High-pressure tank and method for manufacturing high-pressure tank

Abstract

The present invention relates to a high-pressure tank and a method for manufacturing the same. The high-pressure tank includes an assembly, which is an assembly of a tube segment having a tube liner and a tube reinforcement layer covering the outer peripheral surface of the tube liner, a first dome segment having a first dome liner and a first dome reinforcement layer covering the outer peripheral surface of the first dome liner, and a second dome segment having a second dome liner and a second dome reinforcement layer covering the outer peripheral surface of the second dome liner. The tube segment and the first dome segment are assembled so that the first dome liner is located in the outer side portion of the high-pressure tank relative to the tube liner. The tube segment and the second dome segment are assembled so that the second dome liner is located in the outer side portion of the high-pressure tank relative to the tube liner.

Description

Technical Field

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

[0002] A high-pressure tank installed in a fuel cell electric vehicle or the like is known, comprising a liner having a cylindrical tube portion and a pair of dome portions provided at axially opposite ends of the tube portion, and a reinforcement layer made of a fiber-reinforced resin and covering the outer peripheral surface of the liner. The high-pressure tank having this structure is manufactured by first forming the liner and then using the formed liner as a winding core to form the reinforcement layer by winding a fiber bundle impregnated with resin around the outer peripheral surface of the liner using a filament winding method (FW method) (see, for example, Japanese Unexamined Patent Application Publication No. 2012-149739 (JP 2012-149739 A)). Summary of the Invention

[0003] Recently, as an alternative to the above-mentioned manufacturing method, a manufacturing method has been considered in which a mold is used to produce a segmented piece of the reinforcement layer and the segmented piece of the reinforcement layer is placed on the outer side of a separately prepared liner. However, when this manufacturing method is adopted, high-pressure tanks cannot be easily produced due to the required accuracy in dimensional matching between the segmented piece of the liner and the reinforcement layer.

[0004] The present invention provides a high-pressure tank that is easy to manufacture and a method for manufacturing the high-pressure tank.

[0005] A high-pressure tank according to a first aspect of the present invention includes an assembly comprising an assembled tube segment and two dome segments, and a spiral layer disposed outside the assembly. The tube segment includes a tube liner and a tube reinforcement layer covering the outer circumferential surface of the tube liner, and each of the dome segments includes a dome liner and a dome reinforcement layer covering the outer circumferential surface of the dome liner. The tube segment and the two dome segments are assembled so that the dome liner is positioned outside the high-pressure tank relative to the tube liner.

[0006] In the high-pressure tank according to the first aspect, the tube segment includes a tube liner and a tube reinforcement layer covering the outer peripheral surface of the tube liner, and each of the dome segments includes a dome liner and a dome reinforcement layer covering the outer peripheral surface of the dome liner. The tube segment and the two dome segments are assembled so that the dome liner is located outside the high-pressure tank relative to the tube liner. Therefore, the liner can be formed simply by assembling the dome segment and the tube segment, facilitating the manufacture of the high-pressure tank.

[0007] In the high-pressure tank according to the first aspect, the end portion of the tube liner may be a folded end portion folded back toward the outside of the high-pressure tank, and the folded end portion of the tube liner may be in contact with the dome liner in the assembly area of ​​each of the tube segment and the dome segment. With this arrangement, the sealing performance of the liner formed by the tube liner and the dome liner can be ensured.

[0008] In the high-pressure tank according to the first aspect, the spiral layer may include a high spiral layer configured to cover at least the tube segments and an outer spiral layer disposed outside the high spiral layer. The high spiral layer may extend over a portion of each of the dome segments beyond the assembly area of ​​the tube segments and dome segments. This arrangement maintains contact between the tube liner and the dome liner, reducing distortion in the assembly area of ​​the tube segments and the dome segments. This results in enhanced sealing performance of the high-pressure tank.

[0009] The method for manufacturing a high-pressure tank according to the second aspect of the present invention is a method for manufacturing a high-pressure tank as follows, which includes an assembly having a tube segment and two dome segment assembled together, and a spiral layer arranged on the outside of the assembly. The method includes: a segment forming process: forming a tube segment and a dome segment separately, wherein the tube segment has a tube lining and a tube reinforcement layer covering the outer peripheral surface of the tube lining, and each of the dome segments has a dome lining and a dome reinforcement layer covering the outer peripheral surface of the dome lining; an assembly process: forming an assembly by assembling the tube segment with the two dome segment; and a spiral layer forming process: forming a spiral layer on the outside of the assembly. During the assembly process, the tube segment and the two dome segment are assembled so that the dome lining is located in the outer part of the high-pressure tank relative to the tube lining.

[0010] In the method for manufacturing a high-pressure tank according to the second aspect, during assembly, the tube segment and the dome segment are assembled so that the dome liner is located outside the high-pressure tank relative to the tube liner. Therefore, the liner can be formed simply by assembling the dome segment and the tube segment, facilitating the manufacture of the high-pressure tank.

[0011] In the method for manufacturing a high-pressure tank according to the second aspect, during assembly, the tube segment can be press-fitted into each of the dome segments so that the dome liner contacts the tube reinforcement layer without contacting the tube liner. In this case, compared to a case where the tube segment is press-fitted into the dome segment so that the dome liner directly contacts the tube liner, there is no friction between the liners during press-fitting, and damage to the resulting seal can be prevented. Consequently, the liner's sealing performance can be ensured.

[0012] In the method for manufacturing a high-pressure tank according to the second aspect, the helical layer forming process may include a high helical layer forming process for forming a high helical layer covering at least the tube segment and an outer helical layer forming process for forming an outer helical layer outside the high helical layer. In the high helical layer forming process, the high helical layer may be formed to cover the tube segment and extend over a portion of each of the dome segments beyond the assembly area of ​​the tube segment and each of the dome segments. In this manner, outward expansion of the dome segment due to the restoring force of the tube segment can be suppressed, thereby reducing distortion in the assembly area of ​​the tube segment and the dome segment, and maintaining contact between the tube liner and the dome liner.

[0013] The method for manufacturing a high-pressure tank according to the second aspect may further include a seal inspection process to inspect the sealing performance of the assembly between the assembly process and the spiral layer formation process. During the seal inspection process, negative pressure may be applied to the interior of the assembly. In this manner, if a sealing problem occurs within the assembly, the assembly can be disassembled to allow the problematic segment to be replaced with another segment. Consequently, compared to, for example, performing a seal inspection after the spiral layer is formed on the outside of the assembly and the resin is cured or hardened, the problematic segment can be easily replaced.

[0014] According to the second aspect, the high-pressure tank can be easily manufactured. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, wherein like reference numerals represent like elements, and wherein:

[0016] Figure 1 is a schematic cross-sectional view showing the structure of a high-pressure tank according to one embodiment;

[0017] Figure 2 It shows Figure 1 An enlarged cross-sectional view of the portion indicated by A in FIG.

[0018] Figure 3 is a process diagram illustrating a method of manufacturing a high-pressure tank according to an embodiment;

[0019] Figure 4 is a cross-sectional view for describing the formation of a dome segment during the segment formation process;

[0020] Figure 5 is a cross-sectional view for describing the formation of a dome segment during the segment formation process;

[0021] Figure 6 is a cross-sectional view for describing the formation of a tube segment during the segment formation process;

[0022] Figure 7 is a cross-sectional view for describing the formation of a dome segment during the segment formation process;

[0023] Figure 8 is a cross-sectional view for describing the formation of a tube segment during the segment formation process;

[0024] Figure 9 is a cross-sectional view for describing an assembly process for assembling a tube segment and a dome segment;

[0025] Figure 10 is a partially enlarged cross-sectional view illustrating the press fit of the tube segment into the dome segment; and

[0026] Figure 11 It is a cross-sectional view used to describe the formation process of the high helical layer. DETAILED DESCRIPTION

[0027] With reference to the accompanying drawings, a high-pressure tank according to one embodiment of the present invention and a method for manufacturing the high-pressure tank will be described. In this embodiment, the high-pressure tank 1 is installed in a fuel cell electric vehicle, and its interior is filled with high-pressure hydrogen. However, the high-pressure tank 1 can be used in other applications. The gas that the high-pressure tank 1 can be filled with is not limited to high-pressure hydrogen, but can be selected from various compressed gases such as compressed natural gas (CNG), various liquefied gases such as liquefied natural gas (LNG) and liquefied petroleum gas (LPG), and other gases.

[0028] High-pressure tank

[0029] First, based on Figure 1 and Figure 2 Describe the structure of a high pressure tank. Figure 1 is a schematic cross-sectional view showing the structure of a high-pressure tank according to an embodiment, and Figure 2 It shows Figure 1 An enlarged cross-sectional view of the portion indicated by A in FIG. A high-pressure tank 1 of this embodiment is a generally cylindrical high-pressure gas storage container having both ends rounded into a dome shape. The high-pressure tank 1 includes a liner 2 having gas barrier properties, a reinforcement portion 3 covering the outer peripheral surface of the liner 2 and having multiple reinforcement layers, and a boss 4 attached to one end portion of the high-pressure tank 1.

[0030] The liner 2 is a hollow container having a storage space 5 for storing high-pressure hydrogen gas, and is formed from a resin material having gas barrier properties against hydrogen gas. The liner 2 includes a cylindrical tube liner 21 and a pair of dome liners (a first dome liner 22 and a second dome liner 23) located on opposite sides of the tube liner 21. The tube liner 21 extends a predetermined length in the direction of the axis L of the high-pressure tank 1. The first dome liner 22 and the second dome liner 23 are continuously formed on opposite sides of the tube liner 21, and the diameter of each of the first dome liner 22 and the second dome liner 23 decreases in a direction away from the tube liner 21.

[0031] Of the first dome liner 22 and the second dome liner 23, the first dome liner 22 has a tubular portion 221 formed in a portion thereof having the most reduced diameter. An end portion 222 of the first dome liner 22 opposite to the tubular portion 221 is formed to be warped toward the outside of the high-pressure tank 1. Similarly, an end portion 231 of the second dome liner 23 is also formed to be warped toward the outside of the high-pressure tank 1.

[0032] It is preferable that the resin material forming the liner 2 has good gas barrier properties, that is, the ability to retain a filling gas in the storage space 5. Such resin materials include thermoplastic or thermosetting resins to be described later.

[0033] Boss 4 is formed by machining a metal material such as aluminum or an aluminum alloy into a predetermined shape. A valve 6 for filling and discharging hydrogen gas into and from storage space 5 is attached to boss 4. Valve 6 is threadedly connected to boss 4. Valve 6 has an insert portion 61 that is inserted into tubular portion 221 of first dome liner 22 to seal tubular portion 221. Insert portion 61 is provided with a circumferential groove. An O-ring 62 is fitted into the circumferential groove to maintain a seal (in other words, fluid tightness) between insert portion 61 and tubular portion 221.

[0034] The reinforcement portion 3 has the function of reinforcing the liner 2 to improve the mechanical strength of the high-pressure tank 1, such as rigidity and pressure resistance, and has a plurality of (five in this embodiment) reinforcement layers formed of a fiber-reinforced resin or the like, wherein the reinforcing fibers (continuous fibers) are impregnated with the resin. Specifically, the reinforcement portion 3 has: a tube reinforcement layer 31, which covers the outer peripheral surface of the tube liner 21; a first dome reinforcement layer 32, which covers the outer peripheral surface of the first dome liner 22; a second dome reinforcement layer 33, which covers the outer peripheral surface of the second dome liner 23; a high helical layer 34, which covers the entire tube reinforcement layer 31, a portion of the first dome reinforcement layer 32, and a portion of the second dome reinforcement layer 33; and an outer helical layer 35, which covers the entire high helical layer 34, a portion of the first dome reinforcement layer 32, and a portion of the second dome reinforcement layer 33. The high helical layer 34 and the outer helical layer 35 correspond to the "helical layer" mentioned in the claims.

[0035] The pipe reinforcement layer 31 is a reinforcement layer corresponding to the pipe liner 21 and has a cylindrical shape that follows the shape of the pipe liner 21. The pipe reinforcement layer 31 is formed from a fiber-reinforced resin in which reinforcing fibers are impregnated with resin. The reinforcing fibers of the pipe reinforcement layer 31 are circumferentially oriented at an angle generally perpendicular to the axis L of the high-pressure tank 1. In other words, the reinforcing fibers of the pipe reinforcement layer 31 are oriented in the circumferential direction of the high-pressure tank 1.

[0036] The first dome reinforcement layer 32 is a reinforcement layer corresponding to the first dome liner 22, and has a dome shape following the shape of the first dome liner 22. Figure 1 As shown in FIG, the first dome reinforcement layer 32 has a protruding portion 321 that covers the outer circumferential surface of the tubular portion 221. The first dome reinforcement layer 32 is formed of a fiber-reinforced resin in which reinforcing fibers are impregnated with resin. The reinforcing fibers of the first dome reinforcement layer 32 are not oriented in the circumferential direction of the high-pressure tank 1, but extend in various directions intersecting the circumferential direction of the high-pressure tank 1.

[0037] The second dome reinforcement layer 33 is a reinforcement layer corresponding to the second dome liner 23 and has a dome shape that follows the shape of the second dome liner 23. The second dome reinforcement layer 33 is formed from a fiber-reinforced resin in which reinforcing fibers are impregnated with resin. The reinforcing fibers of the second dome reinforcement layer 33 are not oriented in the circumferential direction of the high-pressure tank 1, but extend in various directions intersecting the circumferential direction of the high-pressure tank 1.

[0038] In this regard, the reinforcing fibers of the tube reinforcement layer 31 are discontinuous (not connected) to the reinforcing fibers of the first dome reinforcement layer 32 or the second dome reinforcement layer 33. This is because the tube reinforcement layer 31, the first dome reinforcement layer 32, and the second dome reinforcement layer 33 are formed separately, as will be described below.

[0039] In this embodiment, the pipe liner 21 and the pipe reinforcement layer 31 covering the outer peripheral surface of the pipe liner 21 constitute the pipe segment 11, and the first dome liner 22 and the first dome reinforcement layer 32 covering the outer peripheral surface of the first dome liner 22 constitute the first dome segment 12. The second dome liner 23 and the second dome reinforcement layer 33 covering the outer peripheral surface of the second dome liner 23 constitute the second dome segment 13.

[0040] In the direction of the axis L of the high-pressure tank 1, one end portion of the tube segment 11 is assembled with the first dome segment 12, and the other end portion of the tube segment 11 is assembled with the second dome segment 13, so that the tube segment 11, the first dome segment 12, and the second dome segment 13 form an assembly 10. The tube segment 11 and the first dome segment 12 are assembled so that the first dome liner 22 is located in the outer portion of the high-pressure tank 1 relative to the tube liner 21. Similarly, the tube segment 11 and the second dome segment 13 are assembled so that the second dome liner 23 is located in the outer portion of the high-pressure tank 1 relative to the tube liner 21.

[0041] The opposite end portion of the tube liner 21 in the direction of the axis L of the high-pressure tank 1 is a folded end portion 211 that is folded back toward the outside of the high-pressure tank 1. Specifically, the folded end portion 211 is folded back toward the outside of the high-pressure tank 1 to surround the end portion of the tube reinforcement layer 31 located outside the tube liner 21, and is formed to extend to approximately half the thickness of the tube reinforcement layer 31. In the assembly area of ​​the tube segment 11 and the first dome segment 12 or the second dome segment 13, the folded end portion 211 of the tube liner 21 is in contact with the first dome liner 22 or the second dome liner 23.

[0042] More specifically, in the assembly area of ​​the tube segment 11 and the first dome segment 12, the folded end portion 211 of the tube liner 21 contacts the end portion 222 of the first dome liner 22. In the assembly area of ​​the tube segment 11 and the second dome segment 13, the folded end portion 211 of the tube liner 21 contacts the end portion 231 of the second dome liner 23. The "assembly area" mentioned herein refers to the portion where the tube segment 11 overlaps with the first dome segment 12 or the second dome segment 13.

[0043] Preferably, the thickness of the first dome liner 22 and the thickness of the second dome liner 23 are both greater than the thickness of the tube liner 21. In this case, irregularities in the contact position between the tube liner 21 and the first dome liner 22 or the second dome liner 23 can be absorbed, which produces an effect of ensuring the sealing performance of the liner 2 formed by the tube liner 21, the first dome liner 22, and the second dome liner 23.

[0044] The high helical layer 34 is a reinforcement layer formed by spirally winding a fiber bundle having reinforcing fibers impregnated with resin at a large angle on the outside of the component 10. Spiral winding is a method of winding the fiber bundle at a winding angle greater than 0° and less than 90° relative to the axis L direction of the high-pressure tank 1. Spiral winding is classified into small-angle spiral winding and large-angle spiral winding according to the size of the winding angle. Small-angle spiral winding is spiral winding with a small winding angle (for example, greater than 0° and equal to or less than 30°), and large-angle spiral winding is spiral winding with a large winding angle (for example, greater than 30° and less than 90°).

[0045] Since the high helical layer 34 is formed by large-angle helical winding of a fiber bundle having reinforcing fibers impregnated with resin, the reinforcing fibers of the high helical layer 34 are oriented to be inclined relative to the axis L of the high-pressure tank 1. Figure 1 and Figure 2 , the high helical layer 34 is not only formed over the entire area of ​​the tube reinforcement layer 31, but also one end portion thereof extends over a portion of the first dome segment 12 beyond the assembly area of ​​the tube segment 11 and the first dome segment 12, and the other end portion extends over a portion of the second dome segment 13 beyond the assembly area of ​​the tube segment 11 and the second dome segment 13.

[0046] The outer helical layer 35 is a reinforcement layer located in the outermost portion of the high-pressure tank 1 and is formed by spirally winding a fiber bundle having reinforcing fibers impregnated with resin at a small angle on the outer sides of the assembly 10 and the high helical layer 34. The reinforcing fibers of the outer helical layer 35 are also oriented so as to be inclined relative to the axis L of the high-pressure tank 1.

[0047] In the high-pressure tank 1 constructed as described above, the tube segment 11 has the tube liner 21 and the tube reinforcement layer 31 covering the outer peripheral surface of the tube liner 21, the first dome segment 12 has the first dome liner 22 and the first dome reinforcement layer 32 covering the outer peripheral surface of the first dome liner 22, and the second dome segment 13 has the second dome liner 23 and the second dome reinforcement layer 33 covering the outer peripheral surface of the second dome liner 23. The tube segment 11 is assembled with the first dome segment 12 or the second dome segment 13 so that the first dome liner 22 or the second dome liner 23 is located in the outer portion of the high-pressure tank 1 relative to the tube liner 21. Therefore, the high-pressure tank 1 can be easily manufactured because the liner 2 can be formed simply by assembling the tube segment 11 with the first dome segment 12 and the second dome segment 13.

[0048] The opposite end portion of the tube liner 21 is a folded end portion 211 that is folded back toward the outside of the high-pressure tank 1. The folded end portion 211 contacts the first dome liner 22 in the assembly area of ​​the tube segment 11 and the first dome segment 12, and the folded end portion 211 contacts the second dome liner 23 in the assembly area of ​​the tube segment 11 and the second dome segment 13. With this arrangement, the liner 2 formed by the tube liner 21, the first dome liner 22, and the second dome liner 23 can ensure sealing performance.

[0049] Furthermore, the high helical layer 34 is formed not only over the entire area of ​​the tube reinforcement layer 31 but also has one end portion extending over a portion of the first dome segment 12 beyond the assembly area of ​​the tube segment 11 and the first dome segment 12, and the other end portion extending over a portion of the second dome segment 13 beyond the assembly area of ​​the tube segment 11 and the second dome segment 13. With this arrangement, the contact state between the tube liner 21 and the first dome liner 22, as well as the contact state between the tube liner 21 and the second dome liner 23, is maintained by the high helical layer 34. Consequently, distortion in the assembly area of ​​the tube segment 11 and the first dome segment 12, and in the assembly area of ​​the tube segment 11 and the second dome segment 13, respectively, can be reduced, and the sealing performance of the high-pressure tank 1 can be enhanced.

[0050] Method for manufacturing high-pressure tank

[0051] A method of manufacturing the high-pressure tank 1 will be described. Figure 3 This is a process diagram illustrating a method for manufacturing a high-pressure tank according to one embodiment. The method for manufacturing a high-pressure tank 1 includes a segmented body forming process S1, an assembly process S2, a seal inspection process S3, a high helical layer forming process S4, and an outer helical layer forming process S5. The high helical layer forming process S4 and the outer helical layer forming process S5 constitute the "helical layer forming process" referred to in the claims.

[0052] Segmentation formation process S1

[0053] The segmented body forming process S1 is a process for separately forming the tube segmented body 11, the first dome segmented body 12, and the second dome segmented body 13. The formation of the tube segmented body 11 and the formation of the first and second dome segmented bodies 12 and 13, which are independent of each other, can be performed in parallel, or one can be performed before the other. Here, the method of forming the first and second dome segmented bodies 12 and 13 will be described first, and then the method of forming the tube segmented body 11 will be described.

[0054] In the method of forming the first dome segment 12 and the second dome segment 13, the fiber bundle F1 impregnated with resin is wound on the outer peripheral surface of the mandrel 100 by the FW method, for example, as shown in FIG. Figure 4As shown in . Specifically, the spindle 100 has a main body 101 and a shaft portion 102 extending outward from one end of the main body 101. As viewed in the axial direction of the shaft portion 102, the main body 101 is formed in a circular shape. A groove 101a extending circumferentially around the circumference of the main body 101 is formed in the outer peripheral surface of the middle portion of the main body 101 in the axial direction. The shaft portion 102 is rotatably supported by a rotating mechanism (not shown).

[0055] By rotating the mandrel 100, the wound body 30 is formed by winding the fiber bundle F1 to cover the outer peripheral surface of the mandrel 100. At this time, the fiber bundle F1 is also wound on the outer peripheral surface of the shaft portion 102, thereby forming a cylindrical protrusion 321 having a through hole 322 (see FIG. Figure 5 The fiber bundle F1 is wound at a winding angle of, for example, 30° to 50° relative to the axial direction of the shaft portion 102. The material of the mandrel 100 is not particularly limited, but is preferably metal to ensure strength to prevent the mandrel 100 from being deformed when the fiber bundle F1 is wound thereon.

[0056] The resin used to impregnate the fiber bundle F1 is not particularly limited, and a thermosetting resin, for example, can be used. Preferably, a thermosetting resin such as a phenolic resin, a melamine resin, a urea resin, or an epoxy resin is used. In this case, the fiber bundle F1 is wound around the mandrel 100 while the thermosetting resin is uncured. In particular, the use of an epoxy resin is preferred in terms of mechanical strength and other aspects. Epoxy resin has fluidity in its uncured state and forms a tough cross-linked structure after being thermally cured.

[0057] The resin used to impregnate the fiber bundle F1 may be a thermoplastic resin. Examples of the thermoplastic resin include polyetheretherketone, polyphenylene sulfide, polyacrylate, polyimide, polyamide, nylon 6, nylon 66, and polyethylene terephthalate. In this case, the fiber bundle F1 is wound around the mandrel 100 while the thermoplastic resin is heated and softened.

[0058] As the fibers constituting the fiber bundle F1, glass fibers, aramid fibers, boron fibers, carbon fibers, etc. In particular, carbon fibers are preferably used in terms of light weight and mechanical strength.

[0059] Next, by using the cutter 110 (see Figure 4 ) The wound body 30 formed around the outer peripheral surface of the mandrel 100 is divided into two pieces. Then, the wound body 30 thus divided is separated from the mandrel 100 to form a pair of dome reinforcement layers (a first dome reinforcement layer 32 and a second dome reinforcement layer 33), as shown in FIG. Figure 5 As shown in .

[0060] Specifically, in Figure 4Under the conditions shown in , the boss 4 is attached to the outer peripheral surface of the protruding portion 321. Then, the resin of the wound body 30 (i.e., the resin of the fiber bundle F1) is thermally cured or hardened. That is, when the resin used to impregnate the fiber bundle F1 is a thermosetting resin, the wound body 30 is heated so that the uncured thermosetting resin enters a completely cured state. Here, the "completely cured state" refers to a state in which the polymerization reaction of the uncured thermosetting resin is complete and no further curing occurs by heating. If the shapes of the first and second dome reinforcement layers 32 and 33 can be reliably maintained, the wound body 30 is heated so that the uncured thermosetting resin enters an incompletely cured state.

[0061] The "incompletely cured state" refers to a state in which the polymerization reaction of the uncured thermosetting resin is advanced by heating, and the fluidity of the thermosetting resin is reduced so that its shape can be reliably maintained in subsequent processes. In the following description of the specification, the completely cured state will be referred to as "main cure," and the incompletely cured state will be referred to as "pre-cure," and these will be collectively referred to as "thermal cure." On the other hand, when the resin used to impregnate the fiber bundle F1 is a thermoplastic resin, the softened thermoplastic resin is cooled, and the resin of the fiber bundle F1 is hardened.

[0062] Under the condition that the resin used to impregnate the fiber bundle F1 is thermally cured or hardened, the cutting blade of the cutter 110 is inserted into the groove 101a of the mandrel 100 while the mandrel 100 is rotating. In this way, the fiber bundle F1 is cut by the cutter 110, and the winding body 30 can be divided into two pieces. The separated winding body 30 is separated from the mandrel 100 to form a pair of dome reinforcement layers. One of the dome reinforcement layers thus formed having the protruding portion 321 will be referred to as the first dome reinforcement layer 32, and the other dome reinforcement layer without the protruding portion 321 will be referred to as the second dome reinforcement layer 33. The type of the cutter 110 is not particularly limited, but for example, a cutter having a blade formed on the outer peripheral surface of a rotating disk, a cutter having a blade formed on the side of a thin plate, or a cutter that cuts the fiber bundle F1 using a laser can be used.

[0063] The fiber bundle F1 is cut by the cutter 110 while the resin impregnating the fiber bundle F1 is thermally cured or hardened. Therefore, deformation of the fiber bundle F1 during cutting can be suppressed, and deformation of the first and second dome reinforcement layers 32 and 33 when removed from the mandrel 100 can be suppressed.

[0064] Although the fiber bundle F1 is cut by the cutter 110 under the condition that the resin of the fiber bundle F1 is thermally cured or hardened in this embodiment, the fiber bundle F1 may be cut by the cutter 110 without causing the resin to be thermally cured or hardened. In this case, the resin may be thermally cured or hardened after the fiber bundle F1 is cut by the cutter 110.

[0065] On the other hand, the tube reinforcement layer 31 is formed by winding the fiber sheet F2 on the outer surface of the cylindrical mandrel 200, such as Figure 6 The outer diameter of the mandrel 200 is equivalent to the inner diameter of the tube reinforcement layer 31. Although the material of the mandrel 200 is not particularly limited, it is preferably metal to ensure strength to prevent the mandrel 200 from being deformed when the fiber sheet F2 is attached to the mandrel 200.

[0066] To form the tube reinforcement layer 31, while the mandrel 200 is rotated in the circumferential direction by a rotating mechanism (not shown), the fiber sheet F2 is unwound and wound multiple times around the mandrel 200. The fiber sheet F2 is a reinforcing fiber sheet aligned in one direction and impregnated with resin, and the fiber sheet F2 is wound around the mandrel 200 so that the reinforcing fibers are oriented in the circumferential direction of the mandrel 200. In this way, the tube reinforcement layer 31 having the reinforcing fibers oriented in the circumferential direction is formed.

[0067] As the fiber sheet F2, for example, a so-called UD (unidirectional) sheet is used, in which a plurality of fiber bundles aligned in one direction are interwoven with binding yarns. However, a fiber sheet in which a plurality of fiber bundles aligned in a single direction are interwoven with a plurality of fiber bundles intersecting at right angles to the fiber bundles may also be used.

[0068] The reinforcing fibers of the fiber sheet F2 can be selected from materials similar to those exemplified for the fiber bundle F1 , and the resin used to impregnate the reinforcing fibers can be selected from resins similar to those exemplified for the fiber bundle F1 .

[0069] When the resin of the fiber sheet F2 is a thermosetting resin, the fiber sheet F2 wound on the mandrel 200 can be thermally cured under the conditions (heating temperature and heating time) of pre-curing or main curing, as in the case of the fiber bundle F1. On the other hand, when the resin of the fiber sheet F2 is a thermoplastic resin, the fiber sheet F2 wound on the mandrel 200 can be hardened by cooling, as in the case of the fiber bundle F1.

[0070] After the resin is heat-cured or hardened, the tube reinforcement layer 31 is removed from the mandrel 200. The heat-curing or hardening of the resin enhances the ability of the tube reinforcement layer 31 to maintain its shape. Therefore, the tube reinforcement layer 31 can be easily demolded from the mandrel 200, and when the tube reinforcement layer 31 is removed from the mandrel 200, it is unlikely or impossible for the tube reinforcement layer 31 to be deformed.

[0071] Although the tube reinforcement layer 31 is formed by winding the fiber sheet F2 on the outer surface of the mandrel 200 in this embodiment, the tube reinforcement layer 31 may be formed by hoop-winding a fiber bundle impregnated with resin by the FW method on the outer surface of the mandrel 200. In another method, the tube reinforcement layer 31 may be formed by a so-called centrifugal winding (CW) method (i.e., by attaching the fiber sheet to the inner surface of the rotating mandrel 200).

[0072] Subsequently, the first dome liner 22 is formed on the inner surface of the first dome reinforcement layer 32 to form the first dome partition 12 , and the second dome liner 23 is formed on the inner surface of the second dome reinforcement layer 33 to form the second dome partition 13 .

[0073] Specifically, for example, the first dome liner 22 is formed by applying a liquid or softened resin material to the inner surface of the first dome reinforcement layer 32, or by attaching a sheet made of a resin material to the inner surface of the first dome reinforcement layer 32. Figure 7 As shown in FIG, the end portion 222 of the first dome liner 22 is formed to be warped outward.

[0074] The resin material forming the first dome reinforcement layer 32 preferably has excellent gas barrier properties as described above, and can be selected from, for example, thermoplastic resins or thermosetting resins. Examples of thermoplastic resins include polypropylene resins, nylon resins (e.g., 6-nylon resin or 6,6-nylon resin), polycarbonate resins, acrylic resins, ABS resins, polyamide resins, polyethylene resins, ethylene-vinyl alcohol copolymer resins (EVOH), and polyester resins (e.g., polyethylene terephthalate). Examples of thermosetting resins include epoxy resins, modified epoxy resins represented by vinyl ester resins, phenolic resins, melamine resins, urea resins, unsaturated polyester resins, alkyd resins, polyurethane resins, and thermosetting polyimide resins.

[0075] In another example, the first dome liner 22 may be formed by applying a two-component thermosetting resin, such as epoxy resin, to the inner surface of the first dome reinforcement layer 32 and drying the applied resin. In another example, the first dome liner 22 made of a thermoplastic resin, such as nylon 6, may be formed by applying a resin containing a thermoplastic resin monomer, such as ε-caprolactam, and a catalyst to the inner surface of the first dome reinforcement layer 32 and heating the resin at a temperature equal to or higher than the temperature at which the thermoplastic resin monomer begins its polymerization reaction.

[0076] When the resin material of the first dome liner 22 is a thermosetting resin, the thermosetting resin may be an uncured resin, or may be pre-cured by heating so that the thermosetting resin is not completely cured, or may be cured by heating so that the thermosetting resin is completely cured. When the resin material of the first dome liner 22 is a thermoplastic resin, the thermoplastic resin is hardened.

[0077] When the resin material is thermally cured or hardened, the first dome divided body 12 having the first dome liner 22 and the first dome reinforcement layer 32 covering the outer peripheral surface of the first dome liner 22 is formed.

[0078] The method of forming the second dome segment 13 by forming the second dome liner 23 on the inner surface of the second dome reinforcement layer 33 is similar to the method of forming the first dome segment 12 described above and will not be described. The second dome liner 23 is formed on the inner surface of the second dome reinforcement layer 33 so that the end portion 231 of the second dome liner 23 is warped outward (see Figure 7 ).

[0079] Subsequently, the pipe lining 21 is formed on the inner surface of the pipe reinforcement layer 31 to form the pipe segment 11. The method of forming the pipe segment 11 is similar to the method of forming the first dome segment 12 described above, and therefore will not be described. Figure 8 As shown in FIG, the opposite end portions of the pipe liner 21 thus formed are respectively folded end portions 211 folded outward.

[0080] When the first dome liner 22 is formed on the inner surface of the first dome reinforcement layer 32, the second dome liner 23 is formed on the inner surface of the second dome reinforcement layer 33, and the pipe liner 21 is formed on the inner surface of the pipe reinforcement layer 31, it is preferred that the thicknesses of both the first dome liner 22 and the second dome liner 23 be greater than the thickness of the pipe liner 21. With this arrangement, when the assembly 10 is formed in the subsequent assembly process S2, irregularities at the contact position between the pipe liner 21 and the first dome liner 22 or the second dome liner 23 can be absorbed, so that the liner 2 formed of the pipe liner 21, the first dome liner 22, and the second dome liner 23 can ensure sealing performance.

[0081] Assembly process S2

[0082] In the assembly process S2, the tube segment 11 and the pair of dome segments (the first dome segment 12 and the second dome segment 13) formed in the segment forming process S1 are assembled together to form the assembly 10. Figure 9 As shown in , one end portion of the tube segment 11 is mounted to the first dome segment 12, and the other end portion of the tube segment 11 is mounted to the second dome segment 13. At this time, the first dome segment 12 and the tube segment 11 are assembled so that the first dome liner 22 is located in the outer portion of the high-pressure tank 1 relative to the tube liner 21, and the second dome segment 13 and the tube segment 11 are assembled so that the second dome liner 23 is located in the outer portion of the high-pressure tank 1 relative to the tube liner 21.

[0083] More specifically, if Figure 10 As shown in , first, the pipe segment 11 is press-fitted into the first dome segment 12 at a predetermined extrusion force f, so that the first dome liner 22 contacts the pipe reinforcement layer 31 without contacting the pipe liner 21. Similarly, the pipe segment 11 is press-fitted into the second dome segment 13 at a predetermined extrusion force f, so that the second dome liner 23 contacts the pipe reinforcement layer 31 without contacting the pipe liner 21.

[0084] Then, when the squeezing force f is released, the tube segment 11 expands under the action of the restoring force. As a result, a force is applied from the tube segment 11 located on the inside to the first dome segment 12 or the second dome segment 13, so that the dome segment expands outward. Therefore, both the first dome liner 22 and the tube liner 21 are deformed, and the end portion 222 of the first dome liner 22 abuts against the folded end portion 211 of the tube liner 21 (see FIG. 2 ). Figure 1 ). Then, the sealing portion of the liner 2 is formed at the contact position between the end portion 222 of the first dome liner 22 and the folded end portion 211 of the pipe liner 21. Similarly, the second dome liner 23 and the pipe liner 21 are also deformed, and the end portion 231 of the second dome liner 23 abuts against the folded end portion 211 of the pipe liner 21 (see Figure 1 ). Then, a sealing portion of the liner 2 is formed at a contact position between the end portion 231 of the second dome liner 23 and the folded end portion 211 of the tube liner 21. In this way, the assembly 10 is formed.

[0085] When assembling the tube segment 11 with the first dome segment 12 or the second dome segment 13, the assembly operation can be performed after the tube liner 21, the first dome liner 22, and the second dome liner 23 are heated to promote deformation of the linings. This makes it easier to absorb irregularities at the contact points between the tube liner 21 and the first dome liner 22, and at the contact points between the tube liner 21 and the second dome liner 23, thereby making it easier to ensure the proper contact between the tube liner 21 and the first dome liner 22 or the second dome liner 23. Alternatively, only the tube liner 21, or only the first dome liner 22 and the second dome liner 23, may be heated in addition to the tube liner 21, the first dome liner 22, and the second dome liner 23. When the first dome liner 22 and the second dome liner 23 are formed to have a greater thickness than the tube liner 21, it is preferable to heat the first dome liner 22 and the second dome liner 23.

[0086] Seal inspection process S3

[0087] The sealing inspection process S3 is a process for inspecting the sealing performance of the component 10 formed in the assembly process S2. In the sealing inspection process S3, the sealing performance of the component 10 is inspected by applying negative pressure to the inside of the component 10. By performing the sealing inspection in the state of the component 10 in this way, if air enters the component 10 (that is, if there is a sealing problem), the component 10 can be disassembled to allow the segment causing the problem to be replaced by another segment. Therefore, compared with the case where the sealing inspection is performed after the high helical layer 34 and the outer helical layer 35 are formed on the outside of the component 10 and the resin is cured or hardened, the segment causing the problem can be easily replaced.

[0088] High helical layer formation process S4

[0089] In the high helical layer forming process S4, the high helical layer 34 is formed by winding a fiber bundle impregnated with resin in layers by large-angle helical winding on the outer peripheral surface of at least the tube segment 11 of the module 10 that has no problem in the sealing inspection. The number of layers of the fiber bundle thus wound is not particularly limited as long as sufficient strength of the high helical layer 34 is ensured, but can be, for example, approximately 2 to 10 layers.

[0090] The reinforcing fibers of the fiber bundle may be selected from materials similar to those exemplified above for the fiber bundle F1 , and the resin material used to impregnate the reinforcing fibers may be selected from resins similar to those exemplified above for the fiber bundle F1 .

[0091] like Figure 11, the high helical layer 34 is formed not only over the entire area of ​​the tube reinforcement layer 31, but also is formed so that one end portion of the high helical layer 34 extends over a portion of the first dome segment 12 beyond the assembly area of ​​the tube segment 11 and the first dome segment 12, and the other end portion of the high helical layer 34 extends over a portion of the second dome segment 13 beyond the assembly area of ​​the tube segment 11 and the second dome segment 13.

[0092] Outer helical layer formation process S5

[0093] In the outer helical layer forming process S5, the outer helical layer 35 is formed outside the high helical layer 34. More specifically, a resin-impregnated fiber bundle is spirally wound in layers at a small angle around the outer peripheral surface of the high helical layer 34 formed in the high helical layer forming process S4 and the outer peripheral surfaces of the first dome segment 12 and the second dome segment 13 not covered by the high helical layer 34. The number of layers of fiber bundles thus wound is not limited as long as sufficient strength of the outer helical layer 35 is ensured, but can be, for example, approximately 2 to 10 layers.

[0094] The reinforcing fibers of the fiber bundle may be selected from materials similar to those exemplified above for the fiber bundle F1 , and the resin material used to impregnate the reinforcing fibers may be selected from resins similar to those exemplified above for the fiber bundle F1 .

[0095] When the resin used to impregnate the fiber bundle is a thermosetting resin, the outer helical layer 35 undergoes primary curing after the fiber bundle is wound. At this time, if the resin of the assembly 10 and the resin of the high helical layer 34 are thermosetting resins and have not yet fully cured, these resins also undergo primary curing. When the resin used to impregnate the fiber bundle is a thermoplastic resin, the outer helical layer 35 is left to cool or forced to cool, thereby hardening.

[0096] After the outer helical layer 35 is formed in this manner, as shown in FIG. Figure 1 As shown in , the valve 6 is attached to the boss 4 , thereby completing the manufacture of the high-pressure tank 1 .

[0097] In the method for manufacturing a high-pressure tank according to this embodiment, in assembly process S2, the first dome segment 12 and the tube segment 11 are assembled so that the first dome liner 22 is located in the outer portion of the high-pressure tank 1 relative to the tube liner 21, and the second dome segment 13 and the tube segment 11 are assembled so that the second dome liner 23 is located in the outer portion of the high-pressure tank 1 relative to the tube liner 21. With this arrangement, the liner 2 can be formed simply by assembling the tube segment 11, the first dome segment 12, and the second dome segment 13, thereby facilitating the manufacture of the high-pressure tank 1.

[0098] Furthermore, in assembly process S2, pipe segment 11 is press-fitted into first dome segment 12 such that first dome liner 22 contacts pipe reinforcement layer 31 without contacting pipe liner 21, and pipe segment 11 is press-fitted into second dome segment 13 such that second dome liner 23 contacts pipe reinforcement layer 31 without contacting pipe liner 21. In this manner, compared to a case where press-fitting of these segments is performed such that first dome liner 22 or second dome liner 23 directly contacts pipe liner 21, there is no friction between the liners during fitting, and the resulting seal can be prevented from being damaged. Consequently, the sealing performance of liner 2 can be ensured.

[0099] In the high helical layer forming process S4, the high helical layer 34 is formed not only over the entire area of ​​the tube reinforcement layer 31, but is also formed so that one end portion of the high helical layer 34 extends over a portion of the first dome segment 12 beyond the assembly area of ​​the tube segment 11 and the first dome segment 12, and the other end portion of the high helical layer 34 extends over a portion of the second dome segment 13 beyond the assembly area of ​​the tube segment 11 and the second dome segment 13. In this way, outward expansion of the first dome segment 12 or outward expansion of the second dome segment 13 due to the restoring force of the tube segment 11 can be suppressed, thereby reducing distortion in the assembly area of ​​the tube segment 11 and the first dome segment 12 or the second dome segment 13, and maintaining the contact state between the tube liner 21 and the first dome liner 22 or the second dome liner 23.

[0100] Although one embodiment of the present invention has been described in detail, the present invention is not limited to the illustrated embodiment, but various design changes may be made without departing from the principle of the present invention described in the claims.

Claims

1. A high-pressure tank, characterized in that include: an assembly having a tube segment and two dome segments assembled together; as well as a helical layer, the helical layer being arranged on the outside of the component, The pipe segment has a pipe lining and a pipe reinforcement layer covering the outer peripheral surface of the pipe lining. Each of the two dome segment bodies has a dome lining and a dome reinforcement layer covering the outer peripheral surface of the dome lining. wherein the tube segment and the two dome segment are assembled so that the dome liner is located in the outer portion of the high-pressure tank relative to the tube liner, The end portion of the pipe liner is a folded end portion folded back toward the outside of the high-pressure tank, In an assembly area of ​​the tube segment and each of the two dome segments, the folded end portion of the tube liner is in contact with the dome liner.

2. The high-pressure tank according to claim 1, characterized in that: The helical layer includes a high helical layer configured to cover at least the tube segment and an outer helical layer provided outside the high helical layer. The high helical layer extends over a portion of each of the two dome segments beyond an assembly area of ​​the tube segment and each of the two dome segments.

Images