JP2015169323A - Method for manufacturing high-pressure tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain a gas leak from between mouthpieces and a liner in a high-pressure tank.SOLUTION: A method for manufacturing a high-pressure tank in which mouthpieces are attached to mouthpiece fitting parts of a liner comprises: a surface hardening step of hardening inner surfaces of the mouthpiece fitting parts of the liner; and a press fitting step of pressing the mouthpieces into the mouthpiece fitting parts after hardening the surfaces.

Description

  The present invention relates to a method for manufacturing a high-pressure tank, and more particularly to attachment of a base to a high-pressure tank.

  In Patent Document 1, when the assembly portion of the base is assembled to the assembly portion of the liner, the assembly is assembled with the interval between the assembly portion and the assembly portion being minimized, and then the liner is contracted by annealing treatment. It is described that the attaching part and the part to be assembled are brought into close contact with each other.

JP 2008-303966 A

  However, since the liner (resin) has a lower hardness than the base (made of metal), the assembly part is damaged when the assembly part of the base is assembled to the assembly part of the liner, causing leakage. There was a risk of this.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms.

  According to one form of this invention, the manufacturing method of the high pressure tank with which the nozzle | cap | die was attached to the nozzle | cap | die attachment part of a liner is provided. The manufacturing method includes a surface curing step for curing the inner surface of the base attachment portion of the liner, and a press-fitting step for press-fitting the base into the base attachment portion after the surface is cured. According to the manufacturing method of this embodiment, since the inner surface of the base attachment portion for attaching the base of the liner for the high-pressure tank is hardened, the base is press-fitted, so that the inner surface of the base attachment portion is hardly damaged and a leak occurs. It is hard to do.

  Note that the present invention can be realized in various modes. For example, in addition to the method for manufacturing a high-pressure tank, it can be realized in the form of a method of attaching a base, a method of coupling a joint, and the like.

It is explanatory drawing which shows the external appearance of the high pressure tank created by the manufacturing method of embodiment of this invention. It is explanatory drawing which shows the cross section of a high pressure tank. It is explanatory drawing explaining the manufacturing process of a high pressure tank. It is explanatory drawing which expands and shows the part enclosed by X of FIG.3 (C). It is explanatory drawing which shows the relationship between the stroke (insertion amount) of an insertion part, and the applied pressure required for insertion of an insertion part. It is explanatory drawing which shows the relationship between press injection allowance (DELTA) D and the surface roughness of a nozzle | cap | die attachment part.

  FIG. 1 is an explanatory view showing the appearance of a high-pressure tank 10 created by the manufacturing method of the embodiment of the present invention. FIG. 2 is an explanatory view showing a cross section of the high-pressure tank 10. The high-pressure tank 10 includes a base 100, an outer cylinder 200, and a liner 300. The base 100 is used for filling gas into the high-pressure tank 10 or discharging gas from the high-pressure tank 10. A flange 110 (flange) is formed on the outer periphery of the base 100 near the center in the direction of the central axis 101 of the base 100. The collar 110 is formed to protrude to the outer periphery along a plane perpendicular to the central axis 101. Further, the flange 110 has a tapered shape or a substantially trapezoidal shape such that the tip end side of the flange is thin. Further, when the collar 110 is viewed from the direction along the central axis 101, it has a circular shape in which convex portions or concave portions appear periodically.

  The liner 300 is an inner shell for sealing the inside of the high-pressure tank and storing gas. The liner 300 has a substantially cylindrical shape. Here, the liner 300 includes two divided liners 301 and 302. A base 100 is attached to the upper and lower portions of the liner 300. Note that the base 100 may be provided only on one split liner 301 and the base 100 may not be provided on the other split liner 302. The liner 300 is made of a heat-shrinkable material such as nylon, ethylene vinyl alcohol copolymer (EVOH), or polyethylene. The configuration of the liner 300 may include a plurality of layers including an outer layer made of a heat-shrinkable material and an inner layer made of a non-heat-shrinkable material such as epoxy, glass, or metal. .

  The outer cylinder 200 is formed outside the liner 300 and functions as a pressure shell of the high-pressure tank 10. As a material of the outer cylinder 200, fiber reinforced plastic (FRP) can be used. The end portion of the liner 300 and the end portion of the outer cylinder 200 are in close contact with each other so as to sandwich the flange 110 of the base 100, and gas leakage from the joint portion between the base 100 and the liner 300 is suppressed. In FIG. 1, the liner 300 is covered with the outer cylinder 200.

  FIG. 3 is an explanatory diagram for explaining the manufacturing process of the high-pressure tank. The manufacturing process of the high-pressure tank includes a process of attaching the cap 100 to the split liners 301 and 302, a process of joining the split liners 301 and 302, and a filament winding process. First, as shown in FIG. 3A, a base 100 and a split liner 301 are prepared. For example, the split liner 301 is manufactured using, for example, an injection molding apparatus. The split liner 301 has a cylindrical shape, and one opening 305 of the split liner 301 is narrowed. The base 100 is joined to the narrowed opening 305.

  First, as shown in FIGS. 3A to 3B, a surface curing step is performed in which the inner surface of the base attachment portion 310 of the split liner 301 is annealed and cured. Next, as shown in FIGS. 3B to 3C, a press-in process is performed in which the base 100 is press-fitted into the opening 305 and the base 100 is attached to the base attachment part 310 of the split liner 301. In the annealing oxidation, the surface of the base attaching part 310 is hardened, but the inside is not hardened and has elasticity, so that the base 100 can be press-fitted. In this embodiment, the surface of the base attaching part 310 is annealed and oxidized, but the surface of the base attaching part 310 may be plated and hardened.

  FIG. 4 is an explanatory view showing, in an enlarged manner, a portion surrounded by X in FIG. FIG. 4B is an explanatory diagram showing an enlarged view of a portion surrounded by Y in FIG. The insertion portion 102 of the base 100 into the split liner 301 has a cylindrical shape with a radius Da. On the other hand, half of the inner diameter (radius) of the base attachment portion 310 of the split liner 301 is Db, which is smaller than Da by ΔD. This ΔD is also referred to as “press fit”.

  An O-ring groove 103 is formed along the circumference of the cylindrical surface of the base 100, and an O-ring 150 and a backup ring 155 are fitted in the O-ring groove 103. The O-ring 150 seals between the base 100 and the base attachment part 310 of the split liner 301. The backup ring 155 is a perforated disk-shaped member, and is a member for suppressing the extrusion of the O-ring 150 due to the internal pressure of the liner 300. The distal end of the insertion portion 102 inserted into the split liner 301 of the base 100 has a curved surface portion 104 with rounded corners on the outside of the cylinder. If the tip of the insertion portion 102 of the base 100 has the curved surface portion 104, when the base 100 is press-fitted into the split liner 301, the base attachment portion 310 of the split liner 301 is not easily damaged, and the gas filled in the liner 300 Can be difficult to leak.

  FIG. 5 is an explanatory diagram showing the relationship between the stroke (insertion amount) of the insertion portion 102 and the pressure required to insert the insertion portion 102. Until the curved surface portion 104 of the insertion portion 102 comes into contact with the base attachment portion 310, the insertion portion 102 is inserted with almost no applied pressure. When the curved surface portion 104 of the insertion portion 102 contacts the base attachment portion 310, the applied pressure increases. This point P1 is also referred to as a press-fitting start point P1. The surface of the base attaching part 310 is hardened, but the inside of the base attaching part 310 is not hardened. Therefore, when the base 100 is inserted under pressure, the base mounting portion 310 is elastically deformed and further insertion is possible. In the present embodiment, inserting with pressure is also referred to as press-fitting. When the insertion portion 102 is further inserted, the O-ring 150 fitted in the O-ring groove 103 of the insertion portion 102 comes into contact with the base attachment portion 310. When the O-ring is press-fitted into the base attachment part 310, the applied pressure is further increased. When the insertion portion 102 is further inserted and exceeds the press-fitting end point P2, the applied pressure suddenly increases and exceeds the criteria (reference). Therefore, the insertion of the insertion portion 102 may be stopped immediately before the applied pressure suddenly increases. However, since it is difficult to find immediately before the pressing force suddenly increases, if the insertion of the insertion portion 102 is stopped when the pressing force rapidly increases, the insertion of the insertion portion 102 can be stopped before the criteria are exceeded.

  FIG. 6 is an explanatory diagram showing the relationship between the press-fitting allowance ΔD and the surface roughness of the base attaching part 310. The surface roughness corresponds to the depth of the scratch attached to the base attaching part 310 by inserting the base 100. If the surface roughness is large, the scratches are deep and gas leaks are likely to occur. In the present embodiment, the surface roughness increases as the press-fitting allowance ΔD increases. When the surface roughness exceeds the limit value, gas leakage is likely to occur. In order to make the surface roughness smaller than the limit roughness, the press-fitting allowance ΔD may be made smaller than the limit value ΔDL. As can be seen from the graph, the press-fitting allowance ΔD is better if it is close to zero. When the radius Db of the base attachment part 310 is larger than the radius Da of the base 100, the press-fit allowance ΔD becomes negative. In this case, the base attaching portion 310 is not damaged, but only the O-ring 150 must counteract gas leakage. Therefore, it is preferable that the press-fitting allowance ΔD is a plus close to zero. In addition, since the inner diameter of the die attachment portion 310 shrinks during annealing oxidation, it is difficult to make the press-fitting allowance ΔD close to zero. Therefore, it is preferable to set the press-fitting allowance design value ΔDD to a predetermined value between 0 and the limit value ΔDL.

  Similarly, a split liner 302 having a base 100 is manufactured. The split liner 301 and the split liner 302 are different in the shape of the joint with the other split liner. For example, the shape of the joint portion of the split liner 301 is a male shape, and the shape of the joint portion of the split liner 301 is a female shape.

  Next, as shown in FIG. 3D, the split liners 301 and 302 to which the cap 100 is attached are joined. Specifically, the joint portions on the side opposite to the side to which the cap 100 of the split liners 301 and 302 is attached are aligned. Next, for example, a laser torch is used to irradiate the joint between the two divided liners 301 and 302 with a laser torch. As a result, the resin at the joint between the two split liners 301 and 302 is heated to weld the two split liners 301 and 302. Note that one split liner 301 may be formed of a laser light transmitting resin, and the other split liner 302 may be formed of a laser light absorbing resin. The laser light absorptive resin may be formed to have a laser light absorptivity by making it difficult to transmit the laser light by adding a pigment to the laser light transmissive resin.

  Next, as shown in FIG. 3E, the reinforcing fiber impregnated with the resin is wound around the liner 300. As fibers for reinforcing the resin, glass fibers, carbon fibers, and aramid fibers (for example, polyparaphenylene terephthalamide fibers (Kevlar fiber, Kevlar is a registered trademark)) can be used. In addition, as a resin reinforced with fibers, an epoxy resin, an epoxy acrylate resin, or a polyester resin can be used. In addition, it is possible to adjust mechanical properties, such as tensile strength of the outer cylinder 200, with the pattern of the reinforcing fiber winding. Next, as shown in FIG. 3F, the reinforcing fibers wound around the liner 300 are heat-cured. Thereby, the reinforcing fiber impregnated with the resin becomes FRP, forms the outer cylinder 200, and manufactures the high-pressure tank 10. In this embodiment, the step of winding the reinforcing fiber impregnated with resin around the liner 300 and then heat-curing it to obtain the outer cylinder 200 is called a filament winding step.

  When the conventional base 100 is assembled to the liner 300 (divided liners 301 and 302), and then the liner 300 is contracted by annealing, the base 100 and the liner 300 are brought into close contact with each other, rather than the base 100 (made of metal). Since 300 (made of resin) has a lower hardness, there is a possibility that when the insertion part 102 of the base 100 is inserted into the base attachment part 310 of the liner 300, the base attachment part 310 may be damaged and cause a leak. there were. However, according to the manufacturing method of the present embodiment, the step of curing the inner surface of the base attachment portion 310 to which the base 100 of the liner (divider liners 301 and 302) of the high-pressure tank 10 is attached, and after the surface is cured, And the step of press-fitting the base 100 into the base attachment part 310, so that the inner surface of the base attachment part 310 is not easily damaged when the base 100 is press-fitted. Therefore, after the base 100 is attached to the liner 300, gas leakage from between the base 100 and the base attachment part 310 can be suppressed. Furthermore, since the distal end of the insertion portion 102 has a curved surface portion 104 with rounded corners on the outside of the cylinder, the inner surface of the base attachment portion 310 is less likely to be damaged when the base 100 is press-fitted.

  Further, in the conventional manufacturing method, it is necessary to provide a double seal structure in which two O-rings are provided or to provide a plurality of backup rings 155 for one O-ring 150 in order to securely fix the seal structure. However, according to the present embodiment, the O-ring 150 has a single seal structure, and the backup ring 155 can be made one.

  In the present embodiment, the bonding between the liner 300 (the divided liners 301 and 302) and the base 100 has been described, but the present invention can also be applied to the bonding between a resin pipe and a pipe joint.

  The embodiments of the present invention have been described above based on some examples. However, the above-described embodiments of the present invention are for facilitating the understanding of the present invention and limit the present invention. It is not a thing. The present invention can be changed and improved without departing from the spirit and scope of the claims, and it is needless to say that the present invention includes equivalents thereof.

DESCRIPTION OF SYMBOLS 10 ... High pressure tank 100 ... Base 101 ... Center axis 102 ... Insertion part 103 ... O-ring groove 104 ... Curved part 110 ... Collar 150 ... O-ring 155 ... Backup ring 200 ... Outer cylinder 300 ... Liner 301 ... Split liner 302 ... Split liner 305: Opening 310: Base attachment part P1: Press-in start point P2: Press-in end point ΔDD: Design value ΔDL: Limit value ΔD: Press-in allowance Da ... Radius Db ... Radius

Claims (1)

A method of manufacturing a high-pressure tank in which a base is attached to a base attachment part of a liner,
A surface curing step of curing the inner surface of the base attachment portion of the liner;
After the surface is cured, a press-fitting step of press-fitting the base into the base attachment part;
A method for manufacturing a high-pressure tank.

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