JP7401213B2 - high pressure tank - Google Patents

Description

The present invention relates to a high pressure tank.

For example, as described in Patent Document 1, a high-pressure tank for storing hydrogen used in a fuel cell system includes a protective layer made of glass fiber impregnated with a thermosetting resin on the outside of a reinforcing layer. Are known.

JP2019-27578A

Since the protective layer tends to have a low hydrogen permeability, a structure is known in which cracks are provided in the protective layer in advance to allow hydrogen permeation. When a resin material having a high shrinkage rate due to heat curing is used for the protective layer in order to provide cracks, the warping force at the winding end of the protective layer becomes large, which may cause the protective layer to turn over. Therefore, there has been a desire for a technique that can suppress the occurrence of curling of the winding end.

The present invention has been made to solve the above-mentioned problems, and can be realized as the following forms.
According to one form of the invention, a high pressure tank is provided. This high-pressure tank includes a liner, a reinforcing layer formed on the surface of the liner, and a protective layer formed on the outside of the reinforcing layer, and the protective layer includes a helical layer and an outside of the helical layer. The thickness of the winding end, which is the end of the winding of the hoop layer and represents one round of the end of the winding, is smaller than the thickness of the helical layer, and the thickness of the winding end is smaller than the thickness of the helical layer, The winding tension at the winding end portion is greater than the winding tension at a portion other than the winding end portion, and the thickness of the winding end portion of the liner is thinner than the thickness of the other portion of the liner.

According to one form of the invention, a high pressure tank is provided. This high-pressure tank includes a liner, a reinforcing layer formed on the surface of the liner, and a protective layer formed on the outside of the reinforcing layer, and the protective layer includes a helical layer and an outside of the helical layer. and a wound end portion of the hoop layer has a thickness smaller than the thickness of the helical layer. According to this type of high-pressure tank, the thickness of the winding end of the hoop layer is smaller than the thickness of the helical layer, so the stress that tends to cause the winding end to turn up from the tank surface is reduced, thereby preventing the winding end from turning over. The occurrence can be suppressed.

Note that the present invention can be realized in various forms, such as a method for manufacturing a high-pressure tank, a filament winding device, and a method for controlling a filament winding device.

FIG. 2 is a cross-sectional view showing a schematic structure of a high-pressure tank. FIG. 3 is a process diagram showing an example of a method for manufacturing a high-pressure tank. It is a figure which shows the comparative example of the winding method of a hoop layer. 4 is a cross-sectional view of the protective layer taken along line IV-IV in FIG. 3. FIG. It is a figure which shows the 1st winding method. 6 is a cross-sectional view of the protective layer taken along line VI-VI in FIG. 5. FIG. It is a figure which shows the 2nd winding method. 8 is a cross-sectional view of the protective layer taken along the line VIII-VIII in FIG. 7. FIG. It is a sectional view of a protective layer when it is wound by a third winding method.

FIG. 1 is a cross-sectional view showing a schematic structure of a high-pressure tank 100 manufactured by the high-pressure tank manufacturing method of this embodiment. 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 liner 10, a cap 20, a reinforcing layer 30, and a protective layer 40. FIG. 1 shows an x-axis, a y-axis, and a z-axis that are orthogonal to each other. The x-axis is the axial direction of the high-pressure tank 100, that is, the direction along the longitudinal direction of the high-pressure tank 100. These axes correspond to the axes shown from FIG. 2 onwards.

The liner 10 has a cylindrical portion 12 and two dome portions 14 provided at both ends of the cylindrical portion 12. The liner 10 is made of a resin having gas barrier properties against hydrogen gas, such as polyethylene, nylon, or polypropylene. In this embodiment, the liner 10 is made of resin, but it may be made of metal, or may be formed by mixing a gas impermeable material such as a hydrogen storage alloy with the above resin. . A reinforcing layer 30 is formed on the outer periphery of the cylindrical portion 12 and the dome portion 14. In this embodiment, the caps 20 are provided at both longitudinal ends of the liner 10, but may be provided only at one end.

The reinforcing layer 30 is formed by bundling approximately 10,000 to 40,000 glass fibers or carbon fibers (hereinafter simply referred to as "fibers") and impregnating them with resin. The fiber bundles are formed by filament winding on the outer surface of the liner 10. It is formed by wrapping it around and curing it with heat. A protective layer 40 is formed on the outer surface of the reinforcing layer 30.

The protective layer 40 is formed by, for example, bundling approximately 10,000 to 40,000 fibers and impregnating them with a thermosetting resin such as epoxy, and placing the fiber bundles on the reinforcing layer 30 on the outer periphery of the liner 10 using a filament winding method. It is formed by winding and heat curing. The protective layer 40 is fixed to the outer periphery of the reinforcing layer 30 using a resin component as an adhesive. The protective layer 40 includes a helical layer 41 and a hoop layer 42 formed on the outer side of the helical layer 41 on the cylindrical portion 12 (see FIG. 6 described later). Further, on the outside of the hoop layer 42, a resin layer 43 is formed of a thermosetting resin that comes out from the fibers by thermosetting the fiber bundle (see FIG. 6).

Examples of the resin (matrix resin) with which the fiber bundles forming the reinforcing layer 30 and the protective layer 40 are impregnated include epoxy resin, epoxy-modified polyurethane resin, polyester resin, phenol resin, polymiad resin, polyurethane resin, polyimide resin, and polyvinyl alcohol. Resins, polyvinylporolidone resins, polyethersulfone resins, etc. can be used alone or in combination of two or more.

FIG. 2 is a process diagram showing an example of a method for manufacturing a high-pressure tank in this embodiment. In manufacturing the high-pressure tank of this embodiment, first, in step S100, a resin container with a cap attached is prepared as the liner 10. The liner 10 is prepared, for example, by welding the dome portions 14, to which the caps 20 are attached, to both ends of the cylindrical portion 12.

Next, in step S110, a reinforcing layer 30 is formed by wrapping a resin-impregnated fiber bundle around the outer surface of the liner 10. In this embodiment, two reinforcing layers 30 are formed.

Subsequently, in step S120, a resin-impregnated fiber bundle is helically wound onto the reinforcing layer 30 formed in step S110 to form a helical layer 41. In this embodiment, two helical layers 41 are formed.

Subsequently, in step S130, a resin-impregnated fiber bundle is wound by hoop winding on the helical layer 41 formed in step S120, thereby forming a hoop layer 42. The hoop layer 42 is wound so that the thickness of the wound end portion thereof is smaller than the thickness of the helical layer 41. In this embodiment, the "winding end" is the end of the winding of the hoop layer 42, and indicates one round of winding. The stress that tends to cause the winding end of the hoop layer 42 to turn over is proportional to about the third power of the thickness of the winding end, so the smaller the thickness of the winding end of the hoop layer 42, the more suppressed the occurrence of turning up can be. It is preferable to wind the hoop layer 42 so that the adhesive force adhering to the helical layer 41 at the winding end is greater than the stress that tends to cause it to turn over. Details of the method for winding the hoop layer 42 will be described later. The protective layer 40 is formed by the processing in steps S120 and S130.

Subsequently, in step S140, the resin of the fiber bundle of the reinforcing layer 30 wound in step S110 and the resin of the fiber bundle of the protective layer 40 wound in steps S120 and S130 are cured. More specifically, in a thermosetting furnace equipped with a thermal heater or a high-frequency dielectric heating type thermosetting furnace using a heating coil, the liner 10 is rotated and heated to thermoset the thermosetting resin. A resin layer 43 is formed by this treatment.

Finally, in step S150, the resin is cooled and cured after being thermally cured, and then a pressurization test is performed to confirm the strength of the high-pressure tank 100, and the manufacturing of the high-pressure tank is completed. In step S150, cracks are formed in the resin layer 43 as passages communicating with minute voids in the helical layer 41 and the hoop layer 42 due to shrinkage of the thermoplastic resin.

There are, for example, the following three methods for winding the hoop layer 42 so that the thickness of the winding end is smaller than the thickness of the helical layer 41. The first winding method is a method in which only one hoop layer 42 is formed. The second winding method is a method of winding so that the winding angle at the winding end is different from the winding angle at a portion other than the winding end. The third winding method is a winding method in which the winding tension at the winding end is increased.

FIG. 3 is a diagram showing a comparative example of a method of winding the hoop layer 42. As shown in the upper part of FIG. 3, in the comparative example, winding of the fiber bundle is started from the position of the black circle on the cylindrical portion 12, and the two hoop layers 42 are formed by winding in the direction of the arrow. Specifically, winding is started from an arbitrary position on the cylindrical portion 12 in the +x-axis direction, and is folded back and wrapped in the opposite direction (−x-axis direction) at the end of the cylindrical portion 12 in the +x-axis direction. At the end of the cylindrical portion 12 in the −x-axis direction, it is again folded and wound in the opposite direction (+x-axis direction), and the winding ends near the position of the black circle, which is near the beginning of the winding.

FIG. 4 is a cross-sectional view of the protective layer 40 taken along the line IV--IV in FIG. As described above, in the protective layer 40, the hoop layer 42 is formed on the outside of the helical layer 41, and the resin layer 43 is formed on the outside of the hoop layer 42. As shown in FIG. 4, the winding end portion WE of the hoop layer 42 may overlap the winding start portion WS of the hoop layer. Therefore, the thickness 42t of the winding end WE of the hoop layer 42 may be larger than the thickness 41t of the helical layer 41.

FIG. 5 is a diagram showing the first winding method, and FIG. 6 is a cross-sectional view of the protective layer 40 taken along the line VI-VI in FIG. As shown in FIG. 6, the first winding method is a winding method in which only one hoop layer 42 is formed. Since the helical layer 41 has two layers, the thickness 42t of the winding end WE of the hoop layer 42 is smaller than the thickness 41t of the helical layer 41.

As shown in the upper part of FIG. 5, in the first winding method, (1) first, winding of the fiber bundle is started from the position of the black circle on the cylindrical part 12, and toward the end of the cylindrical part 12 in the +x-axis direction; and wrap it around. When winding is completed to the end of the cylindrical portion 12 in the +x-axis direction, the fiber bundle is cut. (2) Next, start winding the fiber bundle from the position of the white circle, and wind it toward the end of the cylindrical part 12 in the -x direction. Once the fiber bundle has been wound to the end in the −x axis direction of the cylindrical portion 12, the fiber bundle is cut. (3) Finally, start winding the fiber bundle from the double circle position, and wind it in the +x-axis direction to the vicinity of the position where the fiber bundle winding was started in (1) (black circle position). Note that the winding order of (1) and (2) is not limited to this. Further, the winding direction in (3) may also be reversed. In other words, it may be wound in the −x-axis direction from near the position of the black circle to near the position of the white circle.

FIG. 7 is a diagram showing the second winding method. As shown in FIG. 7, in the second winding method, the fiber bundle is wound in the same winding order as in the comparative example, but the winding angle θ2 at the winding end WE is different from the winding angle θ1 at a portion other than the winding end WE. This is a method of wrapping it at an angle. The winding angle is the angle of the fiber bundle in the longitudinal direction with respect to the axis of the high pressure tank 100. It is preferable that the difference between the wrapping angle θ1 and the wrapping angle θ2 is greater than 0 degrees and less than 2 degrees. In FIG. 7, the winding angle θ1 is 89 degrees, and the winding angle θ2 is 90 degrees.

FIG. 8 is a cross-sectional view of the protective layer 40 taken along line VIII-VIII in FIG. As shown in FIG. 8, in the second winding method, the winding end WE is wound at a winding angle θ2 that is different from the winding angle θ1 at the portion other than the winding end WE. As shown in FIG. 8, the hoop layer 42 may be wound onto adjacent fiber bundles, but if the winding end WE and the other portions are wound at different angles, the winding end A gap is created between the fiber bundle and the adjacent fiber bundle wrapped one round before the part WE. Therefore, it is possible to prevent the winding end WE from riding on and winding the adjacent fiber bundle. Moreover, it is possible to suppress the winding end portion WE from overlapping the winding start portion WS of the hoop layer. Thereby, the thickness 42t of the winding end WE of the hoop layer 42 can be suppressed from increasing. Also in the helical layer 41, the thickness 42t of the winding end portion WE of the hoop layer 42 is smaller than the thickness 41t of the helical layer 41, because the fiber bundles may be wound on top of adjacent fiber bundles.

FIG. 9 is a cross-sectional view of the protective layer 40 when wound using the third winding method. In the third winding method, the winding tension at the winding end WE is made larger than the winding tension at a portion other than the winding end WE. For example, increase it within the range of 10% to 30%. As a result, the width of the fiber bundle at the winding end WE is widened, and the thickness 42t becomes thinner in the range of 10% to 30%. Therefore, it is possible to suppress the thickness 42t of the winding end portion WE of the hoop layer 42 from increasing. Since the helical layer 41 is wound with a lower tension than the winding tension at the winding end WE, the thickness 42t of the winding end WE of the hoop layer 42 is smaller than the thickness 41t of the helical layer 41.

In the high-pressure tank 100 of the present embodiment described above, the thickness 42t of the winding end portion WE of the hoop layer 42 is smaller than the thickness 41t of the helical layer 41. Therefore, the stress that tends to cause the winding end WE to turn over from the tank surface is reduced, and the occurrence of the winding end WE turning over can be suppressed.

The present invention is not limited to the above-described embodiments, and can be realized in various configurations without departing from the spirit thereof. For example, the technical features in the embodiments that correspond to the technical features in each form described in the column of the summary of the invention are for solving the above-mentioned problems or achieving some or all of the above-mentioned effects. It is possible to replace or combine them as appropriate. Further, unless the technical feature is described as essential in this specification, it can be deleted as appropriate.

DESCRIPTION OF SYMBOLS 10... Liner, 12... Cylindrical part, 14... Dome part, 20... Cap, 30... Reinforcement layer, 40... Protective layer, 41... Helical layer, 42... Hoop layer, 43... Resin layer, 100... High pressure tank, WE... Winding end, WS...winding beginning

Claims (2)

A high pressure tank,
Raina and
a reinforcing layer formed on the surface of the liner;
a protective layer formed on the outside of the reinforcing layer,
The protective layer has a helical layer and a hoop layer formed outside the helical layer,
The thickness of the winding end, which is the end of the winding of the hoop layer and represents one round of the end of winding, is smaller than the thickness of the helical layer,
The winding tension at the winding end of the hoop layer is greater than the winding tension at a portion other than the winding end,
The high-pressure tank , wherein the liner has a thinner thickness at the winding end than other parts of the liner . The high pressure tank according to claim 1 ,
The high-pressure tank, wherein the winding end of the hoop layer does not overlap with a winding start of the hoop layer.

Images