Manufacturing method of high pressure tank

Abstract

To provide a manufacturing method of a pressure tank, the method capable of more securely counterbalancing a tensile force of a fiber bundle wound on a liner and an inner pressure of the liner and more securely curbing deformation of the liner.SOLUTION: A manufacturing method M of a pressure tank includes liner arrangement step S1, first fiber layer forming step S2, second fiber layer forming step S3, and curing step S5. The liner arrangement step S1 arranges a cylindrical part of a liner inside a fiber-reinforced resin tube. The first fiber layer forming step S2, in a state in which a first inner pressure is applied to the liner, arranges a fiber bundle to which a first tensile force is applied outside a dome part of the liner in a rotationally symmetrical pattern to form a first fiber layer. The second fiber layer forming step S3 applies to the liner a second inner pressure higher than the first inner pressure, winds on the outside of the dome part of the liner a fiber bundle to which a second tensile force higher than the first tensile force is applied, and forms a second fiber layer while counterbalancing the second inner pressure and the second tensile force to fit the dome part into a target shape. The curing step S5 forms a fiber-reinforced resin layer by curing hardening resin impregnated in the fiber bundle.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a method for manufacturing a high-pressure tank. [Background technology]

[0002] There are conventionally known manufacturing methods for high-pressure gas tanks. The high-pressure gas tank described in the following Patent Document 1 includes a liner which is a resin container, a fiber-reinforced resin layer formed on the outer surface of the liner, and a cap provided at both ends in the direction along the central axis (paragraph 0018 and FIG. 1 of the same document).

[0003] Furthermore, the manufacturing method of a high-pressure gas tank described in Patent Document 1 below includes a process of setting the internal pressure of the liner according to the number of fiber layers on the outer surface of the liner (paragraph 0020 and Figure 2 of the same document). In the process of setting the internal pressure of the liner, the internal pressure of the liner is increased as the number of fiber layers increases. Meanwhile, in the process of forming the third and subsequent fiber layers, the tension applied to the fiber bundle wound around the liner is gradually decreased (paragraphs 0038-0040 and Figure 3 of the same document).

[0004] Furthermore, the high-pressure tank described in Patent Document 2 below includes a liner, a reinforcing layer, and a mouthpiece. The liner includes a cylindrical portion extending in the axial direction and hemispherical dome portions on both sides of the cylindrical portion. The reinforcing layer covering the outer surface of the liner includes a hoop layer formed by hoop winding in which the winding angle of the fibers to the axis of the liner is approximately perpendicular, and a helical layer formed by helical winding in which the winding angle of the fibers is smaller than that of the hoop winding (paragraphs 0008 to 0013, Figures 1 and 2 of the same document). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2019-127968 A [Patent Document 2] JP 2020-122543 A Summary of the Invention [Problem to be solved by the invention]

[0006] When manufacturing a high-pressure tank, fibers impregnated with a curable resin are wound around the outside of the liner by hoop winding and helical winding, as described in the above-mentioned Patent Document 2. At this time, as described in Patent Document 1, the internal pressure of the liner is increased to suppress deformation of the liner due to the tension of the fibers.

[0007] However, if the tension of the fibers wound in a hoop around the outer periphery of the cylindrical portion of the liner is balanced with the internal pressure of the liner to suppress deformation of the liner, there is a risk that the balance between the tension of the fibers wound helically around the hoop-wound fibers and the internal pressure of the liner will be lost. If the balance between the tension of the fibers and the internal pressure of the liner is lost, there is a risk that the liner will deform and the pressure resistance of the high-pressure tank will decrease.

[0008] The present disclosure provides a method for manufacturing a high-pressure tank that can more reliably balance the tension of the fiber bundle wound around the liner and the internal pressure of the liner, thereby more reliably suppressing deformation of the liner. [Means for solving the problem]

[0009] One aspect of the present disclosure is a method for manufacturing a high-pressure tank including a liner having a dome portion at each of one and the other ends of a cylindrical portion, and a fiber-reinforced resin layer covering the outside of the liner, the method including: a liner arrangement step of arranging the cylindrical portion of the liner inside a fiber-reinforced resin pipe to expose the dome portion of the liner at each of one and the other ends of the fiber-reinforced resin pipe; and after the liner arrangement step, in a state in which a first internal pressure is applied to the liner, a fiber bundle that has been impregnated with a curable resin and given a first tension is helically wound around each of the dome portions of the liner and the outside of the fiber-reinforced resin pipe a plurality of times, and the fiber bundle is arranged on the outside of both dome portions in a pattern that is rotationally symmetrical with three or more times symmetry about a central axis of the liner to form a first fiber layer. a second fiber layer forming step of, after the first fiber layer forming step, applying a second internal pressure higher than the first internal pressure to the liner, and winding the fiber bundle, which has been impregnated with the curable resin and applied a second tension higher than the first tension, by helical winding a plurality of times around each of the dome portions of the liner and the outside of the fiber reinforced resin pipe so as to cover the first fiber layer, thereby forming a second fiber layer while balancing the second internal pressure and the second tension and shaping both dome portions into a target shape; and a hardening step of hardening the curable resin impregnated in the fiber bundle to integrate the first fiber layer and the second fiber layer with the fiber reinforced resin pipe, thereby forming the fiber reinforced resin layer.

[0010] In the method for manufacturing a high-pressure tank according to the above aspect, in the liner placement step, a liner is used that has a cylindrical portion and a pair of hemispherical dome portions at both ends of the cylindrical portion in the central axis direction. Then, a cylindrical fiber-reinforced resin pipe that has been molded in advance is placed on the outside of the cylindrical portion of the liner. As a result, the outside of the cylindrical portion of the liner is covered with the fiber-reinforced resin pipe, and the pair of dome portions located at both ends of the cylindrical portion in the central axis direction are exposed by protruding from both ends of the fiber-reinforced resin pipe.

[0011] In the first fiber layer forming process following the liner arrangement process, a first internal pressure is applied to the liner with a fiber reinforced resin pipe arranged outside the cylindrical part of the liner, and a fiber bundle impregnated with a curable resin and given a first tension is helically wound around the outer surfaces of the dome parts at both ends of the liner and the outer surfaces of the fiber reinforced resin pipes arranged outside the cylindrical part of the liner to form a first fiber layer.

[0012] Helical winding is a method of winding a fiber bundle around a liner, and compared to hoop winding, in which the fiber bundle is wound circumferentially around the liner at an angle close to 90° to the central axis of the liner, this is a method of winding the fiber bundle at a smaller angle to the central axis of the liner. The internal pressure of the liner suitable for hoop winding of the fiber bundle around the cylindrical part of the liner is not the same as the internal pressure of the liner suitable for helical winding of the fiber bundle around the dome part of the liner.

[0013] In the manufacturing method of the high-pressure tank according to the above aspect, a preformed fiber-reinforced resin pipe is disposed on the outside of the cylindrical portion of the liner in the first fiber layer forming step, and there is no need to wind the fiber bundle around the outside of the cylindrical portion of the liner by hoop winding. Therefore, the fiber bundle can be helically wound around the outside of the dome portion of the liner while balancing the first internal pressure applied to the liner and the first tension applied to the fiber bundle, and the shape of the dome portion can be made closer to the target shape when the first fiber layer is formed.

[0014] In the first fiber layer forming step, the first fiber layer is formed by arranging the fiber bundles in a pattern with three-fold or more rotational symmetry around the central axis of the liner on the outside of the dome portions at both ends of the liner, thereby reinforcing the dome portions at both ends of the liner with the fiber bundles of the first fiber layer wound evenly around the liner in the circumferential direction, and increasing the internal pressure of the liner to a second internal pressure higher than the first internal pressure.

[0015] In the second fiber layer forming process following the first fiber layer forming process, a second internal pressure higher than the first internal pressure is applied to the liner whose dome portions are reinforced by the first fiber layer, and a second tension higher than the first tension is applied to the fiber bundle impregnated with the curable resin. Then, the fiber bundle is helically wound multiple times around each of the dome portions of the liner and the outside of the fiber-reinforced resin pipe so as to cover the first fiber layer, and the second fiber layer is formed while balancing the second internal pressure and the second tension and shaping both dome portions into a target shape.

[0016] This makes it possible to more reliably balance the tension of the fiber bundle wound around the liner and the internal pressure of the liner, more reliably suppress deformation of the liner, and make the shape of the dome portion of the liner match the target shape. Finally, in the curing process, the curable resin impregnated in the fiber bundle is cured to integrate the first and second fiber layers with the fiber reinforced resin pipe to form a fiber reinforced resin layer, thereby manufacturing the high-pressure tank.

[0017] In addition, the manufacturing method of the high-pressure tank of the above aspect may further include a third fiber layer forming step of applying a third internal pressure higher than the second internal pressure to the liner after the second fiber layer forming step and before the curing step, winding the fiber bundle impregnated with the curable resin and applied with the second tension by helical winding a plurality of times around each of the dome portions of the liner and the outside of the fiber reinforced resin pipe so as to cover the second fiber layer, and forming a third fiber layer while balancing the third internal pressure and the second tension and shaping both dome portions into a target shape, and in the curing step, the first fiber layer, the second fiber layer, and the third fiber layer may be integrated with the fiber reinforced resin pipe to form the fiber reinforced resin layer.

[0018] In the third fiber layer forming process, a third internal pressure higher than the second internal pressure is applied to the liner, but the first fiber layer and the second fiber layer are formed in the dome portion. Therefore, if the tension applied to the fiber bundle wound around the dome portion is further increased, the balance between the internal pressure of the liner and the tension of the fiber bundle may be lost, causing the dome portion of the liner to deform inward. Therefore, in the third fiber layer forming process, the tension applied to the fiber bundle is maintained at the second tension in the second fiber layer forming process.

[0019] This makes it possible to more reliably balance the tension of the fiber bundle wound around the liner and the internal pressure of the liner, more reliably suppress deformation of the liner, and make the shape of the dome portion of the liner match the target shape. Finally, in the curing process, the curable resin impregnated in the fiber bundle is cured to integrate the first fiber layer, the second fiber layer, and the third fiber layer with the fiber reinforced resin pipe to form a fiber reinforced resin layer, thereby manufacturing the high-pressure tank. Effect of the Invention

[0020] According to the manufacturing method for a high-pressure tank according to the above-described aspect of the present disclosure, it is possible to provide a manufacturing method for a high-pressure tank that can more reliably balance the tension of the fiber bundle wound around the liner and the internal pressure of the liner, thereby more reliably suppressing deformation of the liner. [Brief description of the drawings]

[0021] [Figure 1] FIG. 2 is a cross-sectional view showing an example of the configuration of a high-pressure tank. [Diagram 2] FIG. 4 is a flow diagram showing a method for manufacturing a high-pressure tank according to an embodiment of the present disclosure. [Diagram 3] 3 is a graph showing the relationship between the internal pressure of the liner and the tension of the fiber bundle in each step of FIG. 2. [Figure 4] 3 is a side view showing an example of a first fiber layer formed in the first fiber layer forming step of FIG. 2. [Diagram 5] 3 is a side view showing an example of a first fiber layer formed in the first fiber layer forming step of FIG. 2. [Figure 6]3 is a side view showing an example of a first fiber layer formed in the first fiber layer forming step of FIG. 2. [Figure 7] 3 is a side view showing an example of a first fiber layer formed in the first fiber layer forming step of FIG. 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Hereinafter, an embodiment of the method for manufacturing a high-pressure tank according to the present disclosure will be described with reference to the drawings. Fig. 1 is a cross-sectional view showing an example of the configuration of a high-pressure tank 1 manufactured by the method for manufacturing a high-pressure tank according to the present disclosure.

[0023] The high-pressure tank 1 is used, for example, as an on-board hydrogen gas tank. The use of the high-pressure tank 1 is not particularly limited, and the tank may be filled with other gases, such as compressed natural gas (CNG), or with a liquid. The high-pressure tank 1 has a liner 11 and a fiber-reinforced resin layer 12. The high-pressure tank 1 also has, for example, nozzles 13 and 14.

[0024] The liner 11 is an inner container made of a resin having gas barrier properties, such as polyamide (PA) or ethylene-vinyl alcohol copolymer (EVOH). The thickness of the liner 11 is, for example, 2.5 mm or less when the material is PA, and is, for example, 1 mm or less when the material is EVOH. The diameter of the liner 11 is, for example, about 300 mm in the case of an on-vehicle hydrogen gas tank, but may be about 700 mm to 2000 mm in the case of other uses.

[0025] The liner 11 has a cylindrical portion 111 and a pair of dome portions 112. The cylindrical portion 111 is, for example, a cylindrical portion having a central axis C parallel to the longitudinal direction of the liner 11. The pair of dome portions 112 are hemispherical or elliptical spherical portions provided at one end and the other end in the direction of the central axis C of the cylindrical portion 111, respectively.

[0026] The liner 11 is molded, for example, in a state where it is divided into two parts at the center in the direction of the central axis C of the cylindrical portion 111, and is integrated by joining the molded first and second parts. An opening 112a is provided at the top of each dome portion 112 that intersects with the central axis C of the cylindrical portion 111 of the liner 11, i.e., the central axis C of the liner 11. A nozzle 13, 14 is joined to each opening 112a of the liner 11.

[0027] The fiber reinforced resin layer 12 is provided so as to cover the outside of the liner 11. The fiber reinforced resin layer 12 has, for example, a fiber reinforced resin pipe 121 and a surface layer portion 122. The fiber reinforced resin pipe 121 is manufactured, for example, by winding a fiber bundle impregnated with a curable resin around a metal mandrel in a hoop winding manner using a filament winding method, and curing the curable resin.

[0028] The fiber reinforced resin pipe 121 can be manufactured using, for example, a fiber bundle of reinforcing fibers such as glass fiber or carbon fiber. Here, hoop winding is a method of winding a fiber bundle in the circumferential direction of the liner 11 at an angle close to 90° with respect to the direction of the central axis C of the liner 11. The fiber reinforced resin pipe 121 is disposed on the outside of the cylindrical portion 111 of the liner 11 in a pre-manufactured state and joined to the liner 11 when the high-pressure tank 1 is manufactured.

[0029] The surface layer 122 is manufactured, for example, by winding a fiber bundle impregnated with a curable resin around the outside of both dome portions 112 of the liner 11 and the outside of the fiber reinforced resin tube 121 in a helical manner using a filament winding method, and then curing the curable resin. For example, a fiber bundle of reinforcing fibers such as glass fiber or carbon fiber can be used to manufacture the surface layer 122. Here, helical winding is a winding method in which the fiber bundle is wound at a smaller angle with respect to the direction of the central axis C of the liner 11, as compared to, for example, hoop winding.

[0030] The surface layer portion 122 includes, for example, a first fiber layer 122a and a second fiber layer 122b. The surface layer portion 122 may also include, for example, a third fiber layer 122c. The surface layer portion 122 may also include, for example, four or more fiber layers. A manufacturing method for the fiber layers of the surface layer portion 122 including the first fiber layer 122a, the second fiber layer 122b, and the third fiber layer 122c will be described later.

[0031] The nozzles 13 and 14 are metal members attached to the high-pressure tank 1. In the example shown in Fig. 1, one nozzle 13 has a fluid passage 131 that communicates between the inside and outside of the high-pressure tank 1, and the other nozzle 14 closes the opening 112a of the liner 11. Note that the high-pressure tank 1 can omit the nozzles 13 and 14 by using a liner 11 that has the opening 112a only at one end, for example.

[0032] The nozzle 13 having the fluid passage 131 is connected to, for example, a valve or the like and functions as a filling port for fluid from the outside to the inside of the high-pressure tank 1 and also functions as a supply port for fluid from the inside to the outside of the high-pressure tank 1. The nozzle 14 not having the fluid passage 131 functions as, for example, a support part for supporting the liner 11 during the manufacture of the high-pressure tank 1.

[0033] Hereinafter, an embodiment of a manufacturing method for a high-pressure tank according to the present disclosure will be described with reference to Fig. 2 to Fig. 7. Fig. 2 is a flow diagram showing an embodiment of a manufacturing method for a high-pressure tank according to the present disclosure. The manufacturing method M for a high-pressure tank of this embodiment is a method for manufacturing a high-pressure tank 1 including a liner 11 having dome portions 112 at one end and the other end of a cylindrical portion 111, and a fiber reinforced resin layer 12 covering the outside of the liner 11, as shown in Fig. 1, for example.

[0034] 2, the manufacturing method M of the high-pressure tank includes a liner arrangement step S1, a first fiber layer formation step S2, a second fiber layer formation step S3, and a hardening step S5. The manufacturing method M of the high-pressure tank may further include a third fiber layer formation step S4. In the manufacturing method M of the high-pressure tank of this embodiment, first, the liner arrangement step S1 is performed.

[0035] In the liner placement process S1, the cylindrical portion 111 of the liner 11 is placed inside a fiber reinforced resin pipe 121 that has been manufactured in advance, and the dome portion 112 of the liner 11 is exposed at one end and the other end of the fiber reinforced resin pipe 121. More specifically, for example, with the nozzles 13, 14 respectively joined to a pair of openings 112a of the liner 11, the liner 11 is supported via the nozzles 13, 14, and the liner 11 is inserted inside the fiber reinforced resin pipe 121. Then, the fiber reinforced resin pipe 121 is placed outside the cylindrical portion 111 of the liner 11, and the cylindrical portion 111 and the fiber reinforced resin pipe 121 are joined.

[0036] In the liner arrangement step S1, the liner 11 may be molded in a state in which it is divided into one part and the other part at the center in the direction of the central axis C, as described above. In this case, for example, the one part and the other part of the liner 11 are inserted from one end and the other end, respectively, of a fiber reinforced resin pipe 121 in which the hardening resin impregnated in the fiber bundle has been pre-hardened, and joined to each other inside the fiber reinforced resin pipe 121, and the hardening resin impregnated in the fiber bundle is hardened. In this way, the one part and the other part of the liner 11 and the liner 11 and the fiber reinforced resin pipe 121 are integrated.

[0037] Next, a first fiber layer forming step S2 is performed as shown in Fig. 2. Fig. 3 is a graph showing the relationship between the internal pressure P of the liner 11 and the tension T of the fiber bundle in the first fiber layer forming step S2, the second fiber layer forming step S3, and the third fiber layer forming step S4 in Fig. 2. Figs. 4 to 7 are side views showing an example of the first fiber layer 122a formed in the first fiber layer forming step S2 in Fig. 2.

[0038] In the first fiber layer forming step S2, with a first internal pressure P1 applied to the liner 11 after the liner arranging step S1, the fiber bundle FB impregnated with a curable resin and applied with a first tension T1 is helically wound multiple times around each of the dome portions 112 of the liner 11 and the outside of the fiber reinforced resin pipe 121. Then, the fiber bundle FB is arranged on the outside of both fiber reinforced resin pipes 121 in a pattern with three-fold or more rotational symmetry about the central axis C of the liner 11 to form a first fiber layer 122a.

[0039] More specifically, in the first fiber layer forming step S2, a first internal pressure P1 is applied to the liner 11 with the fiber reinforced resin pipe 121 disposed outside the cylindrical portion 111 of the liner 11. Then, the fiber bundle FB impregnated with a curable resin and applied with a first tension T1 is helically wound around the outer surfaces of the dome portions 112 at both ends of the liner 11 and the outer surface of the fiber reinforced resin pipe 121 disposed outside the cylindrical portion 111 of the liner 11 to form a first fiber layer 122a.

[0040] Here, the internal pressure P of the liner 11 suitable for hoop winding of the fiber bundle FB around the cylindrical portion 111 of the liner 11 is not the same as the internal pressure P of the liner 11 suitable for helical winding of the fiber bundle FB around the dome portion 112 of the liner 11. In the manufacturing method M of the high-pressure tank of this embodiment, in the first fiber layer formation step S2, a fiber reinforced resin pipe 121 manufactured in advance is placed on the outside of the cylindrical portion 111 of the liner 11, and there is no need to wind the fiber bundle FB around the outside of the cylindrical portion 111 of the liner 11 by hoop winding.

[0041] Therefore, the fiber bundle FB can be helically wound around the outside of the dome portion 112 of the liner 11 while balancing the first internal pressure P1 applied to the liner 11 and the first tension T1 applied to the fiber bundle FB. As a result, the shape of the dome portion 112 can be made closer to the target shape when the first fiber layer 122a is formed. The first internal pressure P1 and first tension T1 that can achieve such a target shape of the dome portion 112 vary depending on conditions such as the material, thickness, and diameter of the liner 11, or the width of the fiber bundle FB.

[0042] Therefore, the first internal pressure P1 and the first tension T1 in the first fiber layer forming step S2 can be calculated, for example, by computer simulation using the above conditions as parameters. Also, for example, the first fiber layer forming step S2 may be performed while measuring the shape of the dome portion 112 of the liner 11 by a method such as 3D scanning, thereby determining the first internal pressure P1 and the first tension T1 capable of achieving the target shape of the dome portion 112 by trial and error. In the manufacturing method M of the high-pressure tank of this embodiment, the internal pressure P of the liner 11 can be set so as not to exceed 1 MPa at most.

[0043] The first tension T1 can be determined, for example, so that the fibers of the fiber bundle FB are oriented as linearly as possible. That is, if the first tension T1 is too small, the fibers of the fiber bundle FB do not extend completely straight, and the strength of the fiber reinforced resin layer 12 decreases, which may reduce the strength development rate of the high-pressure tank 1. Therefore, the first tension T1 applied to the fiber bundle FB is determined within a range in which the fibers of the fiber bundle FB are oriented as linearly as possible and the target shape of the dome portion 112 can be achieved in equilibrium with the first internal pressure P1 when the first fiber layer 122a is formed.

[0044] In other words, the first tension T1 is determined within a range in which the strength development rate of the high-pressure tank 1 is 70% or more. Here, the strength development rate is the ratio of the actual breaking strength of the high-pressure tank 1 to the designed breaking strength of the high-pressure tank 1 in a state in which all the fibers constituting the fiber reinforced resin layer 12 are linearly oriented.

[0045] The first fiber layer 122a formed in the first fiber layer forming step S2 has a minimum configuration of an arrangement pattern of fiber bundles FB with three-fold rotational symmetry as shown in Fig. 4. In addition, as the first internal pressure P1 of the liner 11 increases, an arrangement pattern of fiber bundles FB with four-fold, six-fold, or eight-fold rotational symmetry can be adopted as shown in Figs. 5 to 7. Although not shown, the first fiber layer 122a can also adopt an arrangement pattern of fiber bundles FB with five-fold, seven-fold, nine-fold, or ten-fold or more rotational symmetry.

[0046] Next, as shown in Fig. 2, a second fiber layer forming step S3 is performed. In the second fiber layer forming step S3, after the first fiber layer forming step S2, a second internal pressure P2 higher than the first internal pressure P1 is applied to the liner 11. Then, the fiber bundle FB impregnated with a curable resin and applied with a second tension T2 higher than the first tension T1 is helically wound around each of the dome portions 112 of the liner 11 and the outside of the fiber reinforced resin tube 121 so as to cover the first fiber layer 122a. Then, the second internal pressure P2 and the second tension T2 are balanced to form the second fiber layer 122b while shaping both dome portions 112 into a target shape.

[0047] As described above, in the liner arrangement step S1, the first fiber layer 122a is formed by arranging the fiber bundles FB in a pattern that has three-fold or more rotational symmetry about the central axis C of the liner 11. Therefore, in the first fiber layer formation step S2, the dome portion 112 of the liner 11 is reinforced by the first fiber layer 122a, and the internal pressure P of the liner 11 can be increased from the first internal pressure P1 to the second internal pressure P2 while suppressing the expansion and deformation of the dome portion 112.

[0048] Furthermore, in the first fiber layer forming process S2, the tension T applied to the fiber bundle FB is increased from the first tension T1 to the second tension T2 in response to the internal pressure P of the liner 11 increasing from the first internal pressure P1 to the second internal pressure P2. This makes it possible to more reliably balance the tension T of the fiber bundle FB wound around the liner 11 and the internal pressure P of the liner 11, more reliably suppress deformation of the liner 11, and make it possible to match the shape of the dome portion 112 of the liner 11 with the target shape.

[0049] Here, the second internal pressure P2 and the second tension T2 in the second fiber layer forming step S3 can be determined by computer simulation or trial and error, similar to the first internal pressure P1 and the first internal pressure P1 in the first fiber layer forming step S2. Similarly to the first tension T1, the second tension T2 is determined within a range in which the fibers of the fiber bundle FB are oriented as linearly as possible and the target shape of the dome section 112 can be achieved in equilibrium with the second internal pressure P2 during the formation of the second fiber layer. In other words, the second tension T2 is determined within a range in which the strength development rate of the high-pressure tank 1 is 70% or more, for example.

[0050] Next, as shown in Fig. 2, a third fiber layer forming step S4 is performed. In the third fiber layer forming step S4, after the second fiber layer forming step S3 and before the curing step S5, a third internal pressure P3 higher than the second internal pressure P2 is applied to the liner 11. Then, the fiber bundle FB impregnated with the curable resin and applied with the second tension T2 is helically wound multiple times around each of the dome portions 112 of the liner 11 and the outside of the fiber reinforced resin tube 121 so as to cover the second fiber layer. Then, the third internal pressure P3 and the second tension T2 are balanced to form the third fiber layer 122c while shaping both dome portions 112 into a target shape.

[0051] In the third fiber layer forming step S4, a third internal pressure P3 higher than the second internal pressure P2 is applied to the liner 11, but the first fiber layer 122a and the second fiber layer 122b are formed in the dome portion 112. Therefore, if the tension T applied to the fiber bundle FB wound around the dome portion 112 is further increased from the second tension T2, the balance between the internal pressure P of the liner 11 and the tension T of the fiber bundle FB is lost, and the dome portion 112 of the liner 11 may be deformed inward.

[0052] Therefore, in the third fiber layer forming process S4, the tension T applied to the fiber bundle FB is maintained at the second tension T2 in the second fiber layer forming process S3. This makes it possible to more reliably balance the tension T of the fiber bundle FB wound around the liner 11 and the internal pressure P of the liner 11, more reliably suppress deformation of the liner 11, and make it possible to match the shape of the dome portion 112 of the liner 11 with the target shape.

[0053] 2 is performed. In the curing step S5, the curable resin impregnated in the fiber bundle FB is cured to integrate the first fiber layer 122a and the second fiber layer 122b with the fiber reinforced resin pipe 121 to form the fiber reinforced resin layer 12. In this embodiment, in the curing step S5, the first fiber layer 122a, the second fiber layer 122b, and the third fiber layer 122c are integrated with the fiber reinforced resin pipe 121 to form the fiber reinforced resin layer 12.

[0054] More specifically, when the curable resin impregnated in the fiber bundle FB is a thermosetting resin, the curable resin impregnated in the fiber bundle FB is heated to be cured. On the other hand, when the curable resin impregnated in the fiber bundle FB is a thermoplastic resin, the curable resin impregnated in the fiber bundle FB is cooled to be cured. The curing step S5 may be performed in parallel with the first fiber layer forming step S2, the second fiber layer forming step S3, or the third fiber layer forming step S4, for example.

[0055] As described above, the manufacturing method M of the high-pressure tank of this embodiment is a method for manufacturing a high-pressure tank 1 including a liner 11 having dome portions 112 at one end and the other end of a cylindrical portion 111, and a fiber reinforced resin layer 12 covering the outside of the liner 11. The manufacturing method M of the high-pressure tank includes a liner arrangement step S1, a first fiber layer formation step S2, a second fiber layer formation step S3, and a curing step S5. In the liner arrangement step S1, the cylindrical portion 111 of the liner 11 is arranged inside a fiber reinforced resin pipe 121 to expose the dome portions 112 of the liner 11 at one end and the other end of the fiber reinforced resin pipe 121. In the first fiber layer formation step S2, a first internal pressure P1 is applied to the liner 11 after the liner arrangement step S1. Furthermore, in this state, the fiber bundle FB impregnated with the curable resin and given a first tension T1 is wound helically around each of the dome portions 112 of the liner 11 and the outside of the fiber reinforced resin tube 121 multiple times. Then, the fiber bundle FB is arranged on the outside of both dome portions 112 in a pattern of three-fold or more rotational symmetry around the central axis C of the liner 11 to form the first fiber layer 122a. In the second fiber layer forming step S3, a second internal pressure P2 higher than the first internal pressure P1 is applied to the liner 11 after the first fiber layer forming step S2. Then, the fiber bundle FB impregnated with the curable resin and given a second tension T2 higher than the first tension T1 is wound helically around each of the dome portions 112 of the liner 11 and the outside of the fiber reinforced resin tube 121 multiple times to cover the first fiber layer 122a. Then, the second fiber layer 122b is formed while balancing the second internal pressure P2 and the second tension T2 to shape both dome portions 112 into the target shape. In the curing process S5, the curable resin impregnated in the fiber bundle FB is cured to integrate the first fiber layer 122a and the second fiber layer 122b with the fiber reinforced resin pipe 121, thereby forming the fiber reinforced resin layer 12.

[0056] The manufacturing method M of the high-pressure tank of this embodiment further includes a third fiber layer forming step S4 after the second fiber layer forming step S3 and before the curing step S5. In the third fiber layer forming step S4, a third internal pressure P3 higher than the second internal pressure P2 is applied to the liner 11. Then, the fiber bundle FB impregnated with the curable resin and given the second tension T2 is helically wound around the outside of each of the dome parts 112 of the liner 11 and the fiber reinforced resin pipe 121 to cover the second fiber layer 122b. Then, the third fiber layer 122c is formed while balancing the third internal pressure P3 and the second tension T2 and shaping both dome parts 112 into a target shape. In the manufacturing method M of the high-pressure tank of this embodiment, in the curing step S5, the first fiber layer 122a, the second fiber layer 122b, and the third fiber layer 122c are integrated with the fiber reinforced resin pipe 121 to form the fiber reinforced resin layer 12.

[0057] Therefore, according to the manufacturing method M of the high-pressure tank of this embodiment, the tension T of the fiber bundle FB wound around the liner 11 and the internal pressure P of the liner 11 can be more reliably balanced, and deformation of the liner 11 can be more reliably suppressed.

[0058] The above describes in detail an embodiment of the manufacturing method for a high-pressure tank according to the present disclosure using the drawings, but the specific configuration is not limited to this embodiment, and even if there are design changes, etc., within the scope that does not deviate from the gist of the present disclosure, they are included in the present disclosure. [Explanation of symbols]

[0059] 1. High pressure tank 11 Raina 111 Cylindrical part 112 Dome section 12 Fiber reinforced resin layer 121 Fiber-reinforced plastic pipe 122a First fiber layer 122b Second fiber layer 122c Third fiber layer C center axis FB Fiber bundle M High-pressure tank manufacturing method P1 First internal pressure P2 Second internal pressure P3 3rd internal pressure S1 Liner placement process S2 First fiber layer formation process S3 Second fiber layer forming process S4 Third fiber layer formation process S5 hardening process T1 1st tension T2 2nd tension

Claims

1. A method for manufacturing a high-pressure tank including a liner having a cylindrical portion with a dome portion at each end and a fiber-reinforced resin layer covering the outside of the liner, comprising the steps of: a liner placement process for placing the cylindrical portion of the liner inside a fiber reinforced resin pipe and exposing the dome portion of the liner at one end and the other end of the fiber reinforced resin pipe; a first fiber layer forming step of helically winding a fiber bundle impregnated with a curable resin and given a first tension around each of the dome portions of the liner and the outside of the fiber reinforced resin pipe a plurality of times while applying a first internal pressure to the liner after the liner arrangement step, and arranging the fiber bundle around the outside of both dome portions in a pattern with three-fold or more rotational symmetry about the central axis of the liner to form a first fiber layer; a second fiber layer forming step of applying a second internal pressure higher than the first internal pressure to the liner after the first fiber layer forming step, winding the fiber bundle impregnated with the curable resin and applied with a second tension higher than the first tension by helical winding a plurality of times around each of the dome portions of the liner and the outside of the fiber reinforced resin pipe so as to cover the first fiber layer, and forming a second fiber layer while balancing the second internal pressure and the second tension and shaping both dome portions into a target shape; and a curing step of curing the curable resin impregnated in the fiber bundle to integrate the first fiber layer and the second fiber layer with the fiber reinforced resin pipe to form the fiber reinforced resin layer.

2. a third fiber layer forming step of applying a third internal pressure higher than the second internal pressure to the liner after the second fiber layer forming step and before the curing step, winding the fiber bundle impregnated with the curable resin and applied with the second tension by helical winding a plurality of times around each of the dome portions of the liner and the outside of the fiber-reinforced resin pipe so as to cover the second fiber layer, and forming a third fiber layer while balancing the third internal pressure and the second tension and shaping both dome portions into a target shape, 2. The method for manufacturing a high-pressure tank according to claim 1, wherein in the hardening step, the first fiber layer, the second fiber layer, and the third fiber layer are integrated with the fiber reinforced resin pipe to form the fiber reinforced resin layer.

Images