JPH10332085A - Pressure-resisting container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a pressure-resisting container have a double structure, light and excellent in a pressure-resisting property by supporting a cylindrical head part of an inside shell from an outer peripheral surface by a base part, burying one end side in a center of a thick part of a holder part of the inside shell by making it in a disc shape and projecting the other end side outward along a central axis of the inside shell by making it in a cylindrical shape. SOLUTION: A base head part 4c on one end side of a base part 4 is supported by a shoulder part 5a and a cylindrical head part 5b of an inside shell 5, a disc type burying part 4a on the outside of the one end side is buried between the shoulder parts 5a, 5a' of the inside shell 5, and a cylindrical base part head part 4b is held from the outside on a polar part opening part 3a of a shoulder part 3 of an outside shell. The other end side of the base part 4 is made the cylindrical base part head part 4b and projected outward along a central axis of the inside shell 5. An inside diameter of this cylindrical base part head part 4b is made the same diameter of a diameter of a cylindrical head part extending part 5c of the inside shell 5, and a male screw on a hollow pressing member outer peripheral surface is screwed in a female screw 4h which is engraved on an inner peripheral wall. A nozzle, etc., can be continuously connected and fastened on the base part 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquefied petroleum gas (LPG) for storing Liquefied Petroleum Gas (LPG) for home use, a liquefied petroleum gas cylinder for automobiles suitable for mounting on automobiles, and a compressed natural gas (CNG: Compre
ssed Natural Gas), a pressure vessel that can be used as an industrial cylinder for storing oxygen, nitrogen, etc.

[0002]

2. Description of the Related Art In recent years, so-called non-polluting vehicles have been developed and partially put into practical use for the purpose of preventing environmental deterioration due to automobile exhaust gas. For example, automobiles that operate using natural gas containing methane as a main component as fuel have been certified as low-emission vehicles, and there are already about 1 million vehicles worldwide. The natural gas used at this time is compressed natural gas, and its pressure is as high as 20 MPa to 25 MPa. Therefore, a cylinder having pressure resistance performance is required,
Conventionally, a steel high-pressure cylinder has been used.

[0003] When natural gas is used as fuel for an automobile, a lightweight cylinder is desirable as a mounted cylinder from the viewpoints of improving power performance, reducing collision energy, and improving fuel efficiency. As an alternative to steel cylinders,
Aluminum liners reinforced with carbon fiber are also used, but cylinders made entirely of resin using plastic liners have also been developed to further reduce the weight (for example, -88665 and the like).

The cylinder described in Japanese Patent Publication No. 5-88665 has a resin inner shell (inner wall) having gas barrier properties and a pressure-resistant FRP (fiber reinforced plastic) outer shell (outer wall). The covered gas cylinder is substantially lighter than a metal gas cylinder because it is essentially made of resin. If this is used as a natural gas cylinder for automobiles, improvement in fuel efficiency can be expected.

[0005] Such a gas cylinder is provided with a nozzle mounting base for filling the gas into the cylinder or mounting a nozzle for taking out the gas from the cylinder.
The base part is usually integrally joined with the inner shell, but the base part for screwing the nozzle is usually made of metal,
Since the inner shell is made of a different material (resin or FRP or light metal as described above) from the base portion from the viewpoint of weight reduction or simplification of the manufacturing process, a joint or interface between the inner shell and the base portion is made. Becomes important. Particularly, in the above-mentioned gas cylinder called a CNG tank for automobiles, since a high-pressure gas of about 25 MPa is filled, extremely high gas sealing properties are required. In a conventional gas cylinder, the gas sealing property at the joint or interface between the inner shell and the base is still insufficient.

Japanese Patent Laid-Open No. 6-42 discloses a technique for improving the gas sealing property of a base portion in a resin high-pressure gas cylinder.
No. 698, JP-A-6-137433, JP-A-8-219387 and the like have been proposed.

[0007] The pressure-resistant container described in JP-A-6-42698 has a structure in which the upper and lower lips of the inner shell end receive the disk-shaped flange portion of the base portion, thereby improving the gas sealing property of the base portion. However, since the end of the base is exposed on the inner wall surface of the inner shell and the internal gas pressure is applied directly to the end of the base, even if there is no gas leakage immediately after the pressure-resistant container is manufactured, the product container can be During long-term use, the resin of the inner shell creeps and shrinks, creating a gap at the interface between the inner shell and the base, and gas leakage may occur from the interface gap.

In the pressure-resistant container described in Japanese Patent Application Laid-Open No. Hei 6-137433, locking grooves are provided on the upper and lower surfaces of a disk-shaped flange of a base, and tabs matching the upper and lower locking grooves are provided with inner shells. By forming and connecting to the end, the inner shell expands when the container expands due to internal pressure during storage of high-pressure gas, and shear force acts on both lip parts joined to the locking grooves on the upper and lower surfaces of the disc-shaped flange, The structure is such that the locking groove opposes the force of peeling off both lips. However, also in this pressure-resistant container, the end of the base portion is exposed on the inner wall surface of the inner shell, and the gas internal pressure is directly applied to the end of the base portion, so that gas leakage may occur for the same reason as described above. .

Furthermore, in the pressure vessel described in Japanese Patent Application Laid-Open No. 8-219387, a mouthpiece is interposed inside the opening of the inner shell manufactured by blow molding, and a seal ring such as rubber is fitted to the shoulder of the inner shell. The sealing ring is pressed by a pressing member such as a metal and the like, and the structure is formed by winding the filament on the sealing ring. Even if the pressing member of the seal ring is metal, the fitting portion of the seal ring is only the inner shell made of resin, and even if there is no gas leakage immediately after the production of the pressure-resistant container, even if the product container is used for a long time, Similar to the above-described pressure-resistant container, there is a possibility that the plastic of the inner shell may contract due to creep and cause gas leakage. To increase the number of seal rings accordingly, the product container must be disassembled, and when replacing the deteriorated sealing, the product container must be disassembled, which is not only complicated but also uneconomical. is there.

[0010]

SUMMARY OF THE INVENTION Under such circumstances, the present invention has been completed as a result of intensive studies to provide a pressure vessel capable of solving the above-mentioned drawbacks at once. The objects of the present invention are as follows. 1. To provide a pressure-resistant container having a double-walled structure of an inner shell and an outer shell, which is lightweight but also excellent in pressure resistance. 2. Excellent gas sealing at the interface between the inner shell and the base,
Provided is a pressure-resistant container that can easily cope with a case where an inner shell material contracts due to creep or the like or a sealing material deteriorates. 3. To provide a pressure-resistant container that can be manufactured at a low cost with a simple manufacturing process.

[0011]

In order to achieve the above object, according to the present invention, an inner shell having a gas barrier property, a pressure-resistant outer shell provided to cover the inner shell, In a pressure-resistant container in which a base portion is attached to at least one pole portion of a container to be configured, a pole shoulder portion of an inner shell is formed as a cylindrical neck portion and is projected outward along a central axis of the inner shell. An extension is formed by extending the tip of the protruding cylindrical neck outward in a direction perpendicular to the cylinder neck, and folding the tip of the extension toward the shoulder of the inner shell. Bends to clamp the inside lower end of the base, the base supports the cylindrical neck of the inner shell from the outer peripheral surface, one end side is disc-shaped and is embedded in the thick part of the shoulder of the inner shell The other end is cylindrical and protrudes outward along the center axis of the inner shell, and the protruding cylindrical neck Has an inner diameter substantially equal to the diameter of the cylindrical neck extension of the inner shell, and a female screw is engraved on the inner peripheral wall, and a male screw is engraved on the outer peripheral surface of the female screw. A pressure-resistant container is provided, wherein the pressure member is screwed together, and a nozzle, an orifice, etc. is connected to the base so as to be able to be tightened.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The pressure vessel according to the present invention is constituted by a double shell (wall) of an inner shell (inner wall) and an outer shell (outer wall). The inner shell functions as a core of the pressure vessel, and functions to store the pressurized gas so as not to leak. The inner shell can be made of, for example, a light alloy such as a thin aluminum alloy or a magnesium alloy, a resin material having gas barrier properties, or fiber reinforced plastic (FRP).
Among them, a resin material having gas barrier properties is preferable, and specific examples thereof include polyethylene, cross-linked polyethylene,
Examples include polypropylene, polyamides, ABS resin, polyethylene terephthalate, polybutylene terephthalate, polyacetal, and polycarbonate.

When the material is a light alloy, the inner shell can be manufactured by a rolling method, an extrusion method, or the like. When the material is FRP, it can be manufactured by a conventional molding method using a resin containing reinforcing fibers as a raw material. As the resin, those exemplified above may be used, and the type of the reinforcing fiber may be selected from those described below which can be used when preparing the outer shell described later, and the fiber length is 2 to 10 mm.
Short fibers are preferred. When the material is a resin material, it can be produced by a conventionally known molding technique such as a compression molding method, a blow molding method, or an injection molding method, and among them, a rotational molding method is preferable.

The wall surface of the inner shell needs to have gas barrier properties. However, if the resin material itself has excellent gas barrier properties, it is not necessary to take measures to particularly improve the gas barrier properties of the wall surfaces. If the gas barrier property of the material itself is insufficient, (1) a method in which the wall surface of the inner shell is multilayered, and (2) a method in which a gas barrier layer is separately formed on the inner wall and / or the outer wall of the inner shell. Can also.

In the method (1), when the inner shell is manufactured by rotational molding, for example, after the outer wall surface is formed of polyethylene or the like, a layer of a polyamide resin having excellent gas barrier properties is formed inside. And the like. the above
The method (2) includes a method of forming a coating film of a metal such as aluminum, copper, nickel, or chromium on the outer wall surface of the inner shell manufactured by the rotational molding method.
In this case, it is preferable that the inner shell has a multilayer structure and a resin layer on which a metal plating film is easily formed is disposed on the inner wall and / or the outer wall.

The outer shell is provided so as to cover the inner shell and functions to improve the pressure resistance of the product container. The outer shell is preferably made of fiber reinforced plastic (FRP) in order to improve the pressure resistance of the product container and achieve weight reduction at the same time. F to cover the outer peripheral wall of the inner shell
To form an outer shell made of RP, a winding layer of a reinforcing fiber yarn impregnated with a resin is formed on the outer peripheral wall of the inner shell by a filament winding method or a tape winding method, and then the resin is heated and melted. Alternatively, the outer shell can be formed by curing and molding.

The strength and thickness of the outer shell can be selected according to the shape and size of the pressure-resistant container, the type of gas to be filled, the pressure, and the like. The strength of the outer shell can be selected and combined in various ways such as the type of reinforcing fiber yarn forming the winding layer, the diameter of the yarn, the shape of the yarn, the winding shape, the thickness of the winding layer, the type of resin, the thickness of the resin Thereby, it can be in a suitable range that matches the purpose.

The reinforcing fibers for forming the winding layer include:
High-strength, high-modulus fibers are suitable, and specific examples thereof include carbon fiber yarns, glass fiber yarns, and organic high-modulus fiber (for example, polyaramid fibers) yarns.
More than one type can be used in combination. As these reinforcing fiber yarns, non-twisted fiber yarns having excellent spreadability may be used from the viewpoint of reducing stress concentration due to bending and reducing generation of voids. Among such reinforcing fiber yarns, excellent in specific strength and specific elastic modulus, there is almost no occurrence of yarn breakage or fluff at the time of winding, improving productivity, preventing deterioration of strength characteristics due to yarn seams and mixing of fluff. From the viewpoint of preventing a decrease in impact resistance, carbon fiber yarns are particularly preferable.

Examples of the resin for forming the outer shell include thermosetting resins such as epoxy resin, unsaturated polyester resin, vinyl ester resin, and phenol resin, polyamides, polyethylene terephthalate, polybutylene terephthalate, ABS resin, and polystyrene. Ether ketone, polyphenylene sulfide, poly-4-methylpentene-1,
Thermoplastic resins such as polypropylene are exemplified.

The material for manufacturing the base and the pressing member may be any of metal and resin. Examples of the metal include alloys such as aluminum, copper, nickel, and titanium, composite materials thereof, and chromium-molybdenum alloy.
Examples of the resin include polyamides such as nylon 6, polyethylene terephthalate, polymethylpentene, polycarbonate, polyether polysulfone, polyphenylene sulfide, polyarylate, polyetherimide, polyetheretherketone, polyimide, polyamideimide, polyoxybenzylene, and polysulfone. And the like. The material is not limited to those exemplified. Among metals and resins, metal materials are preferable.

Hereinafter, the pressure vessel according to the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following description unless it departs from the gist. In addition, when the base is attached to only one pole of the pressure vessel,
It is preferable to form a boss on the other pole.

FIG. 1 is a side view of an example of the pressure vessel according to the present invention. In FIG. 1, a pressure-resistant container 1 has a pressure-resistant outer shell 2 provided so as to cover a gas-barrier inner shell 5. The pressure-resistant container 1 has a cylindrical body as a whole, hemispherical shoulders 3 at both ends thereof, and bases 4 attached to both ends (poles) of the hemispherical shoulders.

FIG. 2 is a partially enlarged longitudinal sectional view of the vicinity of the shoulder portion and the base portion of an example of the pressure-resistant container. In the pressure vessel, the pole shoulder 5a of the inner shell 5 is formed as a cylindrical neck 5b, and the cylindrical neck 5b projects outward along the central axis of the inner shell 5.
The protruding cylindrical neck portion 5b is formed in a hollow shape, and extends outward at right angles to the central axis of the cylindrical neck portion 5b to form an extended portion 5c. The inner shell 4 is bent toward the shoulder side to hold the inner lower end 4 c of the base 4, and together with the base 4, is a hollow pressing member 6.
Is fixed.

The base 4 is at one end (on the shoulder side of the pressure-resistant container).
The base neck 4c has a shoulder 5a of the inner shell and a cylindrical neck 5b.
And the outside on one end side is a disc-shaped buried portion 4a.
Is embedded between the shoulders 5a and 5a 'of the inner shell, and the cylindrical base 4b is held from the outside by the pole opening 3a of the shoulder 3 of the outer shell 2. The other end of the base 4 is formed as a cylindrical base 4b and protrudes outward along the center axis of the inner shell. The inner diameter of the cylindrical base 4b is substantially the same as the diameter of the cylindrical neck extension 5c of the inner shell, and a female screw 4d is engraved on the inner peripheral wall.
A male screw is screwed into the female screw 4d on the outer peripheral surface of the hollow pressing member 6. On the inner peripheral wall of the opening of the base 4, a female screw 4h for connecting and tightening a nozzle, an orifice, or the like is formed.

A male screw 4e is engraved on the outer peripheral wall of the base 4, and a tightening nut 7 is screwed into the outer shell. The shoulder 3 of the outer shell is pressed and fastened to the disc-shaped buried part 4a, and the shoulder of the inner shell is pressed. 5a, 5a '
Gas is prevented from leaking from the interface between the disk-shaped buried portion 4a. The male screw 4e is used to connect a gas nozzle, an orifice, and the like to the female screw 4h at the opening of the base 4, and screw a cap nut for tightening the gas nozzle and the orifice to the base 4.

In order to attach the base 4 to the inner shell 5, the base 4 can be integrally connected to the inner shell 5 by an insert molding method in which the base 4 is fixed to a predetermined position of a molding die in advance and molded. . In the case of manufacturing by the insert rotational molding method, a resin powder is filled in a portion where the shoulder portion 5a 'of the inner shell is to be formed in advance, melted by heating, and then the disc-shaped buried portion 5a of the base portion is shouldered. By moving to the part 3 side and pressing, and continuing the rotary molding, it can be integrally connected. Also when manufacturing by a blow molding method or an injection molding method, the base part 4 can be fixed to a predetermined position of a molding die in advance, and the inner shell 5 can be molded to be integrally joined.

Next, as described above, a reinforcing fiber yarn is wound around the outer peripheral surface of the inner shell 5, the surface is coated with a resin for forming the outer shell 2, and the resin is heated and melted or cured to form the outer shell 2. . At this time, it is preferable that the shoulder 3 of the outer shell 2 is formed on the disc-shaped buried portion 4a of the base 4, and the opening 3a of the shoulder 3 is brought into close contact with the base 4b of the base. The opening 3a of the shoulder 3 is tightened by the tightening nut 7 to the disc-shaped buried portion 5a as described above.

In the pressure-resistant container according to the present invention, after the surface of the inner shell is covered with the pressure-resistant outer shell, the pressing member 6 is inserted and fixed in the hollow portion of the base 4. The pressing means 6 has a funnel-like appearance having a large diameter portion 6a, a horizontal portion 6b and a small diameter portion 6c as shown in a perspective view in FIG. 3, and a male screw is formed on the outer peripheral surface of the large diameter portion 6a. The small diameter portion 6c is screwed into a female screw 4d formed on the inner peripheral wall of the base neck portion 4b of the base portion.
Has an outer diameter in contact with the inner peripheral wall of the cylindrical neck portion 5b of the inner shell. A hexagonal cap screw 6e having a hexagonal planar shape is formed inside the large diameter portion 6a, and is used when the male screw of the large diameter portion 6a is screwed into the female screw 4d of the base.

FIG. 3 shows an example in which an annular groove 6d is formed in the horizontal portion 6b so that the seal ring 8 can be arranged when tightening the horizontal portion 6b in opposition to the cylindrical neck extension 5c. 8 is arranged in the cylindrical neck extension 5c.
And may be formed on either one of them. By arranging the seal ring 8 on the surface facing both, gas leakage from the interface between the inner shell and the base can be more effectively prevented. To achieve the same purpose, the end 5d of the cylindrical neck extension shown in FIG.
Modifications can be made as exemplified in (a) and (b).

As the material of the seal ring, natural rubber,
In addition to silicon rubber, fluorine rubber, tetrafluoroethylene, polyamide, polyethylene, polyester resin, and the like, metals such as stainless steel, aluminum, copper, and titanium are further included. Its shape is a round shape, an O-ring shape, a rectangular shape, or the like in a cross section cut at a right angle to the length direction.

As shown in FIG. 5, another example of a pressure-resistant container according to the present invention is a partially enlarged vertical sectional view, in which caps 4, 4 are attached to both pole portions of the container, and small-diameter portions 65c, 65c '.
Are respectively projected inward along the central axis of the inner shell, a male screw is engraved on the distal end 65d of one pressing member 65, and a female screw is engraved on the distal end 65d 'of the other end, and the opening is hexagonal. Hex bolts can be inserted into the cap screws 65e, 65e 'and rotated, and these can be screwed and connected to each other.

FIG. 5 shows an example in which a small-diameter portion 65c of a hollow pressing member 65 screwed to one base portion 4 is provided with a through hole 65d serving as a gas passage communicating with the hollow inside the small-diameter portion. Further, in this example, the pressing member 65 'screwed to the other base 4 is not hollow. It is preferable to attach a sealing plate to the other base 4 outside the pressing member 65 '.

In order to more effectively prevent gas leakage from the interface between the inner shell and the base, as described above, (1) the seal ring 8 is disposed at the tip of the cylindrical neck 5b. (See FIGS. 2, 3, and 4), (2) In addition to embedding the end 5d of the cylindrical neck extension into the base neck 4b (see FIGS. 2 and 4), and the like, (3) A dovetail-shaped projection 4f having a dovetail shape in longitudinal section at the shoulder of the inner shell 5.
(See FIG. 6), (4) a through hole penetrating from one surface of the embedded portion to the other surface of the disc-shaped embedded portion 4a of the base portion embedded in the shoulder of the inner shell 5; A plurality of holes 4g may be formed (see FIG. 7), and (5) an adhesive layer may be provided at the interface. These may be used alone or in combination of two or more.

Examples of the adhesive include thermosetting adhesives such as epoxy, acrylic, polyurethane, and polyester. Among them, an anaerobic reaction type acrylic adhesive is preferable. Specifically, a polyether-based adhesive containing tetraethylene glycol dimethacrylate as an active ingredient, trimethylolpropane trimethacrylate,
Butanediol-1,4-dimethacrylate, 2,2,
An ester adhesive containing 4-trimethyl-1,3-pentanediol methacrylate or polyester methacrylate as an active ingredient is exemplified.

In the pressure vessel according to the present invention, the type of gas to be filled therein is not limited, and examples thereof include natural gas, liquefied petroleum gas, nitrogen, oxygen, helium gas, and argon gas.

Test Example 1 As shown in FIG. 5, a pressure vessel having a structure having caps at both electrodes and having a capacity of 76 liters was manufactured. This pressure vessel has an internal pressure of 25 MPa
Was filled with helium gas, and the pressure-resistant container was placed in a closed container and allowed to stand for 1 hour. After that, the amount of helium gas in the closed container was measured by gas chromatography and was not detected.

Test Example 2 In the example described in Test Example 1, an O-ring was provided between the cylindrical neck portion of the inner shell and the cylindrical neck portion 4b of the base without the cylindrical neck extension portion 5c. A pressure-resistant container in which 8 was not arranged was prepared in the same manner as in Test Example 1. When the amount of helium gas in the closed vessel was measured in the same manner as in Test Example 1, it was 20 cc (gas permeability: 0.26 cc / hour · liter). Therefore, it is understood that the pressure vessel cannot completely prevent the leakage of the high-pressure gas.

[0038]

The present invention has the following particularly advantageous effects, and its industrial value is extremely large. 1. The pressure-resistant container of the present invention has a double wall structure of an inner shell and an outer shell, and is excellent in pressure resistance despite being lightweight. 2. In the pressure-resistant container of the present invention, a pressing member is inserted into the hollow portion of the base, an extension 5c is formed in the cylindrical neck of the inner shell, and this portion and its tip 5d are embedded in the neck 4b of the base. Since the pressing is performed by the extending portion 5c of the cylindrical neck and the horizontal portion 6b of the pressing member, the gas sealing property at the interface between the cylindrical neck of the inner shell and the base is excellent.

3. Even when the inner shell material contracts due to creep, it can be easily handled by pressing the pressing member, and can be used for a long time. 4. In the pressure-resistant container according to the present invention, even when the seal ring disposed between the extending portion 5c of the inner shell and the horizontal portion 6b of the pressing member is deteriorated, the pressing member 6 constituting the base portion is removed and easily replaced. Therefore, gas leakage from inside the container can be completely prevented. 5. The pressure vessel according to the present invention can form the outer shell by the same method as before after completely sealing the joint between the inner shell and the base as described above, so that the manufacturing process is simple and low cost. Can be manufactured.

[Brief description of the drawings]

FIG. 1 is a side view of an example of a pressure vessel according to the present invention.

FIG. 2 is a partially enlarged longitudinal sectional view of the vicinity of a shoulder and a base of an example of a pressure-resistant container.

FIG. 3 is a perspective view of a pressing member of the pressure-resistant container shown in FIG.

FIG. 4 is a partially enlarged longitudinal sectional view showing a modification of the end of the cylindrical neck extension.

FIG. 5 is a partially enlarged longitudinal sectional view of another example of the pressure vessel according to the present invention.

FIG. 6 is a partially enlarged longitudinal sectional view of the vicinity of a shoulder and a base of another example of the pressure-resistant container.

FIG. 7 is a partially enlarged longitudinal sectional view of the vicinity of a shoulder portion and a base portion of still another example of the pressure-resistant container.

[Explanation of symbols]

 1: pressure vessel 2: outer shell 3: shoulder 4: base 5: inner shell 6: pressing member 7: fastening nut 8: seal ring

Claims (6)

[Claims] An inner shell having a gas barrier property, a pressure-resistant outer shell provided so as to cover the inner shell, and a base portion attached to at least one pole of a container composed of the two shells. In the pressure vessel described above, the extreme shoulder portion of the inner shell is formed as a cylindrical neck and is projected outward along the central axis of the inner shell, and the tip of the protruding cylindrical neck is attached to the cylindrical neck. To extend outward in a direction at right angles to form an extending portion, and bending the tip of this extending portion toward the shoulder side of the inner shell to clamp the inner lower end portion of the base portion. The cylindrical neck of the inner shell is supported from the outer peripheral surface, and one end is formed in a disk shape and buried in the thick portion of the shoulder of the inner shell, and the other end is formed in a cylindrical shape and the center axis of the inner shell is formed. The inner diameter of the protruding cylindrical neck is substantially the same as the diameter of the cylindrical neck extension of the inner shell. And a female screw is engraved on the inner peripheral wall, a pressing member with an external screw engraved on the outer peripheral surface is screwed to this female screw, and a nozzle, an orifice, etc. are connected to this base part. A pressure vessel characterized in that it can be tightened. 2. The pressing member has a funnel-like appearance having a large-diameter portion, a horizontal portion, and a small-diameter portion, and has a gas passage formed in a longitudinal direction, and the large-diameter portion has an outer peripheral surface. An external thread is engraved on the internal thread and screwed into a female thread engraved on the inner peripheral wall of the cylindrical neck part protruding from the base, and the small diameter part has an outer diameter in contact with the inner peripheral wall of the cylindrical neck part of the inner shell. The pressure-resistant container according to claim 1, comprising: 3. An annular groove is provided in at least one of a horizontal portion of the pressing member and an extension of a cylindrical neck portion facing the horizontal portion, and a seal ring is arranged in the annular groove. The pressure-resistant container according to claim 2. 4. A pressure-resistant container in which caps are attached to both pole portions of a container, wherein a small-diameter portion of a pressing member disposed on one pole portion and having a gas passage formed therein projects into the inner shell. The end of one small-diameter portion provided with a through-hole connected to the hollow portion on the wall surface can be connected to the end of the small-diameter portion of the pressing member arranged on the other pole. A pressure-resistant container according to claim 3. 5. The pressure-resistant container according to claim 1, wherein the inner shell is made of a resin, and the outer shell is made of a fiber-reinforced plastic. 6. The base member and the pressing member are selected from the group consisting of alloys such as aluminum, copper, nickel and titanium, composite materials thereof, and chromium-molybdenum alloy. Any one of 5
Pressure-resistant container according to the item.