JP2020128010A - Method for manufacturing high-pressure tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a high-pressure tank capable of suppressing misalignment of fibers in a hoop layer and increasing the strength of the high-pressure tank. SOLUTION: In a method of manufacturing a high pressure tank 1, a fiber F impregnated with resin is wound around an outer peripheral surface of a liner 10 having a cylindrical body portion 11 and dome portions 12 provided at both ends of the body portion 11. This is a method of forming a reinforcing layer 20 having a helical layer and a hoop layer. In the method for manufacturing the high-pressure tank 1, one helical layer is formed on the innermost layer of the formed reinforcing layer 20 closest to the outer peripheral surface of the liner 10 at a winding angle of 26 to 40 ° with respect to the axial direction of the body portion 11. It is formed and a plurality of hoop layers are formed on the outside of the formed helical layer. [Selection diagram] Fig. 3

Description

The present invention relates to a method for manufacturing a high pressure tank.

High-pressure tanks such as hydrogen tanks installed in fuel cell vehicles are required to have high strength and the like in order to ensure safety. A filament winding (FW) method is known as a method for manufacturing such a high-pressure tank. Specifically, while rotating a liner having a cylindrical body portion and dome portions provided at both ends of the body portion, the fiber impregnated with the thermosetting resin has a constant tension (that is, a force for winding the fiber). ) Is repeatedly wound around the outer peripheral surface of the liner to form a reinforcing layer composed of a helical layer and a hoop layer, and then the thermosetting resin is thermoset.

As an example, for example, Patent Document 1 below discloses a method for manufacturing a high-pressure tank in which a hoop layer is formed after forming a helical layer in the innermost layer of the reinforcing layer closest to the outer peripheral surface of the liner (Patent Document 1). Paragraphs 0025-0030).

JP, 2013-173304, A

However, in the above-described manufacturing method, when a plurality of hoop layers are formed on the body, the inner (that is, the outer circumferential surface of the liner is wound by the force of winding the fibers of the outer hoop layer (that is, the side far from the outer circumferential surface of the liner)). The fibers of the inner hoop layer are extruded because pressure is applied to the fibers of the (closer side) hoop layer. As a result, the fibers of the inner hoop layer slide sideward along the axial direction of the body portion toward the dome portion, causing a positional shift. When such displacement of the fibers of the hoop layer occurs, the strength of the high-pressure tank may be reduced, which may cause a problem of quality deterioration.

The present invention has been made to solve such a technical problem, and provides a method for manufacturing a high-pressure tank capable of suppressing positional displacement of fibers in the hoop layer and increasing the strength of the high-pressure tank. With the goal.

The method for producing a high-pressure tank according to the present invention comprises winding a resin-impregnated fiber on the outer peripheral surface of a liner having a cylindrical body portion and dome portions provided at both ends of the body portion, and a helical layer. A method for manufacturing a high-pressure tank, comprising forming a reinforcing layer having a hoop layer, wherein the innermost layer closest to the outer peripheral surface of the liner among the reinforcing layers to be formed is 26 to 26 in the axial direction of the body portion. One feature is that a single helical layer is formed at a winding angle of 40°, and a plurality of hoop layers are formed outside the formed helical layer.

It is said that the strength of the high-pressure tank largely depends on several layers from the innermost layer closest to the outer surface of the liner among the reinforcing layers formed. Therefore, it is considered that the strength of the manufactured high-pressure tank can be secured if the displacement of several layers from the innermost layer of the reinforcing layer to be formed can be suppressed. On the other hand, in the method for manufacturing a high-pressure tank according to the present invention, among the reinforcing layers to be formed, one helical layer is formed in the innermost layer closest to the outer peripheral surface of the liner, and a plurality of helical layers are formed outside the formed helical layer. Since the hoop layer is formed, the frictional force with the hoop layer formed outside the helical layer can be increased by utilizing the intersection of the fibers in the helical layer formed as the innermost layer. As a result, it is possible to suppress the positional deviation of the fibers of the hoop layer.

Moreover, when forming the innermost helical layer, since the winding angle is 26 to 40° with respect to the axial direction of the body portion, increase the number of intersections of fibers per unit length in the axial direction of the body portion. Therefore, the frictional force between the helical layer and the hoop layer can be further increased, and the positional deviation of the fibers of the hoop layer can be effectively suppressed. As a result, the strength of the high pressure tank can be increased. Further, since there is only one helical layer, it is possible to increase the number of hoop layers that have a high contribution to the strength of the high-pressure tank without changing the thickness of the reinforcing layer, so it is possible to improve the strength of the high-pressure tank. Become.

According to the present invention, it is possible to suppress the positional deviation of the fibers of the hoop layer and increase the strength of the high pressure tank.

It is sectional drawing which shows the structure of a high-pressure tank. (A) is a perspective view showing formation of a helical layer by helical winding, and (b) is a perspective view showing formation of a hoop layer by hoop winding. It is process drawing which shows the manufacturing method of the high-pressure tank which concerns on embodiment. (A) is a schematic diagram showing a helical layer according to a conventional product, and (b) is a schematic diagram showing a helical layer according to the present invention. It is a figure which shows the relationship between a helical winding angle and the positional shift amount of a fiber. It is a figure which shows the measurement result of the burst pressure regarding this invention product and the conventional product.

Hereinafter, an embodiment of a method for manufacturing a high pressure tank will be described with reference to the drawings, but before that, a structure of the high pressure tank will be described based on FIG. In the following description, "inside" refers to the side closer to the outer surface of the liner, and "outer" refers to the side farther from the outer surface of the liner, unless otherwise specified.

FIG. 1 is a sectional view showing the structure of a high-pressure tank. The high-pressure tank 1 is, for example, a hydrogen tank mounted on a fuel cell vehicle, and has a liner 10 having a storage space for storing high-pressure hydrogen therein, and a reinforcing layer arranged in close contact with the outer peripheral surface of the liner 10. 20 and 20 are provided.

The liner 10 has a gas barrier property against hydrogen gas, and is a hollow container having a cylindrical body portion 11 and substantially hemispherical dome portions 12 provided at the left and right ends of the body portion 11, respectively. Openings are respectively formed at the tops of the two dome portions 12, and the valve side cap 13 is inserted into one of these openings and the end side cap 14 is inserted into the other.

The liner 10 is integrally formed by a rotational/blow molding method using a resin member such as polyethylene or nylon. The liner 10 may be formed of a light metal such as aluminum instead of the resin member. Further, the liner 10 may be formed by joining a plurality of divided members by injection/extrusion molding or the like instead of the integral molding manufacturing method such as the rotation/blow molding method.

The reinforcing layer 20 is formed by winding a plurality of the fibers F impregnated with the thermosetting resin around the outer peripheral surface of the liner 10. The fiber F is formed of a composite material in which carbon fiber (Carbon Fiber), glass fiber (Glass Fiber), aramid fiber (Aromatic Polyamide Fiber), etc. are put in plastic to improve the strength. Further, the fiber F is a fiber bundle formed by bundling single fibers having a diameter of about several μm, and is simply referred to as “fiber” here.

In the present embodiment, for example, two types of fibers F are used, and the carbon fiber impregnated with the thermosetting resin wound on the outer peripheral surface of the liner 10 and the heat further wound on the outer side of the carbon fiber are used. A glass fiber impregnated with a curable resin. Examples of the thermosetting resin include epoxy resin, polyester resin, polyamide resin and the like.

The reinforcing layer 20 includes a helical layer that entirely covers the liner 10 so as to wrap the body 11 and the dome 12, and a hoop layer that is formed so as to cover the body 11.

As shown in FIG. 2A, the helical layer has a winding angle θ of more than 0° and less than 90° with respect to the axis L direction of the liner 10 (that is, the axis L direction of the body portion 11 ), and the body portion 11 And a fiber layer formed in a mesh shape by helically winding the fiber F in the circumferential direction of the dome portion 12. The helical winding is further divided into low-angle helical winding and high-angle helical winding depending on the size of the winding angle θ. The low-angle helical winding is a helical winding when the winding angle θ is small (for example, 0°<θ≦30°), and the winding of the fiber F in the dome portion 12 is performed before the fiber F goes around the axis L of the liner 10. This is a winding method in which folding back occurs in the attaching direction. The high-angle helical winding is a helical winding in the case where the winding angle θ is large (for example, 30°<θ<90°), and the body portion 11 has a fold-back in the winding direction of the fiber F in the dome portion 12. This is a winding method in which the fiber F makes at least one revolution around the axis L of the liner 10.

On the other hand, the hoop layer is formed by hoop-winding the fiber F in the circumferential direction of the body 11 at a winding angle θ substantially perpendicular to the axis L of the liner 10, as shown in FIG. 2B. It is a layer. Here, “substantially vertical” includes both 90° and an angle of about 90° that can be generated by shifting the winding positions of the fibers F so that the fibers F do not overlap each other.

Hereinafter, a method for manufacturing the high-pressure tank according to this embodiment will be described. As shown in FIG. 3, the method for manufacturing the high-pressure tank 1 includes a preparatory step S1 for preparing the liner 10 and the fibers F, a single-layer helical layer forming step S2, a plurality of hoop layer forming step S3, and other helical layers. It includes a layer and hoop layer forming step S4 and a thermosetting step S5 for thermosetting the fiber F.

First, in the preparation step S1, the liner 10 and the fibers F are prepared. Specifically, for example, the resin liner 10 is manufactured by the rotation/blow molding method as described above. A bobbin around which the fiber F impregnated with the thermosetting resin is wound is prepared at the same time as or before or after the manufacturing operation of the liner 10.

In the one-layer helical layer forming step S2 subsequent to the preparation step S1, one helical layer is formed in the innermost layer closest to the outer peripheral surface of the liner 10 in the reinforcing layer 20 to be formed. That is, the fiber F is directly wound around the outer peripheral surfaces of the body portion 11 and the dome portion 12 by helical winding to form only one innermost helical layer. At this time, the helical winding angle θ is set to 26 to 40°.

In a plurality of hoop layer forming steps S3 subsequent to the one-layer helical layer forming step S2, a plurality of hoop layers are formed by hoop winding outside the formed helical layers. Specifically, the hoop layer is sequentially formed outside the helical layer so as to overlap with the formed helical layer.

In another helical layer and hoop layer forming step S4 subsequent to the plurality of hoop layer forming step S3, the fiber F is wound around the formed plurality of hoop layers, and the plurality of helical layers and the plurality of hoop layers are repeated. Form. Such a process is performed until the required number of layers is reached.

In the thermosetting step S5 subsequent to the other helical layer and hoop layer forming step S4, the thermosetting resin impregnated in the fiber F wound around the liner 10 is thermoset. Specifically, the liner 10 in which the fiber F is wound around the outer peripheral surface is placed in a thermosetting oven or a thermostat and heated at a temperature of, for example, about 85° C. for a predetermined time to remove the thermosetting resin in the fiber F. Heat cure. Thereby, the reinforcing layer 20 is formed and the high-pressure tank 1 is manufactured.

According to the method for manufacturing a high-pressure tank according to this embodiment, one helical layer is formed in the innermost layer of the reinforcing layer 20 that is closest to the outer peripheral surface of the liner 10, and a plurality of layers are formed outside the formed helical layer. Since the hoop layer is formed, the frictional force with the hoop layer formed outside the helical layer can be increased by utilizing the intersection of the fibers in the helical layer formed in the innermost layer. As a result, it is possible to suppress the positional deviation of the fibers of the hoop layer. Moreover, when forming the innermost helical layer, since the winding angle is 26 to 40° with respect to the axial direction of the body portion, as shown in FIG. 4, per unit length in the axial direction of the body portion. The number of intersections between fibers can be increased.

FIG. 4(a) is a schematic view showing a helical layer according to a conventional product (helical winding angle=18°), and FIG. 4(b) shows a helical layer according to the present invention product (helical winding angle=32°). It is a schematic diagram. In FIG. 4, the arrow indicates the axial direction of the liner. As shown in FIG. 4, when the helical winding angle is increased, the number of intersections of fibers per unit length in the axial direction increases in the formed helical layer (see black dots in FIG. 4 ). When the number of intersections between the fibers increases, when the hoop layer is formed outside the helical layer, the frictional force between the hoop layer and the helical layer increases, so that the displacement of the fibers in the hoop layer is effectively suppressed. can do. As a result, the strength of the high pressure tank can be increased.

Here, the basis for setting the helical winding angle to 26 to 40° will be described based on FIG. FIG. 5 is a diagram showing the relationship between the helical winding angle and the positional displacement amount of the fiber. As can be seen from FIG. 5, as the helical winding angle increases, the amount of positional deviation of the hoop layer formed on the outer side and its variation decrease. However, since the dome portion has a substantially hemispherical shape, if the helical winding angle becomes too large, it becomes difficult for the fiber to be caught in the dome portion of the liner, and the holding force of the dome portion on the fiber in the axial direction of the liner decreases. In the present embodiment, the lower limit value of the helical winding angle is set to 26° in consideration of the range in which the positional displacement amount of the fibers is allowable. Further, from the viewpoint of securing the holding force of the dome portion on the fiber, the upper limit value of the helical winding angle is set to 40°.

Further, since there is only one helical layer, it is possible to increase the number of hoop layers that have a high contribution to the strength of the high-pressure tank without changing the thickness of the reinforcing layer, so it is possible to improve the strength of the high-pressure tank. Become.

In addition, the inventors of the present application prototyped the product of the present invention (helical winding angle=32°) and the conventional product (helical winding angle=18°) based on the method for manufacturing a high-pressure tank according to the present embodiment, and made the respective bursts. The pressure (that is, compressive strength) was measured. In addition, as a reference, a reference product was prepared by the same manufacturing method when the helical winding angle was 50°, and the burst pressure of the reference product was also measured.

The measurement result of each burst pressure is shown in FIG. It can be seen from FIG. 6 that the burst pressure of the product of the present invention is higher and the variation of the burst pressure is smaller than that of the conventional product and the reference product. It was shown that this can improve the strength of the high-pressure tank according to the present invention. On the other hand, it was found that the burst pressure of the reference product was much lower than that of the conventional product. It is considered that this is because when the helical winding angle becomes too large, the fiber is less likely to be caught in the dome portion of the liner, and the holding force of the dome portion on the fiber is reduced in the axial direction of the liner.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various designs can be made without departing from the spirit of the present invention described in the claims. You can make changes.

1 High-pressure tank 10 Liner 11 Body 12 Dome 13 Valve side cap 14 End side cap 20 Reinforcing layer F Fiber L axis

Claims (1)

A resin-impregnated fiber is wound around the outer peripheral surface of a liner having a cylindrical body portion and dome portions provided at both ends of the body portion to form a reinforcing layer having a helical layer and a hoop layer. A method of manufacturing a tank,
In the innermost layer closest to the outer peripheral surface of the liner among the reinforcing layers formed, a single helical layer is formed at a winding angle of 26 to 40° with respect to the axial direction of the body portion,
A method of manufacturing a high-pressure tank, characterized in that a plurality of hoop layers are formed outside the formed helical layer.

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