Method for manufacturing a high-pressure tank

Abstract

The present disclosure provides a method for manufacturing a high-pressure tank. The method for manufacturing a high-pressure tank includes a liner configuration step, a first fiber layer formation step, a second fiber layer formation step, and a curing step. In the liner configuration step, a cylindrical portion of the liner is disposed inside the fiber-reinforced resin tube. In the first fiber layer formation step, in a state where a first internal pressure is applied to the liner, a fiber bundle to which a first tension is applied is disposed in a rotationally symmetric pattern outside the dome portion of the liner to form a first fiber layer. In the second fiber layer formation step, a second internal pressure higher than the first internal pressure is applied to the liner, and a fiber bundle to which a second tension higher than the first tension is applied is wound around the outside of the dome portion of the liner, and the second internal pressure and the second tension are balanced to shape the dome portion into a target shape and simultaneously form a second fiber layer. In the curing step, a fiber-reinforced resin layer is formed by curing a curable resin impregnated in the fiber bundle.

Description

Technical Field

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

[0002] Conventionally, a method for manufacturing a high-pressure gas tank has been known. The high-pressure gas tank described in Patent Document 1 below includes a liner as a resin container, a fiber-reinforced resin layer formed on the outer surface of the liner, and tube heads provided at both ends in the direction along the central axis (paragraphs 0018 and Figure 1 ).

[0003] In addition, the method for manufacturing a high-pressure gas tank described in Patent Document 1 below includes a step of setting the internal pressure of the liner according to the number of layers of the fiber layer on the outer surface of the liner (paragraphs 0020 and Figure 2 ). In the step of setting the internal pressure of the liner, the internal pressure of the liner is increased as the number of layers of the fiber layer increases. On the other hand, in the step of forming the fiber layer after the third layer, the tension applied to the fiber bundle wound around the liner is gradually reduced (paragraphs 0038 to 0040 and Figure 3 ).

[0004] In addition, the high-pressure tank described in Patent Document 2 below includes a liner, a reinforcing layer, and tube heads. The liner includes a cylindrical portion extending in the axial direction and hemispherical dome portions on both sides thereof. The reinforcing layer covering the outer surface of the liner includes a circumferential layer formed by a circumferential winding method in which the winding angle of the fiber with respect to the axis of the liner is substantially a right angle, and a spiral layer formed by a spiral winding method in which the winding angle of the fiber is smaller than the circumferential winding method (paragraphs 0008 to 0013, Figure 1 and Figure 2 ).

[0005]

Prior Art Documents

[0006]

Patent Documents

[0007]

Patent Document 1

[0008]

Patent Document 2

[0009]

Outline of the Invention

[0010]

Problems to be Solved by the Invention

[0011] In the manufacture of a high-pressure tank, as described in Patent Document 2 above, fibers impregnated with a curable resin are wound around the outside of the liner in a circumferential winding manner and a helical winding manner. At this time, as described in Patent Document 1, in order to suppress the deformation of the liner caused by the tension of the fibers, the internal pressure of the liner is increased.

[0012] However, if the tension of the fibers wound circumferentially around the outer periphery of the cylindrical portion of the liner is balanced with the internal pressure of the liner to suppress the deformation of the liner, the balance between the tension of the fibers wound helically on the circumferentially wound fibers and the internal pressure of the liner may be broken. If the balance between the tension of the fibers and the internal pressure of the liner is broken, the liner may deform and the pressure resistance of the high-pressure tank may decrease.

[0013] The present disclosure provides a method for manufacturing a high-pressure tank that can more reliably balance the tension of a fiber bundle wound around a liner with the internal pressure of the liner, and can more reliably suppress the deformation of the liner.

[0014]

Solution to the Problem

[0015] One aspect of the present disclosure provides a method for manufacturing a high-pressure tank, which is a method for manufacturing a high-pressure tank including: a liner having dome portions at one end and the other end of a cylindrical portion; and a fiber-reinforced resin layer covering the outside of the liner. The method for manufacturing the high-pressure tank is characterized by including: a liner arranging step of arranging the cylindrical portion of the liner inside a fiber-reinforced resin tube, and exposing the dome portions of the liner at one end and the other end of the fiber-reinforced resin tube; a first fiber layer forming step of, after the liner arranging step, in a state where a first internal pressure is applied to the liner, 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 tube in a helical winding manner for multiple turns, and arranging the fiber bundle in a pattern of rotational symmetry of three-fold symmetry or more centered on the central axis of the liner outside both of the dome portions 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, winding the fiber bundle impregnated with the curable resin and given a second tension higher than the first tension around each of the dome portions of the liner and the outside of the fiber-reinforced resin tube in a helical winding manner so as to cover the first fiber layer for multiple turns, balancing the second internal pressure with the second tension to shape both of the dome portions into a target shape and simultaneously forming a second fiber layer; and a curing step of curing the curable resin impregnated in the fiber bundle, thereby integrating the first fiber layer and the second fiber layer with the fiber-reinforced resin tube to form the fiber-reinforced resin layer.

[0016] In the method for manufacturing a high-pressure tank according to the above-described one embodiment, in the liner arrangement step, a liner having a cylindrical portion with a cylindrical shape and a pair of hemispherical dome portions at both ends in the central axis direction of the cylindrical portion is used. And, a preformed cylindrical fiber-reinforced resin tube is arranged outside the cylindrical portion of the liner. As a result, the liner is in a state where the outside of the cylindrical portion is covered with the fiber-reinforced resin tube and a pair of dome portions located at both ends in the central axis direction of the cylindrical portion protrude from both ends of the fiber-reinforced resin tube and are exposed.

[0017] In the subsequent first fiber layer formation step of the liner arrangement step, with the fiber-reinforced resin tube arranged outside the cylindrical portion of the liner, a first internal pressure is applied to the liner. And, a fiber bundle impregnated with a curable resin and given a first tension is wound around the outer surfaces of the dome portions at both ends of the liner and the outer surface of the fiber-reinforced resin tube arranged outside the cylindrical portion of the liner in a helical winding manner to form a first fiber layer.

[0018] Helical winding is one of the methods of winding a fiber bundle around a liner. It is a winding method in which the fiber bundle is wound around the liner at a smaller angle with respect to the central axis direction of the liner compared to circumferential winding in which the fiber bundle is wound around the liner in the circumferential direction at an angle close to 90° with respect to the central axis direction of the liner. The internal pressure of the liner suitable for the circumferential winding of the fiber bundle around the cylindrical portion of the liner is different from the internal pressure of the liner suitable for the helical winding of the fiber bundle around the dome portion of the liner.

[0019] In the method for manufacturing a high-pressure tank according to the above-described one embodiment, in the first fiber layer formation step, a preformed fiber-reinforced resin tube is arranged outside the cylindrical portion of the liner, and it is not necessary to wind the fiber bundle around the cylindrical portion of the liner in a circumferential winding manner. Therefore, in a state where the first internal pressure applied to the liner is balanced with the first tension applied to the fiber bundle, the fiber bundle can be wound around the outside of the dome portion of the liner in a helical winding manner, and the shape of the dome portion can be made close to the target shape when forming the first fiber layer.

[0020] In addition, in the first fiber layer formation step, outside the dome portions at both ends of the liner, the fiber bundle is arranged using a rotationally symmetric pattern with three-fold symmetry or more centered on the central axis of the liner to form the first fiber layer. As a result, by strengthening each of the dome portions at one end and the other end of the liner with the fiber bundles of the first fiber layer wound evenly in the circumferential direction of the liner, the internal pressure of the liner can be increased to a second internal pressure higher than the first internal pressure.

[0021] In the second fiber layer forming step after the first fiber layer forming step, a second internal pressure higher than the first internal pressure is applied to the lining strengthened by the first fiber layer at the dome top, 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 wound around each dome top of the lining and the outside of the fiber reinforced resin tube in a spiral winding manner to cover the first fiber layer for multiple turns, and the second internal pressure and the second tension are balanced to shape both dome tops into the target shape and simultaneously form the second fiber layer.

[0022] Thereby, the tension of the fiber bundle wound around the lining can be more reliably balanced with the internal pressure of the lining, the deformation of the lining can be more reliably suppressed, and the shape of the dome top of the lining can be made to coincide with the target shape. Finally, in the curing step, the curable resin impregnated in the fiber bundle is cured, whereby the first fiber layer and the second fiber layer are integrated with the fiber reinforced resin tube to form a fiber reinforced resin layer, and a high-pressure tank can be manufactured.

[0023] In addition, in the method for manufacturing a high-pressure tank of the above solution, it may be that after the second fiber layer forming step and before the curing step, the method for manufacturing the high-pressure tank further includes a third fiber layer forming step. In this third fiber layer forming step, a third internal pressure higher than the second internal pressure is applied to the lining, and the fiber bundle impregnated with the curable resin and given the second tension is wound around each dome top of the lining and the outside of the fiber reinforced resin tube in a spiral winding manner to cover the second fiber layer for multiple turns, and the third internal pressure and the second tension are balanced to shape both dome tops into the target shape and simultaneously form the third fiber layer. In the curing step, the first fiber layer, the second fiber layer, and the third fiber layer are integrated with the fiber reinforced resin tube to form the fiber reinforced resin layer.

[0024] In the third fiber layer forming step, a third internal pressure higher than the second internal pressure is applied to the lining, but the first fiber layer and the second fiber layer are formed at the dome top. Therefore, if the tension applied to the fiber bundle wound around the dome top is further increased here, the balance between the internal pressure of the lining and the tension of the fiber bundle is broken and the dome top of the lining may deform inward. Therefore, in the third fiber layer forming step, the tension applied to the fiber bundle is maintained at the second tension in the second fiber layer forming step.

[0025] Thereby, the tension of the fiber bundle wound around the lining can be more reliably balanced with the internal pressure of the lining, the deformation of the lining can be more reliably suppressed, and thus the shape of the dome top of the lining can be made to coincide with the target shape. Finally, in the curing step, the curable resin impregnated in the fiber bundle is cured, whereby the first fiber layer, the second fiber layer, and the third fiber layer can be integrated with the fiber reinforced resin tube to form a fiber reinforced resin layer, and a high-pressure tank is manufactured.

[0026]

Advantages of the Invention

[0027] According to the method for manufacturing a high-pressure tank according to the above-described aspect of the present disclosure, it is possible to provide 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 and more reliably suppress deformation of the liner. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a cross-sectional view showing an example of the structure of a high-pressure tank.

[0029] Figure 2 It is a flowchart showing a method for manufacturing a high-pressure tank according to an embodiment of the present disclosure.

[0030] Figure 3 It shows Figure 2 a coordinate diagram showing the relationship between the internal pressure of the liner and the tension of the fiber bundle in each process.

[0031] Figure 4 It is a side view showing an example of the first fiber layer formed by Figure 2 the first fiber layer forming process.

[0032] Figure 5 It is a side view showing an example of the first fiber layer formed by Figure 2 the first fiber layer forming process.

[0033] Figure 6 It is a side view showing an example of the first fiber layer formed by Figure 2 the first fiber layer forming process.

[0034] Figure 7 It is a side view showing an example of the first fiber layer formed by Figure 2 the first fiber layer forming process.

[0035]

Description of the Reference Numerals

[0036] 1 High-pressure tank

[0037] 11 Liner

[0038] 111 Cylindrical portion

[0039] 112 Dome portion

[0040] 12 Fiber-reinforced resin layer

[0041] 121 Fiber-reinforced resin tube

[0042] 122a First fiber layer

[0043] 122b Second fiber layer

[0044] 122c third fiber layer

[0045] C central axis

[0046] FB fiber bundle

[0047] M manufacturing method of autoclave

[0048] P1 first internal pressure

[0049] P2 second internal pressure

[0050] P3 third internal pressure

[0051] S1 liner configuration process

[0052] S2 first fiber layer formation process

[0053] S3 second fiber layer formation process

[0054] S4 third fiber layer formation process

[0055] S5 curing process

[0056] T1 first tension

[0057] T2 second tension Detailed implementation manners

[0058] Hereinafter, with reference to the drawings, an embodiment of the manufacturing method of the autoclave of the present disclosure will be described. Figure 1 It is a cross-sectional view showing an example of the structure of the autoclave 1 manufactured by the manufacturing method of the autoclave of the present disclosure.

[0059] The autoclave 1 is used, for example, as a hydrogen tank for vehicles. It should be noted that the use of the autoclave 1 is not particularly limited. For example, it can be filled with other gases such as compressed natural gas (CNG), or it can be filled with liquid. The autoclave 1 has a liner 11 and a fiber reinforced resin layer 12. Moreover, the autoclave 1 has, for example, pipe heads 13 and 14.

[0060] The liner 11 is, for example, an inner container made of a gas barrier resin such as polyamide (PA) or ethylene-vinyl alcohol copolymer (EVOH). When the raw material is PA, the thickness of the liner 11 is, for example, 2.5 mm or less, and when the raw material is EVOH, the thickness of the liner 11 is, for example, 1 mm or less. In the case of a hydrogen tank for vehicles, the diameter of the liner 11 is, for example, about 300 mm, but in the case of other uses, the diameter of the liner 11 may sometimes be about 700 mm to 2000 mm.

[0061] The lining 11 has a cylindrical portion 111 and a pair of dome portions 112. The cylindrical portion 111 is, for example, a cylindrical part having a central axis C parallel to the longitudinal direction of the lining 11. The pair of dome portions 112 are hemispherical or ellipsoidal parts provided at one end and the other end in the direction of the central axis C of the cylindrical portion 111, respectively.

[0062] The lining 11 is integrally formed, for example, by being formed in a state of being divided into two parts at the central portion in the direction of the central axis C of the cylindrical portion 111 and joining the formed first part and the second part. Openings 112a are provided at the tops of the respective dome portions 112 that intersect the central axis C of the cylindrical portion 111 of the lining 11, that is, the central axis C of the lining 11. Pipe heads 13 and 14 are joined to the respective openings 112a of the lining 11.

[0063] The fiber reinforced resin layer 12 is provided so as to cover the outside of the lining 11. The fiber reinforced resin layer 12 has, for example, a fiber reinforced resin tube 121 and a surface layer portion 122. For example, a fiber bundle impregnated with a curable resin is wound around a metal mandrel by hoop winding based on the filament winding method, and the curable resin is cured to manufacture the fiber reinforced resin tube 121.

[0064] For the manufacture of the fiber reinforced resin tube 121, a fiber bundle of reinforcing fibers such as glass fiber or carbon fiber can be used, for example. Here, hoop winding is a method of winding the fiber bundle along the circumferential direction of the lining 11 at an angle close to 90° with respect to the direction of the central axis C of the lining 11. At the time of manufacturing the autoclave 1, the fiber reinforced resin tube 121 is arranged in a pre-manufactured state on the outside of the cylindrical portion 111 of the lining 11 and joined to the lining 11.

[0065] For example, a fiber bundle impregnated with a curable resin is wound around the outside of the two dome portions 112 of the lining 11 and the outside of the fiber reinforced resin tube 121 by spiral winding based on the filament winding method, and the curable resin is cured to manufacture the surface layer portion 122. In the manufacture of the surface layer portion 122, a fiber bundle of reinforcing fibers such as glass fiber or carbon fiber can be used, for example. Here, spiral 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 lining 11 than, for example, hoop winding.

[0066] The surface layer portion 122 includes, for example, a first fiber layer 122a and a second fiber layer 122b. Moreover, the surface layer portion 122 may include, for example, a third fiber layer 122c. It should be noted that the surface layer portion 122 may include four or more fiber layers, for example. The manufacturing method of the fiber layers of the surface layer portion 122 including the above-mentioned first fiber layer 122a, second fiber layer 122b, and third fiber layer 122c will be described later.

[0067] The pipe heads 13 and 14 are metal components installed on the high-pressure tank 1. In Figure 1 In the example shown, one pipe head 13 has a fluid passage 131 that connects the inside and outside of the high-pressure tank 1, and the other pipe head 14 closes the opening 112a of the liner 11. It should be noted that the high-pressure tank 1 can also omit the pipe heads 13 and 14 by using, for example, a liner 11 that has an opening 112a only at one end.

[0068] The pipe head 13 having the fluid passage 131 is connected to, for example, a valve and functions as a filling port for fluid from the outside to the inside of the high-pressure tank 1 and as a supply port for fluid from the inside to the outside of the high-pressure tank 1. The pipe head 14 without the fluid passage 131 functions, for example, as a support portion for supporting the liner 11 during the manufacture of the high-pressure tank 1.

[0069] Hereinafter, with reference to Figures 2 to 7 , an embodiment of the manufacturing method of the high-pressure tank of the present disclosure will be described. Figure 2 is a flowchart showing an embodiment of the manufacturing method of the high-pressure tank of the present disclosure. The manufacturing method M of the high-pressure tank in this embodiment is a method for manufacturing the high-pressure tank 1. For example, Figure 1 As shown, the high-pressure tank 1 includes: a liner 11 having dome portions 112 at one end and the other end of the cylindrical portion 111; a fiber-reinforced resin layer 12 covering the outside of the liner 11.

[0070] For example, Figure 2 As shown, 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. Moreover, 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 in this embodiment, first, the liner arrangement step S1 is performed.

[0071] In the liner arrangement step S1, the cylindrical portion 111 of the liner 11 is arranged inside a pre-manufactured fiber-reinforced resin tube 121, and the dome portions 112 of the liner 11 are exposed at one end and the other end of the fiber-reinforced resin tube 121, respectively. More specifically, for example, with the pipe heads 13 and 14 joined to the pair of openings 112a of the liner 11, the liner 11 is supported via the pipe heads 13 and 14, and the liner 11 is inserted into the inside of the fiber-reinforced resin tube 121. Then, the fiber-reinforced resin tube 121 is arranged outside the cylindrical portion 111 of the liner 11, and the cylindrical portion 111 is joined to the fiber-reinforced resin tube 121.

[0072] It should be noted that in the lining configuration process S1, the lining 11 can have a structure formed, for example, in a state where it is divided into two parts, a first part and a second part, in the central portion in the direction of the central axis C as described above. In this case, for example, the first part and the second part of the lining 11 are respectively inserted from one end and the other end of the fiber reinforced resin tube 121 in which the curable resin impregnated in the fiber bundle is pre-cured, and are joined to each other inside the fiber reinforced resin tube 121, and the curable resin impregnated in the fiber bundle is cured. Thereby, the first part and the second part of the lining 11 and the lining 11 and the fiber reinforced resin tube 121 are integrated.

[0073] Next, as Figure 2 shown, the first fiber layer forming process S2 is carried out. Figure 3 It is a graph showing Figure 2 the relationship between the internal pressure P of the lining 11 and the tension T of the fiber bundle in the first fiber layer forming process S2, the second fiber layer forming process S3, and the third fiber layer forming process S4. Figures 4 to 7 They are respectively side views showing an example of the first fiber layer 122a formed by Figure 2 the first fiber layer forming process S2.

[0074] In the first fiber layer forming process S2, in a state where a first internal pressure P1 is applied to the lining 11 after the lining configuration process S1, the fiber bundle FB impregnated with the curable resin and given a first tension T1 is wound around each dome portion 112 of the lining 11 and the outside of the fiber reinforced resin tube 121 in a spiral winding manner for multiple turns. And the fiber bundle FB is arranged in a rotationally symmetric pattern with three-fold symmetry or more about the central axis C of the lining 11 on the outside of both fiber reinforced resin tubes 121 to form the first fiber layer 122a.

[0075] More specifically, in the first fiber layer forming process S2, in a state where the fiber reinforced resin tube 121 is arranged outside the cylindrical portion 111 of the lining 11, the first internal pressure P1 is applied to the lining 11. And the fiber bundle FB impregnated with the curable resin and given a first tension T1 is wound around the outer surfaces of the dome portions 112 at both ends of the lining 11 and the outer surface of the fiber reinforced resin tube 121 arranged outside the cylindrical portion 111 of the lining 11 in a spiral winding manner to form the first fiber layer 122a.

[0076] Here, the internal pressure P of the lining 11 suitable for the circumferential winding of the fiber bundle FB around the cylindrical portion 111 of the lining 11 is not the same as the internal pressure P of the lining 11 suitable for the helical winding of the fiber bundle FB around the dome portion 112 of the lining 11. In the manufacturing method M of the high-pressure tank of the present embodiment, in the first fiber layer forming step S2, a prefabricated fiber-reinforced resin tube 121 is disposed outside the cylindrical portion 111 of the lining 11, and it is not necessary to wind the fiber bundle FB around the cylindrical portion 111 of the lining 11 in a circumferential winding manner.

[0077] Therefore, in a state where the first internal pressure P1 applied to the lining 11 is balanced with the first tension T1 applied to the fiber bundle FB, the fiber bundle FB can be wound around the outside of the dome portion 112 of the lining 11 in a helical winding manner. As a result, when forming the first fiber layer 122a, the shape of the dome portion 112 can be made closer to the target shape. The first internal pressure P1 and the first tension T1 that can achieve the target shape of the dome portion 112 vary depending on conditions such as the material, thickness, diameter of the lining 11, or the width of the fiber bundle FB, for example.

[0078] Therefore, the first internal pressure P1 and the first tension T1 in the first fiber layer forming step S2 can be obtained, for example, by performing calculations based on computer simulation with the above-mentioned conditions as parameters. Moreover, for example, the first fiber layer forming step S2 can be implemented while measuring the shape of the dome portion 112 of the lining 11 by means such as 3D scanning, and thus the first internal pressure P1 and the first tension T1 that can achieve the target shape of the dome portion 112 can be determined through trial and error. It should be noted that in the manufacturing method M of the high-pressure tank of the present embodiment, the internal pressure P of the lining 11 can be set to a maximum of not more than 1 Mpa.

[0079] In addition, the first tension T1 can be determined, for example, in such a way 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 straight, the strength of the fiber-reinforced resin layer 12 decreases, and the strength exhibition rate of the high-pressure tank 1 may decrease. Therefore, the first tension T1 applied to the fiber bundle FB is determined within a range where the fibers of the fiber bundle FB are oriented as linearly as possible and can achieve the target shape of the dome portion 112 in balance with the first internal pressure P1 when forming the first fiber layer 122a.

[0080] In other words, the first tension T1 is determined, for example, within a range where the strength exhibition rate of the high-pressure tank 1 is 70% or more. Here, the strength exhibition rate is the ratio of the actual failure strength of the high-pressure tank 1 in a state where all the fibers constituting the fiber-reinforced resin layer 12 are oriented linearly to the design failure strength of the high-pressure tank 1.

[0081] The first fiber layer 122a formed by the first fiber layer forming step S2 is, for example, Figure 4 a structure with a minimum configuration pattern of a three-fold symmetric rotationally symmetric fiber bundle FB as shown. Moreover, as the first internal pressure P1 of the lining 11 increases, as Figures 5 to 7 shown, a configuration pattern of a four-fold symmetric, six-fold symmetric, or eight-fold symmetric rotationally symmetric fiber bundle FB can be adopted. It should be noted that although not shown in the figure, the first fiber layer 122a can also adopt a configuration pattern of a five-fold symmetric, seven-fold symmetric, nine-fold symmetric, or rotationally symmetric fiber bundle FB with ten-fold symmetry or higher.

[0082] Next, as Figure 2 shown, the 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 lining 11. Then, a fiber bundle FB impregnated with a curable resin and given a second tension T2 higher than the first tension T1 is wound around the outer sides of the respective dome portions 112 of the lining 11 and the fiber reinforced resin tube 121 in a spiral winding manner so as to cover the first fiber layer 122a for multiple turns. Then, the second internal pressure P2 and the second tension T2 are balanced to shape the two dome portions 112 into a target shape and at the same time form the second fiber layer 122b.

[0083] As described above, in the lining arrangement step S1, the fiber bundle FB is arranged in a rotationally symmetric pattern with three-fold symmetry or higher about the central axis C of the lining 11 to form the first fiber layer 122a. Therefore, in the first fiber layer forming step S2, the dome portions 112 of the lining 11 are strengthened by the first fiber layer 122a, the expansion deformation of the dome portions 112 can be suppressed, and the internal pressure P of the lining 11 can be increased from the first internal pressure P1 to the second internal pressure P2.

[0084] In addition, in the first fiber layer forming step S2, corresponding to the increase in the internal pressure P of the lining 11 from the first internal pressure P1 to the second internal pressure P2, the tension T applied to the fiber bundle FB is increased from the first tension T1 to the second tension T2. Thereby, the tension T of the fiber bundle FB wound around the lining 11 can be more reliably balanced with the internal pressure P of the lining 11, the deformation of the lining 11 can be more reliably suppressed, and the shape of the dome portion 112 of the lining 11 can be made to coincide with the target shape.

[0085] 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 and trial and error in the same manner as the first internal pressure P1 and the first internal pressure P1 in the first fiber layer forming step S2. Moreover, the second tension T2 is determined, for example, in the same manner as the first tension T1, within a range where the fibers of the fiber bundle FB are aligned as straight as possible and the target shape of the dome portion 112 can be achieved in balance with the second internal pressure P2 during the formation of the second fiber layer. In other words, the second tension T2 is determined, for example, within a range where the strength exhibition rate of the autoclave 1 is 70% or more.

[0086] Next, as Figure 2 shown, 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 given the second tension T2 is wound around the outside of each dome portion 112 of the liner 11 and the fiber reinforced resin tube 121 in a spiral winding manner so as to cover the second fiber layer for multiple turns. Then, the third internal pressure P3 and the second tension T2 are balanced to shape both dome portions 112 into the target shape and simultaneously form the third fiber layer 122c.

[0087] In the third fiber layer forming step S4, the 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 on 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 here, the balance between the internal pressure P of the liner 11 and the tension T of the fiber bundle FB is broken and the dome portion 112 of the liner 11 may deform inward.

[0088] Therefore, in the third fiber layer forming step S4, the tension T applied to the fiber bundle FB is maintained at the second tension T2 in the second fiber layer forming step S3. Thereby, the tension T of the fiber bundle FB wound around the liner 11 can be more reliably balanced with the internal pressure P of the liner 11, the deformation of the liner 11 can be more reliably suppressed, and the shape of the dome portion 112 of the liner 11 can be made to coincide with the target shape.

[0089] Finally, the Figure 2 shown curing step S5 is performed. In the curing step S5, the curable resin impregnated in the fiber bundle FB is cured, whereby the first fiber layer 122a and the second fiber layer 122b are integrated with the fiber reinforced resin tube 121 to form the fiber reinforced resin layer 12. In the present 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 tube 121 to form the fiber reinforced resin layer 12.

[0090] 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 cure it. 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 cure it. It should be noted that the curing step S5 can be carried out in parallel with, for example, the first fiber layer forming step S2, the second fiber layer forming step S3, or the third fiber layer forming step S4.

[0091] As described above, the autoclave manufacturing method M of the present embodiment is a method for manufacturing the autoclave 1, and the autoclave 1 includes: a liner 11 having dome portions 112 at one end and the other end of the cylindrical portion 111; and a fiber reinforced resin layer 12 covering the outside of the liner 11. The autoclave manufacturing method M includes a liner arranging step S1, a first fiber layer forming step S2, a second fiber layer forming step S3, and a curing step S5. In the liner arranging step S1, the cylindrical portion 111 of the liner 11 is arranged inside the fiber reinforced resin tube 121, and the dome portions 112 of the liner 11 are exposed at one end and the other end of the fiber reinforced resin tube 121, respectively. In the first fiber layer forming step S2, after the liner arranging step S1, a first internal pressure P1 is applied to the liner 11. In addition, in this state, the fiber bundle FB impregnated with the curable resin and given a first tension T1 is wound around the outside of each dome portion 112 of the liner 11 and the fiber reinforced resin tube 121 in a spiral winding manner for multiple turns. And the fiber bundle FB is arranged in a rotationally symmetric pattern with three-fold symmetry or more about the central axis C of the liner 11 on the outside of both dome portions 112 to form a first fiber layer 122a. Moreover, 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 the curable resin and given a second tension T2 higher than the first tension T1 is wound around the outside of each dome portion 112 of the liner 11 and the fiber reinforced resin tube 121 in a spiral winding manner to cover the first fiber layer 122a for multiple turns. Then, the second internal pressure P2 is balanced with the second tension T2 to shape both dome portions 112 into a target shape and at the same time form a second fiber layer 122b. In the curing step S5, the curable resin impregnated in the fiber bundle FB is cured, whereby the first fiber layer 122a and the second fiber layer 122b are integrated with the fiber reinforced resin tube 121 to form the fiber reinforced resin layer 12.

[0092] In addition, the manufacturing method M of the high-pressure tank according to the present 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 lining 11. Then, the fiber bundle FB impregnated with the curable resin and given the second tension T2 is wound around each dome portion 112 of the lining 11 and the outside of the fiber reinforced resin tube 121 in a spiral winding manner so as to cover the second fiber layer 122b for multiple turns. Then, the third internal pressure P3 is balanced with the second tension T2 to shape the two dome portions 112 into the target shape and simultaneously form the third fiber layer 122c. Moreover, in the curing step S5 of the manufacturing method M of the high-pressure tank according to the present embodiment, the first fiber layer 122a, the second fiber layer 122b, and the third fiber layer 122c are integrated with the fiber reinforced resin tube 121 to form the fiber reinforced resin layer 12.

[0093] Therefore, according to the manufacturing method M of the high-pressure tank of the present embodiment, the tension T of the fiber bundle FB wound around the lining 11 can be more reliably balanced with the internal pressure P of the lining 11, and the deformation of the lining 11 can be more reliably suppressed.

[0094] As described above, the embodiments of the manufacturing method of the high-pressure tank of the present disclosure have been described in detail with reference to the drawings. However, the specific structure is not limited to this embodiment, and even if there are design changes and the like within the scope not departing from the gist of the present disclosure, they are included in the present disclosure.

Claims

1. A manufacturing method of a high-pressure tank, which is a method for manufacturing a high-pressure tank. The high-pressure tank includes: a liner having dome-shaped portions at one end and the other end of a cylindrical portion; and a fiber-reinforced resin layer covering the outside of the liner. The manufacturing method of the high-pressure tank is characterized by including: A liner arranging step of arranging the cylindrical portion of the liner inside a fiber-reinforced resin tube and exposing the dome-shaped portions of the liner at one end and the other end of the fiber-reinforced resin tube respectively; A first fiber layer forming step of, after the liner arranging step and in a state where a first internal pressure is applied to the liner, winding a fiber bundle impregnated with a curable resin and applied with a first tension around the outside of each of the dome-shaped portions of the liner and the fiber-reinforced resin tube in a spiral winding manner for multiple turns, and arranging the fiber bundle in a pattern of rotational symmetry of three-fold symmetry or more centered on the central axis of the liner on the outside of both dome-shaped portions 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, winding the fiber bundle impregnated with the curable resin and applied with a second tension higher than the first tension around the outside of each of the dome-shaped portions of the liner and the fiber-reinforced resin tube in a spiral winding manner for multiple turns in a manner covering the first fiber layer, and shaping the two dome-shaped portions into a target shape by balancing the second internal pressure and the second tension and simultaneously forming a second fiber layer; A third fiber layer forming step of, after the second fiber layer forming step, applying a third internal pressure higher than the second internal pressure to the liner, winding the fiber bundle impregnated with the curable resin and applied with the second tension around the outside of each of the dome-shaped portions of the liner and the fiber-reinforced resin tube in a spiral winding manner for multiple turns in a manner covering the second fiber layer, and shaping the two dome-shaped portions into a target shape by balancing the third internal pressure and the second tension and simultaneously forming a third fiber layer; and A curing step of curing the curable resin impregnated in the fiber bundle, thereby integrating the first fiber layer, the second fiber layer and the third fiber layer with the fiber-reinforced resin tube to form the fiber-reinforced resin layer.

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