JP7690887B2 - Manufacturing method of high pressure tank - Google Patents

Description

This disclosure relates to a method for manufacturing a high-pressure tank.

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

JP 2014-190495 A

When attaching a protector to a high-pressure tank, adhesive is applied to the outer surface of the dome of the high-pressure tank or the inner surface of the protector, and the protector is pressed against the dome of the high-pressure tank. When the high-pressure tank is formed by the filament winding method, the surface shape of the dome varies from one high-pressure tank to another due to 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 was difficult to make the inner surface of the protector and the outer surface of the dome adhere to each other regardless of the individual differences in the surface shape of the dome. In addition, in order to fix the protector to the high-pressure tank, it is preferable to keep the protector pressed against the dome of the high-pressure tank with a jig until the adhesive hardens. When pressing the protector against the high-pressure tank with a jig, space is required to place the jig, so there was a problem that a large space was occupied for a long time until the adhesive hardened to install the tank and the jig.

This disclosure can be realized in the following forms:

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, the method for manufacturing the high-pressure tank comprising the steps of: applying an adhesive to at least one of an inner surface of an elastic protector having an inner surface with a curvature larger than a curvature of an outer surface of the dome portion or an 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, heating only one end of the protector, which is an end of the protector on the cylindrical portion side, and a portion of the protector other than the one end, while keeping the protector pressed, to harden the adhesive of the one end and fix the one end to the dome portion, and releasing the pressure on the protector after the adhesive of the one end has hardened and the one end of the protector is fixed to the dome portion.
According to this embodiment of the manufacturing method of the high-pressure tank, the inner surface of the protector and the outer surface of the dome portion can be tightly attached to each other regardless of individual differences in the surface shape of the dome portion. Also, by hardening the adhesive at the end of the cylindrical portion of the protector while the inner surface of the protector and the outer surface of the dome portion are in tight contact with each other, the protector can continue to be tightly attached to the dome portion even after the pressure on the protector is released. Therefore, the time required to occupy a large space for installing the tank and the jig can be shortened.

FIG. 2 is a cross-sectional view showing a schematic configuration of a high-pressure tank. 5A to 5C are process diagrams showing a method of attaching a protector to a tank body in the present embodiment. 11 is a cross-sectional view of the tank body and the protector with adhesive applied to the inner surface of the protector. FIG. 11 is a cross-sectional view of the tank body and the protector in a state in which the protector is pressed against a dome portion by a jig. FIG. 13A and 13B are diagrams showing the shape of an inner surface of a protector in a second embodiment.

A. First embodiment:
1 is a cross-sectional view showing a schematic configuration of a high-pressure tank 100. The high-pressure tank 100 contains high-pressure hydrogen of, for example, 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 nozzles 30 and 40.

The liner 10 is a hollow container for storing hydrogen gas and the like inside. The liner 10 may be made of a resin that has gas barrier properties against hydrogen gas, such as polyethylene, nylon, or polypropylene, or may be made of a metal. The axis of the liner 10 coincides with the axis AX of the high-pressure tank 100.

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 a filament winding method. Specifically, the reinforcing layer 20 is formed by winding and laminating fibers impregnated with a thermosetting resin around the outer surface of the liner 10 under tension, and then curing the thermosetting resin by heating. Examples of the fibers that are wound around the liner 10 include carbon fibers, glass fibers, and aramid fibers. Examples of the thermosetting resin that is impregnated into the fibers include epoxy resins, polyester resins, and polyamide resins. The reinforcing layer 20 has a cylindrical portion 21 that is approximately cylindrical in shape, and a dome portion 22 that is approximately hemispherical and provided continuously 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.

The nozzles 30, 40 are provided at the top of each dome portion 22. The nozzles 30, 40 are formed of a metal such as aluminum or an alloy thereof. One nozzle 30 is used to fill the high-pressure tank 100 with gas or to release gas from the high-pressure tank 100. The other nozzle 40 is sealed and is used for centering during manufacturing. Note that the nozzle 40 may be omitted.

The protectors 50 are attached to each dome portion 22 to absorb shock and protect the tank body 110, for example, if the high-pressure tank 100 is dropped. The protectors 50 are formed from elastic resin such as polyurethane, silicone, or polystyrene foam. When viewed along the axis AX of the high-pressure tank 100, the shape of the protector 50 is a donut shape with holes in the areas corresponding to the nozzles 30, 40, and its inner surface is dome-shaped.

Figure 2 is a process diagram showing a method for attaching the protector 50 to the tank body 110 in this embodiment. Attaching the protector 50 to the tank body 110 is performed as one process in the manufacture of the high-pressure tank 100. Before attaching the protector 50 to the tank body 110, the tank body 110 is prepared in advance.

First, in step S10, adhesive is applied to at least one of the inner surface of the protector 50 or the outer surface of the dome portion 22. For example, FIPG is used as the adhesive. It is preferable that the adhesive be one that hardens in a short time under high temperature conditions, and it may be other than FIPG.

Figure 3 shows a cross-sectional view of the tank body 110 and the protector 50 after adhesive 60 has been applied to the inner surface of the protector 50, as an example of step S10 in Figure 2. Figure 3 shows the orthogonal X, Y, and Z directions. The Z direction is parallel to the axis AX of the high-pressure tank 100. The X direction is perpendicular to the paper surface. The Y direction is orthogonal to the X and Z directions. The X, Y, and Z directions in Figure 3 represent the same directions as the X, Y, and Z directions in other figures.

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

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 in which the protector 50 is pressed against the dome portion 22 by the jig 70 in step S20 in 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 come into close contact with each other. The curvature of the inner surface of the protector 50 is set to a curvature that allows them to come into close contact with each other when the protector 50 is pressed against the dome portion 22. The elastic deformation of the protector 50 allows the inner surface of the protector 50 and the outer surface of the dome portion 22 to come into close contact with each other regardless of individual differences in the surface shape of the dome portion 22. In addition, the adhesive 60 spreads thinly and uniformly as the inner surface of the protector 50 and the outer surface of the dome portion 22 come into close contact with each other. The shape of the jig 70 and the direction of pressure applied to the protector 50 may be any shape and direction that allows the inner surface of the protector 50 and the outer surface of the dome portion 22 to come into close contact with each other.

2, the one end 51 of the protector 50, which is the end on the cylindrical portion 21 side, 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, the one end 51 is heated by the heater 80 to harden the adhesive 60 near the one end 51 and fix the one end 51 to the dome portion 22. For example, an infrared heater or a hot air heater can be used as the heater 80. In order to harden the adhesive 60 near the one end 51 in a short time, it is preferable that the thickness of the one end 51 is thinner than the thickness of the portion of the protector 50 other than the one end 51. In this 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.

2, the pressure applied to the protector 50 by the jig 70 is released. When the pressure applied to the protector 50 is released, only the one end 51 of the protector 50 is fixed to the dome portion 22. At this time, the restoring force of the protector 50 generates a force inside the protector 50 that presses the outer surface of the dome portion 22 in the vertical direction. Therefore, if the one end 51 is fixed to the dome portion 22, the inner surface of the protector 50 can be kept in close contact with the outer surface of the dome portion 22 even if the pressure applied to the protector 50 by the jig 70 is released. Therefore, the inner surface of the part of the protector 50 other than the one end 51 can be fixed to the outer surface of the dome portion 22 without keeping the protector 50 pressed against the dome portion 22 by the jig 70.

According to the manufacturing method of the high-pressure tank 100 in this embodiment described above, in the YZ plane, the curvature of the inner surface of the protector 50 is greater than the curvature of the outer surface of the dome portion 22, and 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 come into close contact with each other. Therefore, the inner surface of the protector 50 and the outer surface of the dome portion 22 can be brought into close contact with each other regardless of the individual difference in the surface shape of the dome portion 22. When the one end 51 of the protector 50 is heated by the heater 80 while the protector 50 is pressed against the dome portion 22 and the one end 51 is fixed to the dome portion 22, a force that presses the outer surface of the dome portion 22 in the vertical direction is generated inside the protector 50. Therefore, even if the pressure of the jig 70 on the protector 50 is released after the one end 51 is fixed to the dome portion 22, the protector 50 can be maintained in close contact with the dome portion 22, and the protector 50 can be fixed to the tank body 110. Therefore, the jig 70 is no longer necessary after the one end 51 is fixed to the tank body 110, and it is not necessary 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 hardens. In addition, by pressing the protector 50 against the dome portion 22, the applied adhesive 60 spreads and becomes thinner, so the time it takes for the adhesive 60 near the one end 51 to harden can be shortened.

B. Second embodiment:
5 is a diagram showing the shape of the inner surface of the protector 50a in the second embodiment. The inner surface of the protector 50a is provided with a slit 52 that opens when the protector 50a is pressed against the dome portion 22. The slit 52 is preferably provided in an annular shape 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, it is effective to increase the hardness of the protector 50a or to increase the thickness of the protector 50a in a direction at an angle of 45° with respect to the axis AX of the high-pressure tank 100 in order to improve the shock absorbing performance of the protector 50a, for example. However, if 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 slits 52 in the protector 50a, it is possible to adjust, for example, the reaction force that the jig 70 receives 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. Therefore, by providing the slits 52, the inner surface of the protector 50a can be brought into close contact with the outer surface of the dome portion 22 even in the case of a protector 50a with high shock absorbing performance.

C. Other embodiments:
In each of the above embodiments, the shape of the protector 50 is a doughnut shape having holes in the portions corresponding to the nozzles 30, 40 when viewed along the axis AX of the high-pressure tank 100. In contrast, when the protector 50 is attached to the other dome portion 22 that does not have a nozzle of the tank body 110 having a nozzle 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 a shape that covers 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 does not need to be in contact with the outer surface of the dome portion 22 when the protector 50 is not pressed against the dome portion 22.

The present disclosure is not limited to the above-described embodiments, and can be realized in various configurations without departing from the spirit of the present disclosure. For example, the technical features in the embodiments corresponding to the technical features in each form described in the Summary of the Invention column can be replaced or combined as appropriate to solve some or all of the above-described problems or to achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be deleted as appropriate.

10...liner, 20...reinforcing layer, 21...cylindrical portion, 22...dome portion, 30, 40...ferrule, 50...protector, 51...one end, 52...slit, 60...adhesive, 70...jig, 80...heater, 100...high pressure tank, 110...tank body, AX...axis of high pressure tank

Claims (2)

A method for manufacturing a high-pressure tank having a cylindrical portion and dome portions disposed on both ends of the cylindrical portion, comprising the steps of:
applying an adhesive to at least one of an inner surface of a protector having an inner curvature larger than a curvature of the outer surface of the dome portion and an outer surface of the dome portion;
pressing the protector against the dome portion to bring the inner surface of the protector into intimate contact with the outer surface of the dome portion;
a step of heating only one end portion of the protector, which is an end portion of the protector on the cylindrical portion side, and a portion of the protector other than the one end portion while keeping the protector pressed, to harden the adhesive of the one end portion and fix the one end portion to the dome portion ;
releasing the pressure on the protector after the adhesive at the one end has hardened, while the one end of the protector is fixed to the dome portion ;
A method for manufacturing a high-pressure tank comprising the steps of: A method for manufacturing the high-pressure tank according to claim 1, comprising the steps of:
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 high-pressure tanks.

Images