Method for manufacturing a high-pressure tank

Abstract

To provide a method for manufacturing a high-pressure tank, which avoids occupation of a large space for installing the tank and jigs for a long time until an adhesive cures.SOLUTION: A method for manufacturing a high-pressure tank, which has a cylindrical part and dome parts disposed at both ends of the cylindrical part, comprises: a step of applying an adhesive to at least one of the inner surface of a protector, which has the inner surface of a larger curvature than the curvature of the external surface of the dome part and has elasticity, and the external surface of the dome; a step of pressing the protector against the dome part to closely contact the inner surface of the protector and the external surface of the dome part to each other; a step of, while continuing to press the protector, heating the cylindrical part-side end of the protector to cure the adhesive at the cylindrical part-side end of the protector; and a step of releasing the pressing to the protector after the adhesive at the cylindrical part-side end of the protector is cured.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a method for manufacturing a high-pressure tank.

Background Art

[0002] For example, Patent Document 1 discloses a technique for protecting a dome portion of a high-pressure tank by attaching a protector to the dome portion.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When attaching a protector to a high-pressure tank, an adhesive is applied to the outer surface of the dome portion of the high-pressure tank or the inner surface of the protector, and the protector is pressed against the dome portion of the high-pressure tank. When the high-pressure tank is formed by the filament winding method, the surface shape of the dome portion varies depending on the amount and viscosity of the resin impregnated in the fibers, the tension applied to the fibers, and the variation in the winding position of the fibers. Therefore, it has been difficult to bring the inner surface of the protector into close contact with the outer surface of the dome portion regardless of the individual differences in the surface shape of the dome portion. In addition, in order to fix the protector to the high-pressure tank, it is preferable to keep the protector pressed against the dome portion of the high-pressure tank by a jig until the adhesive hardens. When pressing the protector against the high-pressure tank with a jig, a space for arranging the jig is required, so there has been a problem that a large space for installing the tank and the jig is occupied for a long time until the adhesive hardens.

Means for Solving the Problems

[0005] The present disclosure can be realized in the following forms.

[0006] According to one aspect of the present disclosure, there is provided a method for manufacturing a high-pressure tank having a cylindrical portion and dome portions disposed at both ends of the cylindrical portion. This method for manufacturing a high-pressure tank includes a step of applying an adhesive to the inner surface of a protector having an inner surface with a curvature larger than the curvature of the outer surface of the dome portion and having elasticity, or to at least one of the outer surfaces of the dome portions; a step of pressing the protector against the dome portion to bring the inner surface of the protector into close contact with the outer surface of the dome portion; a step of heating only one end portion, which is the end portion of the protector on the cylindrical portion side, among the one end portion and the portion of the protector other than the one end portion while pressing the protector, to cure the adhesive at the one end portion and fix the one end portion to the dome portion; and a step of releasing the pressing on the protector in a state where the one end portion of the protector is fixed to the dome portion after the adhesive at the one end portion has cured. According to the manufacturing method of the high-pressure tank of this form, the inner surface of the protector can be brought into close contact with the outer surface of the dome portion regardless of the individual differences in the surface shape of the dome portion. Further, by curing the adhesive at the end portion on the cylindrical portion side of the protector in a state where the inner surface of the protector is in close contact with the outer surface of the dome portion, even if the pressing on the protector is released thereafter, the protector can be kept in close contact with the dome portion. Therefore, it is possible to shorten the time during which a large space for installing the tank and the jig is occupied.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Mode for Carrying Out the Invention

[0008] A. First Embodiment: FIG. 1 is a cross-sectional view showing a schematic configuration of a high-pressure tank 100. The high-pressure tank 100 stores, for example, high-pressure hydrogen of 10 to 70 MPa and is mounted on a fuel cell vehicle. The high-pressure tank 100 includes a tank body 110 and a protector 50. The tank body 110 includes a liner 10, a reinforcing layer 20, and bases 30 and 40.

[0009] The liner 10 is a hollow container for storing hydrogen gas or the like therein. The liner 10 may be formed of a resin having gas barrier properties against hydrogen gas, such as polyethylene, nylon, polypropylene, etc., or may be formed of a metal. The axis of the liner 10 coincides with the axis AX of the high-pressure tank 100.

[0010] The reinforcing layer 20 is a layer that covers the periphery of the liner 10 and is a layer for reinforcing the liner 10. The reinforcing layer 20 is formed, for example, by the filament winding method. Specifically, it is formed by winding and laminating fibers impregnated with a thermosetting resin while applying tension to the outer surface of the liner 10, and then curing the thermosetting resin by heating. As the fibers to be wound around the liner 10, for example, carbon fibers, glass fibers, aramid fibers, etc. are used. As the thermosetting resin to be impregnated into the fibers, for example, epoxy resin, polyester resin, polyamide resin, etc. are used. The reinforcing layer 20 has a substantially cylindrical cylindrical portion 21 and substantially hemispherical dome portions 22 continuously provided at both ends of the cylindrical portion 21. The axis of the cylindrical portion 21 and the axis of the dome portion 22 coincide with the axis AX of the high-pressure tank 100.

[0011] The bases 30 and 40 are provided at the tops of the respective dome portions 22. The bases 30 and 40 are formed of a metal such as aluminum or its alloy, for example. One base 30 is used for filling gas into the high-pressure tank 100 or discharging gas from the high-pressure tank 100. The other base 40 is sealed and is used for centering during manufacturing. Note that the base 40 may be omitted.

[0012] The protector 50 is attached to each dome portion 22 in order to absorb impact and protect the tank body 110, for example, when the high-pressure tank 100 drops. The protector 50 is formed of an elastic resin such as polyurethane, silicone, expanded polystyrene, etc., for example. The shape of the protector 50 is a donut shape having holes in the portions corresponding to the bases 30 and 40 when viewed along the axis AX of the high-pressure tank 100, and its inner surface is dome-shaped.

[0013] FIG. 2 is a process diagram showing a method of attaching the protector 50 to the tank body 110 in the present embodiment. The attachment of the protector 50 to the tank body 110 is carried out as one step in the manufacture of the high-pressure tank 100. Before the attachment of the protector 50 to the tank body 110 is carried out, the tank body 110 is prepared in advance.

[0014] First, in step S10, an adhesive is applied to at least one of the inner surface of the protector 50 or the outer surface of the dome portion 22. As the adhesive, for example, FIPG is used. The adhesive is preferably one that cures in a short time under high-temperature conditions, and may be other than FIPG.

[0015] FIG. 3 shows a cross-sectional view of the tank body 110 and the protector 50 in a state where the adhesive 60 is applied to the inner surface of the protector 50 as an example of step S10 in FIG. 2. In FIG. 3, the X, Y, and Z directions perpendicular to each other are shown. The Z direction is a direction parallel to the axis AX of the high-pressure tank 100. The X direction is a direction perpendicular to the paper surface. The Y direction is a direction perpendicular to the X direction and the Z direction. The X, Y, and Z directions in FIG. 3 represent the same directions as the X, Y, and Z directions in other figures.

[0016] The protector 50 is fixed to the tank body 110 in a state of being elastically deformed by being pressed against the dome portion 22. FIG. 3 shows the shape of the protector 50 before being pressed against the dome portion 22. In a state where the protector 50 is not pressed against the dome portion 22, in the YZ plane, the curvature of the inner surface of the protector 50 is larger than the curvature of the outer surface of the dome portion 22. Therefore, a gap exists between the inner surface of the protector 50 and the outer surface of the dome portion 22.

[0017] Next, in step S20 of FIG. 2, the protector 50 is pressed against the dome portion 22. FIG. 4 shows a cross-sectional view of the tank body 110 and the protector 50 in a state where the protector 50 is pressed against the dome portion 22 by the jig 70 in step S20 of FIG. 2. The jig 70 has an annular shape in the XY plane and presses the protector 50 in the -Z direction. By pressing the protector 50 against the dome portion 22 in the -Z direction, the protector 50 is elastically deformed, and the inner surface of the protector 50 and the outer surface of the dome portion 22 are brought into close contact. The curvature of the inner surface of the protector 50 is determined to be a curvature that allows them to be in close contact with each other when the protector 50 is pressed against the dome portion 22. By the elastic deformation of the protector 50, the inner surface of the protector 50 and the outer surface of the dome portion 22 can be brought into close contact regardless of the individual differences in the surface shape of the dome portion 22. Further, when the inner surface of the protector 50 and the outer surface of the dome portion 22 are in close contact, the adhesive 60 spreads thinly and uniformly. Note that the shape of the jig 70 and the pressing direction against the protector 50 may be any shape and pressing direction that can bring the inner surface of the protector 50 and the outer surface of the dome portion 22 into close contact.

[0018] Next, in step S30 of FIG. 2, one end portion 51, which is the end portion on the cylindrical portion 21 side of the protector 50, is heated. In step S30, the protector 50 remains pressed against the dome portion 22 by the jig 70. In step S30, as shown in FIG. 4, by heating the one end portion 51 with the heater 80, the adhesive 60 near the one end portion 51 is cured, and the one end portion 51 is fixed to the dome portion 22. As the heater 80, for example, an infrared heater or a warm air heater can be used. In order to cure the adhesive 60 near the one end portion 51 in a short time, it is preferable that the thickness of the one end portion 51 is thinner than the thickness of the portion of the protector 50 other than the one end portion 51. Note that in the present embodiment, the heater 80 is formed integrally with the jig 70, but the heater 80 does not have to be formed integrally with the jig 70.

[0019] Finally, in step S40 of FIG. 2, the pressing of the protector 50 by the jig 70 is released. When the pressing of the protector 50 is released, only one end portion 51 of the protector 50 is fixed to the dome portion 22. At this time, due to the restoring force of the protector 50, a force is generated inside the protector 50 that presses the outer surface of the dome portion 22 in the vertical direction. Therefore, if one end portion 51 is fixed to the dome portion 22, even if the pressing of the protector 50 by the jig 70 is released, the inner surface of the protector 50 can remain in close contact with the outer surface of the dome portion 22. Thus, even without maintaining the state in which the protector 50 is pressed against the dome portion 22 by the jig 70, the inner surface of the portion of the protector 50 other than the one end portion 51 can be fixed to the outer surface of the dome portion 22.

[0020] According to the method for manufacturing the high-pressure tank 100 in the present embodiment described above, in the YZ plane, the curvature of the inner surface of the protector 50 is larger than the curvature of the outer surface of the dome portion 22. When the protector 50 is pressed against the dome portion 22 in the -Z direction by the jig 70, the protector 50 elastically deforms, so that the inner surface of the protector 50 and the outer surface of the dome portion 22 are in close contact. Therefore, regardless of the individual differences in the surface shape of the dome portion 22, the inner surface of the protector 50 and the outer surface of the dome portion 22 can be brought into close contact. While pressing one end portion 51 with the heater 80 while pressing the protector 50 against the dome portion 22 and fixing one end portion 51 to the dome portion 22, a force is generated inside the protector 50 that presses the outer surface of the dome portion 22 in the vertical direction. Thus, even if the pressing of the protector 50 by the jig 70 is released after fixing one end portion 51 to the dome portion 22, the protector 50 can maintain the state of being in close contact with the dome portion 22, and the protector 50 can be fixed to the tank body 110. Therefore, after one end portion 51 is fixed to the tank body 110, the jig 70 becomes unnecessary, and it is possible to eliminate the need to occupy a large space for installing the high-pressure tank 100 and the jig 70 for a long time until the entire adhesive 60 is cured. Further, by pressing the protector 50 against the dome portion 22, the applied adhesive 60 spreads and becomes thinner, so that the time required for curing the adhesive 60 near one end portion 51 can be shortened.

[0021] B. Second Embodiment: FIG. 5 is a diagram showing the shape of the inner surface of the protector 50a in the second embodiment. A slit 52 that opens when the protector 50a is pressed against the dome portion 22 is provided on the inner surface of the protector 50a. The slit 52 is preferably provided annularly in the XY plane, and the depth direction of the slit 52 is preferably provided in a direction perpendicular to the surface of the dome portion 22. When the space for installing the high-pressure tank 100 is limited, in order to enhance the shock absorption performance of the protector 50a, for example, it is effective to increase the hardness of the protector 50a or increase the thickness of the protector 50a in the direction at an angle of 45° with respect to the axis AX of the high-pressure tank 100. However, when the hardness of the protector 50a is increased or the thickness of the protector 50a in the direction at an angle of 45° with respect to the axis AX of the high-pressure tank 100 is increased, it becomes difficult to bring the inner surface of the protector 50a into close contact with the outer surface of the dome portion 22 when the protector 50a is pressed against the dome portion 22. However, by providing the slit 52 in the protector 50a, for example, the reaction force received by the jig 70 from the protector 50a when the protector 50a is pressed against the dome portion 22 by the jig 70 and the elastic limit of the protector 50a can be adjusted. Therefore, by providing the slit 52, even a protector 50a with high shock absorption performance can bring the inner surface of the protector 50a into close contact with the outer surface of the dome portion 22.

[0022] C. Other Embodiments: In each of the above embodiments, the shape of the protector 50 was a donut shape having a hole in the portion corresponding to the caps 30 and 40 when viewed along the axis AX of the high-pressure tank 100. On the other hand, when the protector 50 is attached to the dome portion 22 without a cap of the tank body 110 having a cap only on one dome portion 22, the shape of the protector 50 may be a dome-shaped inner surface having a curvature larger than the curvature of the outer surface of the dome portion 22 and covering the entire dome portion 22. In this case, it is sufficient that the inner surface of the protector 50 is in close contact with the outer surface of the dome portion 22 when the protector 50 is pressed against the dome portion 22, and the inner surface of the protector 50 corresponding to the apex portion of the dome portion 22 may not be in contact with the outer surface of the dome portion 22 when the protector 50 is not pressed against the dome portion 22.

[0023] The present disclosure is not limited to the above-described embodiments, and can be realized in various configurations without departing from the gist thereof. For example, the technical features in the embodiments corresponding to the technical features in each form described in the summary of the invention can be appropriately replaced or combined in order to solve some or all of the above-described problems or to achieve some or all of the above-described effects. Further, if the technical feature is not described as essential in this specification, it can be appropriately deleted.

Description of Reference Numerals

[0024] 10…liner, 20…reinforcing layer, 21…cylindrical portion, 22…dome portion, 30, 40…caps, 50…protector, 51…one end portion, 52…slit, 60…adhesive, 70…fixture, 80…heater, 100…high-pressure tank, 110…tank body, AX…axis of high-pressure tank

Claims

1. A method for manufacturing a high-pressure tank having a cylindrical portion and dome portions disposed at both ends of the cylindrical portion, comprising: applying an adhesive to at least one of the inner surface of a protector having an inner surface with a curvature greater than the curvature of the outer surface of the dome portion and being elastic, or the outer surface of the dome portion; pressing the protector against the dome portion to bring the inner surface of the protector into close contact with the outer surface of the dome portion; while pressing the protector, heating only one end portion, which is the end portion of the protector on the cylindrical portion side, of the protector to cure the adhesive at the one end portion and fixing the one end portion to the dome portion; after the adhesive at the one end portion has cured, releasing the pressing force applied to the protector with the one end portion of the protector fixed to the dome portion; A method for manufacturing a high-pressure tank, comprising the above steps.

2. The method for manufacturing a high-pressure tank according to Claim 1, wherein: an annular slit is provided on the inner surface of the protector in a plane perpendicular to the axis of the high-pressure tank. A method for manufacturing a high-pressure tank.

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