Tank manufacturing method

Abstract

To provide a manufacturing method for a tank that can shorten the curing time of a formed in place gasket (FIPG), and can save energy.SOLUTION: A manufacturing method for a tank 1 includes a step of forming an intermediate body comprising a liner 2 and a reinforcing layer 3, a step of applying a formed in place gasket (FIPG) to a position in an outer surface of the reinforcing layer 3 corresponding to a dome part, a step of arranging a protector 4 on the outer surface of the reinforcing layer 3 so that an inner surface 43 of the protector 4 is in contact with the position in the reinforcing layer 3 corresponding to the dome part, and a step of curing the FIPG by supplying high-temperature steam into the protector 4 via a blind hole 44 provided in the protector 4 and a pipe 82 of a pressing jig 8.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a method for manufacturing a tank, and more particularly to a method for manufacturing a tank equipped with a protector. [Background technology]

[0002] A known tank, such as a hydrogen tank, to be mounted on a fuel cell vehicle includes a liner having a cylindrical body and dome portions provided at both axial ends of the body, and a reinforcing layer that covers the liner. In addition, to ensure the impact resistance of the tank, protectors are disposed on the outer surface of the reinforcing layer at both ends of the liner (see, for example, Patent Document 1).

[0003] When manufacturing a tank with such a structure, first, a reinforcing layer is formed by winding multiple resin-impregnated fiber bundles around the outer surface of the liner using the filament winding (FW) method, and then a protector, which is made separately from the liner, is fixed to the outer surface of the reinforcing layer with an adhesive. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2014-190495 A Summary of the Invention [Problem to be solved by the invention]

[0005] Recently, in order to improve the airtightness and liquid tightness between the protector and the reinforcing layer, the use of a formed in place gasket (FIPG) to fix the protector to the outer surface of the reinforcing layer has been considered. However, a high temperature and high humidity environment is required to harden the FIPG, and it takes time for the protector and the reinforcing layer to become accustomed to the high temperature and high humidity atmosphere, which causes problems such as a long hardening time for the FIPG and a large input of thermal energy.

[0006] The present invention has been made to solve such technical problems, and has an object to provide a method for manufacturing a tank that can shorten the curing time of FIPG and achieve energy savings. [Means for solving the problem]

[0007] The method for manufacturing a tank according to the present invention is a method for manufacturing a tank including a liner having a cylindrical body portion and dome portions provided on both axial ends of the body portion, a reinforcing layer covering the liner, and a protector fixed to the outer surface of the reinforcing layer and formed of a breathable resin material, the method including the steps of: applying FIPG to at least one of a position on the outer surface of the reinforcing layer corresponding to the dome portion and to the inner surface of the protector, which has an outer surface that is the outside, an inner surface facing the reinforcing layer, and a plurality of holes extending from the outer surface toward the inner surface; arranging the protector on the outer surface of the reinforcing layer so that the inner surface of the protector abuts the position of the dome portion of the reinforcing layer; and hardening the FIPG by supplying high-temperature steam into the interior of the protector through the holes in the protector.

[0008] In the manufacturing method of the tank according to the present invention, the FIPG applied between the reinforcing layer and the protector can be humidified at a high temperature by supplying high-temperature steam to the inside of the protector through the holes in the protector. In addition, since the protector is made of a breathable resin material, the high-temperature steam can easily reach the entire area of ​​the FIPG and harden the FIPG. As a result, the hardening time of the FIPG can be shortened. In addition, the thermal energy can be reduced accordingly, so energy saving can be realized. Effect of the Invention

[0009] According to the present invention, the curing time of FIPG can be shortened, and energy savings can be achieved. [Brief description of the drawings]

[0010] [Figure 1] FIG. 2 is a schematic cross-sectional view showing the structure of the tank. [Diagram 2] 5A to 5C are process diagrams showing a manufacturing method of a tank according to an embodiment. [Diagram 3] 5A to 5C are schematic cross-sectional views for explaining a manufacturing method of the tank according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of a manufacturing method of a tank according to the present invention will be described with reference to the drawings. In the embodiment, the tank will be described as an example in which the tank is mounted on a fuel cell vehicle and filled with high-pressure hydrogen gas, but the tank may be used for other purposes. In addition, the gas that can be filled into the tank is not limited to high-pressure hydrogen gas, and compressed gases such as CNG (compressed natural gas), various liquefied gases such as LNG (liquefied natural gas) and LPG (liquefied petroleum gas), and other gases may be filled into the tank.

[0012] [Tank structure] First, the structure of the tank will be described with reference to Figure 1. As shown in Figure 1, the tank 1 is a high-pressure gas storage container having a generally cylindrical shape with both ends rounded into a dome shape, and includes a liner 2 having gas barrier properties, a reinforcing layer 3 covering the outer surface of the liner 2, and protectors 4 disposed on the outer surface of the reinforcing layer 3 at both ends of the liner 2.

[0013] The liner 2 is a hollow container having a storage space for storing high-pressure hydrogen, and is made of a resin material having gas barrier properties against hydrogen gas. The liner 2 is composed of a cylindrical body 21 and a pair of dome sections (first dome section 22, second dome section 23) provided at both ends of the body 21 in the axial direction. The body 21 extends a predetermined length along the axial L direction of the tank 1. The first dome section 22 and the second dome section 23 are formed continuously on both sides of the body 21, and each has a hemispherical shape so that the diameter decreases as it moves away from the body 21. In the following description, in order to avoid complication of the description, the first dome section 22 and the second dome section 23 may be collectively referred to as the "dome section".

[0014] An opening is formed at the top of each of the first dome section 22 and the second dome section 23. A first end base 5 is attached to the opening of the first dome section 22, and a second end base 6 is attached to the opening of the second dome section 23.

[0015] The liner 2 is integrally formed by rotational blow molding using a resin member such as polyethylene or nylon. The liner 2 may be formed by connecting a plurality of divided members by injection or extrusion molding instead of an integral molding manufacturing method such as rotational blow molding. Furthermore, the liner 2 may be formed by a metal material such as aluminum instead of a resin member.

[0016] The reinforcing layer 3 has a function of reinforcing the liner 2 to improve the mechanical strength of the tank 1, such as its rigidity and pressure resistance, and is formed by winding a fiber-reinforced resin around the outer peripheral surface of the liner 2 by the FW method. The fiber-reinforced resin is formed by impregnating a fiber bundle formed by bundling fibers having a diameter of, for example, about several μm with a thermosetting resin. Examples of the fiber include reinforcing fibers such as glass fiber, carbon fiber, aramid fiber, alumina fiber, boron fiber, steel fiber, PBO fiber, natural fiber, and high-strength polyethylene fiber, and it is particularly preferable to use carbon fiber from the viewpoints of light weight and mechanical strength.

[0017] Examples of the thermosetting resin include epoxy resin, modified epoxy resin such as vinyl ester resin, phenol resin, melamine resin, urea resin, unsaturated polyester resin, alkyd resin, polyurethane resin, and thermosetting polyimide resin. Note that a thermoplastic resin may be used as the resin impregnated into the fiber bundle.

[0018] The first end nozzle 5 and the second end nozzle 6 are each made by processing a metal material such as stainless steel or aluminum into a predetermined shape, and have a substantially cylindrical nozzle body 51, 61 and a flange 52, 62 fitted between the dome portion of the liner 2 and the reinforcing layer 3. The first end nozzle 5 and the second end nozzle 6 may have the same shape or different shapes. Furthermore, the tank 1 does not necessarily have to have two nozzles, and may have only one of them.

[0019] The protector 4 is a buffer member for protecting the tank 1 from impacts and stress due to the internal pressure of the tank 1, and is fixed to the outer surface of the reinforcing layer 3 at a position corresponding to the dome portion of the liner 2. As shown in Fig. 1, the protector 4 is bowl-shaped with an opening 41 in the center, and has an outer surface 42 that is the outside, an inner surface 43 that faces the reinforcing layer 3, and a plurality of blind holes 44 that extend from the outer surface 42 to the inner surface 43.

[0020] The opening 41 has a size that allows the first end cap 5 (or the second end cap 6) to be inserted therethrough. The outer surface 42 extends from the first end cap 5 (or the second end cap 6) side toward the connecting portion between the dome portion of the liner 2 and the body portion 21. The inner surface 43 is formed in an arc shape to fit the shape of the reinforcing layer 3 that covers the dome portion of the liner 2.

[0021] The blind holes 44 are multiple and regularly arranged. For example, when viewed from the axial L direction of the tank 1, these blind holes 44 are radially arranged at regular intervals from the center of the tank 1 toward the outside. Note that the blind holes 44 are so-called non-through holes, and are formed such that one end (open end) is open to the outside of the protector 4 and the other end (closed end) remains inside the protector 4.

[0022] The depth of these blind holes 44 varies depending on the arrangement position. Specifically, the blind holes 44 in this embodiment are arranged parallel to the axial direction L of the tank 1, and are formed so as to become gradually deeper as they move away from the axial direction L of the tank 1. In other words, the blind holes 44 arranged in a position close to the first end cap 5 (or the second end cap 6) are formed relatively shallow, and the blind holes 44 arranged in a position far from the first end cap 5 (or the second end cap 6) are formed relatively deep.

[0023] The protector 4 is made of a resin material having air permeability. A preferable example of the resin material having air permeability is a foamed resin having open cells, such as open-cell urethane foam. The protector 4 is fixed to the outer surface of the reinforcing layer 3 by FIPG.

[0024] [Tank manufacturing method] Next, a manufacturing method of the tank 1 will be described with reference to Figures 2 and 3. As shown in Figure 2, the manufacturing method of the tank 1 mainly includes a step of forming an intermediate having a liner 2 and a reinforcing layer 3 (hereinafter referred to as "first step S1"), a step of applying FIPG to the reinforcing layer 3 (hereinafter referred to as "second step S2"), a step of arranging a protector 4 on the outer surface of the reinforcing layer 3 (hereinafter referred to as "third step S3"), and a step of curing the FIPG (hereinafter referred to as "fourth step S4").

[0025] In the first step S1, a liner 2 having a body portion 21 and a dome portion is integrally formed by a rotational blow molding method using a resin member such as polyethylene or nylon. Next, a first end cap 5 is attached to the opening of the first dome portion 22, and a second end cap 6 is attached to the opening of the second dome portion 23 of the formed liner 2. Next, a fiber reinforced resin is wound around the outer peripheral surface of the liner 2 with the caps attached by a FW method to form a reinforcing layer 3. Next, the thermosetting resin or thermoplastic resin contained in the fiber reinforced resin is cured. As a result, an intermediate body having the liner 2 and the reinforcing layer 3 is formed.

[0026] In the second step S2, FIPG is applied to positions corresponding to the dome portions on the outer surface of the reinforcing layer 3. Specifically, as shown in Fig. 3, for example, FIPG7 having a predetermined thickness is applied to positions corresponding to the first dome portion 22 (or the second dome portion 23) on the outer surface of the reinforcing layer 3. FIPG7 is applied so that the thickness gradually decreases from the center toward both ends in the cross-sectional view shown in Fig. 3.

[0027] In the third step S3, the protector 4 is placed on the outer surface of the reinforcing layer 3 so that the inner surface 43 of the protector 4 abuts against a position corresponding to the dome portion of the reinforcing layer 3. Specifically, the protector 4 is placed on the outer surface of the reinforcing layer 3 so that the inner surface 43 of the protector 4 covers the position of the reinforcing layer 3 to which FIPG7 is applied from the outside. The protector 4 is prepared in advance.

[0028] In the fourth step S4, as shown in FIG. 3, a pressing jig 8 is abutted against the outer surface 42 of the protector 4, and while a pressing force F (see the arrow in FIG. 3) is applied to the protector 4 via the pressing jig 8, high-temperature steam is supplied into the inside of the protector 4 to harden the FIPG7.

[0029] Specifically, the pressing jig 8 is provided with an opening 81 through which the first end nozzle 5 (or the second end nozzle 6) can be inserted. The pressing jig 8 is provided with a plurality of pipes 82 for supplying high-temperature steam.

[0030] The pipes 82 are arranged parallel to the axial direction L of the tank 1. The interval between adjacent pipes 82 is the same as the interval between the blind holes 44 of the protector 4. The pipes 82 have an internal portion provided inside the pressing jig 8 and an exposed portion exposed from the pressing jig 8. The end of the internal portion of the pipe 82 is connected to a gallery 83 built into the pressing jig 8. The gallery 83 is further connected to a pipe 84, and distributes high-temperature steam supplied by the pipe 84 to each pipe 82. The pipe 84 is connected to a steam device (not shown).

[0031] Of the internal portion and exposed portion of the pipe 82, at least the exposed portion has a thickness that allows it to be inserted into the blind hole 44 of the protector 4. The tip of the exposed portion of the pipe 82 is open.

[0032] The pipes 82 having such a configuration are formed to have different lengths corresponding to the blind holes 44 of the protector 4 to be inserted. That is, the pipes 82 corresponding to the blind holes 44 formed relatively shallow are formed relatively short. On the other hand, the pipes 82 corresponding to the blind holes 44 formed relatively deep are formed relatively long.

[0033] Furthermore, a plurality of heaters 85 are built in at predetermined intervals inside the pressing jig 8. The heaters 85 are arranged between adjacent pipes 82, for example, as shown in FIG.

[0034] For this reason, in the fourth step S4, first, the pressing jig 8 and the protector 4 are aligned so that the exposed portions of the pipes 82 are inserted into the corresponding blind holes 44 of the protector 4, and then the pressing jig 8 is brought into contact with the outer surface 42 of the protector 4. Next, with a pressing force F being applied to the protector 4 via the pressing jig 8, high-temperature steam is supplied into the inside of the protector 4 via the pipes 82 of the pressing jig 8 and the blind holes 44 of the protector 4.

[0035] As described above, the protector 4 is formed of a foamed resin having open bubbles, such as open-cell urethane foam, and the foamed resin having open bubbles has a sponge structure in which the bubbles are connected to each other. Therefore, the high-temperature steam supplied through the pipe 82 and the blind hole 44 of the protector 4 is released into the inside of the protector 4 through the connected bubbles, and easily reaches the entire area of ​​the applied FIPG7, thereby heating and humidifying the FIPG7. This allows the FIPG7 to be uniformly cured. In addition, at this time, by simultaneously heating the pressing jig 8 using the heater 85 built into the pressing jig 8, it is possible to suppress a drop in the temperature of the supplied high-temperature steam, and the FIPG can be heated by heat transfer to the FIPG7 through the protector 4.

[0036] Then, after the applied FIPG7 is completely cured, the pressing jig 8 is slid and removed from the protector 4. In this way, the tank 1 is manufactured.

[0037] In the above explanation, an example has been given of applying FIPG to a position on the outer surface of the reinforcing layer 3 corresponding to the dome portion, but instead, FIPG may be applied to the inner surface 43 of the protector 4, or FIPG may be applied to both the position on the outer surface of the reinforcing layer 3 corresponding to the dome portion and the inner surface 43 of the protector 4.

[0038] In the manufacturing method of the tank 1 according to the present embodiment, high-temperature steam is supplied to the inside of the protector 4 through the blind hole 44 of the protector 4 and the pipe 82 inserted into the blind hole 44, so that the FIPG7 applied between the reinforcing layer 3 and the protector 4 can be humidified at a high temperature. In addition, since the blind hole 44 is used, the high-temperature steam coming out of the tip of the pipe 82 is blocked by the closed end of the blind hole 44 and diffuses in the radial direction of the tank 1, so that the FIPG7 can be easily spread over the entire range of the FIPG7 and hardened. Furthermore, since the protector 4 is formed of a foamed resin having continuous bubbles, the high-temperature steam can easily spread over the entire range of the FIPG7 via the continuous bubbles, so that the FIPG7 can be efficiently hardened. As a result, the hardening time of the FIPG7 can be shortened.

[0039] Also, by shortening the curing time of FIPG7, the thermal energy required for curing can be reduced, thereby realizing energy savings. Furthermore, since the curing time of FIPG7 can be shortened, it can contribute to reducing the number of products in stock during the manufacturing process. Moreover, in this embodiment, since high-temperature steam (including cooled white mist) is used instead of the low-temperature mist generated by the vibration element, it is possible to provide a high-temperature and high-humidity environment suitable for curing FIPG7.

[0040] Furthermore, since the high-temperature steam easily spreads over the entire area of ​​the FIPG 7, it is possible to prevent uneven heating of the FIPG 7 and ensure sufficient hardening of the FIPG 7. As a result, it is expected that the adhesive quality between the protector 4 and the reinforcing layer 3 will be improved.

[0041] The holes provided in the protector 4 may be through-holes penetrating the protector 4 instead of the blind holes 44, or may be a combination of blind holes 44 and through-holes. When through-holes are used, the high-temperature steam coming out of the tip of the pipe 82 can directly heat and humidify the FIPG7, and can also be blocked by the reinforcing layer 3 and diffuse in the radial direction of the tank 1, so that it can easily reach the entire range of the FIPG7 and harden the FIPG7.

[0042] 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]

[0043] 1: tank, 2: liner, 3: reinforcing layer, 4: protector, 5: first end cap, 6: second end cap, 7: FIPG, 8: pressing jig, 21: body, 22: first dome portion, 23: second dome portion, 41: opening, 42: outer surface, 43: inner surface, 44: blind hole, 51, 61: cap body, 52, 62: flange portion, 81: opening, 82: pipe, 83: gallery, 84: piping, 85: heater

Claims

[Claim 1] A method for manufacturing a tank including a liner having a cylindrical body and dome portions provided at both axial ends of the body, a reinforcing layer covering the liner, and a protector fixed to an outer surface of the reinforcing layer and made of a breathable resin material, comprising: applying FIPG to at least one of a position on the outer surface of the reinforcing layer corresponding to the dome portion and an inner surface of the protector having an outer surface that is an outer side, an inner surface that faces the reinforcing layer, and a plurality of holes extending from the outer surface toward the inner surface; a step of placing the protector on an outer surface of the reinforcing layer such that the inner surface of the protector abuts against a position corresponding to the dome portion of the reinforcing layer; curing the FIPG by supplying high temperature steam to the inside of the protector through the hole in the protector; A method for manufacturing a tank, comprising:

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