High pressure tank and its manufacturing method

Abstract

To provide a high pressure tank which can be easily manufactured, and to provide a manufacturing method of the high pressure tank.SOLUTION: A high pressure tank 1 includes an assembly 10 which is formed by assembling a pipe split body 11, a first dome split body 12, and a second dome split body 13. The pipe split body 11 has: a pipe liner 21; and a pipe reinforcement layer 31 which covers an outer peripheral surface of the pipe liner 21. The first dome split body 12 has: a first dome liner 22; and a first dome reinforcement layer 32 which covers an outer peripheral surface of the first dome liner 22. The second dome split body 13 has: a second dome liner 23; and a second dome reinforcement layer 33 which covers an outer peripheral surface of the second dome liner 23. The pipe split body 11 and the first dome split body 12 are assembled so that the first dome liner 22 is disposed at the outer side of the high pressure tank 1 relative to the pipe liner 21. The pipe split body 11 and the second dome split body 13 are assembled so that the second dome liner 23 is disposed at the outer side of the high pressure tank 1 relative to the pipe liner 21.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a high-pressure tank and a method for manufacturing the same. [Background technology]

[0002] A high-pressure tank mounted on a fuel cell vehicle or the like is known that includes a liner having a cylindrical pipe section and a pair of dome sections provided at both axial ends of the pipe section, and a reinforcing layer made of fiber-reinforced resin that covers the outer circumferential surface of the liner. A high-pressure tank having such a structure is manufactured by first forming a liner, and then winding a fiber bundle impregnated with resin around the outer circumferential surface of the liner using the filament winding method (FW method) with the formed liner as a winding core to form the reinforcing layer (see, for example, Patent Document 1 below). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-149739 A Summary of the Invention [Problem to be solved by the invention]

[0004] Recently, as an alternative to the above-mentioned manufacturing method, a manufacturing method has been considered in which a mold is used to create the reinforcing layer segments, and the reinforcing layer segments are placed on the outside of a separately prepared liner. However, when this manufacturing method is adopted, a high-precision matching of the sizes of the liner and the reinforcing layer segments is required, which creates the problem that it is not easy to manufacture the high-pressure tank.

[0005] The present invention has been made to solve the above technical problems, and has an object to provide a high-pressure tank that is easy to manufacture and a method for manufacturing the same. [Means for solving the problem]

[0006] The high-pressure tank of the present invention is a high-pressure tank comprising an assembly formed by assembling a pipe segment and two dome segments, and a helical layer provided on the outside of the assembly, wherein the pipe segment has a pipe liner and a pipe reinforcement layer covering the outer peripheral surface of the pipe liner, and the dome segment has a dome liner and a dome reinforcement layer covering the outer peripheral surface of the dome liner, and the pipe segment and the two dome segments are assembled such that the dome liner is positioned outside the high-pressure tank relative to the pipe liner.

[0007] In the high-pressure tank according to the present invention, the pipe segment has a pipe liner and a pipe reinforcing layer covering the outer peripheral surface of the pipe liner, the dome segment has a dome liner and a dome reinforcing layer covering the outer peripheral surface of the dome liner, and the dome segment and the two pipe segments are assembled such that the dome liner is positioned outside the high-pressure tank relative to the pipe liner. This allows the liner to be formed simply by assembling the dome segment and the pipe segment, thereby realizing an easy-to-manufacture high-pressure tank.

[0008] In the high-pressure tank according to the present invention, it is preferable that the end of the pipe liner is a folded end folded back to the outside of the high-pressure tank, and the folded end of the pipe liner abuts against the dome liner at the assembly site between the pipe section and the dome section, thereby ensuring the sealing performance of the liner formed by the pipe liner and the dome liner.

[0009] In the high-pressure tank according to the present invention, the helical layer preferably includes a high helical layer covering at least the pipe segment and an outer helical layer provided on the outside of the high helical layer, and the high helical layer is formed so as to extend beyond the assembly portion between the pipe segment and the dome segment to a part of the dome segment. In this way, the contact state between the pipe liner and the dome liner can be maintained, and distortion of the assembly portion between the pipe segment and the dome segment can be reduced. As a result, the effect of improving the sealing performance of the high-pressure tank is achieved.

[0010] The manufacturing method of the high-pressure tank according to the present invention is a manufacturing method of a high-pressure tank including an assembly formed by assembling a pipe segment and two dome segments and a helical layer provided on the outside of the assembly, and includes a segment forming process for forming the pipe segment having a pipe liner and a pipe reinforcement layer covering an outer peripheral surface of the pipe liner, and the dome segment having a dome liner and a dome reinforcement layer covering an outer peripheral surface of the dome liner, an assembly process for forming the assembled body by assembling the pipe segment and the two dome segments, and a helical layer forming process for forming the helical layer on the outside of the assembled body, and is characterized in that in the assembly process, the pipe segment and the two dome segments are assembled so that the dome liner is positioned outside the high-pressure tank relative to the pipe liner.

[0011] In the manufacturing method of the high-pressure tank according to the present invention, in the assembly step, the pipe segments and the dome segments are assembled so that the dome liner is disposed on the outer side of the high-pressure tank than the pipe liner. In this way, the liner can be formed simply by assembling the dome segments and the pipe segments, which makes it easier to manufacture the high-pressure tank.

[0012] In the manufacturing method of the high-pressure tank according to the present invention, it is preferable that in the assembly step, the pipe segment is press-fitted into the dome segment so that the dome liner abuts against the pipe reinforcing layer without abutting against the pipe liner. In this way, compared to a case where the pipe segment is press-fitted into the dome segment so that the dome liner abuts directly against the pipe liner, there is no rubbing between the liners during press-fitting, and therefore damage to the formed seal portion can be prevented. As a result, the sealing performance of the liner can be ensured.

[0013] In the manufacturing method of the high-pressure tank according to the present invention, the helical layer forming step includes a high helical layer forming step of forming a high helical layer covering at least the pipe segment, and an outer helical layer forming step of forming a helical layer on the outside of the high helical layer, and in the high helical layer forming step, it is preferable that the high helical layer is formed so as to cover the pipe segment and extend beyond the assembly portion between the pipe segment and the dome segment to a part of the dome segment. In this way, the outward expansion of the dome segment caused by the restoring force of the pipe segment can be suppressed, so that the distortion of the assembly portion between the pipe segment and the dome segment can be reduced and the contact state between the pipe liner and the dome liner can be maintained.

[0014] In addition, in the manufacturing method of the high-pressure tank according to the present invention, it is preferable to include a sealability inspection step for inspecting the sealability of the assembled body between the assembly step and the helical layer formation step, and to apply a negative pressure to the inside of the assembled body in the sealability inspection step. In this way, if a problem occurs in the sealability of the assembled body, the assembled body can be disassembled and the divided body in question can be replaced. Therefore, the divided body in question can be easily replaced compared to a case where a helical layer is formed on the outside of the assembled body and the sealability inspection is performed after the resin is cured or solidified. Effect of the Invention

[0015] According to the present invention, the high-pressure tank can be easily manufactured. [Brief description of the drawings]

[0016] [Figure 1] 1 is a schematic cross-sectional view showing a structure of a high-pressure tank according to an embodiment. [Diagram 2] FIG. 2 is an enlarged cross-sectional view showing a portion A in FIG. [Diagram 3] 4A to 4C are process diagrams showing a method for manufacturing a high-pressure tank according to an embodiment. [Figure 4] 10A to 10C are cross-sectional views illustrating the formation of the dome segments in a segment forming step. [Diagram 5] 10A to 10C are cross-sectional views illustrating the formation of the dome segments in a segment forming step. [Figure 6] 10A to 10C are cross-sectional views illustrating the formation of pipe segments in a segment forming step. [Figure 7] 10A to 10C are cross-sectional views illustrating the formation of the dome segments in a segment forming step. [Figure 8] 10A to 10C are cross-sectional views illustrating the formation of pipe segments in a segment forming step. [Figure 9] 10 is a cross-sectional view illustrating an assembly process for assembling a pipe section and a dome section. FIG. [Figure 10] 11 is a partially enlarged cross-sectional view illustrating the press-fitting of a pipe segment into a dome segment. [Figure 11] 10A to 10C are cross-sectional views illustrating a highly helical layer forming step. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of a high-pressure tank and a manufacturing method thereof according to the present invention will be described with reference to the drawings. In this embodiment, the high-pressure tank 1 will be described as an example in which it is mounted on a fuel cell vehicle and filled with high-pressure hydrogen gas, but it may also be used for other purposes. In addition, the gas that can be filled into the high-pressure tank 1 is not limited to high-pressure hydrogen gas, and 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 may be filled.

[0018] [About high pressure tanks] First, the structure of the high-pressure tank will be described with reference to Figures 1 and 2. Figure 1 is a schematic cross-sectional view showing the structure of the high-pressure tank according to the embodiment, and Figure 2 is an enlarged cross-sectional view showing part A in Figure 1. The high-pressure tank 1 of this embodiment is a high-pressure gas storage container having a substantially cylindrical shape with both ends rounded like a dome, and includes a liner 2 having gas barrier properties, a reinforcing part 3 covering the outer peripheral surface of the liner 2 and having a plurality of reinforcing layers, and a cap 4 attached to one end of the high-pressure tank 1.

[0019] The liner 2 is a hollow container having a storage space 5 for storing high-pressure hydrogen, and is made of a resin material having gas barrier properties against hydrogen gas. The liner 2 is composed of a cylindrical pipe liner 21 and a pair of dome liners (a first dome liner 22 and a second dome liner 23) arranged on both sides of the pipe liner 21. The pipe liner 21 extends a predetermined length along the axial direction L of the high-pressure tank 1. The first dome liner 22 and the second dome liner 23 are formed continuously on both sides of the pipe liner 21, and each has a smaller diameter as it moves away from the pipe liner 21.

[0020] Of the first dome liner 22 and the second dome liner 23, the first dome liner 22 has a tubular section 221 formed in a portion with the narrowest diameter. Also, an end 222 of the first dome liner 22 opposite the tubular section 221 is formed so as to be warped outward from the high-pressure tank 1. Correspondingly, an end 231 of the second dome liner 23 is also formed so as to be warped outward from the high-pressure tank 1.

[0021] The resin material forming the liner 2 preferably has a good gas barrier property, that is, a good performance of retaining the filled gas in the storage space 5. Examples of such a resin material include thermoplastic resins and thermosetting resins, which will be described later.

[0022] The nozzle 4 is made by processing a metal material such as aluminum or an aluminum alloy into a predetermined shape. A valve 6 for filling and discharging hydrogen gas into the storage space 5 is attached to the nozzle 4. The valve 6 is screwed into the nozzle 4. The valve 6 has an insertion portion 61 that is inserted into the tubular portion 221 of the first dome liner 22 so as to close the tubular portion 221. A circumferential groove is provided in the insertion portion 61. An O-ring 62 that maintains the sealing property (in other words, hermeticity) between the insertion portion 61 and the tubular portion 221 is fitted into the circumferential groove.

[0023] The reinforcing portion 3 has a 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 reinforcing layers (five in this embodiment) formed of fiber-reinforced resin in which reinforcing fibers (continuous fibers) are impregnated with resin. Specifically, the reinforcing portion 3 has a pipe reinforcing layer 31 covering the outer circumferential surface of the pipe liner 21, a first dome reinforcing layer 32 covering the outer circumferential surface of the first dome liner 22, a second dome reinforcing layer 33 covering the outer circumferential surface of the second dome liner 23, a high helical layer 34 covering the entire pipe reinforcing layer 31, a part of the first dome reinforcing layer 32, and a part of the second dome reinforcing layer 33, and an outer helical layer 35 covering the entire high helical layer 34, a part of the first dome reinforcing layer 32, and a part of the second dome reinforcing layer 33. The high helical layer 34 and the outer helical layer 35 correspond to the "helical layer" described in the claims.

[0024] The pipe reinforcement layer 31 is a reinforcement layer corresponding to the pipe liner 21, and has a cylindrical shape following the shape of the pipe liner 21. The pipe reinforcement layer 31 is formed of a fiber reinforced resin in which reinforcing fibers are impregnated with resin. The reinforcing fibers of the pipe reinforcement layer 31 are circumferentially oriented at an angle substantially perpendicular to the axial direction L of the high-pressure tank 1. In other words, the reinforcing fibers of the pipe reinforcement layer 31 are oriented in the circumferential direction of the high-pressure tank 1.

[0025] The first dome reinforcement layer 32 is a reinforcement layer corresponding to the first dome liner 22, and has a dome shape following the shape of the first dome liner 22. As shown in FIG. 1, the first dome reinforcement layer 32 has a protruding portion 321 covering the outer circumferential surface of the tubular portion 221. This first dome reinforcement layer 32 is formed of a fiber reinforced resin in which reinforcing fibers are impregnated with resin. The reinforcing fibers of the first dome reinforcement layer 32 are not oriented in the circumferential direction of the high-pressure tank 1, but extend in various directions intersecting with the circumferential direction of the high-pressure tank 1.

[0026] The second dome reinforcement layer 33 is a reinforcement layer corresponding to the second dome liner 23, and has a dome shape following the shape of the second dome liner 23. The second dome reinforcement layer 33 is formed of fiber reinforced resin in which reinforcing fibers are impregnated with resin. The reinforcing fibers of the second dome reinforcement layer 33 are not oriented in the circumferential direction of the high-pressure tank 1, but extend in various directions intersecting with the circumferential direction of the high-pressure tank 1.

[0027] The reinforcing fibers of the pipe reinforcement layer 31 are not continuous (connected) with the reinforcing fibers of the first dome reinforcement layer 32 or the second dome reinforcement layer 33. This is because the pipe reinforcement layer 31, the first dome reinforcement layer 32, and the second dome reinforcement layer 33 are formed separately, as described later.

[0028] In this embodiment, the pipe liner 21 and the pipe reinforcement layer 31 covering the outer peripheral surface of the pipe liner 21 constitute the pipe section 11, the first dome liner 22 and the first dome reinforcement layer 32 covering the outer peripheral surface of the first dome liner 22 constitute the first dome section 12, and the second dome liner 23 and the second dome reinforcement layer 33 covering the outer peripheral surface of the second dome liner 23 constitute the second dome section 13.

[0029] 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 assembled body 10 by assembling one end of the pipe segment 11 to the first dome segment 12 and the other end of the pipe segment 11 to the second dome segment 13. The pipe segment 11 and the first dome segment 12 are assembled such that the first dome liner 22 is disposed outside the high-pressure tank 1 relative to the pipe liner 21. Similarly, the pipe segment 11 and the second dome segment 13 are assembled such that the second dome liner 23 is disposed outside the high-pressure tank 1 relative to the pipe liner 21.

[0030] Both ends of the pipe liner 21 in the axial L direction of the high-pressure tank 1 are folded back ends 211, which are 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 so as to surround the ends of the pipe reinforcement layer 31 arranged on the outside thereof, and are formed so as to extend to about half the thickness of the pipe reinforcement layer 31. At the assembly site between the pipe section 11 and the first dome section 12 or the second dome section 13, the folded back ends 211 of the pipe liner 21 abut against the first dome liner 22 or the second dome liner 23.

[0031] More specifically, at the assembly site between the pipe section 11 and the first dome section 12, the folded end 211 of the pipe liner 21 abuts against the end 222 of the first dome liner 22. At the assembly site between the pipe section 11 and the second dome section 13, the folded end 211 of the pipe liner 21 abuts against the end 231 of the second dome liner 23. Note that the "assembly site" here refers to the portion where the pipe section 11 and the first dome section 12 or the second dome section 13 overlap.

[0032] Moreover, it is preferable that the thicknesses of the first dome liner 22 and the second dome liner 23 are both greater than the thickness of the pipe liner 21. This makes it possible to absorb unevenness at the contact position between the pipe liner 21 and the first dome liner 22 or the second dome liner 23, thereby providing an effect of reliably ensuring the sealing performance of the liner 2 formed by the pipe liner 21, the first dome liner 22, and the second dome liner 23.

[0033] The high helical layer 34 is a reinforcing layer formed by high-angle helical winding of a fiber bundle made of reinforcing fibers impregnated with resin on the outside of the assembled body 10. The helical winding is a mode in which the fiber bundle is wound at a winding angle greater than 0° and less than 90° with respect to the axial L direction of the high-pressure tank 1. This helical winding is classified into low-angle helical winding and high-angle helical winding depending on the magnitude of the winding angle. The low-angle helical winding is a helical winding with a small winding angle (e.g., greater than 0° and equal to or less than 30°), and the high-angle helical winding is a helical winding with a large winding angle (e.g., greater than 30° and less than 90°).

[0034] Since the high helical layer 34 is formed by winding a fiber bundle formed by impregnating reinforcing fibers with resin in a high-angle helical manner, the reinforcing fibers of the high helical layer 34 are oriented so as to be inclined with respect to the axial L direction of the high-pressure tank 1. As shown in Figures 1 and 2, the high helical layer 34 is formed not only over the entire pipe reinforcement layer 31, but also so that one end of the high helical layer 34 extends beyond the assembly portion between the pipe section 11 and the first dome section 12 to a part of the first dome section 12, and the other end of the high helical layer 34 extends beyond the assembly portion between the pipe section 11 and the second dome section 13 to a part of the second dome section 13.

[0035] The outer helical layer 35 is a reinforcing layer disposed on the outermost side of the high-pressure tank 1, and is formed by winding a fiber bundle, which is made of reinforcing fibers impregnated with resin, in a low-angle helical manner on the outer side of the assembly 10 and the high-helical layer 34. The reinforcing fibers of the outer helical layer 35 are also oriented so as to be inclined with respect to the axial direction L of the high-pressure tank 1.

[0036] In the high-pressure tank 1 configured as above, the pipe segment 11 has the pipe liner 21 and the pipe reinforcement layer 31 covering the outer circumferential surface of the pipe liner 21, the first dome segment 12 has the first dome liner 22 and the first dome reinforcement layer 32 covering the outer circumferential surface of the first dome liner 22, and the second dome segment 13 has the second dome liner 23 and the second dome reinforcement layer 33 covering the outer circumferential surface of the second dome liner 23. The pipe segment 11 and the first dome segment 12 or the second dome segment 13 are assembled together such that the first dome liner 22 or the second dome liner 23 is disposed outside the high-pressure tank 1 relative to the pipe liner 21. This allows the liner 2 to be formed simply by assembling the pipe segment 11, the first dome segment 12, and the second dome segment 13, thereby realizing a high-pressure tank 1 that is easy to manufacture.

[0037] Moreover, both ends of the pipe liner 21 are folded back to the outside of the high-pressure tank 1, and the folded back ends 211 abut against the first dome liner 22 at the assembly site between the pipe section 11 and the first dome section 12, and the folded back ends 211 abut against the second dome liner 23 at the assembly site between the pipe section 11 and the second dome section 13. In this manner, the sealing performance of the liner 2 formed by the pipe liner 21, the first dome liner 22, and the second dome liner 23 can be ensured.

[0038] Furthermore, the high helical layer 34 is formed not only over the entire pipe reinforcement layer 31, but also so that one end of the high helical layer 34 extends beyond the assembly portion between the pipe section 11 and the first dome section 12 to a part of the first dome section 12, and the other end of the high helical layer 34 extends beyond the assembly portion between the pipe section 11 and the second dome section 13 to a part of the second dome section 13. As a result, the abutting state between the pipe liner 21 and the first dome liner 22 and the abutting state between the pipe liner 21 and the second dome liner 23 are maintained by the high helical layer 34, so that distortion at the assembly portion between the pipe section 11 and the first dome section 12 and the assembly portion between the pipe section 11 and the second dome section 13 can be reduced, and the sealing performance of the high-pressure tank 1 can be improved.

[0039] [About the manufacturing process of high pressure tanks] A method for manufacturing the high-pressure tank 1 will be described below. Fig. 3 is a process diagram showing a method for manufacturing a high-pressure tank according to an embodiment. The method for manufacturing the high-pressure tank 1 includes a division body forming process S1, an assembly process S2, a sealability inspection process S3, a high helical layer forming process S4, and an outer helical layer forming process S5. The high helical layer forming process S4 and the outer helical layer forming process S5 constitute the "helical layer forming process" described in the claims.

[0040] [Divided body formation process S1] The segment forming process S1 is a process for forming the pipe segment 11, the first dome segment 12, and the second dome segment 13. The formation of the pipe segment 11 and the formation of the first dome segment 12 and the second dome segment 13 are independent of each other, and therefore may be performed in parallel, or one of them may be performed first. Here, a method for forming the first dome segment 12 and the second dome segment 13 will be described first, and then a method for forming the pipe segment 11 will be described.

[0041] In a method for forming the first dome segment 12 and the second dome segment 13, as shown in Fig. 4, a fiber bundle F1 impregnated with resin is wound around the outer circumferential surface of a mandrel 100, for example, by the FW method. Specifically, the mandrel 100 has a main body 101 and a shaft 102 extending outward from one end of the main body 101. The main body 101 is formed in a circular shape when viewed from the axial direction of the shaft 102. A groove 101a is formed in the outer circumferential surface of the main body 101 at the axial center thereof, extending around one revolution in the circumferential direction. The shaft 102 is rotatably supported by a rotation mechanism (not shown).

[0042] Then, the mandrel 100 is rotated to wind the fiber bundle F1 so as to cover the outer circumferential surface of the mandrel 100, thereby forming the wound body 30. At this time, the fiber bundle F1 is also wound around the outer circumferential surface of the shaft portion 102, thereby forming a cylindrical protrusion 321 having a through hole 322 (see FIG. 5). The fiber bundle F1 is wound at a winding angle of, for example, 30° to 50° with respect to the axial direction of the shaft portion 102. The material of the mandrel 100 is not particularly limited, but is preferably metal in order to ensure the strength to prevent deformation when the fiber bundle F1 is wound.

[0043] The resin impregnated into the fiber bundle F1 is not particularly limited, but for example, a thermosetting resin can be used. As the thermosetting resin, it is preferable to use a thermosetting resin such as a phenol resin, a melamine resin, a urea resin, or an epoxy resin. In this case, the fiber bundle F1 is wound around the mandrel 100 while the thermosetting resin is in an uncured state. In particular, it is preferable to use an epoxy resin from the viewpoint of mechanical strength, etc. Epoxy resin has fluidity in an uncured state, and forms a tough cross-linked structure after thermal curing.

[0044] The resin impregnated in the fiber bundle F1 may be a thermoplastic resin. Examples of the thermoplastic resin that may be used include polyether ether ketone, polyphenylene sulfide, polyacrylic ester, polyimide, polyamide, nylon 6, nylon 6,6, and polyethylene terephthalate. In this case, the fiber bundle F1 is wound around the mandrel 100 after the thermoplastic resin is heated and softened.

[0045] As the fibers constituting the fiber bundle F1, glass fibers, aramid fibers, boron fibers, carbon fibers, etc. can be used, and in particular, carbon fibers are preferably used from the viewpoints of light weight, mechanical strength, etc.

[0046] Next, the wound body 30 wound around the outer circumferential surface of the mandrel 100 is divided into two pieces using a cutter 110 (see FIG. 4). Thereafter, as shown in FIG. 5, the divided wound body 30 is separated from the mandrel 100 to form a pair of dome reinforcement layers (first dome reinforcement layer 32 and second dome reinforcement layer 33).

[0047] Specifically, in the state shown in FIG. 4, the mouthpiece 4 is attached to the outer circumferential surface of the protruding portion 321. After that, the resin of the wound body 30 (in other words, the resin of the fiber bundle F1) is thermally cured or solidified. That is, when the resin impregnated in the fiber bundle F1 is a thermosetting resin, the wound body 30 is heated so that the uncured thermosetting resin is completely cured. Here, the "completely cured state" refers to a state in which the polymerization reaction of the uncured thermosetting resin is completed, and the resin is not cured any further by heating. However, if the shape retention of the first dome reinforcement layer 32 and the second dome reinforcement layer 33 is ensured, the wound body 30 is heated so that the uncured thermosetting resin is not completely cured.

[0048] Here, "not completely cured" refers to a state in which the polymerization reaction of the uncured thermosetting resin progresses due to heating, and the fluidity of the thermosetting resin is reduced so that shape retention can be ensured in a later process. In the following specification, the completely cured state is referred to as "mainly cured," and the not completely cured state is referred to as "preliminary cured," and these are collectively referred to as "thermosetting." On the other hand, when the resin impregnated in the fiber bundle F1 is a thermoplastic resin, the softened thermoplastic resin is cooled to solidify the resin in the fiber bundle F1.

[0049] In this state where the resin impregnated in the fiber bundle F1 is thermally cured or solidified, the cutting edge of the cutter 110 is inserted into the groove 101a of the mandrel 100 while rotating the mandrel 100. As a result, the fiber bundle F1 is cut by the cutter 110, and the wound body 30 can be divided into two. A pair of dome reinforcement layers is formed by separating the divided wound body 30 from the mandrel 100. Of the pair of dome reinforcement layers formed, the one having the protruding portion 321 is the first dome reinforcement layer 32, and the one not having the protruding portion 321 is the second dome reinforcement layer 33. The cutter 110 is not particularly limited, but may be one having a blade formed on the outer peripheral surface of a rotating disk, one having a blade formed on the side of a thin plate, or one that cuts the fiber bundle F1 with laser light.

[0050] Since the resin impregnated into the fiber bundle F1 is cut by the cutter 110 in a heat-cured or solidified state, deformation of the fiber bundle F1 during cutting can be suppressed, and deformation of the first dome reinforcement layer 32 and the second dome reinforcement layer 33 when removed from the mandrel 100 can be suppressed.

[0051] Although an example has been shown here in which the resin of the fiber bundle F1 is cut by the cutter 110 in a thermally cured or solidified state, the resin of the fiber bundle F1 may be cut by the cutter 110 without being thermally cured or solidified. In this case, the fiber bundle F1 may be thermally cured or solidified after being cut by the cutter 110.

[0052] On the other hand, in a method for forming the pipe reinforcement layer 31, as shown in Fig. 6, for example, the pipe reinforcement layer 31 is formed by winding a fiber sheet F2 around the outer surface of a cylindrical mandrel 200. The outer diameter of the mandrel 200 corresponds to the inner diameter of the pipe reinforcement layer 31. The material of the mandrel 200 is not particularly limited, but is preferably metal in order to ensure the strength to prevent deformation when the fiber sheet F2 is attached.

[0053] When forming the pipe reinforcement layer 31, the unwound fiber sheet F2 is wound (in other words, wound) around the mandrel 200 multiple times while rotating the mandrel 200 in the circumferential direction by a rotation mechanism (not shown). The fiber sheet F2 is a sheet in which reinforcing fibers aligned in one direction are impregnated with resin, and the fiber sheet F2 is wound around the mandrel 200 so that the reinforcing fibers are oriented in the circumferential direction of the mandrel 200. In this way, the pipe reinforcement layer 31 in which the reinforcing fibers are oriented in the circumferential direction is formed.

[0054] As the fiber sheet F2, for example, a so-called UD (Uni-Directional) sheet in which multiple fiber bundles aligned in one direction are woven with restraining yarn is used, but a fiber sheet in which multiple fiber bundles aligned in a single direction are woven with multiple fiber bundles that intersect with these multiple fiber bundles, for example perpendicular to them, may also be used.

[0055] The reinforcing fibers of the fiber sheet F2 may be made of the same materials as those exemplified for the fiber bundle F1, and the resin impregnated into the reinforcing fibers may be made of the same resin as those exemplified for the fiber bundle F1.

[0056] When the resin of the fiber sheet F2 is a thermosetting resin, the fiber sheet F2 wound around the mandrel 200 may be thermally cured under the pre-curing or main curing conditions (heating temperature and heating time) similar to the case of the fiber bundle F1. On the other hand, when the resin of the fiber sheet F2 is a thermoplastic resin, the fiber sheet F2 wound around the mandrel 200 may be solidified by cooling similar to the case of the fiber bundle F1.

[0057] After the resin is thermally cured or solidified, the pipe reinforcement layer 31 is removed from the mandrel 200. The thermal curing or solidification of the resin enhances the shape retention of the pipe reinforcement layer 31. This makes it possible to easily remove the pipe reinforcement layer 31 from the mandrel 200, and makes it possible to suppress deformation of the pipe reinforcement layer 31 when removing the pipe reinforcement layer 31 from the mandrel 200.

[0058] Although an example of forming the pipe reinforcement layer 31 by winding the fiber sheet F2 around the outer surface of the mandrel 200 has been described here, the pipe reinforcement layer 31 may also be formed by hoop-winding a fiber bundle impregnated with resin by the FW method around the outer surface of the mandrel 200. Alternatively, the pipe reinforcement layer 31 may be formed by attaching a fiber sheet to the inner surface of the rotating mandrel 200, a so-called CW (Centrifugal Winding) method.

[0059] Next, the first dome liner 22 is formed on the inner surface of the first dome reinforcement layer 32 to form the first dome section 12, and the second dome liner 23 is formed on the inner surface of the second dome reinforcement layer 33 to form the second dome section 13.

[0060] Specifically, for example, a liquid or softened resin material is applied to the inner surface of the first dome reinforcement layer 32, or a sheet made of a resin material is attached to form the first dome liner 22. At this time, as shown in Fig. 7, the end 222 of the first dome liner 22 is formed so as to be warped outward.

[0061] The resin material here is preferably one having excellent gas barrier properties as described above, and examples thereof include thermoplastic resins and thermosetting resins. Examples of thermoplastic resins include polypropylene resins, nylon resins (e.g., 6-nylon resin or 6,6-nylon resin), polycarbonate resins, acrylic resins, ABS resins, polyamide resins, polyethylene resins, ethylene-vinyl alcohol copolymer resins (EVOH), and polyester resins (e.g., polyethylene terephthalate). Examples of thermosetting resins include epoxy resins, modified epoxy resins such as vinyl ester resins, phenol resins, melamine resins, urea resins, unsaturated polyester resins, alkyd resins, polyurethane resins, and thermosetting polyimide resins.

[0062] Alternatively, a two-component thermosetting resin such as an epoxy resin may be applied to the inner surface of the first dome reinforcement layer 32 and then dried to form the first dome liner 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 reinforcement layer 32 and then heated to a temperature at which the polymerization reaction of the thermoplastic resin monomer starts or higher to form the first dome liner 22 made of a thermoplastic resin such as nylon 6.

[0063] When the resin material of the first dome liner 22 is a thermosetting resin, the thermosetting resin may be uncured, or the resin may be pre-cured by heating so that the thermosetting resin is in an incompletely cured state, or the resin may be fully cured by heating so that the thermosetting resin is in a completely cured state. When the resin material of the first dome liner 22 is a thermoplastic resin, the thermoplastic resin is solidified.

[0064] When such a resin material is thermally cured or solidified, the first dome section 12 having the first dome liner 22 and the first dome reinforcing layer 32 covering the outer peripheral surface of the first dome liner 22 is formed.

[0065] The method for forming the second dome section 13 by forming the second dome liner 23 on the inner surface of the second dome reinforcement layer 33 is similar to that for the above-mentioned first dome section 12, and therefore the description thereof will be omitted. When forming the second dome liner 23 on the inner surface of the second dome reinforcement layer 33, the second dome liner 23 is formed so that its end portion 231 is warped outward (see FIG. 7).

[0066] Next, the pipe section 11 is formed by forming the pipe liner 21 on the inner surface of the pipe reinforcing layer 31. The method for forming the pipe section 11 is similar to that for the above-mentioned first dome section 12, so a description thereof will be omitted. However, as shown in Fig. 8, both end portions of the formed pipe liner 21 become folded end portions 211 that are folded back outward.

[0067] When forming the first dome liner 22 on the inner surface of the first dome reinforcement layer 32, the second dome liner 23 on the inner surface of the second dome reinforcement layer 33, and the pipe liner 21 on the inner surface of the pipe reinforcement layer 31, respectively, it is preferable that the thicknesses of the first dome liner 22 and the second dome liner 23 are all greater than the thickness of the pipe liner 21. In this way, when forming the assembled body 10 in the later assembly step S2, irregularities at the contact position between the pipe liner 21 and the first dome liner 22 or the second dome liner 23 can be absorbed, so that the sealing property of the liner 2 formed by the pipe liner 21, the first dome liner 22, and the second dome liner 23 can be reliably ensured.

[0068] [Assembly process S2] In the assembling process S2, the pipe segment 11 formed in the segment forming process S1 is assembled with a pair of dome segments (first dome segment 12 and second dome segment 13) to form the assembled body 10. As shown in Fig. 9, 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 so that the first dome liner 22 is disposed outside the high-pressure tank 1 relative to the pipe liner 21, and the second dome segment 13 and the pipe segment 11 are assembled so that the second dome liner 23 is disposed outside the high-pressure tank 1 relative to the pipe liner 21.

[0069] 10, first, the pipe section 11 is pressed into the first dome section 12 with a predetermined pressing force f so that the first dome liner 22 abuts on the pipe reinforcement layer 31 without abutting on the pipe liner 21. Similarly, the pipe section 11 is pressed into the second dome section 13 with a predetermined pressing force f so that the second dome liner 23 abuts on the pipe reinforcement layer 31 without abutting on the pipe liner 21.

[0070] When the pressing force f is released, the pipe sections 11 are expanded by a restoring force. As a result, a force acts from the pipe section 11 arranged inside to expand the first dome section 12 or the second dome section 13 outward. As a result, both the first dome liner 22 and the pipe liner 21 are deformed, and the end 222 of the first dome liner 22 comes into contact with the folded end 211 of the pipe liner 21 (see FIG. 1). A seal portion of the liner 2 is formed at the contact position between the end 222 of the first dome liner 22 and the folded end 211 of the pipe liner 21. Similarly, the second dome liner 23 and the pipe liner 21 are deformed, and the end 231 of the second dome liner 23 comes into contact with the folded end 211 of the pipe liner 21 (see FIG. 1). A seal portion of the liner 2 is formed at the contact position between the end 231 of the second dome liner 23 and the folded end 211 of the pipe liner 21. As a result, the assembly 10 is formed.

[0071] When assembling the pipe section 11 and the first dome section 12 or the second dome section 13, the pipe liner 21, the first dome liner 22, and the second dome liner 23 may be heated before assembling them so that they are easily deformed. In this way, unevenness at the contact position between the pipe liner 21 and the first dome liner 22 and unevenness at the contact position between the pipe liner 21 and the second dome liner 23 can be easily absorbed, and therefore the contact state between the pipe liner 21 and the first dome liner 22 or the second dome liner 23 can be more easily secured. Also, among the pipe liner 21 and the first dome liner 22 and the second dome liner 23, only the pipe liner 21 or only the first dome liner 22 and the second dome liner 23 may be heated. On the other hand, when the first dome liner 22 and the second dome liner 23 are formed to be thicker than the pipe liner 21, it is preferable to heat the first dome liner 22 and the second dome liner 23.

[0072] [Sealability inspection process S3] The sealability inspection process S3 is a process for inspecting the sealability of the assembled body 10 formed in the assembly process S2. In the sealability inspection process S3, negative pressure is applied to the inside of the assembled body 10 to inspect the sealability of the assembled body 10. By inspecting the sealability in this manner while the assembled body 10 is in the assembled state, if air has entered the assembled body 10 (i.e., if there is a problem with the sealability), the divided body in question can be replaced by disassembling the assembled body 10. Therefore, compared to, for example, forming the high helical layer 34 and the outer helical layer 35 on the outside of the assembled body 10 and then performing the sealability inspection after the resin has hardened or solidified, the divided body in question can be easily replaced.

[0073] [Highly helical layer formation process S4] In the high helical layer formation step S4, for an assembled body 10 that does not fail the sealing inspection, a fiber bundle impregnated with resin is wound in layers in a high-angle helical manner around at least the outer peripheral surface of the pipe segment 11 to form a high helical layer 34. The number of layers of the fiber bundle to be wound is not particularly limited as long as the strength of the high helical layer 34 is ensured, but is, for example, about 2 to 10 layers.

[0074] The reinforcing fibers of the fiber bundle may be made of the same materials as those exemplified for the fiber bundle F1 above, and the resin material impregnated into the reinforcing fibers may be made of the same resins as those exemplified for the fiber bundle F1.

[0075] When forming the high helical layer 34, as shown in FIG. 11 , the high helical layer 34 is formed not only over the entire pipe reinforcement layer 31, but also so that one end of the high helical layer 34 extends beyond the assembly portion between the pipe section 11 and the first dome section 12 to a portion of the first dome section 12, and the other end of the high helical layer 34 extends beyond the assembly portion between the pipe section 11 and the second dome section 13 to a portion of the second dome section 13.

[0076] [Outer helical layer formation process S5] In outer helical layer forming step S5, outer helical layer 35 is formed on the outside of high helical layer 34. More specifically, fiber bundles impregnated with resin are wound in layers with low-angle helical winding around the outer peripheral surface of high helical layer 34 formed in high helical layer forming step S4 and the outer peripheral surfaces of first dome section 12 and second dome section 13 that are not covered by high helical layer 34. The number of layers of fiber bundles to be wound is not particularly limited as long as the strength of outer helical layer 35 is ensured, but is, for example, about 2 to 10 layers.

[0077] The reinforcing fibers of the fiber bundle may be made of the same materials as those exemplified for the fiber bundle F1 above, and the resin material impregnated into the reinforcing fibers may be made of the same resins as those exemplified for the fiber bundle F1.

[0078] After winding the fiber bundle, if the resin impregnated in the fiber bundle is a thermosetting resin, outer helical layer 35 is fully cured. At that time, if the resin of assembly 10 and highly helical layer 34 are thermosetting resins and have not yet fully cured, these resins are also fully cured. If the resin impregnated in the fiber bundle is a thermoplastic resin, outer helical layer 35 is cooled and solidified by natural cooling or forced cooling.

[0079] After the outer helical layer 35 is formed in this manner, the valve 6 is attached to the mouthpiece 4 as shown in FIG. 1, thereby completing the manufacture of the high-pressure tank 1.

[0080] In the manufacturing method of the high-pressure tank according to this embodiment, in the assembly step S2, the first dome section 12 and the pipe section 11 are assembled so that the first dome liner 22 is disposed outside the high-pressure tank 1 relative to the pipe liner 21, and the second dome section 13 and the pipe section 11 are assembled so that the second dome liner 23 is disposed outside the high-pressure tank 1 relative to the pipe liner 21. In this manner, the liner 2 can be formed simply by assembling the pipe section 11, the first dome section 12, and the second dome section 13, making it easier to manufacture the high-pressure tank 1.

[0081] In addition, in the assembly process S2, the pipe segment 11 is press-fitted into the first dome segment 12 so that the first dome liner 22 abuts against the pipe reinforcing layer 31 without abutting against the pipe liner 21, and the pipe segment 11 is press-fitted into the second dome segment 13 so that the second dome liner 23 abuts against the pipe reinforcing layer 31 without abutting against the pipe liner 21. In this way, compared to when the first dome liner 22 or the second dome liner 23 is press-fitted so that these segments abut directly against the pipe liner 21, there is no rubbing between the liners during press-fitting, and therefore damage to the formed seal portion can be prevented. As a result, the sealing performance of the liner 2 can be ensured.

[0082] Furthermore, in the high helical layer forming step S4, the high helical layer 34 is formed not only over the entire pipe reinforcement layer 31, but also so that one end of the high helical layer 34 extends beyond the assembly portion between the pipe section 11 and the first dome section 12 to a part of the first dome section 12, and the other end of the high helical layer 34 extends beyond the assembly portion between the pipe section 11 and the second dome section 13 to a part of the second dome section 13. In this way, the outward expansion of the first dome section 12 or the outward expansion of the second dome section 13 caused by the restoring force of the pipe section 11 can be suppressed, thereby reducing distortion at the assembly portion between the pipe section 11 and the first dome section 12 or the second dome section 13, and maintaining the contact state between the pipe liner 21 and the first dome liner 22 or the second dome liner 23.

[0083] 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 modifications can be made without departing from the spirit of the present invention as described in the claims. [Explanation of symbols]

[0084] 1. High pressure tank 2 Liner 3 Reinforcement 4. Base 5. Storage space 6 Valves 10 Assembly body 11 Pipe division body 12 First Dome Section 13 Second Dome Section 21 Pipeliner 22 First Dome Liner 23 Second Dome Liner 31 Pipe Reinforcement Layer 32 First Dome Reinforcement Layer 33 Second Dome Reinforcement Layer 34 Highly helical layer 35 Outer helical layer 61 Insertion section 62 O-ring 211 Folded end 221 Tubular part 222,231 end 321 Protrusion

Claims

1. A high-pressure tank comprising an assembly formed by assembling a pipe section and two dome sections, and a helical layer provided on the outside of the assembly, The pipe segment includes a pipe liner and a pipe reinforcing layer covering an outer circumferential surface of the pipe liner, The dome segment includes a dome liner and a dome reinforcing layer covering an outer peripheral surface of the dome liner, the pipe segment and the two dome segments are assembled such that the dome liner is disposed on an outer side of the high-pressure tank than the pipe liner, an end of the pipe liner is a folded end that is folded back to the outside of the high-pressure tank, a folded end of the pipe liner in contact with the dome liner at an assembly site between the pipe segment and the dome segment;

2. The helical layer includes a high helical layer covering at least the pipe section and an outer helical layer provided on the outside of the high helical layer, 2. The high-pressure tank according to claim 1, wherein the high helical layer is formed so as to extend beyond an assembly portion between the pipe section and the dome section and to a portion of the dome section.

3. 1. A method for manufacturing a high-pressure tank comprising an assembly formed by assembling a pipe section and two dome sections, and a helical layer provided on the outside of the assembly, comprising the steps of: a section forming process for forming the pipe section having a pipe liner and a pipe reinforcing layer covering an outer peripheral surface of the pipe liner, and the dome section having a dome liner and a dome reinforcing layer covering an outer peripheral surface of the dome liner; an assembling step of assembling the pipe section and two of the dome sections to form the assembled body; a helical layer forming step of forming the helical layer on an outer side of the assembly; Including, a dome liner that is disposed on an outer side of the high-pressure tank relative to the pipe liner, the dome liner being ... and the pipe liner being disposed on an outer side of the high-pressure tank relative to the dome liner.

4. 4. The method for manufacturing a high-pressure tank according to claim 3, wherein in the assembling step, the pipe segment is press-fitted into the dome segment such that the dome liner abuts against the pipe reinforcing layer without abutting against the pipe liner.

5. the helical layer forming step includes a high helical layer forming step of forming a high helical layer covering at least the pipe segment, and an outer helical layer forming step of forming a helical layer on the outer side of the high helical layer, 5. The method for manufacturing a high-pressure tank according to claim 3, wherein in the high helical layer forming step, the high helical layer is formed so as to cover the pipe segment and extend beyond an assembly portion between the pipe segment and the dome segment to a part of the dome segment.

6. a sealability inspection step for inspecting a sealability of the assembled body between the assembling step and the helical layer forming step, The method for manufacturing a high-pressure tank according to any one of claims 3 to 5, wherein a negative pressure is applied to the inside of the assembly in the sealing property inspection step.

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