High-pressure vessel and method for manufacturing the same

Abstract

The present invention provides a high-pressure vessel and a manufacturing method thereof. The high-pressure vessel (10) has an inner container (12) and a reinforcing layer (14). The reinforcing layer has an inner reinforcing layer (38) and an outer reinforcing layer (40). Moreover, the inner reinforcing layer has a first covering portion (42), a third covering portion (44), and a second covering portion (46). Opposite edge surfaces of the first covering portion and the third covering portion abut against each other. Opposite edge surfaces of the third covering portion and the second covering portion also abut against each other. The outer reinforcing layer covers the outsides of the first covering portion, the third covering portion, and the second covering portion. Accordingly, it is not necessary to prepare molding dies of various shapes or sizes. Therefore, reduction in equipment investment can be achieved. In addition, a space for storing a plurality of molding dies is not required. Therefore, space saving of the manufacturing station for the high-pressure vessel can be achieved.

Description

Technical Field

[0001] The present invention relates to a high-pressure vessel having a hollow liner and a reinforcing layer covering the liner from the outside, and a method for manufacturing the same. Background Art

[0002] High-pressure vessels store, for example, hydrogen supplied to a fuel cell. Since the gas is stored at a high pressure, the high-pressure vessel needs to have high strength. Therefore, the high-pressure vessel has a liner and a reinforcing layer covering the liner from the outside. The expansion of the liner is suppressed by the reinforcing layer, making the entire high-pressure vessel have high strength.

[0003] Here, it is required that the high-pressure vessel be lightweight. Therefore, in most cases, a fiber-reinforced resin is selected as the material for the reinforcing layer. In addition, resins are mostly selected as the raw materials for the liner.

[0004] The high-pressure vessel having the above structure is manufactured as follows. First, the liner is manufactured. Specifically, for example, a plurality of divided pieces are obtained by injection molding using molten resin. Then, the liner is obtained by joining the divided pieces to each other. Alternatively, the liner can also be obtained by blow molding as described in Japanese Patent Application Laid-Open No. 2018-83391. In this case, gas is supplied to a hollow preform inserted into a molding die. As a result, the preform expands.

[0005] Next, as described in Japanese Patent Application Laid-Open No. 2018-83391, an impregnated resin reinforcing fiber is wound around the outer wall of the liner by a fiber winding method or the like. As the resin cures, a reinforcing layer is formed. In addition, the following method is proposed in Japanese Patent Application Laid-Open No. 2017-140809. First, a sheet body is wound around a cylindrical main body portion of the liner by a sheet winding method. Then, a wire body is wound by a fiber winding method to form a reinforcing layer. The sheet body and the wire body are impregnated resin reinforcing fibers. Summary of the Invention

[0006] The same molding die can only obtain liners of the same shape and the same size. Therefore, in the case of producing high-pressure vessels having different shapes or sizes from each other, molding dies having different cavity shapes or sizes need to be prepared. However, in this case, the equipment investment increases. In addition, space for storing a plurality of molding dies is required.

[0007] An object of the present invention is to solve the above technical problems.

[0008] According to an embodiment of the present invention, a high-pressure vessel is provided, which has a hollow inner container and a reinforcing layer covering the inner container from the outside. The inner container has: a cylindrical main body portion; and a first circular top portion and a second circular top portion, which are respectively connected to both end portions in the long side direction of the main body portion. The reinforcing layer has: an inner reinforcing layer, which is made of a fiber-reinforced resin and covers the inner container from the outside; and an outer reinforcing layer, which is made of a fiber-reinforced resin and covers the inner reinforcing layer from the outside. The inner reinforcing layer has: a first covering portion that covers the first circular top portion; a second covering portion that covers the second circular top portion; and a third covering portion that covers the main body portion. A first edge surface of the first covering portion facing the third covering portion abuts against a second edge surface of the third covering portion facing the first covering portion, and a third edge surface of the third covering portion facing the second covering portion abuts against a fourth edge surface of the second covering portion facing the third covering portion. The outer reinforcing layer covers the first covering portion, the third covering portion, and the second covering portion from the outside.

[0009] In addition, according to another embodiment of the present invention, there is provided a method for manufacturing a high-pressure vessel having a hollow inner liner and a reinforcing layer covering the inner liner from the outside. The method for manufacturing the high-pressure vessel includes a first forming step, a second forming step, a pre-assembly step, a reinforcing layer forming step, an insertion step, and an inner liner forming step. In the first forming step, a reinforcing fiber impregnated with resin is wound around a first forming die to form a cylindrical body made of fiber-reinforced resin. In the second forming step, a reinforcing fiber impregnated with resin is wound around a second forming die to simultaneously form a first covering portion and a second covering portion made of fiber-reinforced resin. In the pre-assembly step, a part or all of the cylindrical body is used as a third covering portion, and a first edge surface of the first covering portion facing the third covering portion is brought into contact with a second edge surface of the third covering portion facing the first covering portion, and a third edge surface of the third covering portion facing the second covering portion is brought into contact with a fourth edge surface of the second covering portion facing the third covering portion to pre-assemble an inner reinforcing layer having the first covering portion, the third covering portion, and the second covering portion. In the reinforcing layer forming step, a reinforcing fiber impregnated with resin is wound around the inner reinforcing layer to obtain an outer reinforcing layer covering the inner reinforcing layer from the outside, thereby obtaining a reinforcing layer having the inner reinforcing layer and the outer reinforcing layer. In the insertion step, a hollow preform is inserted into the inner reinforcing layer through a first opening formed in the first covering portion or the second covering portion and a second opening formed in the outer reinforcing layer and overlapping with the first opening. In the inner liner forming step, after gas is supplied into the hollow preform to expand the hollow preform, the expanded hollow preform is cured to obtain an inner liner having a first dome portion, a main body portion, and a second dome portion, and the outside of the first dome portion is covered by the first covering portion, the outside of the main body portion is covered by the third covering portion, and the outside of the second dome portion is covered by the second covering portion.

[0010] In the present invention, the reinforcing layer has an inner reinforcing layer and an outer reinforcing layer. The inner reinforcing layer has a first covering portion, a second covering portion, and a third covering portion. By manufacturing the third covering portion with an appropriate length and providing an outer reinforcing layer outside the inner reinforcing layer, a reinforcing layer with a desired length can be obtained. Then, a hollow preform having a length matching that of the reinforcing layer is expanded within the reinforcing layer. Accordingly, a high-pressure vessel with a desired length can be obtained.

[0011] Therefore, it is not necessary to prepare forming dies of various shapes or sizes. Therefore, the equipment investment can be reduced. In addition, there is no need to provide space for storing multiple forming dies. Therefore, the manufacturing station of the high-pressure vessel can also be made more space-saving.

[0012] The above objects, features, and advantages should be readily understood from the following description of the embodiments with reference to the accompanying drawings. Description of the Drawings

[0013] Figure 1 It is a schematic cross-sectional view of the side surface of the high-pressure vessel according to the embodiment of the present invention in the longitudinal direction.

[0014] Figure 2 It is an enlarged view of the main part of the first circular top and the vicinity of the first circular top.

[0015] Figure 3 It is an enlarged view of the main part of the second circular top and the vicinity of the second circular top.

[0016] Figure 4 It is a schematic flowchart of the method for manufacturing the high-pressure vessel according to the embodiment of the present invention.

[0017] Figure 5 It is a side view schematically showing the state of manufacturing a cylindrical body using a cylindrical mandrel.

[0018] Figure 6A It is a schematic cross-sectional view of the side surface of the cylindrical body. Figure 6B It is a schematic cross-sectional view of the side surface of the segmented piece separated from the cylindrical body. Figure 6C It is a schematic cross-sectional view of the side surface of the segmented piece whose edge surface has been processed.

[0019] Figure 7 It is an enlarged view of the main part showing the state of forming a conical inclined surface when impregnated fibers are wound around a cylindrical mandrel.

[0020] Figure 8A It is a schematic top view of a sheet body whose dimension in the width direction gradually changes. Figure 8B It is a schematic overall perspective view showing the state of winding the sheet body around a cylindrical mandrel to form a third covering portion.

[0021] Figure 9 It is a side view schematically showing the state of manufacturing the first covering portion and the second covering portion using a capsule-shaped mandrel.

[0022] Figure 10A It is a schematic cross-sectional view of the side surface of the first covering portion and the second covering portion after detachment. Figure 10B It is a schematic cross-sectional view of the side surface of the first covering portion and the second covering portion whose edge surfaces have been processed.

[0023] Figure 11A It is a schematic cross-sectional view of the side surface showing the state where the edge surfaces of the first covering portion and the third covering portion are in contact with each other. Figure 11B It is a schematic cross-sectional view of the side surface showing the state where the edge surfaces of the third covering portion and the second covering portion are in contact with each other.

[0024] Figure 12 It is a schematic side cross-sectional view showing the state of forming an outer reinforcing layer on a pre-assembly.

[0025] Figure 13 It is a schematic side cross-sectional view showing the state where a lubricant is coated on the inner wall of the inner reinforcing layer.

[0026] Figure 14 It is a schematic side cross-sectional view showing the state of inserting a hollow preform into the reinforcing layer.

[0027] Figure 15 It is a schematic side cross-sectional view showing the state of forming an inner bladder by expanding the hollow preform in the reinforcing layer.

[0028] Figure 16 It is a schematic side cross-sectional view showing the state where the shape of the inner bladder is corrected. Detailed implementation mode

[0029] Hereinafter, an inclined surface with a gradually decreasing or increasing diameter is defined as a "conical inclined surface".

[0030] Figure 1 It is a schematic side cross-sectional view of the high-pressure vessel 10 according to this embodiment along the long side direction. The high-pressure vessel 10 has an inner bladder 12 as an inner layer and a reinforcing layer 14 as an outer layer.

[0031] The inner bladder 12 is made of, for example, resins such as polyethylene, polypropylene, polyamide, and polycarbonate. Alternatively, the inner bladder 12 is made of a metal such as stainless steel. The inner bladder 12 has a first dome portion 16, a main body portion 18, and a second dome portion 20. The main body portion 18 is clamped between the first dome portion 16 and the second dome portion 20.

[0032] The first dome portion 16 has a cup shape with a diameter decreasing from the main body portion 18 toward the away direction. A first cylindrical portion 221 projects from the central portion in the radial direction of the first dome portion 16. The first cylindrical portion 221 extends in a direction away from the main body portion 18. As Figure 2 shown in detail, a first interface 241 is provided on the first cylindrical portion 221. The first interface 241 has a first inner interface 261 and a first outer interface 281. The first cylindrical portion 221 is clamped between the first inner interface 261 and the first outer interface 281.

[0033] The main body 291 of the first inner interface 261 is inserted into the hollow interior of the first cylindrical portion 221. A first passage 301 extending in the longitudinal direction of the first cylindrical portion 221 is formed in the main body 291. In addition, a end cap portion 321 is provided at the top end of the first inner interface 261. An internal thread 331 is formed on the inner peripheral wall of the end cap portion 321. In contrast, an external thread 332 is formed at the top end of the first outer interface 281. The top end of the first outer interface 281 enters the interior of the end cap portion 321. Moreover, the external thread 332 is screwed with the internal thread 331.

[0034] The diameter of the main body portion 18 (see Figure 1 ) is substantially constant along the longitudinal direction of the main body portion 18. Therefore, the main body portion 18 has a slightly elongated cylindrical shape.

[0035] The second dome portion 20 is the same as the first dome portion 16. The second dome portion 20 is formed in a cup shape by reducing its diameter in a direction away from the main body portion 18. The second cylindrical portion 222 protrudes from the central portion in the radial direction of the second dome portion 20. The second cylindrical portion 222 extends in a direction away from the main body portion 18. Therefore, the second cylindrical portion 222 faces the opposite direction to the first cylindrical portion 221. The first cylindrical portion 221 and the second cylindrical portion 222 are located on a single imaginary central axis L. The imaginary central axis L passes through the radial center of the first dome portion 16 and the radial center of the second dome portion 20, and extends along the longitudinal direction of the inner container 12. Hereinafter, the direction along the imaginary central axis L will be referred to as the "axial direction of the high-pressure container 10".

[0036] As Figure 3 shown in detail, a second interface 242 is provided on the second cylindrical portion 222. The second interface 242 has a second inner interface 262 and a second outer interface 282. The second cylindrical portion 222 is clamped between the second inner interface 262 and the second outer interface 282.

[0037] The main body 292 of the second inner interface 262 is inserted into the hollow interior of the second cylindrical portion 222. A second passage 302 extending in the longitudinal direction of the second cylindrical portion 222 is formed in the main body 292. In addition, a end cap portion 322 is provided at the top end of the second inner interface 262. An internal thread 331 is formed on the inner peripheral wall of the end cap portion 322. In contrast, an external thread 332 is formed at the top end of the second outer interface 282. The top end of the second outer interface 282 enters the interior of the end cap portion 322. Moreover, the external thread 332 is screwed with the internal thread 331.

[0038] As Figure 1As shown, the reinforcing layer 14 has an inner reinforcing layer 38 that covers the inner side of the inner container 12 from the outside and an outer reinforcing layer 40 that covers the inner reinforcing layer 38 from the outside. The inner reinforcing layer 38 and the outer reinforcing layer 40 are made of a fiber-reinforced resin (FRP) in which reinforcing fibers are impregnated with a resin base material. That is, the inner reinforcing layer 38 and the outer reinforcing layer 40 are respectively formed by winding the Figure 5 impregnated fibers 47 shown in etc. multiple times. In addition, the impregnated fibers 47 are reinforcing fibers impregnated with a resin. As the reinforcing fibers, long fibers or short fibers of carbon fiber or glass fiber are exemplified. In the inner reinforcing layer 38 and the outer reinforcing layer 40, the resin cures.

[0039] The inner reinforcing layer 38 has a first covering portion 42, a third covering portion 44, and a second covering portion 46. The first covering portion 42 covers the first dome portion 16 from the outside. The third covering portion 44 covers the main body portion 18 from the outside. The second covering portion 46 covers the second dome portion 20 from the outside. The first covering portion 42, the third covering portion 44, and the second covering portion 46 are arranged in a straight line.

[0040] The first covering portion 42 is formed by low-helix winding of the impregnated fibers 47 (refer to Figure 5 ). The second covering portion 46 is also formed by low-helix winding of the impregnated fibers 47. That is, the first covering portion 42 and the second covering portion 46 are low-helix layers. In contrast, the third covering portion 44 is formed by circumferential winding of the impregnated fibers 47. That is, the third covering portion 44 is a circumferential layer. The third covering portion 44 may also be set as a mixed layer of a circumferential layer and a low-helix layer.

[0041] A first through hole 481 (refer to Figure 2 ) is formed at the radial center portion of the first covering portion 42. In addition, the end portion of the first covering portion 42 facing the third covering portion 44 is an open end. This open end has a first edge surface 501. The inner peripheral edge of the first edge surface 501 is close to the first dome portion 16, and the outer peripheral edge of the first edge surface 501 is close to the main body portion 18. That is, the first edge surface 501 is a conical inclined surface whose protruding amount increases as it approaches the main body portion 18 from the inner periphery to the outer periphery.

[0042] Both ends of the third covering portion 44 are open ends. The open end facing the first edge surface 501 of the first covering portion 42 has a second edge surface 521. The inner peripheral edge of the second edge surface 521 is close to the first dome portion 16, and the outer peripheral edge of the second edge surface 521 is close to the main body portion 18. That is, the second edge surface 521 is a conical inclined surface whose protruding amount decreases as it approaches the first dome portion 16 from the inner periphery to the outer periphery. The inclination directions of the first edge surface 501 and the second edge surface 521 are opposite to each other. The first edge surface 501 and the second edge surface 521 are in contact with each other.

[0043] In addition, the third covering portion 44 has a third edge surface 522 facing the open end of the second covering portion 46. The inner peripheral edge of the third edge surface 522 is close to the second dome top 20, and the outer peripheral edge of the third edge surface 522 is close to the main body portion 18. That is, the third edge surface 522 is a conical inclined surface whose amount of protrusion toward the second dome top 20 decreases as it goes from the inner periphery toward the outer periphery.

[0044] The second covering portion 46 is the same as the first covering portion 42. However, in the axial direction of the high-pressure vessel 10, the second covering portion 46 faces the opposite direction to the first covering portion 42. A second through hole 482 (see Figure 3 ) is formed at the central portion in the radial direction of the second covering portion 46.

[0045] The end portion of the second covering portion 46 facing the third covering portion 44 is an open end. This open end has a fourth edge surface 502. The inner peripheral edge of the fourth edge surface 502 is close to the second dome top 20, and the outer peripheral edge of the fourth edge surface 502 is close to the main body portion 18. That is, the fourth edge surface 502 is a conical inclined surface whose amount of protrusion toward the main body portion 18 increases as it goes from the inner periphery toward the outer periphery. The inclination directions of the third edge surface 522 and the fourth edge surface 502 are opposite to each other. The third edge surface 522 and the fourth edge surface 502 are in contact with each other.

[0046] A lubricating layer 53 is formed on the inner wall of the inner reinforcing layer 38 (the first covering portion 42, the third covering portion 44, and the second covering portion 46) facing the inner tank 12. The lubricating layer 53 is formed by coating a lubricant 102 (see Figure 13 ) described later. The lubricating layer 53 is used to prevent the outer wall of the inner tank 12 from adhering to the inner wall of the inner reinforcing layer 38. In addition, a demolding material in injection molding or the like is cited as a preferred specific example of the lubricant 102. A typical example of the demolding material is a silicone-based compound.

[0047] The outer reinforcing layer 40 covers the entire inner reinforcing layer 38 from the outside. The outer reinforcing layer 40 is mainly formed by high helix winding of the impregnated fiber 47. However, it is also possible to form a portion covering the first covering portion 42 and the second covering portion 46 by low helix winding. In this case, the outer reinforcing layer 40 is a mixed layer of a high helix layer and a low helix layer. It can also be replaced by a single layer of a high helix layer. In this case, the outer reinforcing layer 40 is not laminated near the radial center of the first covering portion 42. Similarly, the outer reinforcing layer 40 is not laminated near the radial center of the second covering portion 46.

[0048] A third through hole 541 (see Figure 2)。In the axial direction of the high-pressure container 10, the third through-hole 541 overlaps with the first through-hole 481 of the first covering portion 42. The first cylindrical portion 221 passes through the first through-hole 481 and the third through-hole 541 (see Figure 2 ). The top end of the first cylindrical portion 221 is exposed to the outside of the outer reinforcing layer 40. A first interface 241 is installed at the top end of the first cylindrical portion 221. In addition, a fourth through-hole 542 is formed in the outer reinforcing layer 40 (see Figure 3 ). In the axial direction of the high-pressure container 10, the fourth through-hole 542 overlaps with the second through-hole 482 of the second covering portion 46. The second cylindrical portion 222 passes through the second through-hole 482 and the fourth through-hole 542 (see Figure 3 ). The top end of the second cylindrical portion 222 is exposed to the outside of the outer reinforcing layer 40. A second interface 242 is installed at the top end of the second cylindrical portion 222.

[0049] As Figure 2 shown, the first end of the first circulation pipe 601 is connected to the first passage 301 of the first inner interface 261 via a first pipe joint (not shown). The second end of the first circulation pipe 601 is connected to a high-pressure gas supply source (not shown). A first valve 621 is provided on the first circulation pipe 601. In addition, as Figure 3 shown, the first end of the second circulation pipe 602 is connected to the second passage 302 of the second inner interface 262 via a second pipe joint (not shown). The second end of the second circulation pipe 602 is connected to a high-pressure gas receiver (not shown). A second valve 622 is provided on the second circulation pipe 602.

[0050] The high-pressure container 10 according to this embodiment is basically configured as described above. Hereinafter, an example of mounting the high-pressure container 10 on a fuel cell vehicle will be described. However, Figures 1 - 3 components other than those shown are not particularly illustrated.

[0051] In this case, the high-pressure gas is hydrogen. In addition, the high-pressure gas supply source is, for example, a hydrogen storage tank installed at a hydrogen station. Furthermore, the high-pressure gas receiver is a fuel cell.

[0052] When the hydrogen in the high-pressure container 10 reaches below a specified pressure, it is necessary to fill hydrogen into the high-pressure container 10. In this case, the driver drives the fuel cell vehicle to move it to a hydrogen station. After that, the driver or operator connects a supply hose to the second end of the first circulation pipe 601. By this connection, the main valve provided on the supply hose and the first valve 621 provided on the first circulation pipe 601 are automatically opened. The second valve 622 remains closed.

[0053] Since the main valve and the first valve 621 are open while the second valve 622 is closed, hydrogen gas flows into the inner container 12 through the first passage 301, the first pipe joint, and the first flow tube 601. The hydrogen gas is stored inside the inner container 12.

[0054] When the hydrogen gas in the high-pressure container 10 rises above a specified pressure, the main valve and first valve 621 close. The driver or operator removes the supply hose from the first flow tube 601. Furthermore, when the driver presses the start switch of the fuel cell vehicle, the second valve 622 opens, supplying hydrogen to the fuel cell. At this point, the high-pressure gas discharged from the inner liner 12 flows through the second passage 302, the second pipe joint, and the second flow tube 602.

[0055] When the driver stops the operation of the fuel cell vehicle, the second valve 622 is closed, thereby stopping the supply of hydrogen gas from the high-pressure container 10 to the fuel cell.

[0056] However, the molecular radius of hydrogen (hydrogen molecules) is extremely small. Therefore, when the inner liner 12 is made of resin, hydrogen inevitably permeates the inner liner 12. Here, a lubricating layer 53 is formed on the inner wall of the inner reinforcing layer 38. This lubricating layer 53 inhibits the outer wall of the inner liner 12 and the inner wall of the inner reinforcing layer 38 from adhering to each other. Therefore, when hydrogen permeates the inner liner 12, the pressure of the hydrogen easily separates the outer wall of the inner liner 12 and the inner wall of the inner reinforcing layer 38. Therefore, hydrogen easily accumulates between the inner liner 12 and the inner reinforcing layer 38.

[0057] When the pressure of the hydrogen gas within the inner liner 12 decreases, the hydrogen gas between the inner liner 12 and the inner reinforcing layer 38 returns to the first passage 301 or the second passage 302 via a guide passage (not shown) provided in the high-pressure container 10. The hydrogen gas eventually merges with the hydrogen gas within the inner liner 12. Thus, by forming the lubricating layer 53 on the inner wall of the inner reinforcing layer 38, the hydrogen gas that has permeated the inner liner 12 can be easily returned to the inner liner 12.

[0058] Furthermore, the lubricating layer 53 prevents the outer wall of the inner liner 12 from adhering to the inner wall of the inner reinforcing layer 38. This prevents fatigue failure originating at the point of adhesion between the outer wall of the inner liner 12 and the inner wall of the inner reinforcing layer 38. This improves the durability of the high-pressure container 10.

[0059] Next, a method for manufacturing the high-pressure container 10 according to this embodiment will be described. Figure 4 1 is a schematic flow chart of a method for manufacturing a high-pressure container 10. The method includes a first molding step S10, a second molding step S20, a pre-assembly step S30, a reinforcement layer forming step S40, an insertion step S50, and a liner molding step S60.

[0060] When performing the first molding step S10, use Figure 5The shown cylindrical mandrel 70 (first molding die). The cylindrical mandrel 70 can be rotated about the first rotation axis 72 by a rotation mechanism (not shown).

[0061] In the first molding process S10, for example, the fiber winding method is performed. Specifically, first, the first rotation axis 72 and the cylindrical mandrel 70 are integrally rotated. The impregnated fiber 47 is fed from a bobbin (not shown) to the cylindrical mandrel 70. The impregnated fiber 47 is wound substantially circumferentially. As a result, circumferential layers are sequentially laminated on the cylindrical mandrel 70, thereby forming a cylindrical body 76. The cylindrical body 76 is made of a fiber-reinforced resin. At this time, it is not particularly necessary to form the second edge surface 521 and the third edge surface 522 into conical inclined surfaces.

[0062] Next, as Figure 6A shown, the cylindrical body 76 is detached from the cylindrical mandrel 70. The length of the cylindrical mandrel 70 is, for example, approximately the length of four third covering portions 44 of the high-pressure vessel 10. Therefore, the cylindrical body 76 is cut along the cutting line CL in Figure 6A , and as Figure 6B shown, a plurality of (for example, four) divided pieces 78 of appropriate length are obtained. By obtaining the divided pieces 78 of the desired length, a high-pressure vessel 10 of the desired length can be obtained. For example, the entire cylindrical body 76 can also be used as one third covering portion 44.

[0063] Next, the second edge surface and third edge surface processing process S15 is performed. That is, the edge surfaces of the first end portion and the second end portion in the longitudinal direction of one divided piece 78 (or the uncut cylindrical body 76) are processed. Through this processing, as Figure 6C shown, a second edge surface 521 whose outer diameter gradually decreases conically toward the top is formed at the first end portion of the divided piece 78. A third edge surface 522 whose outer diameter gradually decreases conically toward the top is formed at the second end portion of the divided piece 78. That is, the third covering portion 44 having the second edge surface 521 and the third edge surface 522 as conical inclined surfaces is obtained.

[0064] In addition, in the case where the entire cylindrical body 76 is used as one third covering portion 44, the second edge surface 521 and the third edge surface 522 as conical inclined surfaces can also be formed when the impregnated fiber 47 is wound around the cylindrical mandrel 70. Specifically, as the second edge surface 521 is enlarged in Figure 7As shown, the layer thickness of the circumferential layer is minimized at the tips of the first end and the second end, which are the end portions in the long side direction. Further, the layer thickness of the circumferential layer increases as it moves away from the tip towards the middle portion in the long side direction. For this reason, when winding the upper layer 82 after winding the lower layer 80 of the circumferential layer, the winding start position of the upper layer 82 is set to a position closer to the middle portion in the long side direction than the winding start position of the lower layer 80. As a result, the second edge surface 521 and the third edge surface 522 are formed as conical inclined surfaces. In this case, the second edge surface and third edge surface processing step S15 is not required.

[0065] Further, as Figure 8A and Figure 8B shown, a sheet body 84 impregnated with fibers 47 can also be used for the sheet winding method. In this case, when the entire cylindrical body 76 is used as one third covering portion 44, it is preferable to use the Figure 8A sheet body 84 shown. In this sheet body 84, the dimension in the width direction orthogonal to the long side direction gradually becomes shorter. That is, if the width of the leading portion sent out first is set as W1 and the width of the trailing portion sent out later is set as W2, then W1 > W2 holds.

[0066] Therefore, as the sheet body 84 is wound around the cylindrical mandrel 70, as Figure 8B shown, the width of the upper layer 82 of the circumferential layer becomes narrower than that of the lower layer 80. That is, the both end portions in the long side direction of the upper layer 82 are closer to the middle portion in the long side direction than the both end portions in the long side direction of the lower layer 80. As a result, the second edge surface 521 and the third edge surface 522 are formed as conical inclined surfaces. Therefore, in this case, the second edge surface and third edge surface processing step S15 is not required either.

[0067] The second forming step S20 will be described. In addition, the first forming step S10 and the second forming step S20 can be implemented in different orders. Alternatively, the second forming step S20 can be implemented simultaneously with the first forming step S10. In this case, the first forming step S10 is carried out at an arbitrary working station, and at the same time, the second forming step S20 is carried out at another working station. In this way, it is not particularly necessary to carry out one of the first forming step S10 and the second forming step S20 first, and then carry out the remaining one of the first forming step S10 and the second forming step S20.

[0068] When implementing the second forming step S20, use Figure 9The shown capsule mandrel 90 (second forming die). The capsule mandrel 90 has a first cup-shaped forming portion 921 and a second cup-shaped forming portion 922. In each of the first cup-shaped forming portion 921 and the second cup-shaped forming portion 922, one end portion is an open end, and the remaining other end portion is a closed end. The first cup-shaped forming portion 921 and the second cup-shaped forming portion 922 are held by the second rotating shaft 94. At this time, the open ends of the first cup-shaped forming portion 921 and the second cup-shaped forming portion 922 face each other in a state of being slightly separated from each other.

[0069] The capsule mandrel 90 can be rotated about the second rotating shaft 94 by a rotating mechanism (not shown).

[0070] In the second forming process S20, for example, the fiber winding method is performed. Specifically, first, the second rotating shaft 94 and the capsule mandrel 90 (the first cup-shaped forming portion 921 and the second cup-shaped forming portion 922) are integrally rotated. The impregnated fiber 47 is fed from a line (not shown) to the capsule mandrel 90. The impregnated fiber 47 is substantially wound in a low helix. As a result, the low helix layers are sequentially stacked on the capsule mandrel 90 to form a capsule-shaped body 96 made of a fiber-reinforced resin.

[0071] Next, while the capsule-shaped body 96 continues to rotate, the cutter 98 is made to travel from the outside of the capsule-shaped body 96 to the separation portion (cutting line CM) between the first cup-shaped forming portion 921 and the second cup-shaped forming portion 922. Accordingly, the capsule-shaped body 96 is divided into two parts. As a result, the first covering portion 42 and the second covering portion 46 are obtained. After that, as Figure 10A shown, the first covering portion 42 and the second covering portion 46 are detached from the capsule mandrel 90. Since the impregnated fiber 47 is not wound around the second rotating shaft 94, a first through hole 481 is formed in the first covering portion 42. Similarly, a second through hole 482 is formed in the second covering portion 46. The first through hole 481 and the second through hole 482 are the first openings.

[0072] Next, the first edge surface and the fourth edge surface processing process S25 is performed. That is, as Figure 10B shown, the edge surface of the open end of the first covering portion 42 is processed. By this processing, a first edge surface 501 whose inner diameter expands in a conical shape as it approaches the top of the open end is formed on the first covering portion 42. The edge surface of the open end of the second covering portion 46 is also processed in the same manner. By this processing, a fourth edge surface 502 whose inner diameter expands in a conical shape as it approaches the top of the open end is formed on the second covering portion 46. That is, the first covering portion 42 having the first edge surface 501 as a conical inclined surface and the second covering portion 46 having the fourth edge surface 502 as a conical inclined surface are obtained.

[0073] Next, a pre-assembly process S30 for pre-assembling the inner reinforcing layer 38 is performed. First, as Figure 11A shown, the first edge surface 501 of the first covering portion 42 is brought into contact with the second edge surface 521 of the third covering portion 44. The first edge surface 501 and the second edge surface 521 are conical inclined surfaces with the same inclination direction. Therefore, the first edge surface 501 and the second edge surface 521 overlap and adhere to each other. Therefore, the first covering portion 42 and the third covering portion 44 are not easily displaced relative to each other.

[0074] After that, as Figure 11B shown, the third edge surface 522 of the third covering portion 44 is brought into contact with the fourth edge surface 502 of the second covering portion 46. The third edge surface 522 and the fourth edge surface 502 are also conical inclined surfaces with the same inclination direction. Therefore, the third edge surface 522 and the fourth edge surface 502 overlap and adhere to each other. Therefore, the third covering portion 44 and the second covering portion 46 are not easily displaced relative to each other. Thus, a pre-assembled body of the inner reinforcing layer 38 is obtained.

[0075] As described above, by making the first edge surface 501 to the fourth edge surface 502 be conical inclined surfaces, the first covering portion 42 and the second covering portion 46 can be easily positioned with respect to the third covering portion 44. In addition, conversely to the above, after bringing the third edge surface 522 into contact with the fourth edge surface 502, the first edge surface 501 may be brought into contact with the second edge surface 521.

[0076] After that, the first external interface 281 is inserted into the first through hole 481 of the first covering portion 42. In addition, the second external interface 282 is inserted into the second through hole 482 of the second covering portion 46. In this state, then, a reinforcing layer forming process S40 is performed. In the reinforcing layer forming process S40, an outer reinforcing layer 40 is provided outside the inner reinforcing layer 38.

[0077] Specifically, for example, as Figure 12 shown, the impregnated fiber 47 is wound around the pre-assembled body (inner reinforcing layer 38) by a fiber winding method. At this time, mainly high helix winding is performed, and high helix layers are sequentially laminated. Thus, an outer reinforcing layer 40 that covers the inner reinforcing layer 38 from the outside is obtained. The reinforcing layer 14 is formed by the inner reinforcing layer 38 and the outer reinforcing layer 40. In addition, a part of the outer reinforcing layer 40 can be a low helix layer.

[0078] The outer reinforcing layer 40 covers a part of the portion of the first outer interface 281 exposed from the first through-hole 481. Similarly, the outer reinforcing layer 40 covers a part of the portion of the second outer interface 282 exposed from the second through-hole 482. Therefore, a third through-hole 541 connected to the first through-hole 481 and a fourth through-hole 542 connected to the second through-hole 482 are formed in the outer reinforcing layer 40. The third through-hole 541 and the fourth through-hole 542 are the second openings.

[0079] The first outer interface 281 passes through the first through-hole 481 and the third through-hole 541. The top end of the first outer interface 281 is exposed from the third through-hole 541 to the outside of the outer reinforcing layer 40. In addition, the second outer interface 282 passes through the second through-hole 482 and the fourth through-hole 542. The top end of the second outer interface 282 is exposed from the fourth through-hole 542 to the outside of the outer reinforcing layer 40.

[0080] Next, a coating process is performed. For example, as Figure 13 shown, the coating nozzle 100 is passed through the inside of the first outer interface 281, and the coating nozzle 100 is inserted into the inside of the inner reinforcing layer 38. The coating nozzle 100 faces the inner wall of the inner reinforcing layer 38. In this state, the lubricant 102 is ejected from the coating nozzle 100. The coating nozzle 100 rotates relative to the inner reinforcing layer 38 and moves relative to the inner reinforcing layer 38 from the first covering portion 42 toward the second covering portion 46. Accordingly, the lubricant 102 is coated on the entire inner wall of the inner reinforcing layer 38. The lubricant 102 adheres to the inner wall of the inner reinforcing layer 38. Accordingly, a lubricating layer 53 (refer to Figure 14 ) is formed.

[0081] Next, an insertion process S50 is performed. In the insertion process S50, as Figure 14 shown, the hollow preform 110 is inserted into the inner reinforcing layer 38. In addition, the hollow preform 110 expands as described later to become the inner bladder 12. The hollow preform 110 is made of the above resin, for example, and has a cylindrical shape.

[0082] When the hollow preform 110 is inserted into the reinforcing layer 14, the second end 1122 in the long side direction of the hollow preform 110 passes through the inside of the first outer interface 281. In other words, the second end 1122 passes through the first through-hole 481 and the third through-hole 541 of the reinforcing layer 14 via the first outer interface 281. After that, the second end 1122 is inserted into the inside of the second outer interface 282. In addition, the first end 1121 in the long side direction of the hollow preform 110 is inserted into the inside of the first outer interface 281. Accordingly, the hollow preform 110 is supported by the first outer interface 281 and the second outer interface 282.

[0083] Next, Figure 14The enclosed member 114 shown is installed on, for example, the second end 1122 of the hollow preform 110. Further, the hollow preform 110 is heated via the reinforcing layer 14 to soften the hollow preform 110. In this state, the inner liner forming process S60 is performed. That is, compressed gas (for example, compressed air) is supplied into the hollow preform 110 via the first end 1121. The hollow preform 110 expands under the pressure of the compressed gas.

[0084] A part of the outer wall of the expanded hollow preform 110 abuts against the inner wall of the inner reinforcing layer 38 earlier than other parts. After that, other parts of the hollow preform 110 expand. During this process, the part of the hollow preform 110 that has abutted against the inner wall of the inner reinforcing layer 38 slides relative to the inner wall of the inner reinforcing layer 38. Therefore, the outer wall of the hollow preform 110 can extend in the surface direction after abutting against the inner reinforcing layer 38. Therefore, it is possible to make the hollow preform expand more easily.

[0085] The expansion of the hollow preform 110 ends, for example, when most of the outer wall of the hollow preform 110 abuts against the inner wall of the inner reinforcing layer 38. At this time, the shape of the hollow preform 110 roughly corresponds to the shape of the inner reinforcing layer 38. That is, the hollow preform 110 changes into Figure 15 the inner liner 12 shown. The inner liner 12 has a first dome portion 16, a main body portion 18, and a second dome portion 20. As described above, the first dome portion 16 is covered by the first covering portion 42. The main body portion 18 is covered by the third covering portion 44. The second dome portion 20 is covered by the second covering portion 46. The first end 1121 is a first cylindrical portion 221, and the second end 1122 is a second cylindrical portion 222.

[0086] In this way, in the inner liner forming process S60, blow molding is performed in which the inner reinforcing layer 38 is used as a simulated molding die to expand the hollow preform 110. It is also possible that, at the moment when the blow molding is completed, for example, some gaps are formed between the first dome portion 16 and the first covering portion 42, and between the second dome portion 20 and the second covering portion 46.

[0087] After the hollow preform 110 has fully expanded to become the inner liner 12, the supply of compressed gas to the inner liner 12 is stopped. Although the inner liner 12 can be cured in this state, it is more preferable to supply cooling gas into the inner liner 12. This is because the cooling gas promotes the curing of the inner liner 12.

[0088] In this case, it is preferable to supply the cooling gas at a high pressure higher than the pressure of the compressed gas supplied during blow molding. The cooling gas presses the inner bladder 12 from the inside to the outside. Accordingly, when there is a portion (e.g., the first circular top portion 16) on the inner bladder 12 where the outer wall does not contact the inner wall of the inner reinforcing layer 38, this portion is pressed toward the inner reinforcing layer 38. As a result, as Figure 16 shown, the outer wall of this portion contacts the inner wall of the inner reinforcing layer 38. In addition, the cooling gas suppresses the inner bladder 12 from contracting inward due to thermal shrinkage.

[0089] In this way, by making the pressure of the cooling gas higher than the compressed gas during blow molding, the shape of the inner bladder 12 during the cooling process can be maintained. Therefore, the volume of the internal space of the inner bladder 12 is sufficiently increased. That is, the inner bladder 12 has an internal space capable of storing a large amount of gas (such as hydrogen).

[0090] In this way, a high-pressure vessel 10 having an inner bladder 12 on the inside and a reinforcing layer 14 on the outside can be obtained. For the above reasons, an inner bladder 12 with insufficient expansion is avoided. In addition, since the inner reinforcing layer 38 restricts the hollow preform 110, a situation where the thickness varies depending on the portion on the expanded inner bladder 12 is avoided. Moreover, the formation of an excessive gap between the inner bladder 12 and the first circular top portion 16 or the second circular top portion 20 can be suppressed.

[0091] After that, the internal thread 331 of the end cap portion 321 of the first internal interface 261 is screwed onto the external thread 332 at the top end of the first external interface 281 (refer to Figure 2 ). Similarly, the internal thread 331 of the end cap portion 322 of the second internal interface 262 is screwed onto the external thread 332 at the top end of the second external interface 282 (refer to Figure 3 ). Accordingly, the first interface 241 is provided on the first cylindrical portion 221, and the second interface 242 is provided on the second cylindrical portion 222.

[0092] In addition, at the moment when blow molding is completed, most of the outer wall of the inner bladder 12 contacts the inner wall of the inner reinforcing layer 38. When the cooling gas is supplied, the portion where the outer wall contacts the inner wall of the inner reinforcing layer 38 is pressed by the reinforcing layer 14. Therefore, the expansion of this portion is suppressed.

[0093] In general blow molding, a molded part imitating the shape of the molding die can be obtained. Therefore, for example, when molding inner bladders 12 having different lengths separately by blow molding, it is necessary to manufacture molding dies having different lengths separately. As a result, the equipment investment increases significantly.

[0094] In the present embodiment, as described above, the length of the third covering portion 44 of the inner reinforcing layer 38 can be appropriately determined. In other words, it is easy to obtain reinforcing layers 14 of different lengths separately. For example, when the length of the reinforcing layer 14 is large, a hollow preform 110 with a longer length is selected. On the contrary, when the length of the reinforcing layer 14 is small, a hollow preform 110 with a shorter length is selected. Then, as described above, the hollow preform 110 is expanded within the reinforcing layer 14. Accordingly, an inner bladder 12 having a length corresponding to the length of the reinforcing layer 14 can be obtained.

[0095] From this, it can be seen that according to the present embodiment, it is not necessary to prepare molding dies of various lengths. Therefore, high-pressure vessels 10 of a desired length can be mass-produced at low cost. In addition, there is no need for space to store the molding dies. Therefore, space saving of the manufacturing station of the high-pressure vessel 10 can be achieved.

[0096] As described above, according to the present embodiment, there is provided a high-pressure vessel (10) having a hollow inner bladder (12) and a reinforcing layer (14) covering the inner bladder from the outside. The inner bladder has: a cylindrical main body portion (18); and a first dome portion (16) and a second dome portion (20) respectively connected to both end portions in the longitudinal direction of the main body portion. The reinforcing layer has: an inner reinforcing layer (38) made of a fiber-reinforced resin and covering the inner bladder from the outside; and an outer reinforcing layer (40) made of a fiber-reinforced resin and covering the inner reinforcing layer from the outside. The inner reinforcing layer has: a first covering portion (42) covering the first dome portion; a second covering portion (46) covering the second dome portion; and a third covering portion (44) covering the main body portion. A first edge surface (501) of the first covering portion facing the third covering portion abuts against a second edge surface (521) of the third covering portion facing the first covering portion, and a third edge surface (522) of the third covering portion facing the second covering portion abuts against a fourth edge surface (502) of the second covering portion facing the third covering portion. The outer reinforcing layer covers the first covering portion, the third covering portion, and the second covering portion from the outside.

[0097] In this structure, by fabricating the third covering portion with an appropriate length and providing an outer reinforcing layer outside the inner reinforcing layer, a reinforcing layer of a desired length can be obtained. Then, a hollow preform having a length matching the length of the reinforcing layer is expanded within the reinforcing layer. Accordingly, a high-pressure vessel of a desired length can be obtained.

[0098] Preferably, the first edge surface, the second edge surface, the third edge surface, and the fourth edge surface are conical inclined surfaces. In this case, misalignment of the first covering portion relative to the third covering portion is less likely to occur. Similarly, misalignment of the second covering portion relative to the third covering portion is less likely to occur. That is, the first covering portion, the third covering portion, and the second covering portion can be easily arranged in a straight line.

[0099] Preferably, a lubricating layer (53) is formed on the inner wall of the inner reinforcing layer facing the inner container. The lubricating layer inhibits the inner container from adhering to the inner reinforcing layer. When the inner container is made of resin and stores a gas with a small molecular radius such as hydrogen, the gas permeates through the inner container. Since the inner container is not adhered to the inner reinforcing layer, the gas can easily stay between the inner container and the inner reinforcing layer.

[0100] In addition, according to another embodiment, a method for manufacturing a high-pressure vessel (10) is provided. The high-pressure vessel (10) has a hollow inner liner (12) and a reinforcing layer (14) covering the inner liner from the outside. The method for manufacturing the high-pressure vessel (10) includes a first molding step (S10), a second molding step (S20), a pre-assembly step (S30), a reinforcing layer forming step (S40), an insertion step (S50), and an inner liner molding step (S60). In the first molding step (S10), a resin-impregnated reinforcing fiber (47) is wound around a first molding die (70) to mold a cylindrical body (76) made of a fiber-reinforced resin. In the second molding step (S20), a resin-impregnated reinforcing fiber is wound around a second molding die (90) to simultaneously mold a first covering portion (42) and a second covering portion (46) made of a fiber-reinforced resin. In the pre-assembly step (S30), a part or all of the cylindrical body is used as a third covering portion (44), and a first edge surface (501) of the first covering portion facing the third covering portion is brought into contact with a second edge surface (521) of the third covering portion facing the first covering portion, and a third edge surface (522) of the third covering portion facing the second covering portion is brought into contact with a fourth edge surface (502) of the second covering portion facing the third covering portion to pre-assemble an inner reinforcing layer (38) having the first covering portion, the third covering portion, and the second covering portion. In the reinforcing layer forming step (S40), a resin-impregnated reinforcing fiber is wound around the inner reinforcing layer to obtain an outer reinforcing layer (40) covering the inner reinforcing layer from the outside, thereby obtaining a reinforcing layer having the inner reinforcing layer and the outer reinforcing layer. In the insertion step (S50), a hollow preform (110) is inserted into the inner reinforcing layer through a first opening (481, 482) formed in the first covering portion or the second covering portion and a second opening (541, 542) formed in the outer reinforcing layer and overlapping with the first opening. In the inner liner molding step (S60), after supplying gas into the hollow preform to expand the hollow preform, the expanded hollow preform is cured to obtain an inner liner having a first dome portion (16), a main body portion (18), and a second dome portion (20), and the outside of the first dome portion is covered by the first covering portion, the outside of the main body portion is covered by the third covering portion, and the outside of the second dome portion is covered by the second covering portion.

[0101] In this manufacturing method, the cylindrical body molded in the first molding step can be obtained in an arbitrary length. For example, when manufacturing a long cylindrical body, a long hollow preform can be expanded in the reinforcing layer to obtain a long high-pressure vessel. On the contrary, when manufacturing a short cylindrical body, a short hollow preform can be expanded in the reinforcing layer to obtain a short high-pressure vessel.

[0102] In this embodiment, after the reinforcing layer of a desired length is fabricated, a hollow preform having a length matching that of the reinforcing layer is used to form the inner liner. Therefore, it is not necessary to prepare molding dies of various shapes or sizes. As a result, reduction in equipment investment can be achieved. In addition, a space for storing a plurality of molding dies is not required. Therefore, space saving of the manufacturing station for high-pressure vessels can also be achieved.

[0103] Preferably, when curing the expanded hollow preform, a cooling gas having a temperature lower than the gas supplied when expanding the hollow preform and a pressure higher than that is supplied. Since the temperature of the cooling gas is low, cooling (curing) of the hollow preform is promoted. In addition, in the case where there is a portion where the expansion of the hollow preform is insufficient, the portion can be expanded before the portion is cured. This is because the pressure of the cooling gas is high. That is, the shape of the hollow preform can be corrected.

[0104] The cylindrical body obtained in the first molding step may be divided into a plurality of divided pieces (78). In this case, one divided piece is used as the third covering portion to pre-assemble the inner reinforcing layer. Accordingly, a plurality of third covering portions having desired lengths can be obtained by one first molding step.

[0105] In this case, preferably, after the first molding step, a second edge surface and a third edge surface processing step (S15) are performed on each divided piece. That is, the second edge surface and the third edge surface of the third covering portion are processed into conical inclined surfaces. In addition, preferably, after the second molding step, a first edge surface and a fourth edge surface processing step (S25) are performed on the first covering portion and the second covering portion. That is, the first edge surface of the first covering portion and the fourth edge surface of the second covering portion are processed into conical inclined surfaces. In the pre-assembly step, the first edge surface is brought into contact with the second edge surface, and the third edge surface is brought into contact with the fourth edge surface. Accordingly, displacement of the first covering portion relative to the third covering portion is less likely to occur. Similarly, displacement of the second covering portion relative to the third covering portion is less likely to occur.

[0106] The entire cylindrical body can also be used as the third covering portion. In this case, preferably, when the resin-impregnated reinforcing fiber (impregnated fiber) is wound around the first molding die to obtain a cylindrical body, the thicknesses of both end portions in the longitudinal direction of the cylindrical body are made smaller, and the thickness becomes larger as it approaches the middle portion in the longitudinal direction of the cylindrical body. Accordingly, in the first molding step, a cylindrical body having a second edge surface and a third edge surface formed of conical inclined surfaces can be obtained.

[0107] Specifically, after winding the impregnated fiber around the first forming die to form the lower layer (80), the upper layer (82) is laminated. At this time, the winding start position of the upper layer is closer to the middle part in the longitudinal direction than the winding start position of the lower layer. By repeating this operation, the thickness at both ends in the longitudinal direction of the cylindrical body is smaller, and the thickness increases as it approaches the middle part in the longitudinal direction of the cylindrical body.

[0108] Alternatively, a sheet body (84) whose size in the width direction orthogonal to the longitudinal direction gradually decreases is used. In this case, in the first forming process, the side with the longer dimension in the width direction of the sheet body is wound around the first forming die as the front end. As the winding progresses, the end in the width direction of the upper layer is closer to the middle part in the longitudinal direction of the cylindrical body than the end in the width direction of the lower layer. Therefore, by repeatedly winding, the thickness at both ends in the longitudinal direction of the cylindrical body is smaller, and the thickness increases as it approaches the middle part in the longitudinal direction of the cylindrical body.

[0109] In either case, there is no need to perform the second edge surface and the third edge surface processing steps. In addition, preferably, corresponding to forming the second edge surface and the third edge surface into conical inclined surfaces, the first edge surface of the first covering part and the fourth edge surface of the second covering part are formed into conical inclined surfaces. That is, after the second forming process, the first edge surface and the fourth edge surface processing step (S25) of processing the first edge surface and the fourth edge surface into conical inclined surfaces is performed.

[0110] In addition, as a specific method for obtaining the cylindrical body, a sheet winding method or a fiber winding method is exemplified.

[0111] Preferably, before performing the insertion process, a lubricant (102) is applied to the inner wall of the inner reinforcing layer (coating process). Thereby, adhesion of the inner bladder to the inner reinforcing layer is suppressed. Therefore, when the inner bladder is made of resin, the gas passing through the inner bladder easily enters between the inner bladder and the inner reinforcing layer. In addition, in the inner bladder forming process, the outer wall of the expanded hollow preform slides relative to the inner wall of the inner reinforcing layer. Therefore, the portion of the hollow preform that abuts against the inner wall of the inner reinforcing layer can extend along the surface direction. Therefore, the hollow preform can further expand.

[0112] As a result, an inner bladder with insufficient deformation is avoided. That is, it is prevented that the inner bladder has different thicknesses depending on the location. In addition, it is also possible to prevent the inner bladder from being distorted in shape.

[0113] In addition, the present invention is not limited to the above-described embodiments, and various structures can be adopted without departing from the gist of the present invention.

[0114] For example, it is not particularly necessary to dispose the second interface 242 on the second circular top 20. In this case, the central portions in the radial direction of the second circular top 20 and the second covering portion 46 are closed ends. Blow molding is performed using a hollow preform having a closed end at the second end to obtain the high-pressure vessel 10.

[0115] It is also possible to install a valve instead of installing the first inner interface 261 (or the second inner interface 262) on the first outer interface 281 (or the second outer interface 282).

Claims

1. A high-pressure vessel (10) having a hollow inner container (12), a reinforcing layer (14) covering the inner container from the outside, and an interface (241) provided separately from the inner container, characterized in that, the inner container has: a cylindrical main body portion (18); and a first circular top portion (16) and a second circular top portion (20) respectively connected to both ends of the main body portion in the longitudinal direction, the reinforcing layer has: an inner reinforcing layer (38) made of fiber-reinforced resin and covering the inner container from the outside; and an outer reinforcing layer (40) made of fiber-reinforced resin and covering the inner reinforcing layer from the outside, the inner reinforcing layer has: a first covering portion (42) covering the first circular top portion; a second covering portion (46) covering the second circular top portion; and a third covering portion (44) covering the main body portion, a first edge surface (501) of the first covering portion facing the third covering portion abuts against a second edge surface (521) of the third covering portion facing the first covering portion, and a third edge surface (522) of the third covering portion facing the second covering portion abuts against a fourth edge surface (502) of the second covering portion facing the third covering portion, the outer reinforcing layer covers the first covering portion, the third covering portion, and the second covering portion from the outside, at least one of the first circular top portion or the second circular top portion integrally has a cylindrical portion that extends away from the main body portion starting from the central portion in the radial direction of the first circular top portion or the second circular top portion, the interface has an inner interface (261) and an outer interface (281), wherein the outer peripheral portion of the inner interface abuts against the inner peripheral portion of the cylindrical portion, and the inner peripheral portion of the outer interface abuts against the outer peripheral portion of the cylindrical portion.

2. The high-pressure vessel according to claim 1, characterized in that, the first edge surface, the second edge surface, the third edge surface, and the fourth edge surface are conical inclined surfaces.

3. The high-pressure vessel according to claim 1, characterized in that, a lubricating layer (53) is formed on the inner wall of the inner reinforcing layer facing the inner container.

4. A manufacturing method of a high-pressure vessel (10) having a hollow inner container (12) and a reinforcing layer (14) covering the inner container from the outside, the manufacturing method of the high-pressure vessel (10) is characterized in that, it includes a first forming process (S10), a second forming process (S20), a pre-assembly process (S30), a reinforcing layer forming process (S40), an insertion process (S50), and an inner container forming process (S60), wherein, in the first forming process, a reinforcing fiber (47) impregnated with resin is wound around a first forming die (70) to form a cylindrical body (76) made of fiber-reinforced resin; in the second forming process, a reinforcing fiber impregnated with resin is wound around a second forming die (90) while forming a first covering portion (42) and a second covering portion (46) made of fiber-reinforced resin; In the pre-assembly process, a part or all of the cylindrical body is used as the third covering portion (44), the first edge surface (501) of the first covering portion facing the third covering portion is brought into contact with the second edge surface (521) of the third covering portion facing the first covering portion, and the third edge surface (522) of the third covering portion facing the second covering portion is brought into contact with the fourth edge surface (502) of the second covering portion facing the third covering portion, to pre-assemble the inner reinforcing layer (38) having the first covering portion, the third covering portion, and the second covering portion; In the reinforcing layer forming process, the reinforcing fiber impregnated with resin is wound around the inner reinforcing layer to obtain an outer reinforcing layer (40) covering the inner reinforcing layer from the outside, thereby obtaining a reinforcing layer having the inner reinforcing layer and the outer reinforcing layer; In the insertion process, the cylindrical hollow preform (110) is inserted into the inner reinforcing layer via a first opening (481, 482) formed in the first covering portion or the second covering portion and a second opening (541, 542) formed in the outer reinforcing layer and overlapping with the first opening; In the inner liner forming process, after supplying gas into the hollow preform to expand the hollow preform, the expanded hollow preform is cured to obtain an inner liner having a first dome portion (16), a main body portion (18), and a second dome portion (20), and the outside of the first dome portion is covered by the first covering portion, the outside of the main body portion is covered by the third covering portion, and the outside of the second dome portion is covered by the second covering portion; 5. The method for manufacturing a high-pressure vessel according to claim 4, wherein when curing the hollow preform, a cooling gas having a temperature lower than and a pressure higher than that of the gas supplied when expanding the hollow preform is supplied.

6. The method for manufacturing a high-pressure vessel according to claim 4, wherein the cylindrical body obtained in the first forming process is divided into a plurality of divided pieces (78), and in the pre-assembly process, one of the divided pieces is used as the third covering portion to pre-assemble the inner reinforcing layer.

7. The method for manufacturing a high-pressure vessel according to claim 6, wherein a second edge surface and third edge surface processing step (S15) and a first edge surface and fourth edge surface processing step (S25) are performed, wherein the second edge surface and third edge surface processing step is a step of processing the second edge surface and the third edge surface into conical inclined surfaces after the first forming process; the first edge surface and fourth edge surface processing step is a step of processing the first edge surface and the fourth edge surface into conical inclined surfaces after the second forming process.

8. The method for manufacturing a high-pressure vessel according to claim 4, wherein In the first molding step, when the reinforcing fiber impregnated with resin is wound around the first molding die to obtain the cylindrical body, the thicknesses of both end portions in the longitudinal direction of the cylindrical body are made smaller, and the thickness increases as it approaches the middle portion in the longitudinal direction of the cylindrical body, whereby the second edge surface and the third edge surface are formed as conical inclined surfaces, and, After the second molding step, a first edge surface and fourth edge surface processing step (S25) of processing the first edge surface and the fourth edge surface into conical inclined surfaces is performed. In the pre-assembly step, the entire cylindrical body is used as the third covering portion, and the inner reinforcing layer is pre-assembled using the first covering portion and the second covering portion that have undergone the first edge surface and fourth edge surface processing step.

9. The method for manufacturing a high-pressure vessel according to claim 4, wherein: The cylindrical body is formed by a sheet winding method or a fiber winding method.

10. The method for manufacturing a high-pressure vessel according to claim 4, wherein: Before performing the insertion step, a coating step of coating a lubricant (102) on the inner wall of the inner reinforcing layer is performed.

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