High-pressure tank and liner manufacturing method

Abstract

To provide a method for manufacturing liners for high-pressure tanks and high-pressure tanks that can prevent unnecessary weight increases in high-pressure tanks.SOLUTION: The method of manufacturing a liner for a high-pressure tank has a shaft preparation process for preparing a shaft assembly 102 in which an annular first attachment 22 and a second attachment 24 are attached to the periphery of a tubular shaft 86 having air supply holes 94. The method also has a parison supply process for placing the shaft assembly 102 inside the parison, a blow molding process for closing a mold device 62 and supplying air into the parison through the air supply holes 94 to expand the parison to obtain a liner molding body 104, and a release process for removing the shaft 86 from the first attachment 22 and the second attachment 24 and taking the shaft 86 out of the liner molding body 104.SELECTED DRAWING: Figure 11

Description

[Technical Field]

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

[0002] The liner of the pressure vessel in Patent Document 1 is formed from a resin material and includes a body portion and a pair of dome portions formed at both ends of the body portion. The pressure vessel is extrusion molded using a blow molding machine. When manufacturing the pressure vessel, a cylindrical parison is extruded from the blow molding machine into the interior of a mold, and air is then supplied through holes in a tubular rod placed inside the parison. Mouthpieces are placed at both ends of the tubular rod. The pressure of the air drawn out from the holes in the rod pushes the parison outward and presses it against the inner surface of the mold. The tops of the pair of dome portions are formed coaxially with the rod, and each dome portion holds a mouthpiece together with both ends of the rod. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-150517 Summary of the Invention [Problem to be solved by the invention]

[0004] In the pressure vessel of Patent Document 1, the rod and nozzle portion used when blow molding the liner are held in a pair of dome portions, so the rod remains attached to the pressure vessel, which creates the problem of increasing the weight of the pressure vessel by the weight of the rod.

[0005] The present invention aims to solve the above-mentioned problems. [Means for solving the problem]

[0006] A first aspect of the present invention is a method for manufacturing a liner having a cylindrical cylinder portion, a first dome portion disposed at one axial end of the cylinder portion, and a second dome portion disposed at the other axial end of the cylinder portion, the method including a shaft preparation step of preparing a shaft assembly having an annular first attachment and an annular second attachment attached to an outer periphery of a tubular shaft having an air supply hole and extending linearly, wherein a first annular boss can be attached to the first attachment, a second annular boss can be attached to the second attachment, the first attachment and the second attachment are disposed at a distance from each other in the axial direction of the shaft, and the shaft is detachable from the first attachment and the second attachment. a parison supplying process of supplying a cylindrical parison made of a resin material to a mold device for molding the liner and placing the shaft assembly inside the parison; a blow molding process of closing the mold device and supplying air into the parison through the air supply hole of the shaft to expand the parison, thereby obtaining a liner molded body in which the first attachment having a first hole portion is integrally molded with the first dome portion and the second attachment having a second hole portion arranged concentrically with the first hole portion is integrally molded with the second dome portion; and a detaching process of removing the shaft from the first attachment and the second attachment after the blow molding process and taking the shaft out of the liner molded body.

[0007] According to this liner manufacturing method, in the blow molding process that molds a liner having a cylinder portion and first and second dome portions, the first and second attachments are integrally molded with the first and second dome portions of the liner so that the first hole of the first attachment and the second hole of the second attachment are concentric, thereby ensuring coaxiality between the first boss and the second boss when the first boss is assembled to the first attachment and the second boss is assembled to the second attachment. Because the shaft can be axially removed from the first and second attachments of the shaft assembly after the liner molded body is molded, unnecessary weight increase of the high-pressure tank due to use of the shaft can be prevented compared to a configuration in which the shaft remains assembled in the liner molded body.

[0008] Between the blow molding process and the removal process, there may be a filament winding process in which reinforcing fibers are wound around the outer peripheral surface of the liner, and in the filament winding process, the liner molding may be supported by the shaft and rotated via the shaft.

[0009] This manufacturing method allows the shaft to be used as a jig for fixing and rotating the liner during the filament winding process, eliminating the need to prepare and attach a separate jig for rotation, and allowing the filament winding process to be carried out efficiently.

[0010] The outer peripheral surface of the shaft has a first male threaded portion and a second male threaded portion provided at different positions in the axial direction of the shaft, the inner peripheral surface of the first attachment has a first female threaded portion that can be threaded onto the first male threaded portion, and the inner peripheral surface of the second attachment has a second female threaded portion that can be threaded onto the second male threaded portion, and in the shaft assembly, the first male threaded portion and the first female threaded portion are threaded together, and the second male threaded portion and the second female threaded portion are threaded together, and in the removal process, the shaft may be rotated relative to the liner molding to unthread the first male threaded portion and the first female threaded portion, and the second male threaded portion and the second female threaded portion may be unthreaded together.

[0011] With this manufacturing method, in the removal process, the shaft is rotated relative to the liner molding, thereby releasing the threaded engagement between the first male threaded portion and the first female threaded portion and also releasing the threaded engagement between the second male threaded portion and the second female threaded portion, thereby making it possible to easily remove the shaft from the liner molding.

[0012] The second attachment may have an inner diameter larger than the inner diameter of the first attachment, and in the removing step, the shaft may be moved relative to the liner molding in a direction from the first attachment toward the second attachment.

[0013] According to this manufacturing method, after the second male thread portion of the shaft is released from the second female thread portion of the second attachment in the release step, the first thread of the shaft can be removed without rotating the shaft relative to the liner molded body. 1 Male thread is 2 Attachment No. 2 The shaft can pass through the female thread portion, which makes it easy to remove the shaft from the liner molding.

[0014] The shaft has a shaft body extending in the axial direction of the shaft, a first holding mechanism provided on the shaft body and detachably holding the first attachment, and a second holding mechanism provided on the shaft body at a position spaced from the first holding mechanism in the axial direction of the shaft and detachably holding the second attachment, the first holding mechanism having a first locking member displaceable in the radial direction of the shaft body and protruding from the outer circumferential surface of the shaft body to lock the first attachment, and a first resilient member that urges the first locking member outward in the radial direction of the shaft body, the second holding mechanism having a second locking member displaceable in the radial direction of the shaft body and protruding from the outer circumferential surface of the shaft body to lock the second attachment, and a second resilient member that urges the first locking member outward in the radial direction of the shaft body. and a second resilient member that biases the shaft radially outward, and in the shaft preparation process, the first locking member and the second locking member protrude from the outer peripheral surface of the shaft body, and the first and second attachments engage with the shaft in the axial direction of the shaft, and in the detachment process, as the shaft moves axially relative to the liner molding, the first attachment displaces the first locking member radially inward of the shaft body against the biasing force of the first resilient member, and the second attachment displaces the second locking member radially inward of the shaft body against the biasing force of the second resilient member, thereby disengaging the first and second attachments from the shaft in the axial direction of the shaft.

[0015] With this manufacturing method, in the shaft preparation step, the first and second locking members, which are biased radially outward and protrude from the outer circumferential surface of the shaft body, prevent the shaft from moving axially relative to the first and second attachments, so the first and second attachments can be stably fixed to the shaft. In the detachment step, the first and second locking members are housed radially inward from the outer circumferential surface against the elastic force, allowing the shaft to move axially relative to the first and second attachments, and the shaft can be detached from the first and second attachments.

[0016] A second aspect of the present invention comprises a liner made of a resin material having a cylindrical cylinder portion, a curved first dome portion located at one axial end of the cylinder portion, and a curved second dome portion located at the other axial end of the cylinder portion; a circular first attachment integrally molded with the first dome portion on the axis of the cylinder portion and having a first hole portion passing through the cylinder portion in the axial direction; a circular second attachment integrally molded with the second dome portion on the axis of the cylinder portion and having a second hole portion passing through the cylinder portion in the axial direction and located concentrically with the first hole portion; a circular first boss fixed concentrically to the first attachment; and a circular second boss fixed concentrically to the second attachment.

[0017] With this high-pressure tank, the first and second attachments are integrally molded with the first and second dome portions of the liner, so that when the first boss is assembled to the first attachment and the second boss is assembled to the second attachment, coaxiality between the first boss and the second boss can be ensured. [Effects of the Invention]

[0018] According to the present invention, in the blow molding process for molding a liner having a cylinder portion and first and second dome portions, the first and second attachments are integrally molded with the first and second dome portions of the liner so that the first hole of the first attachment and the second hole of the second attachment are concentric, thereby ensuring coaxiality between the first boss and the second boss when the first boss is assembled to the first attachment and the second boss is assembled to the second attachment. Since the shaft can be axially removed from the first and second attachments of the shaft assembly after the liner molded body is molded, unnecessary weight increase of the high-pressure tank due to use of the shaft can be prevented compared to a configuration in which the shaft remains assembled in the liner molded body. [Brief explanation of the drawings]

[0019] [Figure 1]FIG. 1 is an overall cross-sectional view of a high-pressure tank including a liner according to an embodiment of the present invention. [Figure 2] FIG. 2 is an enlarged cross-sectional view of the vicinity of the first attachment in the high-pressure tank of FIG. [Figure 3] FIG. 3 is an enlarged cross-sectional view of the vicinity of the second attachment in the high-pressure tank of FIG. [Figure 4] FIG. 4 is a front view of the appearance of the first and second attachments. [Figure 5] Fig. 5A is an enlarged cross-sectional view showing the vicinity of first and second attachments according to a modified example, and Fig. 5B is a cross-sectional view taken along line VB-VB in Fig. 5A. [Figure 6] FIG. 6 is an overall structural view of a mold device showing a state in which a shaft assembly is set in a mold. [Figure 7] FIG. 7 is an overall cross-sectional view of a shaft assembly made up of a shaft, a first attachment, and a second attachment. [Figure 8] FIG. 8 is an explanatory view showing a shaft preparation step for constructing a shaft assembly and a parison supply step for supplying a parison into a mold of a mold device. [Figure 9] FIG. 9 is an explanatory view showing a process of closing the mold of the mold device of FIG. [Figure 10] FIG. 10 is an explanatory view showing the blow molding process of the liner molded body in the mold apparatus of FIG. [Figure 11] FIG. 11 is an explanatory view showing the process of opening the mold and removing the liner molded body. [Figure 12] FIG. 12 is an explanatory diagram showing a filament winding step in which reinforcing fibers are wound around the outer peripheral surface of the liner molded body. [Figure 13] FIG. 13 is an explanatory view showing a removing step for removing the shaft from the liner molded body. [Figure 14] Fig. 14A is an enlarged view of the vicinity of the first and second attachments in the liner molded body, and Fig. 14B is an explanatory view of the operation when removing the shaft from the first and second attachments of the liner molded body in Fig. 14A. [Figure 15] Fig. 15A is an enlarged configuration diagram of the vicinity of the first and second attachments showing a first modified example, and Fig. 15B is an explanatory diagram of the operation when the shafts are removed from the first and second attachments in Fig. 15A. [Figure 16] Fig. 16A is an enlarged configuration diagram of the vicinity of the first and second holding mechanisms according to the second modified example, and Fig. 16B is an explanatory diagram of the operation when removing the shafts from the first and second attachments in the first and second holding mechanisms of Fig. 16A. DETAILED DESCRIPTION OF THE INVENTION

[0020] The high-pressure tank 10 according to this embodiment is used for storing hydrogen gas. The gas stored in the high-pressure tank 10 may be a gas other than hydrogen gas, such as nitrogen gas. The high-pressure tank 10 is mounted on a fuel cell vehicle. The high-pressure tank 10 stores hydrogen gas to be supplied to a fuel cell system.

[0021] As shown in FIG. 1, the high-pressure tank 10 according to this embodiment includes a liner 12, a reinforcing layer 14 provided on the outer peripheral surface of the liner 12, and first and second bosses 16a, 16b provided at the axial end of the liner 12.

[0022] The liner 12 is a hollow body made of a resin material. The liner 12 is the inner layer of the high-pressure tank 10. The liner 12 is injection blow molded using a molding device 62, which will be described later. The liner 12 includes a cylindrical cylinder portion 18, a pair of dome portions 20 (hereinafter referred to as first and second dome portions 20a, 20b) disposed at the axial ends of the cylinder portion 18, and a pair of first and second attachments 22, 24.

[0023] The cylinder portion 18 is cylindrical and has a constant diameter along the axial direction. The interior of the cylinder portion 18 has a gas filling chamber 26 that is filled with hydrogen gas.

[0024] As shown in FIG. 2, the first dome section 20a is disposed at one axial end of the cylinder section 18. The first dome section 20a has a curved shape that gradually curves radially inward in a direction away from the cylinder section 18. When viewed from a direction perpendicular to the axial direction of the liner 12, the cross-sectional shape of the first dome section 20a is approximately semicircular. The cross-sectional shape of the first dome section 20a may be, for example, elliptical. The first dome section 20a has a first recessed section 28 at its center that is recessed axially relative to the first dome section 20a. The first recessed section 28 is disposed on the axis of the first dome section 20a.

[0025] As shown in FIG. 3, the second dome section 20b is disposed at the other axial end of the cylinder section 18. The second dome section 20b is curved so as to gradually curve radially inward in a direction away from the cylinder section 18. When viewed from a direction perpendicular to the axial direction of the liner 12, the cross-sectional shape of the second dome section 20b is semicircular. In the axial direction of the liner 12, the first dome section 20a and the second dome section 20b curve so as to reduce inward in diameter in a direction away from each other. The center of the second dome section 20b has a second recessed section 30 that is recessed in the axial direction relative to the second dome section 20b. The second recessed section 30 is disposed on the axis of the second dome section 20b.

[0026] As shown in Fig. 4, the first and second attachments 22, 24 are formed in an annular shape from a metal material. As shown in Fig. 2, the first attachment 22 is disposed at the axial center of the first dome portion 20a. The first attachment 22 is disposed on the axis of the liner 12. The axis of the first attachment 22 and the axis of the liner 12 are coaxial.

[0027] The first attachment 22 is disposed on the axis of the cylinder portion 18. The first attachment 22 is integrally molded concentrically with the first dome portion 20a. A portion of the first attachment 22 is disposed in the first recess 28 of the first dome portion 20a. The first attachment 22 includes a cylindrical first tubular portion 32 and a first flange 34 extending radially outward from the end of the first tubular portion 32. The diameter of the first tubular portion 32 is constant in the axial direction. The interior of the first tubular portion 32 has a first hole 36. The first hole 36 is formed at the axial center of the first tubular portion 32 and passes through the first attachment 22 along the axial direction. The first tubular portion 32 is insert-molded into the first dome portion 20a. The first tubular portion 32 is disposed on the axis of the first dome portion 20a.

[0028] The first cylindrical portion 32 has a first female thread portion 38. The first female thread portion 38 is provided on the inner circumferential surface of the first hole portion 36 of the first attachment 22. The first female thread portion 38 is formed along the axial direction of the first hole portion 36.

[0029] The outer peripheral surface of the first cylindrical portion 32 has a first groove 40 and a first fastening portion 42. The first groove 40 is formed in an annular shape along the circumferential direction of the outer peripheral surface of the first cylindrical portion 32. The first groove 40 is recessed into the outer peripheral surface of the first cylindrical portion 32. A plurality of first grooves 40 are provided spaced apart in the axial direction of the first cylindrical portion 32. When the first cylindrical portion 32 is insert-molded into the first dome portion 20a, a portion of the first dome portion 20a is inserted into the first groove 40. This fixes the first cylindrical portion 32 to the first dome portion 20a, preventing axial movement of the first attachment 22 relative to the first dome portion 20a.

[0030] The first fastening portion 42 is disposed on the tip side of the first cylindrical portion 32 relative to the first groove portion 40. The first fastening portion 42 has a male thread formed on its outer peripheral surface. The first flange portion 34 is formed in an annular shape. The first flange portion 34 is disposed on the axial center side of the cylinder portion 18 relative to the first cylindrical portion 32. The first flange portion 34 is disposed facing the gas-filled chamber 26.

[0031] As shown in FIG. 3, the second attachment 24 is disposed on the axis of the cylinder portion 18. The second attachment 24 is integrally molded concentrically with the second dome portion 20b. The second attachment 24 and the first attachment 22 are disposed coaxially. A portion of the second attachment 24 is disposed in the second recessed portion 30 of the second dome portion 20b. The second attachment 24 includes a cylindrical second tubular portion 44 and a second flange portion 46 extending radially outward from the end of the second tubular portion 44. The diameter of the second tubular portion 44 is constant in the axial direction. The second tubular portion 44 has a second hole portion 47 formed therein. The second hole portion 47 is formed at the axial center of the second tubular portion 44 and penetrates the second attachment 24 along the axial direction. The second tubular portion 44 of the second attachment 24 is insert-molded into the second dome portion 20b. The second cylindrical portion 44 is disposed on the axis of the second dome portion 20b. The second hole portion 47 and the first hole portion 36 are disposed concentrically.

[0032] The second cylindrical portion 44 has a second female thread portion 48. The second female thread portion 48 is provided on the inner circumferential surface of the second hole portion 47 of the second attachment 24. The second female thread portion 48 is formed along the axial direction of the second hole portion 47. The first female thread portion 38 and the second female thread portion 48 of the first attachment 22 have the same thread pitch.

[0033] The outer peripheral surface of the second cylindrical portion 44 has a second groove portion 50 and a second fastening portion 52. The second groove portion 50 is formed in an annular shape along the circumferential direction of the outer peripheral surface of the second cylindrical portion 44. The second groove portion 50 is recessed into the outer peripheral surface of the second cylindrical portion 44. A plurality of second groove portions 50 are provided spaced apart in the axial direction of the second cylindrical portion 44. When the second cylindrical portion 44 is insert-molded into the second dome portion 20b, a portion of the second dome portion 20b is inserted into the second groove portion 50. This fixes the second cylindrical portion 44 to the second dome portion 20b, preventing axial movement of the second attachment 24 relative to the second dome portion 20b.

[0034] The second fastening portion 52 is disposed on the tip side of the second cylindrical portion 44 relative to the second groove portion 50. The second fastening portion 52 has a male thread formed on its outer circumferential surface. The second flange portion 46 is formed in an annular shape. The second flange portion 46 is disposed on the axial center side of the cylinder portion 18 relative to the second cylindrical portion 44. The second flange portion 46 is disposed facing the gas-filled chamber 26.

[0035] The first and second grooves 40, 50 of the first and second attachments 22, 24 are not limited to being formed annularly along the circumferential direction of the first and second cylindrical portions 32, 44. A liner 12a according to a modified example shown in FIG. 5A includes first and second attachments 22a, 24a. The first cylindrical portion 32 of the first attachment 22a has a first groove 40a. The first groove 40a is formed on the outer circumferential surface of the first cylindrical portion 32. The first groove 40a extends along the axial direction of the first cylindrical portion 32. As shown in FIG. 5B, a plurality of first grooves 40a are provided spaced apart from one another along the outer circumferential surface of the first cylindrical portion 32. As shown in FIG. 5A, the second cylindrical portion 44 of the second attachment 24a has a second groove 50a. The second groove 50a is formed on the outer circumferential surface of the second cylindrical portion 44. The second groove 50a extends along the axial direction of the second cylindrical portion 44. As shown in FIG. 5B, a plurality of second grooves 50a are provided along the outer circumferential surface of the second cylindrical portion 44 and spaced apart from one another.

[0036] 5A, when the first cylindrical portion 32 is insert-molded into the first dome portion 20a, a portion of the first dome portion 20a is inserted into the first groove portion 40a. This fixes the first cylindrical portion 32 to the first dome portion 20a, and the first groove portion 40a prevents the first attachment 22a from moving in the rotational direction relative to the first dome portion 20a. When the second cylindrical portion 44 is insert-molded into the second dome portion 20b, a portion of the second dome portion 20b is inserted into the second groove portion 50a. This fixes the second cylindrical portion 44 to the second dome portion 20b, and the second groove portion 50a prevents the second attachment 24a from moving in the rotational direction relative to the second dome portion 20b.

[0037] As shown in FIG. 1, the reinforcing layer 14 is disposed on the outer peripheral surface of the liner 12. The reinforcing layer 14 covers the outer peripheral surface of the cylinder portion 18 and the outer peripheral surfaces of the first and second dome portions 20a, 20b. The reinforcing layer 14 is formed of fiber reinforced plastic (FRP) in which reinforcing fibers 14a are impregnated with a resin matrix. During the manufacturing process of the high-pressure tank 10, the resin-impregnated reinforcing fibers 14a are wound multiple times around the outer peripheral surface of the liner 12 using a filament winding device (not shown). The reinforcing layer 14 is a laminate formed by winding the reinforcing fibers 14a around the liner 12 and then heating the reinforcing fibers 14a to harden the resin.

[0038] As shown in Figures 2 and 3, the first and second bosses 16a, 16b are annular metal nozzles. The first and second bosses 16a, 16b are disposed on the first and second dome portions 20a, 20b, respectively. Each of the first and second bosses 16a, 16b includes a boss body 54 and a flange portion 56. The boss body 54 is cylindrical and includes a gas flow path 58. The gas flow path 58 axially passes through the center of the boss body 54. A pipe (not shown) can be connected to the tip of the boss body 54. The boss body 54 has a fastening portion 60 on the inner circumferential surface at its base end. The fastening portion 60 has a female thread formed on the inner circumferential surface.

[0039] The flange portion 56 is disposed at the base end of the boss body 54. The flange portion 56 extends radially outward from the outer peripheral surface of the boss body 54. The flange portion 56 of the first boss 16a is housed in and fixed to the first recess 28 (see FIG. 2). The flange portion 56 of the second boss 16b is housed in and fixed to the second recess 30 (see FIG. 3).

[0040] 2, when the first boss 16a is fixed in the first recess 28, the tip of the first tubular portion 32 of the first attachment 22 is inserted into the base end of the first boss 16a, and the first fastening portion 42 is fastened to the fastened portion 60. This axially connects the first boss 16a and the first attachment 22. The first boss 16a and the first attachment 22 are fixed concentrically. The gas flow path 58 of the first boss 16a and the gas-filled chamber 26 of the liner 12 communicate with each other via the first hole 36.

[0041] 3, when the second boss 16b is fixed in the second recess 30, the tip of the second tubular portion 44 of the second attachment 24 is inserted into the base end of the second boss 16b, and the second fastening portion 52 is fastened to the fastened portion 60. This axially connects the second boss 16b and the second attachment 24. The second boss 16b and the second attachment 24 are fixed concentrically. A gas flow path 58 of the second boss 16b communicates with the gas-filled chamber 26 of the liner 12 via the second hole 47.

[0042] Next, the mold device 62 for blow molding the liner 12 will be described.

[0043] The mold device 62 shown in FIG. 6 is a blow molding device that obtains the liner 12 from a deformed parison P by injection blow molding a parison P (see FIG. 8) made of a thermoplastic resin.

[0044] The mold device 62 has a mold 64 capable of molding the liner 12. The mold 64 has first and second molding dies 66, 68 that are formed from a metal material and are separable. Inside the mold 64 is a molding section 70 that corresponds to the outer shape of the molded product, the liner 12. The molding section 70 is formed so as to straddle the first molding die 66 and the second molding die 68. The first and second molding dies 66, 68 are halves that divide the molding section 70 into two. The molding section 70 has a cylinder molding section 72 and first and second dome molding sections 74, 76 that are arranged at the ends of the cylinder molding section 72.

[0045] The cylinder molding portion 72 is perpendicular to the parting direction of the first and second molding dies 66, 68. When viewed from a direction perpendicular to the parting direction of the first and second molding dies 66, 68, the cross-sectional shape of the cylinder molding portion 72 is circular. The first dome molding portion 74 is disposed at one end of the cylinder molding portion 72 in the axial direction. The first dome molding portion 74 has a hemispherical shape that is convex in the direction away from the cylinder molding portion 72. The second dome molding portion 76 is disposed at the other end of the cylinder molding portion 72 in the axial direction. The second dome molding portion 76 has a hemispherical shape that is convex in the direction away from the cylinder molding portion 72.

[0046] The mold 64 has first and second connecting portions 78, 80. The first connecting portion 78 is disposed above the first dome molding portion 74. When the mold 64 shown in FIG. 9 is closed, the first connecting portion 78 is a portion that holds one end of the parison P between the first molding die 66 and the second molding die 68. The second connecting portion 80 is disposed below the second dome molding portion 76. When the mold 64 is closed, the second connecting portion 80 is a portion that holds the other end of the parison P between the first molding die 66 and the second molding die 68.

[0047] The first connecting portion 78 has a first retaining hole 82 capable of holding the first attachment 22 when molding the liner 12. The first retaining hole 82 extends along the axial direction of the mold 64 and communicates with the first dome molding portion 74. The first retaining hole 82 is formed to straddle the first molding die 66 and the second molding die 68. The second connecting portion 80 has a second retaining hole 84 capable of holding the second attachment 24 when molding the liner 12. The second retaining hole 84 extends along the axial direction of the mold 64 and is formed to straddle the first molding die 66 and the second molding die 68. The second retaining hole 84 penetrates in the axial direction from the second dome molding portion 76 to the outside of the mold 64.

[0048] Next, a method for manufacturing the liner 12 (high-pressure tank 10) will be described. The liner 12 and the high-pressure tank 10 including the liner 12 shown in Figures 8 to 13 are schematic diagrams of the structure.

[0049] 6, a shaft assembly 102 is prepared. The shaft assembly 102 includes a shaft 86 having an air supply hole 94, and first and second attachments 22, 24 attached to the outer periphery of the shaft 86.

[0050] The shaft 86 is a straight tubular body and is disposed in the center of the mold 64. The shaft 86 is disposed along the axial direction of the mold 64. The shaft 86 is disposed on the parting line between the first molding die 66 and the second molding die 68. The diameter of the shaft 86 is constant in the axial direction.

[0051] 7, the shaft 86 has a shaft main body 86a, a first support portion 88, a second support portion 90, an air flow path 92, and an air supply hole 94. The first support portion 88 and the second support portion 90 are arranged spaced apart from each other in the axial direction of the shaft 86. The first support portion 88 is provided at one end of the shaft main body 86a in the axial direction. The first support portion 88 detachably supports the first attachment 22.

[0052] The outer peripheral surface of the first support portion 88 has a first male thread portion 96. The first male thread portion 96 is formed within a predetermined range in the axial direction of the first support portion 88. The first male thread portion 96 can be threadably engaged with the first female thread portion 38 of the first attachment 22. Note that the first support portion 88 and the first attachment 22 may be supported by being fitted together, or the first support portion 88 and the first attachment 22 may be engaged with each other in the axial direction by a protrusion or the like protruding from at least one of the first support portion 88 and the first attachment 22.

[0053] The second support part 90 is provided on the other axial end side of the shaft main body 86a relative to the first support part 88. The second support part 90 detachably supports the second attachment 24. The second support part 90 and the second attachment 24 may be fitted together to support each other, or the second support part 90 and the second attachment 24 may be axially engaged with each other by a protrusion or the like protruding from at least one of the second support part 90 and the second attachment 24.

[0054] The outer peripheral surface of the second support portion 90 has a second male thread portion 98. The second male thread portion 98 is formed over a predetermined range in the axial direction of the second support portion 90. The second male thread portion 98 can be threadably engaged with the second female thread portion 48 of the second attachment 24. The first male thread portion 96 and the second male thread portion 98 are spaced apart from each other and disposed at different positions in the axial direction of the shaft 86. The first male thread portion 96 and the second male thread portion 98 have the same thread pitch.

[0055] 6, the air flow path 92 is formed inside the shaft 86. The air flow path 92 opens to the other axial end of the shaft 86. An air supply pipe 100 is connected to the other axial end of the shaft 86, and air is supplied to the air flow path 92 through the air supply pipe 100. The air flow path 92 does not open in the axial direction at one axial end of the shaft 86.

[0056] The air supply holes 94 open to the outer peripheral surface of the shaft main body 86a. A plurality of air supply holes 94 are provided and are arranged at approximately equal intervals in the axial and circumferential directions of the shaft 86. Each air supply hole 94 penetrates the shaft 86 in the radial direction and communicates with the air flow path 92. When air is supplied to the air flow path 92, the air is discharged radially outward from the outer peripheral surface of the shaft main body 86a through the plurality of air supply holes 94.

[0057] As shown in Figure 7, the first support portion 88 of the shaft 86 is inserted into the first hole portion 36 of the first attachment 22. The first female thread portion 38 of the first attachment 22 is screwed into the first male thread portion 96 of the first support portion 88. The second support portion 90 of the shaft 86 is inserted into the second hole portion 47 of the second attachment 24. The second female thread portion 48 of the second attachment 24 is screwed into the second male thread portion 98 of the second support portion 90. The other end side of the shaft 86 is exposed to the outside of the mold 64 through the second retaining hole 84 of the mold 64 (see Figure 6).

[0058] In the shaft preparation process, the first support portion 88 of the shaft 86 is inserted into the first hole portion 36 of the first attachment 22. By rotating the shaft 86 and the first attachment 22 relative to each other, the first male thread portion 96 and the first female thread portion 38 are threadedly engaged. The first attachment 22 is held by the first support portion 88. The second support portion 90 of the shaft 86 is inserted into the second hole portion 47 of the second attachment 24. By rotating the shaft 86 and the second attachment 24 relative to each other, the second male thread portion 98 and the second female thread portion 48 are threadedly engaged. The second attachment 24 is held by the second support portion 90. As a result, in the shaft preparation process, a shaft assembly 102 is formed in which the first attachment 22 is held by the first support portion 88 of the shaft 86 and the second attachment 24 is held by the second support portion 90 of the shaft 86. The first attachment 22 and the second attachment 24 are arranged spaced apart from each other in the axial direction of the shaft 86. The first cylindrical portion 32 of the first attachment 22 and the second cylindrical portion 44 of the second attachment 24 are arranged in directions spaced apart from each other in the axial direction of the shaft 86. An air supply pipe 100 is connected to the other end of the shaft 86.

[0059] Next, in the parison supplying step shown in FIG. 8 , the first and second molding dies 66, 68 of the mold device 62 are placed in an open state with the first and second molding dies 66, 68 spaced apart from each other, and a cylindrical parison P made of a resin material is extruded from an extruder (not shown) and supplied to the molding section 70 of the mold 64. Alternatively, a parison P preformed by the extruder may be supplied to the mold 64. The parison P is placed between the first molding die 66 and the second molding die 68, and is arranged perpendicular to the parting direction of the first molding die 66 and the second molding die 68. The parison P is supplied axially to the outer periphery of the shaft assembly 102. As a result, the shaft assembly 102 is housed inside the parison P. The parison P and the shaft assembly 102 are arranged coaxially. The outer periphery of the shaft 86 and the parison P are arranged radially spaced apart. Alternatively, the shaft assembly 102 may be inserted inside a parison P that has been placed in advance. The first attachment 22 faces the first connecting portions 78 (first retaining holes 82) of the first and second molding dies 66, 68. The second attachment 24 faces the second connecting portions 80 (second retaining holes 84) of the first and second molding dies 66, 68.

[0060] Next, a blow molding step is performed in which the liner 12 is blow molded from the parison P.

[0061] First, as shown in FIG. 9 , the first molding die 66 and the second molding die 68 are moved toward each other to close the mold 64. The mold closing direction is perpendicular to the axial direction of the shaft 86. As the mold 64 closes, the parison P, the first attachment 22, and the first support member 88 are clamped by the first connecting portion 78. At this time, a portion of the parison P, the first attachment 22, and the first support member 88 are held by the first retaining hole 82 of the mold 64. A portion of the parison P is crushed radially inward by the first connecting portion 78, reducing its diameter. As the mold 64 closes, the parison P, the second attachment 24, and the second support member 90 are clamped by the second connecting portion 80. At this time, a portion of the parison P, the second attachment 24, and the second support member 90 are held by the second retaining hole 84 of the mold 64. A portion of the parison P is crushed radially inward by the second connecting portion 80, reducing its diameter. The other end of the shaft 86 is disposed outside the mold 64 through the second retaining hole 84. Inside the mold 64, the outer peripheral surface of the parison P faces the molding portion 70. One axial end of the parison P protrudes outside one end of the first and second molding dies 66, 68. The other axial end of the parison P protrudes outside the other end of the first and second molding dies 66, 68.

[0062] As shown in FIG. 10 , air is supplied from an air supply source (not shown) through air supply piping 100 to the air flow path 92 of the shaft 86. Air in the air flow path 92 is discharged to the outside of the shaft 86 through multiple air supply holes 94. The amount of air discharged from the air supply holes 94 is approximately uniform in the axial and circumferential directions of the shaft 86. When air is discharged from the shaft 86 into the interior of the parison P, the parison P is pushed outward toward the molding section 70 by the pressure of the air, causing it to expand (deform). As the parison P expands due to the air, the outer surface of the parison P is pressed against the molding section 70. As the parison P deforms to fit along the cylinder molding section 72 and the first and second dome molding sections 74, 76, the parison P, which is in close contact with the molding section 70, becomes cylindrical. At this time, the thickness of the parison P, which has deformed along the molding section 70, is approximately constant.

[0063] The cylinder portion 18 of the liner 12 is molded from the parison P in the cylinder molding section 72, and the first and second dome portions 20a, 20b are molded from the parison P in the first and second dome molding sections 74, 76, respectively. The first cylindrical portion 32 of the first attachment 22 and the parison P are integrally molded (insert molded) at the top of the first dome molding section 74. The first attachment 22 is molded concentrically with the first dome portion 20a. At this time, a portion of the parison P fits into the first groove portion 40 of the first cylindrical portion 32. The second cylindrical portion 44 of the second attachment 24 and the parison P are integrally molded (insert molded). The second attachment 24 is molded concentrically with the second dome portion 20b. At this time, a portion of the parison P fits into the second groove portion 50 of the second cylindrical portion 44.

[0064] After the parison P has cooled and solidified, the supply of air to the shaft 86 is stopped. This results in a liner molded body 104 having a cylinder portion 18 and first and second dome portions 20a, 20b formed at both ends of the cylinder portion 18, with the first and second attachments 22, 24 integrally molded with the first and second dome portions 20a, 20b. The air supply piping 100 is removed from the other end of the shaft 86.

[0065] Next, as shown in Figure 11, the first and second molding dies 66, 68 are opened to remove the liner molding body 104. The first molding die 66 and the second molding die 68 are moved away from each other, and the liner molding body 104 is removed from the molding section 70 of the opened mold 64. The mold opening direction of the mold 64 is perpendicular to the axial direction of the shaft 86. Excess portions Pa of the parison P are formed at one end and the other end in the axial direction of the liner molding body 104. The excess portions Pa are unnecessary portions of the parison P that are surplus outside the mold 64. The excess portions Pa are cut off by a cutting device (not shown).

[0066] Next, as shown in FIG. 12, a boss attachment process is performed to attach the first and second bosses 16a, 16b to the first and second attachments 22, 24, and a filament winding process is performed to form the reinforcing layer 14 on the outer peripheral surface of the liner molded body 104. In the boss attachment process, the first boss 16a is brought close to the first cylindrical portion 32 of the first attachment 22 from the flange portion 56 side. The flange portion 56 is inserted into the first recess 28, and the fastened portion 60 of the boss body 54 is screwed into the first fastening portion 42 of the first cylindrical portion 32 (see FIG. 2). This coaxially connects the first attachment 22 and the first boss 16a. The gas flow path 58 of the first boss 16a communicates with the first hole 36.

[0067] In the boss mounting process, the second boss 16b is brought close to the second cylindrical portion 44 of the second attachment 24 from the flange portion 56 side. The flange portion 56 is inserted into the second recess 30, and the fastened portion 60 of the boss body 54 and the second fastening portion 52 of the second cylindrical portion 44 are screwed together (see FIG. 3). This coaxially connects the second attachment 24 and the second boss 16b, and the first boss 16a and the second boss 16b are concentrically arranged. The gas flow path 58 of the second boss 16b and the second hole 47 are connected to each other.

[0068] After the boss attachment process, the filament winding process is carried out. One end and the other end in the axial direction of the shaft 86 are supported by a rotary drive unit 106 of a filament winding device (not shown). By driving the rotary drive unit 106, the liner molding 104 rotates around the shaft 86. After winding the reinforcing fibers 14a multiple times around the outer circumferential surface of the liner molding 104, the resin is heated to harden, thereby forming the reinforcing layer 14. That is, in the filament winding process, the shaft 86 can be used as a jig for fixing and rotating the liner molding 104. By forming the reinforcing layer 14 on the outer circumferential surface of the liner molding 104, the high-pressure tank 10 including the liner molding 104 is constructed.

[0069] 13, a removal step is performed to remove the shaft 86 from the liner molding 104. The removal step may be performed before the filament winding step. In this case, instead of the shaft 86, a separate jig is used to rotate the liner 12 from which the shaft 86 has been removed.

[0070] In the process of removing the shaft 86, the shaft 86 is rotated relative to the liner molding 104 while the liner molding 104 shown in FIG. 14A is held. The direction of rotation of the shaft 86 is opposite to the direction of rotation when the shaft 86 is assembled to the first and second attachments 22, 24 (when forming the shaft assembly 102). As the shaft 86 rotates, the first male threaded portion 96 of the first support portion 88 is disengaged from the first female threaded portion 38 of the first attachment 22 (see FIG. 14B), and the second male threaded portion 98 of the second support portion 90 is disengaged from the second female threaded portion 48 of the second attachment 24. In other words, the state in which the shaft 86 is held by the first and second attachments 22, 24 is released, and the shaft 86 becomes detachable from the first and second attachments 22, 24. 13, by moving the shaft 86 axially from the first attachment 22 toward the second attachment 24, the first hole 36 and the second hole 47 are arranged concentrically. The shaft 86 is taken out of the liner molding 104 through the first and second hole portions 36, 47. This results in a liner 12 (high-pressure tank 10) from which the shaft 86 has been removed from the liner molding 104.

[0071] As shown in a first modified example in FIG. 15A , the inner diameter of the second hole 47a of the second attachment 24b may be larger than the inner diameter of the first hole 36a of the first attachment 22b, and the diameter of the second support portion 90 of the shaft 86 may be larger than the diameter of the first support portion 88 of the shaft 86. As a result, as shown in FIG. 15B , in the detachment process, the shaft 86 is removed from the first and second attachments 22b, 24b. In the detachment process, the shaft 86 is rotated relative to the liner molding 104 to release the engagement between the first male thread portion 96 and the first female thread portion 38a, and also release the engagement between the second male thread portion 98 and the second female thread portion 48a. The shaft 86 is moved relative to the liner molding 104 in a direction from the first attachment 22b toward the second attachment 24b.

[0072] The configuration for detachably holding the shaft 86 to the first attachment 22, 22b and the second attachment 24, 24b is not limited to the configuration formed by the first female threaded portions 38, 38a of the first attachments 22, 22b and the first male threaded portion 96 of the shaft 86, and the second female threaded portions 48, 48a of the second attachments 24, 24b and the second male threaded portion 98 of the shaft 86. First and second holding mechanisms 110, 112 according to a second modified example shown in FIG. 16A are provided on the shaft 114. The first holding mechanism 110 is provided on a shaft main body 114a of the shaft 114 and detachably holds the first attachment 22 to the shaft main body 114a. The second holding mechanism 112 is provided on the shaft main body 114a of the shaft 114 and detachably holds the second attachment 24 to the shaft main body 114a.

[0073] The first retaining mechanism 110 is disposed on the first support portion 88 of the shaft main body 114a. The first retaining mechanism 110 includes a pair of first locking members 116a, 116b and a pair of first resilient members 118a, 118b. The first accommodating hole 120 of the shaft main body 114a opens in a radial direction perpendicular to the axis of the shaft 114. When the first support portion 88 of the shaft 114 is held by the first attachment 22, the pair of first locking members 116a, 116b and the first accommodating hole 120 are disposed on both axial sides of the first attachment 22. The pair of first locking members 116a, 116b and the first accommodating hole 120 are disposed in pairs, spaced apart in the axial direction. That is, the pair of first locking members 116a, 116b are disposed on both axial sides of the first attachment 22 in the axial direction of the shaft 114.

[0074] The pair of first locking members 116a, 116b are housed in the first accommodating hole 120 and are displaceable in the radial direction of the shaft main body 114a. The first locking members 116a, 116b are arranged radially outward in the first accommodating hole 120. The first locking members 116a, 116b protrude radially outward from the outer circumferential surface of the shaft main body 114a, thereby locking the first attachment 22 in the axial direction of the shaft main body 114a (shaft 114). The first locking members 116a, 116b are locked to the shaft main body 114a so as not to come off radially outward.

[0075] The first resilient members 118a, 118b are disposed radially inward relative to the first locking members 116a, 116b. The first resilient members 118a, 118b have a resilient force that urges the first locking members 116a, 116b radially outward from the shaft main body 114a. The resilient force of the first resilient members 118a, 118b causes the pair of first locking members 116a, 116b to protrude radially outward from the outer circumferential surface of the first support portion 88. As a result, the first attachment 22 is locked to the shaft 114 in the axial direction by the first locking members 116a, 116b. Relative movement in the axial direction between the first support portion 88 of the shaft 114 and the first attachment 22 is prevented.

[0076] 16B, when the shaft 114 having the first holding mechanism 110 moves axially relative to the first attachment 22, the first attachment 22 and the first locking member 116a come into contact with each other, and the first locking member 116a moves radially inward against the elastic force of the first resilient member 118a. At this time, the first locking member 116a can move to a position where it does not protrude radially outward from the outer circumferential surface of the first support portion 88 (shaft main body 114a). When the first locking member 116a is accommodated in the first accommodating hole 120, the engagement of the first attachment 22 with the shaft 114 in the axial direction of the shaft 114 is released. The shaft 114 can then move axially relative to the first attachment 22.

[0077] 16A, the second holding mechanism 112 is disposed on the second support portion 90, spaced apart from the first holding mechanism 110 in the axial direction of the shaft 114. The second holding mechanism 112 has a pair of second locking members 122a, 122b and a pair of second resilient members 124a, 124b. The second accommodating hole 126 of the shaft main body 114a opens in a radial direction perpendicular to the axis of the shaft 114. When the second support portion 90 of the shaft 114 is held by the second attachment 24, the pair of second locking members 122a, 122b and the second accommodating hole 126 are disposed on both axial sides of the second attachment 24. The pair of second locking members 122a, 122b and the second accommodating hole 126 are disposed in pairs, spaced apart in the axial direction. That is, in the axial direction of the shaft 114, a pair of second locking members 122a, 122b are arranged on both axial sides of the second attachment 24.

[0078] The pair of second locking members 122a, 122b are housed in the second accommodating hole 126 and are displaceable in the radial direction of the shaft main body 114a. The second locking members 122a, 122b are arranged radially outward in the second accommodating hole 126. The second locking members 122a, 122b protrude radially outward from the outer circumferential surface of the shaft main body 114a, thereby enabling the second attachment 24 to be locked in the axial direction of the shaft main body 114a (shaft 114). The second locking members 122a, 122b are locked to the shaft main body 114a so as not to come off radially outward.

[0079] The second resilient members 124a, 124b are disposed radially inward relative to the second locking members 122a, 122b. The second resilient members 124a, 124b have a resilient force that biases the second locking members 122a, 122b radially outward from the shaft main body 114a. The resilient force of the second resilient members 124a, 124b causes the pair of second locking members 122a, 122b to protrude radially outward from the outer circumferential surface of the second support portion 90. As a result, the second locking members 122a, 122b axially lock the second attachment 24 to the shaft 114. Relative axial movement between the second support portion 90 of the shaft 114 and the second attachment 24 is prevented.

[0080] 16B, when the shaft 114 having the second holding mechanism 112 moves axially relative to the second attachment 24, the second attachment 24 and the second locking member 122a come into contact with each other, and the second locking member 122a moves radially inward against the elastic force of the second elastic member 124a. At this time, the second locking member 122a can move to a position where it does not protrude radially outward from the outer circumferential surface of the second support portion 90 (shaft main body 114a). When the second locking member 122a is accommodated in the second accommodating hole 126, the engagement of the second attachment 24 with the shaft 114 is released in the axial direction of the shaft 114. The shaft 114 can then move axially relative to the second attachment 24.

[0081] The embodiments of the present invention have the following advantages.

[0082] In an embodiment of the present invention, as shown in Fig. 10, the first and second attachments 22, 24 are integrally molded with the first and second dome portions 20a, 20b of the liner 12 during the blow molding process for molding the liner 12. Therefore, as shown in Fig. 12, when the first boss 16a is attached to the first attachment 22 and the second boss 16b is attached to the second attachment 24, concentricity between the first boss 16a and the second boss 16b can be ensured. As shown in Fig. 13, after the liner molding 104 is molded, the shaft 86 can be axially removed from the first and second attachments 22, 24 of the shaft assembly 102. This prevents unnecessary weight increase of the high-pressure tank 10 due to the use of the shaft 86, compared to a configuration in which the shaft remains incorporated in the liner molding.

[0083] 12, in the filament winding process, the shaft 86 of the liner molded body 104 can be used as a jig for fixing and rotating the liner 12. Therefore, in the filament winding process, there is no need to prepare and attach a separate jig for rotation, and the filament winding process can be carried out efficiently.

[0084] 7, in the shaft assembly 102, the first male threaded portion 96 of the shaft 86 is threadedly engaged with the first female threaded portion 38 of the first attachment 22, and the second male threaded portion 98 of the shaft 86 is threadedly engaged with the second female threaded portion 48 of the second attachment 24. Therefore, as shown in FIG. 14B, in the process of removing the shaft 86 from the liner molding 104, the first male threaded portion 96 can be disengaged from the first female threaded portion 38 and the second male threaded portion 98 can be disengaged from the second female threaded portion 48 by rotating the shaft 86 relative to the liner molding 104. This allows the shaft 86 to be easily removed from the liner molding 104 in the process of removing the shaft 86.

[0085] 15A, the inner diameter of the second hole 47a of the second attachment 24b is larger than the inner diameter of the first hole 36a of the first attachment 22b. Therefore, as shown in FIG. 15B, during the process of removing the shaft 86 from the liner molding 104, after the first male thread portion 96 of the shaft 86 has been removed from the first female thread portion 38a of the first attachment 22, the first male thread portion 96 of the shaft 86 can pass through the second female thread portion 48a of the second attachment 24 without rotating the shaft 86 relative to the liner molding 104. This makes it easy to remove the shaft 86 from the liner molding 104.

[0086] 16A, the shaft 114 has first locking members 116a, 116b and second locking members 122a, 122b. Therefore, in the shaft preparation step of assembling the shaft 114 to the first and second attachments 22, 24, the first locking members 116a, 116b and the second locking members 122a, 122b, which are biased radially outward and protrude from the outer circumferential surface of the shaft main body 114a, prevent the shaft 114 from moving axially relative to the first and second attachments 22, 24. This allows the first and second attachments 22, 24 to be stably fixed to the shaft 114. In the process of removing the shaft 114, the first locking members 116a, 116b and the second locking members 122a, 122b move radially inward from the outer circumferential surface of the shaft main body 114a against the resilient forces of the first resilient members 118a, 118b and the second resilient members 124a, 124b, and are accommodated in the first and second accommodating holes 120, 126. This releases the state in which the first locking members 116a, 116b and the second locking members 122a, 122b have prevented the shaft 114 from moving in the axial direction, allowing the shaft 114 to move axially relative to the first and second attachments 22, 24, and the shaft 114 can be removed from the first and second attachments 22, 24.

[0087] The above embodiment can be summarized as follows.

[0088] The above embodiment is a method for manufacturing a liner, which manufactures a liner (12) having a cylindrical cylinder portion (18), a first dome portion (20a) disposed at one end in the axial direction of the cylinder portion, and a second dome portion (20b) disposed at the other end in the axial direction of the cylinder portion, a shaft preparation step of preparing a shaft assembly (102) in which a first annular attachment (22) and a second annular attachment (24) are attached to the outer periphery of a tubular shaft (86, 114) that has an air supply hole (94) and extends linearly, wherein a first annular boss (16a) can be attached to the first attachment, and a second annular boss (16b) can be attached to the second attachment, the first attachment and the second attachment are arranged at a distance from each other in the axial direction of the shaft, and the shaft is detachable from the first attachment and the second attachment; a parison supplying step of supplying a cylindrical parison (P) made of a resin material toward a mold device (62) for molding the liner and disposing the shaft assembly inside the parison; a blow molding process in which the mold device is closed, and air is supplied into the parison from the air supply hole of the shaft to expand the parison, thereby obtaining a liner molded body (104) in which the first attachment having a first hole portion is integrally molded with the first dome portion, and the second attachment having a second hole portion arranged concentrically with the first hole portion is integrally molded with the second dome portion; a removing step of removing the shaft from the first attachment and the second attachment after the blow molding step, and taking the shaft out of the liner molded body; It has.

[0089] a filament winding step of winding reinforcing fibers (14a) around the outer peripheral surface of the liner between the blow molding step and the removing step; In the filament winding step, the liner molded body is supported by the shaft and rotated via the shaft.

[0090] The outer peripheral surface of the shaft has a first male thread portion (96) and a second male thread portion (98) provided at different positions in the axial direction of the shaft, The inner peripheral surface of the first attachment has a first female thread portion (38, 38a) that can be threadedly engaged with the first male thread portion, The inner peripheral surface of the second attachment has a second female thread portion (48, 48a) that can be threadedly engaged with the second male thread portion, In the shaft assembly, the first male threaded portion and the first female threaded portion are threadedly engaged with each other, and the second male threaded portion and the second female threaded portion are threadedly engaged with each other, In the removal process, the shaft is rotated relative to the liner molding to release the threaded engagement between the first male threaded portion and the first female threaded portion, and also release the threaded engagement between the second male threaded portion and the second female threaded portion.

[0091] The inner diameter of the second attachment is larger than the inner diameter of the first attachment, In the removing step, the shaft is moved relative to the liner molded body in a direction from the first attachment toward the second attachment.

[0092] The shaft a shaft body (114a) extending in the axial direction of the shaft; a first holding mechanism (110) provided on the shaft body and configured to detachably hold the first attachment; a second holding mechanism (112) that is provided on the shaft body at a position spaced from the first holding mechanism in the axial direction of the shaft and that detachably holds the second attachment; the first holding mechanism includes first locking members (116a, 116b) that are displaceable in the radial direction of the shaft body and protrude from the outer circumferential surface of the shaft body to lock the first attachment, and first resilient members (118a, 118b) that urge the first locking members outward in the radial direction of the shaft body, the second holding mechanism includes second locking members (122a, 122b) that are displaceable in the radial direction of the shaft body and protrude from the outer circumferential surface of the shaft body to lock the second attachment, and second resilient members (124a, 124b) that urge the second locking members outward in the radial direction of the shaft body, In the shaft preparation step, the first locking member and the second locking member protrude from the outer circumferential surface of the shaft body, and the first and second attachments engage with the shaft in the axial direction of the shaft; In the disengagement process, as the shaft moves relative to the liner molding in the axial direction, the first attachment displaces the first locking member radially inward of the shaft body against the biasing force of the first resilient member, and the second attachment displaces the second locking member radially inward of the shaft body against the biasing force of the second resilient member, thereby releasing the engagement of the first and second attachments with the shaft in the axial direction of the shaft.

[0093] a liner made of a resin material having a cylindrical cylinder portion, a curved first dome portion disposed at one axial end of the cylinder portion, and a curved second dome portion disposed at the other axial end of the cylinder portion; a first annular attachment that is integrally molded with the first dome portion on the axis of the cylinder portion and has a first hole portion (36) that penetrates the cylinder portion in the axial direction; a second attachment having an annular shape, which is integrally molded with the second dome portion on the axis of the cylinder portion, and has a second hole portion (47) which penetrates the cylinder portion in the axial direction and is arranged concentrically with the first hole portion; an annular first boss concentrically fixed to the first attachment; a second annular boss concentrically fixed to the second attachment; Equipped with.

[0094] The present invention is not limited to the above disclosure, and various configurations can be adopted without departing from the gist of the present invention. [Explanation of symbols]

[0095] 10...High-pressure tank 12, 12a...liner 14...Reinforcement layer 16a...First boss 16b...Second boss 18...Cylinder section 20a...First dome section 20b...Second dome section 22, 22a, 22b...First attachment 24, 24a, 24b...Second attachment 62...Molding equipment 86, 114...shaft 94...Air supply hole 102...shaft assembly P...Parison

Claims

1. 1. A method for manufacturing a liner having a cylindrical cylinder portion, a first dome portion disposed at one end in an axial direction of the cylinder portion, and a second dome portion disposed at the other end in the axial direction of the cylinder portion, the method comprising: a shaft preparation step of preparing a shaft assembly in which a first annular attachment and a second annular attachment are attached to the outer periphery of a tubular shaft having an air supply hole and extending linearly, wherein a first annular boss can be attached to the first attachment and a second annular boss can be attached to the second attachment, the first attachment and the second attachment are arranged spaced apart in the axial direction of the shaft, and the shaft is detachable from the first attachment and the second attachment; a parison supplying step of supplying a cylindrical parison made of a resin material toward a mold device for molding the liner and disposing the shaft assembly inside the parison; a blow molding process in which the mold device is closed, and air is supplied into the parison through the air supply hole of the shaft to expand the parison, thereby obtaining a liner molded product in which the first attachment having a first hole is integrally molded with the first dome portion, and the second attachment having a second hole arranged concentrically with the first hole is integrally molded with the second dome portion; a removing step of removing the shaft from the first attachment and the second attachment after the blow molding step, and taking the shaft out of the liner molded body; a filament winding step, which is provided between the blow molding step and the separating step, and which winds reinforcing fibers around an outer peripheral surface of the liner; and In the filament winding step, the liner molding is supported by the shaft.

2. The manufacturing method according to claim 1, In the filament winding step, the liner molding is rotated via the shaft.

3. The manufacturing method according to claim 1 or 2, the outer peripheral surface of the shaft has a first male thread portion and a second male thread portion provided at different positions in the axial direction of the shaft, an inner circumferential surface of the first attachment has a first female thread portion that can be threadably engaged with the first male thread portion; an inner circumferential surface of the second attachment has a second female thread portion that can be threadedly engaged with the second male thread portion; In the shaft assembly, the first male threaded portion and the first female threaded portion are threadedly engaged with each other, and the second male threaded portion and the second female threaded portion are threadedly engaged with each other, In the removal process, the shaft is rotated relative to the liner molding to release the threaded engagement between the first male thread portion and the first female thread portion and to release the threaded engagement between the second male thread portion and the second female thread portion.

4. The manufacturing method according to claim 3, The inner diameter of the second attachment is larger than the inner diameter of the first attachment, In the removing step, the shaft is moved relative to the liner molding in a direction from the first attachment toward the second attachment.

5. A method for manufacturing a liner, comprising: manufacturing a liner having a cylindrical cylinder portion, a first dome portion disposed at one axial end of the cylinder portion, and a second dome portion disposed at the other axial end of the cylinder portion, a shaft preparation step of preparing a shaft assembly in which a first annular attachment and a second annular attachment are attached to the outer periphery of a tubular shaft having an air supply hole and extending linearly, wherein a first annular boss can be attached to the first attachment and a second annular boss can be attached to the second attachment, the first attachment and the second attachment are arranged spaced apart in the axial direction of the shaft, and the shaft is detachable from the first attachment and the second attachment; a parison supplying step of supplying a cylindrical parison made of a resin material toward a mold device for molding the liner and disposing the shaft assembly inside the parison; a blow molding process in which the mold device is closed, and air is supplied into the parison through the air supply hole of the shaft to expand the parison, thereby obtaining a liner molded product in which the first attachment having a first hole is integrally molded with the first dome portion, and the second attachment having a second hole arranged concentrically with the first hole is integrally molded with the second dome portion; a removing step of removing the shaft from the first attachment and the second attachment after the blow molding step, and taking the shaft out of the liner molded body; and The shaft a shaft body extending in the axial direction of the shaft; a first holding mechanism provided on the shaft body and configured to detachably hold the first attachment; a second holding mechanism that is provided on the shaft body at a position spaced from the first holding mechanism in the axial direction of the shaft and that detachably holds the second attachment, the first holding mechanism includes a first locking member that is displaceable in a radial direction of the shaft body and protrudes from an outer peripheral surface of the shaft body to lock the first attachment, and a first resilient member that biases the first locking member outward in the radial direction of the shaft body, the second holding mechanism includes a second locking member that is displaceable in the radial direction of the shaft body and protrudes from the outer circumferential surface of the shaft body to lock the second attachment, and a second resilient member that biases the second locking member outward in the radial direction of the shaft body, In the shaft preparation step, the first locking member and the second locking member protrude from the outer circumferential surface of the shaft main body, and the first and second attachments engage with the shaft in the axial direction of the shaft; In the removal process, as the shaft moves axially relative to the liner molding, the first attachment displaces the first locking member radially inward of the shaft body against the biasing force of the first resilient member, and the second attachment displaces the second locking member radially inward of the shaft body against the biasing force of the second resilient member, thereby releasing the engagement of the first and second attachments with the shaft in the axial direction of the shaft.

6. a liner made of a resin material having a cylindrical cylinder portion, a curved first dome portion disposed at one axial end of the cylinder portion, and a curved second dome portion disposed at the other axial end of the cylinder portion; a cylindrical first attachment that is integrally molded with the first dome portion on the axis of the cylinder portion and has a first hole that penetrates the cylinder portion in the axial direction; a cylindrical second attachment that is integrally molded with the second dome portion on the axis of the cylinder portion, that has a second hole portion that penetrates the cylinder portion in the axial direction and is arranged concentrically with the first hole portion; a cylindrical first boss that is concentrically fixed to the first attachment and has a first gas flow passage that penetrates in the axial direction; a cylindrical second boss that is concentrically fixed to the second attachment and has a second gas flow passage that penetrates in the axial direction; Equipped with A high-pressure tank, wherein the first hole portion and the first gas flow path are arranged side by side in the axial direction, and the second hole portion and the second gas flow path are arranged side by side in the axial direction.

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