Method for manufacturing tank

Abstract

To provide a method for manufacturing a tank capable of confirming quality of a liner even when the liner is integrated with a nozzle.SOLUTION: A method for manufacturing a tank 10 comprises: forming two or more liner split bodies, including an opening split body having an opening part 13 formed therein, and a nozzle 14; press-fitting the nozzle 14 into the opening part 13 of the opening split body; joining the opening split body and the nozzle 14 by heating an overlapping part 130 of the opening split body with the nozzle 14 from inside the opening split body; and forming a liner 11 by assembling two or more liner split bodies including the opening split body.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a method for manufacturing a tank. [Background technology]

[0002] Conventionally, an example of such a technical field is described in Patent Document 1. The tank described in Patent Document 1 includes a liner having a tank shape, and a nozzle that is integrated with the liner and has a flange portion, and the flange portion of the nozzle is provided with a key groove and a plurality of holes to prevent the nozzle from falling off the liner.

[0003] When manufacturing a tank having such a structure, a metal mouthpiece having a key groove and a plurality of holes is first formed in the flange portion, and then a liner is formed by insert molding so that the liquid polymer material flows into the key groove and the plurality of holes. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2012-514727 Summary of the Invention [Problem to be solved by the invention]

[0005] In the tank manufacturing method described above, the nozzle and liner are integrated by insert molding, so when inspecting the joint between the liner and nozzle for foreign objects or voids, for example with X-rays, halation occurs near the nozzle, making it impossible to confirm the quality of the liner.

[0006] The present invention has been made to solve such technical problems, and aims to provide a tank manufacturing method that allows the quality of the liner to be confirmed even when the liner and nozzle are integrated. [Means for solving the problem]

[0007] The method for manufacturing a tank according to the present invention is a method for manufacturing a tank having a resin liner having an opening and a metal nozzle pressed into the opening, and is characterized by including a first step of forming two or more liner divisions including an opening division in which the opening is formed and the nozzle, a second step of pressing the nozzle into the opening of the opening division, a third step of joining the opening division and the nozzle by heating the overlapping portion of the opening division and the nozzle from inside the opening division, and a fourth step of forming the liner by assembling the two or more liner divisions including the opening division.

[0008] In the tank manufacturing method according to the present invention, after forming two or more liner segments including an opening segment with an opening formed therein, and a mouthpiece, the mouthpiece is press-fitted into the opening of the opening segment, so that, compared to conventional insert molding, the quality of the liner segments can be checked before the mouthpiece is pressed in. As a result, even when the liner and the mouthpiece are integrated, the quality of the liner can be checked.

[0009] In the tank manufacturing method according to the present invention, it is preferable that in the third step, an infrared-transparent member is disposed from the inside of the opening divided body, and the overlapping portion of the opening divided body is heated by an infrared heater via the infrared-transparent member while the overlapping portion of the opening divided body is held by the infrared-transparent member. In this way, the overlapping portion can be heated while the shape of the overlapping portion of the opening divided body is maintained by the infrared-transparent member.

[0010] In the method for manufacturing a tank according to the present invention, it is preferable that in the first step, the surface of the nozzle that contacts the overlapping portion of the opening divided body is anodized, and in the third step, heating is performed at a temperature below the melting point of the resin material forming the liner. By anodizing the surface of the nozzle that contacts the overlapping portion of the opening divided body, it becomes possible to join the nozzle and the liner at a relatively low temperature. Therefore, even if the nozzle and the liner are heated at a temperature below the melting point of the resin material forming the liner, the nozzle and the liner can be joined. Moreover, since the heating is performed at a temperature below the melting point of the resin material forming the liner, it is possible to suppress sagging of the resin material. Effect of the Invention

[0011] According to the present invention, the quality of the liner can be confirmed even when the liner and the nozzle are integrated. [Brief description of the drawings]

[0012] [Figure 1] FIG. 2 is a schematic cross-sectional view showing the structure of the tank. [Diagram 2] FIG. 4 is a flow diagram showing a manufacturing method of a tank according to the embodiment. [Diagram 3] FIG. 4 is a cross-sectional view showing the formation of a liner split body. [Figure 4] FIG. 4 is a cross-sectional view showing the press-fitting of a base. [Diagram 5] 10 is a schematic cross-sectional view showing heating of the overlapping portion of the first divided body or the opening divided body. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Below, an embodiment of a manufacturing method for the tank 10 will be described with reference to the drawings, but before that, the structure of the tank 10 will be described with reference to Fig. 1. The tank 10 is a high-pressure tank that is mounted on, for example, a fuel cell vehicle and filled with high-pressure hydrogen gas. The tank 10 is not limited to fuel cell vehicles and may be applied to other uses. In addition, the gas that can be filled into the tank 10 is not limited to hydrogen gas, but may be various compressed gases such as CNG (compressed natural gas), various liquefied gases such as LNG (liquefied natural gas) and LPG (liquefied petroleum gas), or other gases.

[0014] Fig. 1 is a schematic cross-sectional view showing the structure of a tank. The tank 10 is a storage container having a substantially cylindrical shape with both ends rounded into a dome shape, and includes a liner 11 having hydrogen gas barrier properties, and a resin reinforcement layer 12 made of a fiber-reinforced resin material that covers the outer surface of the liner 11. A substantially pot-shaped opening 13 (see Fig. 3) is formed at one end of the liner 11 in the axial L direction, and a nozzle 14 is attached to the opening 13. No opening is formed at the other end of the liner 11 in the axial L direction, and no nozzle is provided.

[0015] The liner 11 is a resin member that forms the storage space 15 filled with hydrogen gas. The resin that constitutes the liner 11 is preferably a resin that has good hydrogen gas barrier properties, that is, the ability to retain the hydrogen gas filled within the storage space 15. Examples of such resins include thermoplastic resins such as polyamide, polyethylene, ethylene-vinyl alcohol copolymer resin (EVOH), and polyester, and thermosetting resins such as epoxy.

[0016] The liner 11 of this embodiment is formed by assembling two or more liner divisions including an opening division having an opening 13. For example, as shown in Fig. 3(a), the liner 11 may be composed of three liner divisions, such as a dome-shaped first division (opening division) 111 having an opening 13 at its tip, a cylindrical second division 112, and a dome-shaped third division 113 located on the opposite side to the first division 111, or as shown in Fig. 3(b), the liner 11 may be composed of two liner divisions, such as a substantially bell-shaped opening division 114 having an opening 13 at its tip, and a substantially bell-shaped non-opening division 115 having no opening.

[0017] The nozzle 14 is made by processing a metal material such as stainless steel or aluminum into a generally pot-like shape. The nozzle 14 has a neck 141 that is held by the resin reinforcing layer 12, a curved shoulder 142 that bulges outward, and a sloped body 144 that gradually narrows from the curved shoulder 142 to a bottom 143. A through hole 145 that communicates with the storage space 15 of the tank 10 is provided in the center of the nozzle 14.

[0018] The resin reinforcing layer 12 covers the outer surface of the liner 11 and has the function of reinforcing the liner 11 to improve the mechanical strength, such as the rigidity and pressure resistance, of the tank 10. In addition, the resin reinforcing layer 12 is formed so as to cover the outer peripheral wall of the neck portion 141 of the nozzle 14, and reinforces the bonding state between the nozzle 14 and the liner 11.

[0019] A manufacturing method for the tank 10 will be described below with reference to Figures 2 to 5. As shown in Figure 2, the manufacturing method for the tank 10 according to this embodiment includes a liner segment body forming step S1, a mouthpiece forming step S2, a mouthpiece press-fitting step S3, a step S4 of joining the mouthpiece and the liner by heating, a liner segment body assembling step S5, and a resin reinforcing layer forming step S6.

[0020] The liner division body forming step S1 and the mouthpiece forming step S2 correspond to the "first step" described in the claims. Since the liner division body forming step S1 and the mouthpiece forming step S2 are independent steps, they may be performed in parallel, or either step may be performed first.

[0021] In step S1, each liner segment is formed by injection molding using a resin material. When the liner 11 is composed of three liner segments as shown in Fig. 3(a), for example, a thermoplastic resin is heated to a high temperature and melted, and then the resin is forced into a mold at a predetermined injection pressure and solidified to form a first segment 111, a second segment 112, and a third segment 113. When the first segment 111 is formed, an opening 13 for inserting a nozzle 14 is also formed at the same time.

[0022] 3(a), in conjunction with the formation of the opening 13, an enclosing portion 120 that surrounds and holds a portion of the curved shoulder portion 142 of the base 14, and an overlapping portion 130 that overlaps with the inclined body portion 144 of the base 14 to support the inclined body portion 144 are formed at the tip of the first divided body 111. In other words, the opening 13 is a space formed by the enclosing portion 120 and the overlapping portion 130.

[0023] Furthermore, when forming the first division 111 and the third division 113, it is preferable that the thickness of each dome end portion becomes thinner from the inside to the outside, and the thickness of both ends of the second division 112 in the axial L direction becomes thinner from the outside to the inside. In this way, when the first division 111 and the third division 113 are later assembled and joined to the second division 112, steps are less likely to be formed at the joint portions.

[0024] On the other hand, as shown in Fig. 3(b), when the liner 11 is composed of two liner division bodies, for example, a thermoplastic resin is heated to a high temperature and melted, and then pressed into a mold at a predetermined injection pressure and solidified to form an opening division body 114 and a non-opening division body 115. When the opening division body 114 is formed, the opening 13 into which the nozzle 14 is pressed is also formed at the same time. Similarly, accompanying the formation of the opening 13, an enclosure portion 120 and an overlapping portion 130 are formed at the tip of the opening division body 114.

[0025] Furthermore, when forming the opening divided body 114 and the non-opening divided body 115, it is preferable that the thickness of the end portion of one of these liner divided bodies (e.g., the opening divided body 114) becomes thinner from the inside to the outside, and the thickness of the end portion of the other (e.g., the non-opening divided body 115) becomes thinner from the outside to the inside. In this way, when the opening divided body 114 and the non-opening divided body 115 are later assembled and joined, a step is less likely to be formed at the joint portion.

[0026] In step S2, the nozzle 14 having the neck 141, the curved shoulder 142, the bottom 143, the beveled body 144 and the through hole 145 is formed by cutting, for example, using an aluminum material. At this time, it is preferable to apply an anodizing treatment to the surface of the nozzle 14 that contacts the overlapping portion 130 of the first divided body 111 (or the opening divided body 114) (i.e., the surface of the beveled body 144). In addition to the surface of the beveled body 144, it is further preferable to apply an anodizing treatment to the surface of the nozzle 14 that contacts the enclosure portion 120 of the first divided body 111 (or the opening divided body 114) (i.e., the surface of the curved shoulder 142).

[0027] The die press-fitting step S3 corresponds to the "second step" described in the claims. In this step S3, for example, as shown in Fig. 4, the die formed in step S2 is press-fitted into the opening 13 of the first divided body 111 (or the opening divided body 114) formed in step S1.

[0028] Step S4 of bonding the nozzle and the liner by heating corresponds to the "third step" described in the claims. In this step S4, the first divided body 111 (or the opening divided body 114) and the nozzle 14 are bonded by heating the overlapping portion 130 of the first divided body 111 (or the opening divided body 114) from the inside of the first divided body 111 (or the opening divided body 114).

[0029] Specifically, for example, as shown in Fig. 5, the first divided body 111 (or the opening divided body 114) into which the base 14 is press-fitted is arranged so that the base 14 is on the upper side and the first divided body 111 (or the opening divided body 114) is on the lower side. Next, an infrared transparent member 20 is arranged from the inside of the first divided body 111 (or the opening divided body 114), and while the infrared transparent member 20 holds the overlapping portion 130 of the first divided body 111 (or the opening divided body 114), the overlapping portion 130 is heated by the infrared heater 30 via the infrared transparent member 20. That is, in this step S4, the overlapping portion 130 is hot-pressed by utilizing the weight of the base 14.

[0030] The infrared transparent member 20 is formed of, for example, quartz glass, and has a bottomed cylindrical shape so as to fit the shape of the overlapping portion 130 of the first divided body 111 (or the opening divided body 114) and the bottom 143 of the base 14. Specifically, the infrared transparent member 20 has a bottom plate portion 201 that holds the bottom surface of the bottom 143 of the base 14 and the overlapping portion 130 of the first divided body 111 (or the opening divided body 114), and a side wall portion 202 that holds the overlapping portion 130.

[0031] When heating with the infrared heater 30, it is preferable to heat at a temperature below the melting point of the resin material forming the liner 11. As shown in Fig. 5, the infrared heater 30 is disposed near the side wall portion 202 of the infrared transparent member 20, and heats the overlapping portion 130 of the first divided body 111 (or the opening divided body 114) through the side wall portion 202. In order to ensure the quality of the liner 11, it is preferable not to heat any portion other than the overlapping portion 130 of the first divided body 111 (or the opening divided body 114).

[0032] After heating for a predetermined time, the infrared heater 30 is removed from the first divided body 111 (or the opening divided body 114), and further the infrared transparent member 20 is removed and removed.

[0033] The liner division assembly step S5 corresponds to the "fourth step" described in the claims. In this step S5, the liner divisions are assembled to form the liner 11. Specifically, when the liner 11 is composed of three liner divisions, the first division 111 joined to the mouthpiece 14 is assembled to one end of the second division 112, and the third division 113 is assembled to the other end of the second division 112 to form the liner 11. At that time, these liner divisions are assembled so that the end portions of the first division 111 and the third division 113 are positioned outside the end of the second division 112. An adhesive can be used when assembling these liner divisions.

[0034] Furthermore, when the liner 11 is composed of two liner segments, the opening segment 114 joined to the mouthpiece 14 and the non-opening segment 115 are assembled to form the liner 11. At that time, these liner segments are assembled so that the end portion of the opening segment 114 is positioned outside the end portion of the non-opening segment 115. An adhesive can be used when assembling these liner segments.

[0035] In the resin reinforcement layer formation step S6, a fiber bundle impregnated with resin is wound so as to cover the outer surface of the liner 11 and part of the outer surface of the nozzle 14, for example using a filament winding method (FW method), to form the resin reinforcement layer 12.

[0036] The resin impregnated into the fiber bundle is not particularly limited, and may be, for example, a thermosetting resin. As the thermosetting resin, it is preferable to use a thermosetting resin such as a phenol resin, a melamine resin, a urea resin, or an epoxy resin, and it is particularly preferable to use an epoxy resin from the viewpoint of mechanical strength, etc. Furthermore, a thermoplastic resin may be used as the resin impregnated into the fiber bundle. As the thermoplastic resin, polyether ether ketone, polyphenylene sulfide, polyacrylic ester, polyimide, polyamide, etc. may be used.

[0037] The fibers constituting the fiber bundle may be glass fibers, aramid fibers, boron fibers, carbon fibers, etc., and it is particularly preferable to use carbon fibers from the viewpoints of weight reduction and mechanical strength.

[0038] Next, the wound resin reinforcement layer 12 is solidified (in other words, the resin in the fiber bundle is solidified). The method for solidifying the resin reinforcement layer 12 is not particularly limited, but when the resin in the fiber bundle is made of a thermosetting resin, the resin in the fiber bundle is solidified by conveying it to a heat curing furnace and heating it at a predetermined temperature for a predetermined time. On the other hand, when the resin in the fiber bundle is made of a thermoplastic resin, the resin in the fiber bundle is solidified by cooling.

[0039] In the manufacturing method of the tank 10 according to the present embodiment, after forming two or more liner divisions including the first division 111 (or the opening division 114) with the opening 13 formed therein and the mouthpiece 14, the mouthpiece 14 is press-fitted into the opening 13 of the first division 111 (or the opening division 114), so that the quality of the liner division can be confirmed before the mouthpiece 14 is press-fitted, as compared with the conventional insert molding. That is, before the mouthpiece 14 is press-fitted, the first division 111 (or the opening division 114) is inspected for foreign matter, voids, etc. in the first division 111 (or the opening division 114) by, for example, X-rays while the first division 111 (or the opening division 114) is in a stand-alone state, and the mouthpiece 14 is press-fitted using the first division 111 (or the opening division 114) that has passed the quality inspection, and then the mouthpiece 14 is joined by heating. As a result, even when the liner 11 and the mouthpiece 14 are integrated, the quality of the liner 11 can be confirmed.

[0040] Furthermore, in step S4, an infrared-transparent member 20 is placed from the inside of the first divided body 111 (or the opening divided body 114), and while the overlapping portion 130 is held by the infrared-transparent member 20, the overlapping portion 130 is heated by the infrared heater 30 via the infrared-transparent member 20. Therefore, the overlapping portion 130 can be heated while the shape of the overlapping portion 130 is maintained by the infrared-transparent member 20.

[0041] Furthermore, by subjecting the surface of the inclined body portion 144 in contact with the overlapping portion 130 of the nozzle 14 to anodizing, it becomes possible to join the nozzle 14 and the first divided body 111 (or the opening divided body 114) at a relatively low temperature. Therefore, even when heating at a temperature below the melting point of the resin material forming the liner 11, the nozzle 14 and the liner 11 can be joined. Moreover, since heating is performed at a temperature below the melting point of the resin material forming the liner 11, there is an effect of suppressing sagging of the resin material.

[0042] [Example] As described in step S4 above, the inventors positioned the first divided body 111 with the nozzle 14 pressed into it so that the nozzle 14 was on the upper side and the first divided body 111 was on the lower side, then placed an infrared-transparent member 20 from the inside of the first divided body 111, held the overlapping portion 130 of the first divided body 111 with the infrared-transparent member 20, and heated the overlapping portion 130 with an infrared heater 30 to the temperatures shown in Table 1 below, and evaluated the bonding strength at each temperature.

[0043] A polyamide 6 (PA6) film was used for the first divided body 111, and aluminum was used for the nozzle 14. The surface of the inclined body portion 144 of the nozzle 14 was anodized. The evaluation of the bonding strength was performed in accordance with the international standard ISO19095 (bonding characteristic evaluation test). As shown in Table 1, the heating temperature was set lower than the melting point of PA6 (225°C) in both cases.

[0044] As can be seen from Table 1, when the bonding strength between the first divided body 111 and the base 14 at 80° C. is taken as the standard, the bonding strength at 150° C. is 1.3 times the standard, and the bonding strength at 200° C. is 1.5 times the standard. This shows that, under conditions below the melting point of the resin material that forms the liner, the higher the heating temperature, the higher the bonding strength.

[0045] TIFF2025014164000002.tif35157

[0046] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various design modifications can be made without departing from the spirit of the present invention as described in the claims. [Explanation of symbols]

[0047] 10: tank, 11: liner, 12: resin reinforcing layer, 13: opening, 14: nozzle, 20: infrared-transmitting member, 30: infrared heater, 111: first divided body, 112: second divided body, 113: third divided body, 114: opening divided body, 115: non-opening divided body, 120: enclosure, 130: overlapping portion, 141: neck portion, 142: curved shoulder portion, 143: bottom portion, 144: sloping body portion, 145: through hole, 201: bottom plate portion, 202: side wall portion

Claims

1. A method for manufacturing a tank having a resin liner having an opening and a metal cap press-fitted into the opening, comprising the steps of: a first step of forming two or more liner divisions including an opening division having the opening formed therein, and the mouthpiece; a second step of press-fitting the base into the opening of the opening division body; a third step of joining the aperture division body and the die by heating an overlapping portion of the aperture division body and the die from inside the aperture division body; a fourth step of forming the liner by assembling the two or more liner segments including the opening segment; A method for manufacturing a tank, comprising:

2. 2. The method for manufacturing a tank as described in claim 1, wherein in the third step, an infrared-transparent member is placed from the inside of the opening divider, and the overlapping portion of the opening divider is heated by an infrared heater via the infrared-transparent member while the infrared-transparent member holds the overlapping portion of the opening divider.

3. In the first step, a surface of the mouthpiece that comes into contact with the overlapping portion of the opening divided body is anodized, 3. The method for manufacturing a tank according to claim 1, wherein in the third step, the liner is heated at a temperature lower than the melting point of the resin material that forms the liner.

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