JP2022177745A - high pressure tank - Google Patents

Abstract

To provide a high pressure tank capable of making effective use of a whole space including a loading space such as a floor tunnel of a vehicle, of which the diameter is gradually enlarged from a small diameter to a large diameter, while securing the mechanical strength.SOLUTION: A high pressure tank 10 includes a liner 11 and a reinforcing layer 14 formed on the outer surface of the liner 11, the liner 11 having a trunk part 21 shaped cylindrical, and gradually diameter-enlarged as extending along the axial direction, a semispherical first dome part 22 closing the small-diameter side end of the trunk part 21, and a semispherical second dome part 23 closing the large-diameter side end of the trunk part 21, the reinforcing layer 14 having a hoop layer 61 formed by hoop-winding reinforcing fibers, and a helical layer 62 formed by helical-winding the reinforcing fibers, the hoop layer 61 is thicker at the second dome part 23 side than at the first dome part 22 side.SELECTED DRAWING: Figure 2

Description

The present invention relates to a high pressure tank having a liner and a reinforcing layer formed on the outer surface of the liner.

As a high-pressure tank of this kind, a liner having a cylindrical body portion with a constant outer diameter and dome portions provided at both ends in the axial direction of the body portion, and a reinforcing fiber are formed by winding a hoop. A hoop layer and a helical layer formed by helically winding reinforcing fibers are disclosed (see Patent Document 1).

JP 2020-169656 A

When a rear-wheel drive vehicle structure equipped with an internal combustion engine and a transmission is adopted as it is for the vehicle structure of a fuel cell vehicle (FCV: Fuel Cell Vehicle), the transmission described in Patent Document 1 is installed in the floor tunnel. Installing a high-pressure tank is rational because the diameter of the high-pressure tank can be made relatively large. However, the space in the floor tunnel is formed in a tapered shape in which the front space is large when viewed from the driver seated in the driver's seat, and the space gradually decreases toward the rear. If the high-pressure tank described in Patent Document 1 is installed in this space, there is a problem that an empty space is generated in front of the floor tunnel, making the space unusable. On the other hand, if the high-pressure tank has a tapered shape that gradually expands along the axial direction in order to effectively utilize the space in the floor tunnel, it is necessary to secure the mechanical strength of the high-pressure tank. .

SUMMARY OF THE INVENTION The present invention has been made to solve such problems. An object of the present invention is to provide a high-pressure tank capable of ensuring a sufficient strength.

(1) A high-pressure tank according to the present invention is a high-pressure tank having a liner and a reinforcing layer formed on the outer surface of the liner, wherein the liner is cylindrical and moves along the axial direction. It has a body portion whose diameter gradually increases, a hemispherical first dome portion that closes the small diameter side end of the body portion, and a hemispherical second dome portion that closes the large diameter side end of the body portion. and the reinforcing layer includes a hoop layer formed by hoop-winding reinforcing fibers and a helical layer formed by helically-winding the reinforcing fibers, and the hoop layer is formed by the first dome portion The second dome portion side is thicker than the side. With this configuration, the body of the high-pressure tank gradually expands in diameter, so it can be installed to fit the space in the floor tunnel of a fuel cell vehicle, which has a rear-wheel drive vehicle structure equipped with an internal combustion engine and transmission. can be used and the entire space is effectively utilized. Further, since the hoop layer is formed thicker on the second dome portion side than on the first dome portion side, the mechanical strength of the large diameter side of the body portion is ensured.

(2) In the high-pressure tank according to the present invention, the thickness of the hoop layer increases in proportion to the outer diameter of the body. This configuration ensures uniform mechanical strength from the small-diameter end to the large-diameter end of the body.

(3) The high-pressure tank according to the present invention is characterized in that a mouthpiece communicating between the inside and the outside of the high-pressure tank is attached to the first dome portion. This configuration ensures the mechanical strength of the first dome portion formed by helical winding. That is, since the number of turns of the helical winding is determined so as to ensure the mechanical strength on the large diameter side, the thickness of the helical layer of the first dome portion having a smaller area is smaller than the thickness of the helical layer of the second dome portion having a large area. A thick layer is formed. As a result, the first dome portion has a higher mechanical strength than the second dome portion. Although high mechanical strength is required for the mounting portion of the base, the base is attached to the first dome portion having higher mechanical strength.

(4) In the high-pressure tank according to the present invention, the mouthpiece has a shaft portion penetrating the reinforcing layer and a flange portion expanded in diameter from the shaft portion and in contact with the outer wall surface of the first dome portion. It is characterized by With this configuration, the base is attached to the first dome portion in close contact with the flange portion.

(5) The high-pressure tank according to the present invention is characterized in that an end boss having a smaller diameter than the shaft portion of the mouthpiece is attached to the second dome portion. This configuration ensures the mechanical strength of the second dome portion as a result. That is, the end boss only has the function of chucking one end of the liner when the liner is set in the filament winding device, and is not required to have high mechanical strength as compared to the mouthpiece. Moreover, the shaft portion of the end boss does not need to have a function of circulating gas, and it is not necessary to pass through the liner and attach it to the second dome portion, so the diameter of the shaft portion may be relatively small. By making the shaft portion of the end boss smaller in diameter than the shaft portion of the mouthpiece, the load exerted by the end boss on the reinforcing layer of the second dome portion is reduced, and the second dome portion has lower mechanical strength than the first dome portion. An end boss can be attached to the

ADVANTAGE OF THE INVENTION According to the present invention, there is provided a high-pressure tank capable of effectively utilizing the entire space where the mounting space such as a floor tunnel of a vehicle gradually expands from a small diameter to a large diameter and ensuring mechanical strength. can do.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure of the high pressure tank which concerns on embodiment of this invention, Fig.1 (a) shows the side view of the high pressure tank installed in the floor tunnel, FIG.1(b) is cut in the direction orthogonal to a center axis line. 1 shows a cross-sectional view of a high-pressure tank in which FIG. 1B is a diagram of a high-pressure tank according to an embodiment of the present invention, showing a cross-sectional view taken along line AA of FIG. 1B. 3(a) shows a side view, FIG. 3(b) shows a front view seen from B, and FIG. , shows a cross-sectional view taken along line CC of FIG. 3(b). 4(a) is a side view, FIG. 4(b) is a front view seen from D, and FIG. , shows a cross-sectional view taken along line EE of FIG. 4(b). BRIEF DESCRIPTION OF THE DRAWINGS FIG. 5A is a diagram illustrating a method of winding reinforcing fibers in a high-pressure tank according to an embodiment of the present invention, FIG. 5A is a schematic diagram of hoop winding, and FIG. 5B is a schematic diagram of helical winding; show.

A high-pressure tank 10 according to an embodiment to which the high-pressure tank according to the present invention is applied will be described with reference to the drawings.
The high-pressure tank 10 according to the embodiment has a liner 11, a mouthpiece 12, an end boss 13, and a reinforcing layer 14, as shown in FIGS. 1(a) and 1(b). The high-pressure tank 10 has a gas-impermeable property, that is, a so-called gas barrier property, and is configured to supply a high-pressure gas such as hydrogen to the inside.

The high-pressure tank 10 is installed in a floor tunnel formed in the center of the driver's seat of the fuel cell vehicle in the left-right direction. This fuel-powered vehicle uses a rear-wheel drive vehicle structure equipped with an internal combustion engine and a transmission, that is, a vehicle structure of a vehicle having an internal combustion engine, as it is for a fuel-powered vehicle. A floor tunnel is a space in which a transmission is installed in a vehicle having an internal combustion engine, and is formed below a floor tunnel top line indicated by a dashed line. This space has a tapered shape with a large diameter at the front and a smaller diameter toward the rear.

As shown in FIGS. 1(b) and 2, the liner 11 consists of a cylindrical hollow container, and includes a body portion 21 whose diameter gradually increases from a small diameter to a large diameter along the axial direction, a first It has a dome portion 22 and a second dome portion 23 . The liner 11 is made of, for example, engineering plastics having high mechanical strength such as polyethylene, polyamide resin (PA), nylon, etc., and is integrally formed by rotational molding or blow molding.

The liner 11 may be made of light metal such as aluminum instead of engineering plastic. Further, the liner 11 is formed by dividing the liner 11 into two parts and separately molding them by injection molding, extrusion molding, etc., instead of the integral molding manufacturing method such as the rotation molding method or the blow molding method, for example, by infrared welding. , laser welding, hot plate welding, vibration welding, or ultrasonic welding.

As shown in FIGS. 1A and 2, the first dome portion 22 is formed in a hemispherical shape and closes the small-diameter end of the body portion 21 . The first dome portion 22 has a base mounting portion 31 and has higher mechanical strength than the second dome portion 23, as will be described later. The base 12 is attached to the base mounting portion 31 having high mechanical strength. A through-hole 32 is formed in the mouthpiece mounting portion 31 to allow gas to flow therethrough. Like the first dome portion 22 , the second dome portion 23 is formed in a hemispherical shape and closes the large-diameter end of the body portion 21 . The second dome portion 23 has an end boss mounting portion 33 to which the end boss 13 is mounted.

As shown in FIGS. 2, 3(a), 3(b) and 3(c), the mouthpiece 12 has a shaft portion 41 and a flange portion 42. The shaft portion 41 and the flange portion 42 is integrally formed of a metal material. A through hole 43 is formed through the shaft portion 41 and the flange portion 42 in the axial direction. The through hole 43 is continuous with the through hole 32 of the mouthpiece mounting portion 31 , and gas flows between the inside and the outside of the high pressure tank 10 via the through hole 32 of the mouthpiece fitting portion 31 .

A valve (not shown) such as a shut valve is attached to the base 12, and the through hole 43 and the through hole 32 are brought into communication or non-communication by the valve. The valve is opened when high pressure gas is supplied to the inside of the high pressure tank 10, and is closed when the supply of gas is finished. Moreover, the valve is opened as necessary, and the high-pressure gas filled inside is supplied to the outside through the valve.

The shaft portion 41 is formed in a cylindrical shape with a diameter D<b>1 , penetrates the reinforcing layer 14 , and protrudes axially outward from the first dome portion 22 . The flange portion 42 protrudes radially from the shaft portion 41 and has a disc shape, and is attached to the first dome portion 22 in contact with the outer wall surface of the mouthpiece attachment portion 31 of the first dome portion 22 .

The end boss 13 has a shaft portion 51 and a flange portion 52, as shown in FIGS. 2, 4(a), 4(b) and 4(c). 52 is integrally formed of a metal material.

The shaft portion 51 is formed in a cylindrical shape with a diameter D2 smaller than the diameter D1 of the shaft portion 41 of the base 12 , penetrates the reinforcing layer 14 , and protrudes axially outward from the second dome portion 23 . The flange portion 52 is formed in a disc shape protruding radially from the shaft portion 51, contacts the end boss mounting portion 33 of the second dome portion 23, and is mounted on the second dome portion 23 by, for example, adhesion. .

The end boss 13 has a function of chucking one end of the liner 11 when the liner 11 is set in the filament winding device, and does not require high mechanical strength compared to the mouthpiece 12 . Therefore, the shaft portion 51 is formed with a diameter D2 that is smaller than the diameter D1 of the shaft portion 41 of the mouthpiece 12 . In addition, since the shaft portion 51 does not require gas to flow, a through hole penetrating the shaft portion 51 is not required. The end boss 13 is mounted such that the flange portion 52 is in close contact with the outer wall surface of the end boss mounting portion 33 of the second dome portion 23 .

The mouthpiece 12 is provided with a hole in the center as a fuel charging/discharging port, and has a boss to which a valve is attached in the hole. An end boss 13 is arranged on the liner 11 on the side opposite to the mouthpiece 12 . The end boss 13 has a boss at its center for supporting the shaft during filament winding. The hole diameter of the reinforcing layer 14 around the neck portion of the mouthpiece 12 is usually larger than the hole diameter of the reinforcing layer 14 around the end boss 13 . Therefore, the surface pressure generated on the contact surface between the flange portion 42 of the mouthpiece 12 and the reinforcing layer 14 is greater than the surface pressure generated on the contact surface between the flange portion 52 of the end boss 13 and the reinforcing layer 14 . It is possible to reduce the surface pressure on the mouthpiece 12 side by securing a flange contact area corresponding to the hole area ratio, but this increases the flange diameter of the mouthpiece 12, which poses problems such as an increase in cost. not targeted. Based on the above, it is rational to install the mouthpiece 12 on the thick first dome portion 22 of the reinforcing layer 14 .

As shown in FIGS. 1(b), 2, 5(a) and 5(b), the reinforcing layer 14 is a hoop layer 61 formed on the outer surface of the liner 11 by hoop-winding reinforcing fibers F. and a helical layer 62 formed on the outer surface of the liner 11 by helically winding the reinforcing fibers F. The hoop layer 61 and the helical layer 62 are formed by a filament winding device (not shown) by, for example, a filament winding process.

The reinforcing fibers F are formed, for example, by impregnating uncured thermosetting resin into a fiber bundle formed by bundling single fibers having a diameter of about several μm. Examples of the reinforcing fibers F include carbon fiber reinforced plastics (CFRP) and glass fiber reinforced plastics (GFRP).

Single fibers include fibers such as carbon fibers, glass fibers, aramid fibers, alumina fibers, boron fibers, steel fibers, PBO fibers (poly p-phenylene benzobisoxazole fibers), natural fibers, and high-strength polyethylene fibers. can be done. Examples of thermosetting resins include resins such as epoxy resins, modified epoxy resins represented by vinyl ester resins, phenol resins, melamine resins, urea resins, unsaturated polyester resins, alkyd resins, polyurethane resins, and thermosetting polyimide resins. can be mentioned.

As shown in FIG. 5A, the hoop winding is a method of winding the liner 11 in the circumferential direction at a winding angle substantially perpendicular to the central axis L of the liner 11 . A hoop layer 61 is formed on the body by hoop winding. Here, "substantially perpendicular" includes both 90° and an angle of about 90° that can be generated by shifting the winding position of the reinforcing fibers F so that the reinforcing fibers F do not overlap each other.

Hoop winding is a method of winding the reinforcing fibers F to obtain strength in the radial direction. As shown in FIG. 2, the stress σθ ( It is a winding method to obtain mechanical strength against MPa). Let ta1 be the thickness of the hoop layer 61 at one end T1 of the body portion 21, ta2 be the thickness of the hoop layer 61 at the other end T2 of the body portion 21, and x (mm) be an arbitrary distance from one end T1 to the other end T2. , and let Dx (mm) be the outer diameter of the body portion 21 at the distance x, the thickness tax of the hoop layer 61 at the outer diameter Dx is linearly proportional to the outer diameter Dx.

That is, the thickness tax of the hoop layer 61 at the outer diameter Dx and the outer diameter Dx have a relationship of tax=kDx, and the thickness tax increases as the outer diameter Dx increases. Note that the constant k is a positive value, and is appropriately selected based on data such as experimental values and setting specifications such as the size, material, and shape of the high-pressure tank 10 according to the embodiment.

In the hoop winding, when the reinforcing fibers F are wound by the filament winding device, if the rotation speed (rpm) of the liner 11 is constant, the hoop layer 61 can be formed by the following method so as to satisfy tax=kDx. can. That is, the positional movement speed (mm/s) in the axial direction of the delivery end OT shown in FIG. By doing so, the hoop layer 61 on the large diameter side can be formed thick so as to satisfy tax=kDx.

Helical winding is a method of winding the reinforcing fibers F to obtain strength in the axial direction. This is a winding method that covers the liner 11 entirely. The helical layer 62 formed by helical winding provides mechanical strength against the stress σz (MPa) generated in the axial direction of the liner 11 due to the internal pressure P (MPa) acting on the body portion 21 of the high-pressure tank 10 .

By helical winding, as shown in FIG. 5B, the reinforcing fibers F are wrapped around the hoop layer 61, the first dome portion 22, and the second dome portion at a winding angle of greater than 0° and less than 90° with respect to the central axis L of the liner 11. A helical layer 62 is formed by wrapping around the outer surface of the portion 23 . The body portion 21 of the liner 11 has a tapered shape, and the second dome portion 23 has a larger diameter than the first dome portion 22 . It is formed so that it gradually becomes thicker as it shifts to the smaller diameter side along the direction. That is, the helical layer 62 is formed with a thickness tb1 at one end T1 of the body portion 21 and a thickness tb2 at the other end T2 of the body portion 21, which is thicker than the thickness tb1, as shown in FIG. The reinforcing fibers F forming the helical layer 62 may be made of fibers different from those of the hoop layer 61 or impregnated resin.

Helical winding is a winding method in which the liner 11 is sequentially wound around the entire circumference, that is, a winding method in which the reinforcing fibers F are sequentially wound so as to perform a so-called unicursal stroke. Then, the number of winding turns is the same. In helical winding, the greater the number of winding turns, the higher the mechanical strength. It is determined based on the large diameter side, that is, it is determined so as to ensure the mechanical strength of the large diameter side of the liner 11 . Therefore, the thickness of the helical layer 62 of the first dome portion 22, which has a smaller area, is larger than the thickness of the helical layer 62 of the second dome portion 23, which has a large area, as shown in FIG. Thickness increases. As a result, the first dome portion 22 has a surplus strength higher than the mechanical strength of the second dome portion 23 . In order to utilize this surplus strength, the mouthpiece 12 is installed on the small-diameter first dome portion 22 in this embodiment.

A component force of the internal pressure P acting on the periphery of the inner wall of the through hole of the helical layer 62 through which the shaft portion 41 of the mouthpiece 12 penetrates, ie, a so-called flange donut area, is transmitted to the helical layer 62 from the inner wall of the through hole. Since this component force of the internal pressure P acts additionally in addition to the force of the internal pressure P acting on the helical layer 62, the helical layer 62 in contact with the flanged donut area has a larger force than other areas other than the flanged donut area. High mechanical strength is required. That is, since the helical layer 62 in the flange donut area is easily deformed and stress concentration occurs, the helical layer 62 around the shaft portion 41 of the mouthpiece 12 requires higher mechanical strength. The base 12 is installed on the first dome portion 22 having surplus strength because the helical layer 62 has higher mechanical strength than the second dome portion.

With respect to the flange donut area of the mouthpiece 12, the component force of the internal pressure P acting on the flange donut area around the inner wall of the through hole of the helical layer 62 through which the shaft portion 51 of the end boss 13 penetrates is the same as the flange donut area of the mouthpiece 12. , is transmitted to the helical layer 62 from the inner wall of the through hole. Similar to the flanged donut area of the mouthpiece 12, this component force of the internal pressure P acts additionally in addition to the force of the internal pressure P acting on the reinforcing layer 14. , becomes smaller.

Therefore, even if the mechanical strength of the second dome portion 23 is smaller than the mechanical strength of the first dome portion 22, the diameter D2 of the shaft portion 51 of the end boss 13 is equal to the diameter of the shaft portion 41 of the mouthpiece 12. Since it is formed to be smaller than D1, the component force of the internal pressure P acting on the flange donut area of the end boss 13 is also reduced. As a result, the mechanical strength required for the second dome portion 23 is ensured. 2 indicates the thickness of the helical layer required for strength, the thickness of the helical layer 62 of the first dome portion 22 is formed thicker than the thickness of the helical layer required for strength. It is

The winding angle, thicknesses ta1, ta2, tb1, tb2, D1, and D2 of the helical winding are based on data such as set specifications such as the size, material, and shape of the high-pressure tank 10 according to the embodiment, and experimental values. Selected as appropriate.

Effects of the high-pressure tank 10 according to the embodiment will be described.
(1) The high-pressure tank 10 according to the embodiment has a liner 11 and a reinforcing layer 14. The liner 11 is cylindrical and has a body portion 21 whose diameter gradually increases along the axial direction. It has a hemispherical first dome portion 22 that closes the small diameter side end of the portion 21, and a hemispherical second dome portion 23 that closes the large diameter side end of the body portion 21. The reinforcing layer 14 is It has a hoop layer 61 formed by hoop-winding the reinforcing fibers F and a helical layer 62 formed by helically-winding the reinforcing fibers F. The dome portion 23 side is formed thicker.

With this configuration, the body portion 21 of the high-pressure tank 10 is gradually expanded in diameter, so that it fits into the space in the floor tunnel of the fuel cell vehicle, which is constructed with a rear-wheel drive vehicle structure equipped with an internal combustion engine and a transmission. It can be installed in a wide space, and the effect of being able to effectively utilize the entire space is obtained. When a so-called oval tank formed by a conventional straight cylindrical body is installed in a floor tunnel, the upper space in front of the oval tank becomes an empty space. On the other hand, since the high-pressure tank 10 has an enlarged diameter at the front, there is no empty space in the upper front space, and more gas can be stored than the oval tank. As a result, the cruising range of the fuel cell vehicle can be extended. In addition, since the hoop layer 61 is formed thicker on the second dome portion 23 side than on the first dome portion 22 side, the mechanical strength of the large diameter side of the body portion 21 can be ensured. is obtained.

(2) In the high-pressure tank 10 according to the embodiment, the thickness of the hoop layer 61 is formed to be large in proportion to the outer diameter of the body portion 21 . With this configuration, it is possible to obtain an effect that uniform mechanical strength can be secured from the small diameter side end to the large diameter side end of the body portion 21 .

(3) In addition, the high-pressure tank 10 has a mouthpiece 12 attached to the first dome portion 22 that communicates between the inside and the outside of the high-pressure tank 10 . This configuration secures the mechanical strength of the mouthpiece mounting portion 31 of the first dome portion 22 formed by helical winding. That is, the helical winding is a winding method in which the reinforcing fibers F are sequentially wound so as to perform a so-called unicursal writing, and the number of winding turns is determined so as to ensure the mechanical strength on the large diameter side. , the thickness of the helical layer 62 of the first dome portion 22 having a small area can be formed thicker than the thickness of the helical layer 62 of the second dome portion 23 having a large area. As a result, the first dome portion 22 can obtain mechanical strength higher than that of the second dome portion 23 . Since the mouthpiece 12 is attached to the first dome portion 22 which is reinforced by the reinforcing layer 14 and has high mechanical strength, the function of the mouthpiece 12 to open or close the gas supply path by attaching a valve is effectively performed. can be fulfilled.

(4) In the high-pressure tank 10 according to the embodiment, the mouthpiece 12 includes a shaft portion 41 that penetrates the reinforcing layer 14 and a flange portion 42 that is enlarged in diameter from the shaft portion 41 and contacts the outer wall surface of the first dome portion 22. have With this configuration, the mouthpiece 12 can be mounted in close contact with the outer wall surface of the first dome portion 22 via the flange portion 42, and the shaft portion 41 is provided with a valve that opens or closes the gas flow path. Can be worn.

(5) In the high-pressure tank 10 according to the embodiment, the end boss 13 having a smaller diameter D2 than the shaft portion 41 of the mouthpiece 12 is attached to the second dome portion 23 . This configuration ensures the mechanical strength of the second dome portion 23 as a result. That is, the end boss 13 only has the function of chucking one end of the liner 11 when the liner 11 is set in the filament winding device. No mechanical strength is required. In addition, since the shaft portion 51 does not need to have a function of allowing gas to flow, and it is not necessary to attach the end boss 13 to the second dome portion 23 by penetrating the liner 11, the diameter D1 of the shaft portion 51 can be relatively small. Also good. By setting the diameter D2 of the shaft portion 51 of the end boss 13 to be smaller than the diameter D1 of the shaft portion 41 of the mouthpiece 12, the load exerted by the end boss 13 on the reinforcing layer 14 of the second dome portion 23 is reduced. The end boss 13 can be attached to the second dome portion 23 having a mechanical strength lower than that of the second dome portion 23 .

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 scope of the invention described in the claims. Changes can be made.

DESCRIPTION OF SYMBOLS 10... High-pressure tank 11... Liner 12... Base 13... End boss 14... Reinforcement layer 21... Body part 22... First dome part 23. Second dome portion 31 Mouthpiece mounting portion 32, 43 Through hole 33 End boss mounting portion 41, 51 Shaft portion 42, 52 Flange portion 61... hoop layer, 62... helical layer, D1... diameter of shaft portion of base, D2... diameter of shaft portion of end boss, F... reinforcing fiber

Claims (5)

A high-pressure tank having a liner and a reinforcing layer formed on the outer surface of the liner,
The liner includes a cylindrical body portion that gradually expands in diameter as it shifts along the axial direction, a hemispherical first dome portion that closes the small-diameter side end of the body portion, and a and a hemispherical second dome portion that closes the radial end,
The reinforcing layer includes a hoop layer formed by hoop-winding reinforcing fibers and a helical layer formed by helically-winding the reinforcing fibers, and the hoop layer is formed from the first dome portion side. and the second dome portion side of the high pressure tank is thicker. 2. The high-pressure tank according to claim 1, wherein the thickness of the hoop layer increases in proportion to the outer diameter of the body. 2. The high-pressure tank according to claim 1, wherein a mouthpiece communicating between the inside and the outside of said high-pressure tank is attached to said first dome portion. 4. The base according to claim 3, wherein the base has a shaft penetrating through the reinforcing layer, and a flange having an enlarged diameter from the shaft and abutting against an outer wall surface of the first dome. high pressure tank. 5. The high-pressure tank according to claim 4, wherein an end boss having a smaller diameter than the shaft of said mouthpiece is attached to said second dome portion.

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