Can and method of manufacturing a can

Abstract

The present application relates to a can and a method of manufacturing the can, which can improve the adhesion of a joint to a liner. The can is provided with: a liner; and a joint configured to an opening portion of the liner and having a hole, the liner having: an inner surface portion which is a site extending from an opening portion of the hole of the joint along an inner surface of the hole of the joint; and an outer surface portion which is a site extending from the opening portion of the hole of the joint along an outer surface of the joint, at an end portion of the inner surface portion, the distribution of crystallinity of the liner is in a dispersed state and not in a layered state.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a can and a manufacturing method of a can. BACKGROUND

[0002] Patent Document 1 discloses a configuration in which a liner is arranged around a mouthpiece of a can.

[0003] Patent Document 2 discloses a configuration in which a plurality of holes are provided in a liner groove on the inner side of a mouthpiece, and falling of the liner groove is prevented.

[0004] Patent Document 1: Japanese Patent Application Publication No. H11-210988

[0005] Patent Document 2: Japanese Patent Application Publication No. 2012-514727

[0006] In a can, the object is to ensure sealing by the interface between an inactive mouthpiece and a liner, but the adhesion strength of the mouthpiece and the liner is weak, and it is necessary to improve the adhesion strength in order to ensure sealing. SUMMARY

[0007] The present disclosure aims to provide a can in which the adhesion of a mouthpiece and a liner can be improved. In addition, a manufacturing method therefor is provided.

[0008] The present disclosure was achieved as a result of the inventors' intensive research, and the insight that if the distribution of the crystallinity of a liner in the flow direction of the liner resin is layered, when a stress in the shear direction is generated, the destruction easily progresses, resulting in a decrease in the adhesion strength of the mouthpiece and the liner, was obtained, thereby completing the present disclosure.

[0009] The present disclosure discloses a can, comprising: a liner; and a mouthpiece arranged at an opening portion of the liner and having a hole, the liner having: an inner surface portion that is a portion extending from the opening portion of the hole of the mouthpiece along the inner surface of the hole of the mouthpiece; and an outer surface portion that is a portion extending from the opening portion of the hole of the mouthpiece along the outer surface of the mouthpiece, the distribution of the crystallinity of the liner at the end portion of the inner surface portion being in a dispersed state and not being layered.

[0010] The liner can be configured to have a sprue mark in the outer surface portion.

[0011] In addition, the present disclosure discloses a manufacturing method of a can, comprising: a step of arranging a mouthpiece having a hole on a mold; and a step of injecting a resin from a sprue to the mold, the resin being branched by the step of injecting the resin to flow along a path for the resin to flow from the sprue along the inner surface of the hole of the mouthpiece and a path for the resin to flow from the sprue along the outer surface of the mouthpiece.

[0012] According to the present disclosure, since there is a portion in which the distribution of crystallinity of the liner is not layered in the end portion, the adhesion strength of the joint to the liner can be improved since the failure does not easily progress when a stress in the shearing direction is generated. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 is a view showing the appearance of the tank.

[0014] Figure 2 is a cross-sectional view of a portion of the tank.

[0015] Figure 3 is a view showing a portion of Figure 2 enlarged.

[0016] Figure 4 (a) of is a view of an example in which the distribution of crystallinity is in a dispersed state, Figure 4 (b) of is a view of an example in which the distribution of crystallinity is layered.

[0017] Figure 5 (a) of is a view of an example in which the distribution of orientation is in a dispersed state, Figure 5 (b) of is a view of an example in which the distribution of orientation is layered.

[0018] Figure 6 is a view explaining insert molding.

[0019] BRIEF DESCRIPTION OF DRAWINGS

[0020] 10 high-pressure tank; 11 tank main body; 12 liner; 12d inner surface portion; 12e outer surface portion; 13 reinforcing layer; 15 joint; 15c sealing surface; 15d step portion. DETAILED DESCRIPTION

[0021] 1. Configuration of high-pressure tank

[0022] Figure 1 in which the appearance of the high-pressure tank 10 according to one embodiment is schematically shown, Figure 2 in which a cross section of a portion of the joint 15 in which a valve is installed is shown using a cross section along the axis L of the high-pressure tank 10. From these drawings, it is known that in the present embodiment, the high-pressure tank 10 has a tank main body 11 and a joint 15. The respective configurations will be described below.

[0023] 1.1. Tank main body

[0024] The tank main body 11 holds the contents (for example, hydrogen) received therein without leaking, and has a strength that can withstand a high-pressure state inside. Therefore, in the present embodiment, the tank main body 11 is provided with a liner 12 and a reinforcing layer 13 disposed on the outer periphery of the liner 12.

[0025] 1.1.1. Liner

[0026] The liner 12 is a hollow member that divides the internal space of the high-pressure tank 10, and is cylindrical in this embodiment. For the liner 12, the openings of both ends of a main body portion 12a of which the diameter is substantially constant are narrowed by dome-shaped side end portions 12b, and a joint 15 is disposed at the narrowed openings 12c.

[0027] The liner 12 only needs to be composed of a material that can hold an article (for example, hydrogen) housed in the internal space thereof without leaking, and a publicly known material can be used. Specifically, for example, it is composed of a nylon resin or a polyethylene-based synthetic resin.

[0028] Further, the thickness of the liner 12 is not particularly limited, and is preferably 0.5 mm to 1.0 mm.

[0029] The liner 12 has the following configuration at the portion in contact with the joint 15. Figure 3 The portion is enlarged and shown in FIG. 3. Figure 2 The portion is enlarged and shown in FIG. 3. Figure 2 、 Figure 3 As is apparent from FIG. 3, the liner 12 has an inner surface portion 12d that extends from the opening portion 15e of the hole 15a of the joint 15 disposed on the inside of the tank main body along the inner surface of the hole 15a of the joint 15, and an outer surface portion 12e that extends from the opening portion 15e of the hole 15a of the joint 15 along the outer surface of the joint 15 on the inside of the tank main body.

[0030] Here, the inner surface portion 12d is disposed at the stepped portion 15f of the joint 15 that is formed to have a large diameter on the opening portion 15e side. The size LI of the inner surface portion 12d in the direction along the axis L is not particularly limited, but is preferably 6 mm or more. Thereby, as will be described later, the crystallinity distribution in the liner resin at the end portion 12f of the inner surface portion 12d is in a dispersed state and not in a layered state.

[0031] On the other hand, the outer surface portion 12e of the liner 12 is the portion of the side end portion 12b of the liner 12 that covers the outer surface of the joint 15 on the inside of the tank main body 11.

[0032] Here, for the liner 12, the crystallinity distribution is in a dispersed state and not in a layered state at least at the end portion 12f in the inner surface portion 12d thereof. The state in which the crystallinity distribution is dispersed and not in a layered state means a state in which the crystallinity distribution is dispersed as shown in (a) of FIG. 4 and not in a layered state. On the other hand, at the end portion 12f of the inner surface portion 12d and in the outer surface portion 12e of the liner 12, the crystallinity distribution can be in a layered state as shown in (b) of FIG. 4. Figure 4 Figure 4 ​As shown in (b), the crystalline distribution is layered. However, it is not limited to this; the crystalline distribution may also be dispersed, except at the end 12f of the inner surface portion 12d of the lining 12 and in part or all of the outer surface portion 12e.

[0033] Here, "crystallinity" refers to the degree of crystallinity, specifically its distribution. In the case of layered crystallinity, portions with similar crystallinity aggregate to form layers. In a dispersed distribution, crystallinity is a mixture of portions with different crystallinities that do not form layers. This is determined by the crystallization peak (1203 cm⁻¹) obtained from the IR spectrum in each subdivided region. -1 Area and amorphous peak (1172cm) -1 The degree of crystallinity is obtained by the ratio of the area.

[0034] By dispersing the crystalline distribution at least in the end 12f of the inner surface portion 12d, the bond strength between the joint 15 and the lining 12 is improved, as failure is less likely to develop under shear stress. According to the inventors, dispersing the crystalline distribution in the end 12f increases the bond strength by 75% compared to the layered form.

[0035] Such differences in the distribution of crystallinity can also be confirmed through orientation. Figure 5 The distribution of orientation is shown in the figure. Figure 5 (a) indicates that with Figure 4 (a) Distribution of orientation at the same location, Figure 5 (b) indicates that with Figure 4 (b) Distribution of orientation at the same location. Here, orientation refers to the distribution of the resin's orientation state. The crystallization peak (1203 cm⁻¹) of the resin was determined from the IR spectrum measured from the sample via polarizers (0°, 90°). -1 The distribution of such orientation states is obtained by measuring the infrared 2-color ratio of the area.

[0036] In addition, such as Figure 3 As shown by reference numeral 12g in the attached drawing, a gate trace 12g is formed on the outer surface 12e of the liner 12 at the location of the injection port for the flow of molten resin during molding. Figure 3 The gate mark 12g is shown in slightly exaggerated form. Since the gate mark 12g is usually identifiable when the liner 12 is formed by injection molding, it is sufficient to use the gate mark in its normal form as the gate mark 12g.

[0037] Since the gate mark 12a is provided to the outer surface portion 12e, it means that the molten resin flows from the outer surface portion to the inner surface portion and reaches the end portion of the inner surface portion at the time of molding as described later, so the molten resin is intercepted at the end portion of the inner surface portion and stirred, and the distribution of crystallinity becomes as described in the above explanation.

[0038] 1.1.2. Reinforcing layer

[0039] For the reinforcing layer 13, fiber bundles formed of carbon fibers or the like are layered over multiple layers, and the fiber bundles are impregnated with cured resin. Specifically, the fiber bundles are wound around the outer periphery of the liner 12 over multiple layers to a prescribed thickness. Since the thickness of the reinforcing layer 13 is determined according to the required strength, it is not particularly limited, but is about 10 mm to 30 mm.

[0040] As the fiber that reinforces the resin, carbon fibers, aramid fibers (for example, poly-paraphenylene terephthalamide fibers) can be used. In addition, as the fiber that reinforces the resin, glass fibers can also be used. In addition, as the resin that is reinforced by the fiber, thermosetting resins such as epoxy resins, epoxy acrylate resins, and polyester resins can be used.

[0041] 1.2. Joint

[0042] The joint 15 is a member that is attached to each of the two openings 12c of the liner 12, and on the other hand, functions as an opening that communicates the inside and outside of the high-pressure tank 10, and is attached with a valve.

[0043] Therefore, the joint 15 on at least the side of the joint 15 to which the valve is attached is provided with a hole 15a that is circular in cross section for the valve to be disposed.

[0044] An internal thread 15b that corresponds to the external thread of the valve is provided to the inner surface of the hole 15a. By combining the external thread of the valve to the internal thread 15b, the valve is fixed to the joint 15.

[0045] In addition, on the inner surface of the hole 15a, a sealing surface 15c that is a smooth surface is provided on the tank inner side (high-pressure side) than the internal thread 15b. A sealing member provided to the outer periphery of the valve comes into contact with the sealing surface 15c to perform airtightness (sealing) of the inside of the high-pressure tank 10.

[0046] Furthermore, a stepped portion 15f, wider in diameter than the sealing surface 15c, is provided at the innermost (high-pressure side) end of the port 15a of the connector 15. The stepped portion 15f has a stepped shape relative to the sealing surface 15c in such a way that its diameter is wider than the sealing surface 15c. The stepped portion 15f is arranged around the inner surface of the high-pressure side end of the port 15a. Moreover, the stepped portion 15f is filled with resin constituting the lining 12, forming an inner surface portion 12d.

[0047] The shape of the step portion 15f is formed along the shape of the inner surface portion 12d.

[0048] The components constituting the connector 15 are not particularly limited as long as they possess the required strength; examples include copper, iron, and aluminum. When aluminum is used for the connector 15, it is preferable to treat the surface of the connector 15 that contacts the liner 12 with an alumite coating. The film formed by the alumite coating contains a porous layer with numerous tiny pores. During molding, the resin forming the liner penetrates into these tiny pores, further improving adhesion.

[0049] 2. Can manufacturing method

[0050] The can 10 described above can be manufactured, for example, as follows. One example of the can manufacturing method S10 includes an insert forming process, a can component joining process, and a reinforcing layer forming process.

[0051] 2.1. Insert molding process

[0052] In the insert molding process, a liner 12 with a connector 15 is formed by insert molding. In this process, the connector 15 is installed as an insert component in a mold (not shown), and resin is injection molded to produce a liner component with the connector 15. Here, the liner component is half the total length (size along the axis L) of the liner 12. Furthermore, a liner component with another connector 15 (a connector without a hole) is also produced in the same manner. As described above, the resin used for injection molding is, for example, a thermoplastic resin such as nylon or polyethylene.

[0053] Here, as Figure 6 As shown, resin is injected (cast) from the position corresponding to the aforementioned gate mark 12g. Thus, the injected resin branches as follows: Figure 6 The path of flow along the outer surface of connector 15 as shown in A and as... Figure 6 As shown in B, the resin flows along the path from the inner surface of the joint 15 to the step portion 15f. The resin reaching the step portion 15f collides with the walls of the step portion 15f and the sealing portion 15c, causing turbulent flow. Thus, as described above, the crystalline distribution at the end 12f of the inner surface portion 12d of the liner 12 can be dispersed.

[0054] By so disposing the resin injection port at the portion that becomes the outer surface portion and disposing the portion that becomes the inner surface portion in connection therewith, the flow of the resin can be controlled as described above to make the distribution of crystallinity at the end portion of the inner surface portion into a dispersed state.

[0055] 2.2. Process of joining the can parts

[0056] In the process of joining the can parts, the two can parts produced in the insert process are joined.

[0057] In this process, the end portion of the liner of one of the can parts is aligned with the end portion of the liner of the other can part, and, for example, a laser welding gun is used to irradiate laser light to the aligned portions of the two liners. By this, the resins of the joint portions of the two liner parts are heated to fuse the two liner parts.

[0058] In this case, it is preferable that one of the liner parts be formed of a laser-absorbing resin and the other of a laser-transmitting resin. By this, the fusion of the two liner parts becomes easy. Also, in this case, it is preferable that the resin materials of the two liner parts be the same, and that one of the liner parts be made to have laser-absorbing properties by adding a pigment to the resin material of the one liner part. This is because, if the materials of the two liner parts are the same, there will be no difference in strength between the two liner parts. As the pigment, for example, carbon black, ferrous oxide (FeO) can be used.

[0059] 2.3. Process of forming the reinforcing layer

[0060] In the process of forming the reinforcing layer, a fiber bundle impregnated with resin is wound around the outer surface of the joint 15 that is more outward than the liner 12 and the liner 12. Here, the mechanical properties of the can can be adjusted by the mode of winding of the fiber bundle. Then, by heat-curing the resin of the wound fiber bundle impregnated with resin, the reinforcing layer 13 is formed.

[0061] 3. Effects, etc.

[0062] According to the present disclosure, at least in the end portion of the inner side portion of the liner, the distribution of crystallinity is in a dispersed state, and the adhesion strength of the liner to the joint can be improved.

Claims

1. A can, comprising: a liner; and a joint configured to an opening portion of the liner and having a hole, wherein an end portion of the joint on a side where the liner is configured in the hole has a stepped portion in which a diameter is widened, the liner has: an inner surface portion that extends from an opening portion of the hole of the joint along an inner surface of the hole of the joint, is configured to the stepped portion of the joint, and has a portion where an end portion thereof abuts against a wall of the stepped portion; and an outer surface portion that extends from the opening portion of the hole of the joint along an outer surface of the joint and has a portion where a gate mark is present, a crystallinity of the liner at the end portion of the inner surface portion is in a dispersed state and not in a layered state.

2. A method of manufacturing the can of claim 1, wherein, comprising: a process of configuring a joint having a hole to a mold; and a process of injecting a resin to the mold from a position corresponding to a gate mark, the joint has a stepped portion in which a diameter is widened at an end portion of the joint on a side where the resin is configured in the hole, by the process of injecting the resin, the resin flows in a path for the resin to flow from the position corresponding to the gate mark along a path in which an inner surface of the joint reaches the stepped portion and the resin flows in a manner of abutting against a wall of the stepped portion and a path for the resin to flow from the position corresponding to the gate mark along an outer surface of the joint.

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