JP6927013B2 - High pressure tank - Google Patents

Description

The present invention relates to a high pressure tank provided with a liner for accommodating gas and a reinforcing layer arranged on the outer periphery of the liner.

For example, natural gas vehicles or fuel cell vehicles use high-pressure tanks for storing high-pressure gas as fuel. As a high-pressure tank of this type, Patent Document 1 discloses a high-pressure tank including a metal liner for accommodating gas and a reinforcing layer arranged on the outer periphery of the liner. The metal liner of this high-pressure tank has a cylindrical body portion and dome-shaped side ends formed continuously on both sides of the body portion.

Japanese Unexamined Patent Publication No. 2016-176735

Compared with the resin liner, the metal liner as described in Patent Document 1 is less likely to expand and contract with respect to the internal pressure of the high pressure tank. Here, for example, due to the pressure of the gas in the high-pressure tank, stress acts on the side end portion of the liner (mainly near the base portion) along the axial direction of the high-pressure tank, and the liner near the base portion of the liner. And the deformation of the reinforcing layer follow. However, in the boundary region between the body portion and the side end portion, the liner cannot follow the reinforcing layer due to its shape, and a gap may be generated in this portion. That is, in the part where this gap is generated, only the liner is repeatedly subjected to the pressure of the gas in the high-pressure tank as the gas is filled and released, and the stress is more likely to be concentrated than in other parts, which causes strain of the liner. (Deformation) becomes large, and as a result, the fatigue strength of the liner may decrease.

The present invention has been made in view of the above points, and the present invention provides a high-pressure tank capable of suppressing a decrease in fatigue strength of a metal liner.

In order to solve the above problems, the present invention comprises a metal liner for accommodating gas, a reinforcing layer arranged on the outer periphery of the liner, and an adhesive layer arranged between the liner and the reinforcing layer. A high-pressure tank comprising, the liner has a cylindrical body portion and dome-shaped side ends continuously formed on both sides of the body portion, and the liner has a surface of the liner. Among the surfaces of the liner, the reinforcing layer and the adhesive layer for adhering the liner are formed on the surface of at least the boundary region between the body portion and each side end portion. The reinforcing layer is arranged on the surface of the internal region located between the boundary regions on both sides of the liner without the adhesive layer.

According to the present invention, when stress acts on the side end portion of the liner (mainly near the base portion) due to the pressure of the gas in the high pressure tank, the liner and the reinforcing layer are formed in the vicinity of the base portion of the liner. The deformation of is followed. At this time, on the surface of the boundary region between the body portion and the side end portion, the reinforcing layer and the liner are adhered by an adhesive layer, so that the reinforcing layer and the liner are uniformly deformed, and a gap is formed in this portion. Will not occur. Therefore, in the boundary region, the strain of the liner can be reduced because the liner alone does not repeatedly receive the pressure of the gas. Therefore, it is possible to suppress a decrease in the fatigue strength of the liner.

(A) is a schematic cross-sectional view of the high-pressure tank according to the first embodiment, and (b) is a schematic enlarged cross-sectional view of the vicinity of the adhesive layer. (A) is a schematic cross-sectional view of a high-pressure tank according to a modified example of the first embodiment, and (b) is a schematic enlarged cross-sectional view of the vicinity of the adhesive layer.

Hereinafter, embodiments and modifications thereof according to the present invention will be described with reference to FIGS. 1 and 2. FIG. 1A is a schematic cross-sectional view of the high-pressure tank 1 according to the first embodiment, and FIG. 1B is a schematic enlarged cross-sectional view of the vicinity of the adhesive layer 4.

The high-pressure tank 1 according to the present embodiment is used for a natural gas vehicle, a fuel cell vehicle, or the like. As shown in FIG. 1A, in the high-pressure tank 1 of the present embodiment, the liner 2, the reinforcing layer 3 arranged on the outer periphery of the liner 2, and the adhesive arranged between the liner 2 and the reinforcing layer 3 are adhered to each other. Layer 4 and.

The liner 2 is a part that is also referred to as an inner shell or an inner container of the high-pressure tank 1, and houses gas inside. Examples of the gas to be accommodated include fuel gas and hydrogen gas.

In this embodiment, the liner 2 is a metal liner. Examples of the metal constituting the liner 2 include an aluminum alloy and steel. Examples of the aluminum alloy include Al-Mg-Si based alloys. Examples of steel include stainless steel.

The liner 2 has a body portion 21 and side end portions 22, 22. The body portion 21 has a cylindrical shape having a predetermined length and extending along the axis X of the high-pressure tank 1 shown in FIG. 1 (a) of the high-pressure tank 1. The side end portions 22, 22 have a dome-shaped shape continuously formed on both sides of the body portion 21. The diameter of each side end portion 22 is reduced as the distance from the body portion 21 is increased, and openings 22a and 22a are formed at the center of the most reduced diameter portion, and the base portions 5 and 5 are formed in the openings 22a and 22a. It is formed.

The reinforcing layer 3 constitutes the outer wall of the body portion 21 and each side end portion 22. The reinforcing layer 3 is formed by winding a resin-impregnated fiber bundle around the liner 2 by hoop winding and helical winding so as to cover the outer surface of the liner 2.

Examples of the material of the reinforcing layer 3 include those in which reinforcing fibers are impregnated with a thermoplastic resin or a thermosetting resin. Examples of the reinforcing fiber include glass fiber, carbon fiber, and aramid fiber. Examples of the thermoplastic resin include polyester-based resin, polypropylene-based resin, nylon-based resin, and the like. Examples of the thermosetting resin include epoxy resins and vinyl ester resins.

As shown in FIG. 1B, in the present embodiment, the reinforcing layer 3 and the liner 2 are formed on the surfaces of at least the boundary regions 23 and 23 between the body portion 21 and the side end portions 22 of the surface of the liner 2. Adhesive layers 4 and 4 for adhering to and are formed. That is, the reinforcing layer 3 is wound around the surface of the boundary region 23 via the adhesive layer 4.

Each boundary region 23 on which the adhesive layer 4 is formed is centered on the boundary P shown in FIG. 1B, along the axis X of the high-pressure tank 1, toward both sides of each base portion 5 and the internal region 24. It is postponed. The boundary P is a position where the tubular body portion 21 transitions to the dome-shaped side end portions 22. The width d of each adhesive layer 4 is preferably 2.5% with respect to the total length L of the high-pressure tank 1 centering on the boundary P. Here, the total length L of the high-pressure tank 1 is, as shown in FIG. 1A, from the end of one base portion 5 to the end of the other base portion 5 along the axial center X of the high-pressure tank 1. Is up to.

Further, in the present embodiment, of the surface of the liner 2, the reinforcing layer 3 is arranged on the surface of the internal region 24 located between the boundary regions 23 on both sides of the liner 2 without the intervention of the adhesive layer 4. There is. That is, the adhesive layer 4 is not formed on the surface of the inner region 24 of the surface of the liner 2, and the reinforcing layer 3 is wound around the surface.

The range of the adhesive strength of the adhesive layer 4 is in the range of 10 MPa to 90 GPa in consideration of the stress σz applied along the axial center X of the high-pressure tank 1 calculated by the following equation 1. Is preferable.

σz = (Pr) / (2t) (Equation 1)
Here, P is the internal pressure of the high-pressure tank, r is the internal radius of the liner, and t is the thickness of the liner.

As the material of the adhesive layer 4, an adhesive that does not corrode the metal of the liner 2 is preferable. Specifically, an epoxy resin or the like can be mentioned. Further, the adhesive layer 4 may use a resin different from the resin constituting the reinforcing layer 3.

By the way, when the internal pressure of the liner 2 rises due to the gas filled in the liner 2, the pressure of the gas in the high pressure tank 1 causes a stress in the vicinity of the base 5 of the liner 2 along the axis X of the high pressure tank 1. It acts, and in the vicinity of the base portion 5 of the liner 2, the deformation of the liner 2 and the reinforcing layer 3 follows.

Here, in the conventional high-pressure tank (high-pressure tank without the adhesive layer 4), the liner cannot follow the reinforcing layer in the boundary region between the body portion and the side end portion due to its shape. , A gap may occur in this part. In the portion where this gap is generated, only the liner is repeatedly subjected to the pressure of the gas in the high-pressure tank as the gas is filled and released, and the fatigue strength of the liner may decrease.

On the other hand, according to the present embodiment, when the pressure of the gas in the high-pressure tank 1 causes a stress to act along the axis X of the high-pressure tank 1 in the vicinity of the mouthpiece 5 at the side end of the liner 2. In the vicinity of the base portion 5 of the liner 2, the deformation of the liner 2 and the reinforcing layer 3 follows.

At this time, in the boundary region 23 between the body portion 21 and the side end portion 22, the reinforcing layer 3 and the liner 2 are adhered by the adhesive layer 4, so that the reinforcing layer 3 and the liner 2 are uniformly deformed. Therefore, there is no gap in this part as in the past. Therefore, since this portion is not repeatedly subjected to the gas pressure only by the liner 2, the strain of the liner 2 can be reduced. As a result, it is possible to suppress a decrease in the fatigue strength of the liner 2.

Further, according to the present embodiment, of the surface of the liner 2, the surface of the inner region 24 located between the boundary regions 23 on both sides of the liner 2 is on the surface of the liner 2 without the intervention of the adhesive layer 4. The reinforcing layer 3 is directly arranged. As a result, the cost of the high-pressure tank 1 can be reduced as compared with the case where the entire surface between the reinforcing layer 3 and the liner 2 including the internal region 24 is bonded.

Further, according to the present embodiment, when a material (for example, carbon fiber) that easily corrodes (galvanic corrosion) the metal liner 2 is used for the reinforcing layer 3, between the liner 2 and the reinforcing layer 3. Since the adhesive layer 4 that is resistant to corrosion is provided, it is possible to reduce the corrosion of the liner 2 from the reinforcing layer 3 as compared with the case where the adhesive layer 4 is not provided.

The manufacturing method of the high pressure tank 1 according to the present embodiment will be described below. First, in the manufacturing method of the present embodiment, the liner 2 is prepared. In the preparation step, a body member corresponding to the body portion 21 and two side end members corresponding to each side end portion 22 are prepared. In each side end member, openings 22a and 22a are formed at the most reduced diameter top, and mouthpieces 5 and 5 are formed at each opening 22a. Next, the side end members are joined to both ends of the body member by welding or the like. In the liner 2 prepared in this way, as shown in FIGS. 1A and 1B, an internal region 24 is formed between the two boundary regions 23 and 23.

After the preparatory step, the adhesive layer 4 is formed. In the adhesive layer forming step, an uncured adhesive made of a thermosetting resin to be an adhesive layer 4 is applied to the surfaces of the boundary regions 23 and 23 of the surface of the liner 2 prepared in the preparatory step.

After the adhesive layer forming step, the reinforcing layer 3 is formed. In the reinforcing layer forming step, a fiber bundle impregnated with an uncured thermosetting resin, which is the reinforcing layer 3, is prepared. This fiber bundle is wound around the surface of the liner 2 in a layered manner by hoop winding and helical winding by a filament winding method (FW method). Then, by heating the high-pressure tank 1, the uncured thermosetting resin of the reinforcing layer 3 and the uncured thermosetting resin of the adhesive layer 4 are cured. As a result, the liner 2 and the reinforcing layer 3 are adhered to each other via the adhesive layer 4. In this way, the high-pressure tank 1 shown in FIGS. 1 (a) and 1 (b) described above can be manufactured.

Next, with reference to FIGS. 2 (a) and 2 (b), a modified example of the high-pressure tank 1 of the present embodiment will be described below. FIG. 2A is a schematic cross-sectional view of the high-pressure tank 1 according to the modified example of the first embodiment, and FIG. 2B is a schematic enlarged cross-sectional view of the vicinity of the adhesive layer 4.

As shown in FIGS. 2A and 2B, the high-pressure tank 1 according to this modification differs from that of the above-described embodiment on the surfaces of the boundary regions 23 and 23 of the surface of the liner 2. In addition, the adhesive layer 4 is also formed on the surfaces of the end regions 25, 25 of the side end portions 22, 22. Therefore, the differences will be described below, and the same members and parts as those in the above-described embodiment will be designated by the same reference numerals and detailed description thereof will be omitted.

In this modification, the adhesive layer 4 is formed on the surfaces of the edge regions 25 and 25 in addition to the surfaces of the boundary regions 23 and 23. The end region 25 is a continuous region from the end of each boundary region 23 on the side of each base portion 5 to each base portion 5, and is a region covered with the reinforcing layer 3. Therefore, in this modification, the reinforcing layer 3 and the liner 2 are adhered to each other by the adhesive layer 4 formed on the surfaces of the boundary regions 23 and 23 to the end regions 25 and 25.

As a result, the reinforcing layer 3 and the liner 2 are integrally deformed in the continuous portion up to the boundary region 23 and the end region 25, so that the decrease in the fatigue strength of the liner 2 is more reliably suppressed as described above. be able to.

<CAE analysis>
The inventor created a model of a high-pressure tank in which an adhesive layer was formed on the entire surface of the liner as a reference example and a high-pressure tank in which no adhesive layer was formed as a comparative example, and performed CAE analysis. In this model, the inner diameter of the liner is 300 mm, and the thickness of the liner 2 is 4 mm.

As the physical characteristic value of the liner, the physical characteristic value of the aluminum alloy material (A6061-T6) was used, and as the physical characteristic value of the reinforcing layer, the physical characteristic value of CFRP in which carbon fiber was impregnated with an epoxy resin was used.

In the case of the reference example, instead of providing the adhesive layer, the analysis was performed under the condition that the deformation of the boundary between the liner and the reinforcing layer was restrained. On the other hand, in the case of the comparative example, since the adhesive layer was not provided, the analysis was performed under the condition that the deformation of the liner, the reinforcing layer and the boundary was not constrained and the deformation was independent. In this analysis, the internal pressure of the high pressure tank was set to 87.5 MPa.

As a result of CAE analysis of the test specimens related to the reference example and the comparative example, the stress was maximum in the shoulder portion of the liner, that is, the boundary region, and the stress in the reference example was about 40% as compared with the comparative example. It was reduced.

From this result, in the shoulder part of the liner of the reference example, the adhesive layer restrains the reinforcing layer and the liner, so that no gap is generated in this shoulder part, the strain in the shoulder part is reduced, and the stress applied to the liner is reduced. Can be said to be even reduced. Therefore, it is considered that at least a decrease in fatigue strength of the liner can be suppressed by providing an adhesive layer on the surface of this boundary region.

Although one embodiment of the present invention has been described in detail above, the present invention is not limited to the above-described embodiment, and various types are described within the scope of the claims as long as the spirit of the present invention is not deviated. It is possible to make design changes.

1: High pressure tank 2: Liner 3: Reinforcing layer 4: Adhesive layer, 21: Body part, 22: Side end part, 23: Boundary area, 24: Internal area

Claims (1)

A high-pressure tank including a metal liner for accommodating gas, a reinforcing layer arranged on the outer periphery of the liner, and an adhesive layer arranged between the liner and the reinforcing layer.
The liner has a cylindrical body portion and dome-shaped side ends continuously formed on both sides of the body portion.
Of the surface of the liner, the surface of the boundary region between said body portion said each side end portion, and the reinforcing layer, and an adhesive layer for bonding said liner is formed,
On the surface of the inner region located between the boundary regions on both sides of the liner , and on the surface of the end region of the side end located outside the boundary region of the liner. Is a high-pressure tank characterized in that the reinforcing layer is arranged without passing through the adhesive layer.

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