Tank and tank manufacturing method

Abstract

To provide a tank capable of enhancing adhesiveness of a cap and a liner.SOLUTION: A tank comprises a liner, and a cap 15 arranged at an opening part of the liner and having a hole. The liner has an inner surface part 12d extending from an opening part of the hole in the cap along an inner surface of the hole in the cap, and an outer surface part 12e extending from the opening part of the hole in the cap along an outer surface of the cap, where at an end part of the inner surface, crystalline distribution of the liner is not layered but dispersed.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to tanks and methods of manufacturing tanks. [Background technology]

[0002] Patent Document 1 discloses a structure in which a liner is disposed around a nozzle in a tank. Patent Document 2 discloses that a plurality of holes are provided in the liner groove inside the nozzle to prevent the liner from falling out of the groove. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-210988 [Patent Document 2] Special Publication No. 2012-514727 Summary of the Invention [Problem to be solved by the invention]

[0004] In tanks, the aim is to ensure sealing by not moving the interface between the nozzle and the liner, but the adhesive strength between the nozzle and the liner is weak, so it is necessary to increase the adhesive strength to ensure sealing.

[0005] The present disclosure aims to provide a tank that can improve adhesion between a mouthpiece and a liner, and also provides a manufacturing method therefor. [Means for solving the problem]

[0006] After extensive research, the inventor discovered that if the crystallinity of the liner is distributed in layers in the flow direction of the liner resin, when shear stress occurs, the fracture will easily progress and the adhesive strength between the nozzle and the liner will decrease, and this led to the completion of this invention.

[0007] The present application discloses a tank comprising a liner and a nozzle having a hole disposed at the opening of the liner, wherein the liner has an inner surface portion that is a portion extending from the opening of the hole in the nozzle along the inner surface of the hole in the nozzle, and an outer surface portion that is a portion extending from the opening of the hole in the nozzle along the outer surface of the nozzle, and wherein the crystallinity distribution of the liner at the end of the inner surface portion is not layered but is dispersed.

[0008] The liner may be configured to have a gate mark on its outer surface.

[0009] The present application also discloses a method for manufacturing a tank, the method comprising the steps of placing a nozzle having a hole in a mold and injecting resin into the mold from a gate, wherein the resin flow branches into a path in which the resin flows from the gate along the inner surface of the hole in the nozzle and a path in which the resin flows from the gate along the outer surface of the nozzle. [Effects of the Invention]

[0010] According to the present disclosure, there are portions at the end where the distribution of crystallinity of the liner is not layered, so that even when shear stress occurs, the fracture does not easily progress and the adhesive strength between the nozzle and the liner can be increased. [Brief explanation of the drawings]

[0011] [Figure 1] Figure 1 shows the appearance of the tank. [Figure 2] FIG. 2 is a cross-sectional view of a portion of the tank. [Figure 3] FIG. 3 is an enlarged view of a part of FIG. [Figure 4] In FIG. 4, (a) is a diagram showing an example in which the crystallinity distribution is in a dispersed state, and (b) is a diagram showing an example in which the crystallinity distribution is in a layered state. [Figure 5] In FIG. 5, (a) is a diagram showing an example in which the orientation distribution is dispersed, and (b) is a diagram showing an example in which the orientation distribution is layered. [Figure 6] FIG. 6 is a diagram illustrating insert molding. DETAILED DESCRIPTION OF THE INVENTION

[0012] 1. High-pressure tank structure Fig. 1 shows a schematic view of the appearance of a high-pressure tank 10 according to one embodiment, and Fig. 2 shows a cross section of the high-pressure tank 10 along its axis L, showing the area surrounding a nozzle 15 to which a valve is attached. As can be seen from these figures, in this embodiment, the high-pressure tank 10 has a tank body 11 and a nozzle 15. Each component will be described below.

[0013] 1.1.Tank body The tank body 11 is strong enough to hold the contents (e.g., hydrogen) without leaking and to withstand the high pressure inside. Therefore, in this embodiment, the tank body 11 is provided with a liner 12 and a reinforcing layer 13 arranged on the outer periphery of the liner 12.

[0014] 1.1.1. Liner The liner 12 is a hollow member that defines the internal space of the high-pressure tank 10 and is cylindrical in this embodiment. The liner 12 has a body portion 12a with a generally constant diameter, and openings at both ends of the body portion 12a are narrowed by dome-shaped side end portions 12b, and a nozzle 15 is disposed in the narrowed opening 12c. The liner 12 may be made of any material that can hold the contents (e.g., hydrogen) stored in its internal space without leaking, and any known material can be used, such as nylon resin or polyethylene-based synthetic resin. The thickness of the liner 12 is not particularly limited, but is preferably 0.5 mm to 1.0 mm.

[0015] The liner 12 has the following configuration at the portion that comes into contact with the nozzle 15. Figure 3 shows an enlarged view of the portion indicated by III in Figure 2. As can be seen from Figures 2 and 3, the liner 12 has an inner surface portion 12d that extends from an opening 15e of the hole 15a of the nozzle 15 on the side that is disposed inside the tank body, along the inner surface of the hole 15a of the nozzle 15, and an outer surface portion 12e that extends from the opening 15e of the hole 15a of the nozzle 15 along the outer surface of the nozzle 15 on the inside of the tank body. Here, the inner surface portion 12d is disposed on a stepped portion 15f formed with a larger diameter on the opening portion 15e side of the die 15. The size L1 of the inner surface portion 12d in the direction along the axis L is not particularly limited, but is preferably 6 mm or more. This allows the crystallinity distribution of the liner resin at the end portion 12f of the inner surface portion 12d to be dispersed rather than layered, as will be described later. On the other hand, the outer surface portion 12e of the liner 12 is a portion of the side end portion 12b of the liner 12 that covers the outer surface of the mouthpiece 15 inside the tank body 11.

[0016] Here, the liner 12 has a dispersed, rather than layered, distribution of crystallinity at least at the end 12f of its inner surface 12d. A dispersed, rather than layered, distribution of crystallinity refers to a state in which the crystallinity is dispersed without forming layers, as shown in FIG. 4(a). On the other hand, the crystallinity may be layered in the inner surface 12d of the liner 12 other than the end 12f and in the outer surface 12e, as shown in FIG. 4(b). However, this is not limited thereto, and the crystallinity may be dispersed in the inner surface 12d of the liner 12 other than the end 12f and in part or all of the outer surface 12e. Here, "crystallinity" refers to the degree of crystallinity and its distribution. When the crystallinity is layered, it means that particles of similar crystallinity gather together to form layers, while when the crystallinity distribution is dispersed, it means that particles of different crystallinity are mixed together without forming layers. The degree of crystallinity was measured by measuring the crystal peak (1203 cm) obtained from the IR spectrum of each subdivided portion. -1 ) area and amorphous peak (1172 cm -1 ) is obtained from the area ratio.

[0017] In this way, by having the crystallinity distributed in a dispersed state at least at the end 12f of the inner surface 12d, even when shear stress occurs, the fracture does not easily progress, and the adhesive strength between the nozzle 15 and the liner 12 can be increased. According to the inventor's findings, by having the crystallinity distributed in a dispersed state at the end 12f, the adhesive strength can be increased by 75% compared to when it is layered.

[0018] Such differences in the distribution of crystallinity can also be confirmed by the orientation. The orientation distribution is shown in Figure 5. Figure 5(a) shows the orientation distribution in the same area as Figure 4(a), and Figure 5(b) shows the orientation distribution in the same area as Figure 4(b). Here, the orientation is a distribution that represents the orientation state of the resin. Such an orientation state distribution can be confirmed by detecting the crystalline peak (1203 cm) of the resin from the IR spectrum measured through polarizing plates (0°, 90°) on the sample. -1 ) area is obtained from the value of the infrared dichroic ratio.

[0019] 3, a gate mark 12g is formed on the outer surface 12e of the liner 12 at a position that serves as an injection port through which molten resin flows during molding. Although the gate mark 12g is shown slightly exaggerated in FIG. 3, when the liner 12 is molded by injection molding, the gate mark 12g is usually recognizable, so the gate mark 12g in the usual form can be used as the gate mark 12g. The gate trace 12a provided on the outer surface portion 12e means that, as will be described later, the molten resin flows from the outer surface portion to the inner surface portion during molding and reaches the end of the inner surface portion, so that the molten resin is blocked and stirred at the end of the inner surface portion, resulting in the crystallinity distribution as described above.

[0020] 1.1.2. Reinforcement layer The reinforcing layer 13 is formed by laminating fiber bundles made of carbon fiber or the like in multiple layers, and the fiber bundles are impregnated with hardened resin. Specifically, the fiber bundles are wound in multiple layers around the outer periphery of the liner 12 to a predetermined thickness. The thickness of the reinforcing layer 13 is determined by the required strength and is not particularly limited, but is generally about 10 mm to 30 mm. Carbon fiber or aramid fiber (e.g., polyparaphenylene terephthalamide fiber) can be used as the fiber to reinforce the resin. Glass fiber may also be used as the fiber to reinforce the resin. Thermosetting resins such as epoxy resin, epoxy acrylate resin, and polyester resin can also be used as the resin to be reinforced by the fiber.

[0021] 1.2.Socket The nozzles 15 are members attached to the two openings 12c of the liner 12, one of which functions as an opening that connects the inside and outside of the high-pressure tank 10 and has a valve attached to it. Therefore, at least the base 15 on the side where the bulb is attached is provided with a hole 15a having a circular cross section in which the bulb is to be placed.

[0022] The inner surface of the hole 15a is provided with a female thread 15b that corresponds to the male thread of the valve. The valve is fixed to the base 15 by mating the male thread of the valve with this female thread 15b. The inner surface of the hole 15a has a smooth sealing surface 15c on the tank inner side (high-pressure side) from the female thread 15b. A sealing member provided on the outer periphery of the valve comes into contact with this sealing surface 15c, thereby sealing the inside of the high-pressure tank 10.

[0023] Furthermore, a stepped portion 15f having a larger diameter than the sealing surface 15c is provided at the end of the hole 15a of the nozzle 15 that is closest to the inside of the tank (high-pressure side). The stepped portion 15f has a shape with a step relative to the sealing surface 15c so that the diameter is larger than that of the sealing surface 15c. The stepped portion 15f is arranged around the entire inner surface of the high-pressure side end of the hole 15a. The resin that constitutes the liner 12 is filled into the stepped portion 15f to form the inner surface portion 12d.

[0024] The shape of the step portion 15f is configured to follow the shape of the inner surface portion 12d.

[0025] The material constituting the nozzle 15 is not particularly limited as long as it has the required strength, but examples thereof include copper, iron, and aluminum. When aluminum is used for the nozzle 15, it is preferable that the surface of the nozzle 15 that comes into contact with the liner 12 is anodized. The anodized coating has a porous layer with countless fine holes formed in it. The resin that forms the liner penetrates into these fine holes during molding, further improving adhesion.

[0026] 2. Tank manufacturing method The tank 10 described above can be manufactured, for example, as follows: A method S10 for manufacturing a tank according to one example includes an insert molding step, a joining step of tank members, and a step of forming a reinforcing layer.

[0027] 2.1.Insert molding process In the insert molding process, the liner 12 with the nozzle 15 disposed therein is formed by insert molding. In this process, the nozzle 15 is attached to a mold (not shown) as an insert part, and resin is injection molded to produce a liner member with the nozzle 15. Here, the liner member is half the total length (size along the axis L) of the liner 12. Furthermore, in the same manner, a half liner member with another nozzle 15 (a nozzle without a hole) is also produced. The injected resin is, as described above, for example, a thermoplastic resin such as nylon or polyethylene.

[0028] Here, as shown in Figure 6, resin is injected (injected) from a position corresponding to the gate mark 12g described above. As a result, the injected resin branches into two paths: one that flows along the outer surface of the die 15 as shown by A in Figure 6, and the other that reaches the step 15f on the inner surface of the die 15 as shown by B in Figure 6. The resin that reaches the step 15f collides with the wall of the step between the step 15f and the seal portion 15c, causing the flow to become turbulent. This allows the crystallinity distribution to be dispersed at the end 12f of the inner surface 12d of the liner 12, as described above. In this way, by providing a resin injection port in the part that will become the outer surface portion and providing a part that will become the inner surface portion adjacent to this, the flow of resin can be controlled as described above, and the crystallinity distribution can be made dispersed at the end of the inner surface portion.

[0029] 2.2.Tank component joining process In the tank member joining process, the two tank members produced in the insert process are joined together. In this process, the end of the liner of one tank member is joined to the end of the liner of the other tank member, and a laser is irradiated onto the joint between the two liners using, for example, a laser torch, which heats the resin at the joint between the two liner members and welds them together. In this case, it is preferable that one liner member is formed from a laser-absorbent resin and the other liner member is formed from a laser-transmittable resin. This makes it easier to weld the two liner members. Furthermore, in this case, it is preferable that the resin material of the two liner members is the same and that a pigment is added to the resin material of one liner member to make it laser-absorbent. This is because if the two liner members are made from the same material, there will be no difference in strength between the two liner members. For example, carbon black or ferrous oxide (FeO) can be used as the pigment.

[0030] 2.3. Step of forming the reinforcing layer In the process of forming the reinforcing layer, fiber bundles impregnated with resin are wound around the outer surface of the nozzle 15 that is outside the liner 12, and around the liner 12. The mechanical properties of the tank can be adjusted by changing the winding pattern of the fiber bundles. The reinforcing layer 13 is then formed by heating and curing the resin of the wound resin-impregnated fibers.

[0031] 3. Effects etc. According to the present disclosure, the crystallinity distribution is dispersed at least at the end of the inner part of the liner, which can increase the adhesive strength between the liner and the mouthpiece. [Explanation of symbols]

[0032] 10...High-pressure tank, 11...Tank body, 12...Liner, 12d...Inner surface, 12e...Outer surface, 13...Reinforcing layer, 15...Flange, 15c...Sealing surface, 15d...Step portion

Claims

1. A tank comprising a liner and a nozzle having a hole disposed at an opening of the liner, the nozzle has a stepped portion with an enlarged diameter at an end of the hole on the side where the liner is disposed, The liner comprises: an inner surface portion that extends from an opening of the hole of the base along an inner surface of the hole of the base, is disposed in the stepped portion of the base, and has an end that abuts against a wall of the stepped portion; an outer surface portion that extends from the opening of the hole of the base along the outer surface of the base and has a gate mark; and the crystallinity distribution of the liner at the end of the inner surface portion is not layered but dispersed; tank.

2. A method for manufacturing a tank, comprising: placing a die having a hole in a mold; and injecting resin into the mold through a gate. the nozzle has a stepped portion with an enlarged diameter at an end of the hole on a side where the resin is disposed, By the resin injection step, a path along which the resin flows from the gate along the step portion of the hole of the die and the resin flows so as to strike a wall of the step portion; a path in which the resin flows from the gate along the outer surface of the die; Tank manufacturing method.

Images