspect the sealing of the assembly 10. In this way, if air enters the inside of the assembly 10 (that is, if there is a problem with the sealing), the problematic split body can be replaced by disassembling the assembly 10. Therefore, compared with the case where the high helical layer 34 and the outer helical layer 35 are formed on the outside of the assembly 10 and the resin is cured or the sealing inspection is performed after the curing, the problematic split body can be easily replaced.

[0087] [Highly Helical Layer Forming Step S9]

[0088] In the high helical layer forming step S9, for the assembly 10 that has no problem in the sealing inspection, the high helical layer 34 is formed by winding the fiber bundle impregnated with resin at a high angle in a layered manner at least on the outer peripheral surface of the tube segment 11 (see Fig.10 The number of layers of the wound fiber bundle is not particularly limited as long as the strength of the high helical layer 34 can be ensured, and is, for example, about 2 to 10 layers.

[0089] The reinforcing fibers of the fiber bundle used to form the highly helical layer 34 may be the same materials as those exemplified in the fiber reinforced resin sheet F1, and the resin material impregnated in the reinforcing fibers may be the same resin as that exemplified in the fiber reinforced resin sheet F1.

[0090] When forming the high helical layer 34, as Fig.10 As shown, the high helical layer 34 is formed not only in the whole tube reinforcing layer 31, but also in such a manner that one end of the high helical layer 34 extends to a part of the first dome segment 12 beyond the assembly portion of the tube segment 11 and the first dome segment 12, and the other end of the high helical layer 34 extends to a part of the second dome segment 13 beyond the assembly portion of the tube segment 11 and the second dome segment 13. In this way, it is possible to suppress the outward expansion of the first dome segment 12 or the outward expansion of the second dome segment 13 caused by the restoring force of the tube segment 11, thereby reducing the strain at the assembly portion of the tube segment 11 and the first dome segment 12 or the second dome segment 13, and maintaining the contact state between the tube portion 21 and the first dome portion 22 or the second dome portion 23.

[0091] [Outer Helical Layer Forming Step S10]

[0092] In the outer helical layer forming step S10, the outer helical layer 35 is formed on the outer side of the high helical layer 34 formed in the high helical layer forming step S9. Specifically, the fiber bundle impregnated with resin is wound in layers at a low angle spirally around the outer peripheral surface of the high helical layer 34 and the outer peripheral surfaces of the first dome segment 12 and the second dome segment 13 not covered by the high helical layer 34. The number of layers of the wound fiber bundle is not particularly limited as long as the strength of the outer helical layer 35 can be ensured, and is, for example, about 2 to 10 layers.

[0093] The reinforcing fibers of the fiber bundle used in the outer helical layer 35 may be the same materials as those exemplified in the fiber reinforced resin sheet F1 , and the resin material impregnated in the reinforcing fibers may be the same resins as those exemplified in the fiber reinforced resin sheet F1 .

[0094] After the fiber bundle is wound, if the resin impregnated in the fiber bundle is a thermosetting resin, the thermosetting resin in the outer helical layer 35 is cured by heating. On the other hand, if the resin impregnated in the fiber bundle is a thermoplastic resin, the thermoplastic resin in the outer helical layer 35 is cured by cooling.

[0095] Thus, the manufacture of the high-pressure tank 1 is completed.

[0096] According to the manufacturing method of the high-pressure tank 1 of the present embodiment, the first dome reinforcement layer 32 and the second dome reinforcement layer 33 are manufactured by stacking a plurality of fiber-reinforced resin sheets F1 crosswise to form a disk-shaped dome reinforcement layer intermediate, and stamping the formed dome reinforcement layer intermediate into a dome shape. Therefore, the first dome reinforcement layer 32 and the second dome reinforcement layer 33 can be efficiently manufactured, and the productivity of the high-pressure tank 1 can be improved. Moreover, since a plurality of fiber-reinforced resin sheets F1 are stacked crosswise to each other, the strength of the manufactured first dome reinforcement layer 32 and the second dome reinforcement layer 33 can be improved compared to the case where the fiber-reinforced resin sheets F1 are stacked in parallel (i.e., not crosswise).

[0097] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the gist of the present invention described in the claims.

Claims

1. A method for manufacturing a high-pressure tank, the high-pressure tank comprising a liner and a reinforcement portion, the liner comprising a cylindrical tube portion and a first dome portion and a second dome portion provided at both ends of the tube portion in an axial direction, the reinforcement portion comprising a tube reinforcement layer covering an outer peripheral surface of the tube portion, a first dome reinforcement layer covering an outer peripheral surface of the first dome portion, and a second dome reinforcement layer covering an outer peripheral surface of the second dome portion, the method for manufacturing the high-pressure tank being characterized in that: The manufacturing method of the high-pressure tank comprises the following steps: A first dome reinforcement layer manufacturing step, comprising: forming a circular plate-shaped dome reinforcement layer intermediate by cross-stacking a plurality of fiber-reinforced resin sheets, and forming the formed dome reinforcement layer intermediate into a dome shape by stamping; a first dome segmentation body forming step of forming the first dome portion on the inner surface of the first dome reinforcement layer produced in the first dome reinforcement layer producing step, thereby forming a first dome segmentation body having the first dome portion and the first dome reinforcement layer, wherein an end portion of the first dome portion is warped outward; A second dome reinforcement layer manufacturing step, comprising: forming a circular plate-shaped dome reinforcement layer intermediate by cross-stacking a plurality of fiber-reinforced resin sheets, and forming the formed dome reinforcement layer intermediate into a dome shape by stamping; a second dome segmentation body forming step of forming the second dome portion on the inner surface of the second dome reinforcement layer produced in the second dome reinforcement layer producing step, thereby forming a second dome segmentation body having the second dome portion and the second dome reinforcement layer, wherein the end of the second dome portion is warped outward; a tube reinforcement layer manufacturing step of winding a fiber sheet on the outer surface of a cylindrical mandrel to manufacture the tube reinforcement layer; a tube segment forming step of forming the tube portion on the inner surface of the tube reinforcing layer to form a tube segment, and forming the tube portion in such a manner that both ends of the tube portion are folded back outward; and an assembling step of assembling the first dome segment formed in the first dome segment forming step, the second dome segment formed in the second dome segment forming step, and the tube segment formed in the tube segment forming step to form an assembly; The tube segment body is pressed into the first dome segment body with a predetermined pressing force in a manner that the first dome portion does not abut against the tube portion but abuts against the tube reinforcement layer, and the tube segment body is pressed into the second dome segment body with a predetermined pressing force in a manner that the second dome portion does not abut against the tube portion but abuts against the tube reinforcement layer, Furthermore, when the pressing force is released, the tube segment expands due to the restoring force, thereby exerting a force that expands the first dome segment and the second dome segment from the tube segment arranged on the inner side toward the outer side, and the first dome portion and the tube portion are both deformed, and the end of the first dome portion abuts against the folded-back end of the tube portion, and a sealing portion of the lining is formed at the abutting position between the end of the first dome portion and the folded-back end of the tube portion, and the second dome portion and the tube portion are also deformed, and the end of the second dome portion abuts against the folded-back end of the tube portion, and a sealing portion of the lining is formed at the abutting position between the end of the second dome portion and the folded-back end of the tube portion.

2. The method for manufacturing a high pressure tank according to claim 1, in, In the first dome reinforcement layer manufacturing step, a jig having a cylindrical guide recess and a shaft erected at a central position of the guide recess is used, and the plurality of fiber reinforced resin sheets are stacked on the guide recess in a manner rotated around the shaft, thereby forming a first dome reinforcement layer intermediate.

3. The method for manufacturing a high-pressure tank according to claim 1, in, In the second dome reinforcing layer manufacturing step, the plurality of fiber reinforced resin sheets are stacked on the guide recess using a jig having a cylindrical guide recess so as to rotate around the center of the guide recess, thereby forming a second dome reinforcing layer intermediate.

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