JPH1144399A - Pressure vessel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure vessel which is excellent in pressure resistance in spite of being lightweight and is excellent in gas sealing performance of an interface part between an inside shell and a base part and whose manufacturing process is simple and which can be inexpensively manufactured in a double structure of the inside shell and an outside shell. SOLUTION: In a pressure vessel 1 which has a double structure of an inside shell 3 and an outside shell and in which a base part is installed at least in one pole part, a cylindrical neck part and a plate-like extending part extending outward are continuously connected in order to a pole part of the inside shell 3, and the base part is composed of a pair of flanges arranged by sandwiching the extending part from both surfaces. A lower side flange 6 is formed so as to support one of the cylindrical neck part and the plate-like extending part from a shoulder part of the inside shell 3, and an upper side flange 7 can be fastened to this lower side flange 6.

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, an inner shell having gas barrier properties, a pressure-resistant outer shell provided so as to cover the inner shell, and a container comprising both of these shells In a pressure-resistant container in which a base comprising a pair of vertically arranged flanges is attached to at least one of the poles, a cylindrical neck is formed at the center of the pole of the inner shell from the pole opening of the outer shell. The protruding cylindrical neck portion is extended outwardly along the shape of the lower flange to form an extended portion, and a pair of flanges is formed. The lower flange supports the cylindrical neck of the inner shell from the outside, and one end side is disc-shaped and is embedded between the shoulder of the inner shell and the opening of the outer shell. , So that the other end supports the lower surface of the disk-shaped extension of the inner shell. Is made by, it provides a pressure vessel which is characterized by comprising an upper flange being capable Me combination clamped to the lower flange.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below 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, polyether ketone, and the like. Thermoplastic resins such as polyphenylene sulfide, poly-4-methylpentene-1, and polypropylene are exemplified.

Hereinafter, the pressure-resistant container 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 examples unless it exceeds the gist. In addition, in the example described below, an example is shown in which the base is attached to only one pole of the pressure-resistant container, but the base can be attached to the other pole in the same procedure. When the base is formed on only one pole, 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 gas-barrier inner shell and a pressure-resistant outer shell 2 provided so as to cover the inner shell. The pressure-resistant container 1 includes a cylindrical body as a whole, hemispherical shoulders 4 at both ends thereof, and a lower flange 6 and an upper flange 7 at one of the tips (poles) of the hemispherical shoulders. The base 5 is attached.

FIG. 2 is a partially enlarged longitudinal sectional view of the vicinity of the shoulder and the base of the pressure-resistant container shown in FIG. In the pressure-resistant container 1, the pole of the shoulder 3a of the inner shell 3 is a cylindrical neck 3b, and from the pole opening 2a of the shoulder 4 of the hemispherical outer shell, along the central axis of the cylindrical neck 3b. Protrude outward. Cylindrical neck 3
The inside of b is hollow and serves as a gas passage 3c. At the tip of the cylindrical neck portion 3b, a disk-shaped extending portion 3d extending outward at right angles to the cylindrical neck portion 3b and having a hole in the center is provided.
And the base 5 is constituted by a pair of flanges sandwiching the disc-shaped extending portion 3d.

A lower flange (refers to a flange disposed on the inner shell side) 6 supports the cylindrical neck 3b from the outside,
One end side (shoulder side of the pressure-resistant container) is disc-shaped, and is buried between the shoulder 3a of the inner shell, the shoulder 4 of the outer shell, and the pole opening 2a, and the other end is disc-shaped. To support the lower surface of the extending portion 3d. The lower flange is attached to the upper flange (refers to the flange disposed on the side away from the inner shell).
Are combined to form the base 5. At this time, the upper flange and the lower flange are closely contacted via the extending portion of the inner shell without any gap. The disc-shaped embedded portion 6a may be a flat plate,
The shape may be a convex shape along the shoulder 4 of the semicircular sphere, or may be an inverted concave shape.

Base part 5 (lower flange and upper flange)
The material for production may be either a metal or a resin. Examples of the metal include alloys such as aluminum, copper, nickel, and titanium, composites thereof, and chromium-molybdenum alloy. As the resin, nylon 6, nylon 66, nylon 12, polyethylene terephthalate, polybutylene terephthalate, polymethylpentene, polycarbonate, modified polyphenylene oxide, polyether sulfone, polyphenylene sulfide, polyarylate, polyetherimide, polyetheretherketone, polyimide , Polyamideimide, polyoxybenzylene, polysulfone and the like. The material for manufacturing the base is not limited to those exemplified. Among metals and resins, metal materials are preferred.

When the inner shell 3 is manufactured by a rotational molding method, the inner flange 3 is formed by an insert rotational molding method in which the lower flange 6 constituting the mouthpiece 5 is fixed to a predetermined position of a rotational molding die in advance and molded. It can be integrally connected to the shell 3. When the inner shell 3 is manufactured by the blow molding method, for example, a multilayer structure in which a resin layer such as a polyamide resin having excellent gas sealing properties is used as an inner layer may be employed. When manufacturing by a blow molding method or an injection molding method, the lower flange 6 constituting the die portion can be fixed to a molding die in advance, and the inner shell 3 can be molded to be integrally joined.

Next, a reinforcing fiber yarn is wound around the outer peripheral surface of the inner shell 3, and the surface is covered with a resin for forming the outer shell 2 to form the outer shell 2. At this time, it is preferable that the shoulder portion 4 is formed on the embedded portion 6a of the lower flange, and the opening 2a of the shoulder portion 4 is brought into close contact with the neck support portion 6b of the lower flange. In the vicinity of the shoulder 4 and the neck support 6b, a space is provided in which a nut 9 for tightening the bolt 8 can be inserted.

In the example shown in FIG. 2, the disc-shaped buried portion 6a at one end (the shoulder side of the pressure-resistant container) of the lower flange 6 of the pair of upper and lower flanges has the shoulder portion 3a of the inner shell and the outer side. A neck support 6b is embedded between the shoulder 4 of the shell and the pole opening 2a, and a neck support 6b for supporting the cylindrical neck 3b of the inner shell from the outside is connected to the disc-shaped buried portion 6a. The neck support 6b is further connected to a disc-shaped flange 6c that projects the lower surface of the disc-shaped extension 3d outward. Disc flange 6
The diameter of c is larger than the diameter of the extension 3d,
The upper flange 7 is placed on the disc-shaped flange 6c, and is tightened by a plurality of bolts 8 and nuts 9. A plurality of holes 6e for inserting the bolts 8 are drilled at regular intervals in the disc-shaped flange 6c, and a plurality of holes 7a for inserting the bolts 8 are drilled at regular intervals also in the upper flange 7. .

A gas passage 7b is formed in the upper flange 7, and a male screw 7c is formed in the inner wall surface of the gas passage 7b. A filling port for filling the pressure-resistant container with a gas is provided. Equipment and parts such as nozzles and orifices can be connected.

When tightening the lower flange 6 and the upper flange 7 with a plurality of bolts 8 and nuts 9, the seal ring 1 is provided between the disc-shaped extending portion 3d and the upper flange 7.
When 0 is arranged, it is possible to prevent gas from leaking from this portion. When arranging the seal ring 10,
As shown as a partial cross-sectional view in FIG.
It is preferable to form an annular groove 3e at the center in the width direction d. It is preferable to form the annular groove 3e in the disk-shaped extending portion 3d and to dispose the seal ring 10 therein, since the deformation of the seal ring 10 is restricted by the internal pressure of the container or the negative pressure.

When the seal ring 10 is disposed between the disc-shaped extending portion 3d and the upper flange 7, the internal pressure acts on the seal ring 10. When a pressure vessel is used for a long time,
Even if the inner shell 3 contracts due to creep or the like, the seal ring 10
Absorbs the contraction, gas leakage from between the disc-shaped extending portion 3d and the upper flange 7 is substantially completely prevented, and high sealing performance can be maintained for a long time.
When the pressure vessel is used for a long time and the seal ring 10 needs to be replaced due to aging or the like, the nut 9 is removed from the tightening bolt 8, the upper flange 7 is removed, and the seal ring 10 is easily replaced with a new seal ring 10. Can be economical.

The material and shape of the seal ring 10 disposed between the disk-shaped extending portion 3d and the upper flange 7 are not particularly limited as long as they are used for the purpose of preventing gas leakage. Examples of the seal ring 10 that can be used include synthetic rubber such as natural rubber, silicon rubber, and fluorine rubber, resins such as tetrafluoroethylene, polyamide, polyethylene, and polyester, and metals such as stainless steel, aluminum, copper, and titanium. The shape of the seal ring 10 is not particularly limited, and a cross-sectional view when cut at a right angle to the length direction may be a circle, an O-shape, a square shape, or the like.

Since the inner shell 3 and the lower flange 6 are made of different materials and have different coefficients of thermal expansion, there is a concern that the interface between the disk-shaped extending portion 3d and the disk-shaped flange 6c is likely to peel off. It is. This fear can improve the interface between them slightly in the following manner. These may be used alone or in combination of two or more.

The first is a method of complicating the structure of the interface between the two. As shown in FIG. 3 as an example of a partially enlarged longitudinal sectional view, a disk-shaped extending portion 3d is provided at the outermost periphery. Shell 3
4 (a) and 4 (b) are partially enlarged longitudinal sectional views showing a modified example of the annular projection 3f protruding toward the shoulder 3a. By forming the annular projection 3f, the interface between the inner shell 3 and the neck support 6b of the lower flange can be made hard to peel off.

As shown in FIG. 5, a plurality of dovetail-shaped projections 6f are formed on the upper and lower surfaces of the disc-shaped buried portion 6a of the lower flange 6, as shown in a partially enlarged vertical sectional view of FIG. FIG.
A plurality of holes 6g penetrating vertically are formed in the embedded portion 6a of the lower flange 6 as shown in FIG. These dovetail-shaped projections 6f and through holes 6g
The surface of the buried portion 6a and the shoulder 3a of the inner shell 3
Interface separation between the outer shell 2 and the shoulder 4 can be prevented. Inside the inner shell 3 in FIG. 6, the distribution state of a plurality of holes 6g penetrating vertically formed in the disc-shaped buried portion 6a is shown as a schematic plan view.

In the method (3), an adhesive resin layer can be formed on the interface between the two or an adhesive can be applied alone or in combination with the above method or in order to reduce the separation at the interface between the two. Examples of the adhesive resin include an unsaturated carboxylic acid-modified ethylene-based resin. Examples of the adhesive include thermosetting adhesives such as epoxy-based, acrylic-based, polyurethane-based, and polyester-based adhesives. Among them, an anaerobic adhesive which is a reactive acrylic adhesive is preferable.

As such an anaerobic adhesive, there are a polyether type and an ester type. A typical example of the polyether type is tetraethylene glycol dimethacrylate. Those containing, as an active ingredient, methylolpropane trimethacrylate, butanediol-1,4-dimethacrylate, 2,2,4-trimethyl-1,3-pentanediol dimethacrylate, polyester acrylate and the like.

FIG. 7 is a partially enlarged longitudinal sectional view showing another example of the pressure-resistant container according to the present invention, in the vicinity of the shoulder portion 4 and the base 5. In this example, of the pair of upper and lower flanges, the disc-shaped buried portion 6a at one end side (shoulder side of the pressure-resistant container) of the lower flange 6 includes the shoulder 3a of the inner shell and the shoulder 4 of the outer shell 2. A neck support 6b buried between the pole opening 2a and the disc-shaped buried portion 6a is connected to a neck support 6b for supporting the cylindrical neck 3b of the inner shell from the outside. The end of 6b is in close contact with the lower surface of the disk-shaped extension 3d.

The diameter of the neck supporting portion 6b is the same as that of the disk-shaped extending portion 3.
The outer diameter of the neck support portion 6b is slightly larger than the outer diameter of d, and an external thread 6h is engraved on the outer peripheral wall of the neck support portion 6b. The upper flange 11
A female screw 11c screwed with the male screw 6h is engraved on the inside of the downward peripheral edge portion 11b connected to the top plate portion 11a, and a gas is provided at the center of the top plate portion 11a. A passage 11d is formed. When tightening the upper flange 11 having a cap-like structure on the neck support 6b, the seal ring 1 is placed between the disc-shaped extending portion 3d and the top plate 11a.
1 is arranged. Reference numeral 12 denotes a female threaded base, which fixes the opening 2a of the outer shell 2 while pressing the opening 2a against the shoulder 3a of the inner shell.

FIG. 8 is a partially enlarged longitudinal sectional view of the vicinity of the shoulder portion 4 and the base 5 as still another example of the pressure-resistant container according to the present invention. In this example, of the pair of upper and lower flanges, the disc-shaped buried portion 6a at one end side (shoulder side of the pressure-resistant container) of the lower flange 6 includes the shoulder 3a of the inner shell and the shoulder 4 of the outer shell 2. It is buried between the pole opening 2a and the disc-shaped buried portion 6
a is connected to a neck support 6b for supporting the cylindrical neck 3b of the inner shell from the outside, and the neck support 6b has a lower surface of an extension 3d extending along the shape of an annular protrusion protruding outward from the container. Are connected to each other, and the upper flange 7 which fits into the cylindrical flange and is fitted into the cylindrical neck portion is tightly fitted with no gap therebetween with the extending portion 3d interposed therebetween.

The diameter of the disk-shaped flange 6c is
The upper flange 7 is placed on the disk-shaped flange 6c, and a plurality of bolts 8 and nuts 9 are provided.
And be tightened by. A plurality of holes 6e through which the bolts 8 are inserted are formed in the disc-shaped flange 6c at regular intervals, and a plurality of holes 7a through which the bolts 8 are inserted are also drilled in the upper flange 7 at regular intervals. . When tightened by the lower flange 6, the upper flange 7, the plurality of bolts 8, and the nuts 9, the extending portion that enters the cylindrical neck of the upper flange 7 between the extending portion 3 d and the upper flange 7. By disposing the seal ring 10 at a portion that is in close contact with 3d and at the top of the protruding extension 3d, it is possible to prevent gas from leaking from this portion.

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] With the configuration shown in FIGS. 1 and 2,
In addition, a pressure-resistant container having a capacity of 76 liters was produced. The pressure vessel is filled with helium gas to an internal pressure of 25 MPa, and the pressure vessel is placed in a closed vessel for 1 hour.
When the amount of helium gas in the closed vessel was measured by gas chromatography, no gas was confirmed.

Test Example 2 In the example described in Test Example 1,
When the amount of helium gas in the sealed container was measured by the same method as in Test Example 1 without disposing a seal ring on the base,
5cc (gas permeability: 0.20cc / hour / liter)
Met. In a pressure-resistant container in which a seal ring is not provided in the base portion, gas leakage when high-pressure gas is filled cannot be completely prevented.

[0044]

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 vessel of the present invention, the inner shell 3 is connected to the cylindrical neck 3b from the shoulder 3a, and the lower flange does not directly contact the gas filled in the cylinder. Are better.

3. In the pressure-resistant container of the present invention, even when the inner shell 3 contracts due to creep, the seal ring is arranged between the extending portion 3d of the inner shell and the upper flange 7, so that the gas sealing property can be maintained. 4. In the pressure vessel of the present invention, even when the seal ring disposed between the extending portion 3d of the inner shell and the upper flange 7 is deteriorated, the upper flange forming the base portion can be removed and replaced easily, Gas leakage from inside the container can be completely prevented. 5. Since the pressure vessel according to the present invention can completely form the outer shell by the conventional method after completely sealing the interface between the inner shell and the base as described above, the manufacturing process is simple and can be manufactured at low cost. Can be.

[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 the pressure-resistant container shown in FIG.

FIG. 3 is a partially enlarged cross-sectional view of an extending portion.

FIG. 4 is a partially enlarged longitudinal sectional view showing a modification of an annular projection provided on the outermost periphery of an extending portion.

FIG. 5 is a partially enlarged longitudinal sectional view of an example in which a buried portion of a lower flange is modified.

FIG. 6 is a partially enlarged longitudinal sectional view of another modification of the embedded portion of the lower flange.

FIG. 7 is a partially enlarged longitudinal sectional view of the vicinity of a shoulder and a base of another example of the pressure-resistant container according to the present invention.

FIG. 8 is a partially enlarged longitudinal sectional view of the vicinity of a shoulder and a base of still another example of the pressure-resistant container according to the present invention.

[Explanation of symbols]

 1: pressure vessel 2: outer shell 3: inner shell 4: shoulder of outer shell 5: base 6: lower flange 7: upper flange 8: tightening bolt 9: tightening nut 10: seal ring 11: upper side of cap type Flange 12: Base with female screw

Claims (8)

[Claims] 1. An inner shell having a gas barrier property, a pressure-resistant outer shell provided to cover the inner shell, and at least one pole of a container constituted by these two shells, which are vertically arranged. In a pressure-resistant container in which a mouth portion consisting of a pair of flanges is attached, a cylindrical neck portion is connected to the pole portion of the inner shell by protruding outward along the center axis from the pole opening portion of the outer shell. The tip of the protruding cylindrical neck portion extends outward along the shape of the lower flange to form an extension portion, and the extension portion is sandwiched between a pair of flanges. Supports the cylindrical neck of the inner shell from the outside, one end is disc-shaped and is embedded between the shoulder of the inner shell and the opening of the outer shell, and the other end is a disc-shaped extension of the inner shell. The lower flange is attached to the lower flange. A pressure-resistant container characterized in that the container can be tightened in combination. 2. A pair of upper and lower flanges, wherein a lower flange is formed in a disk shape that protrudes outward while supporting a lower surface of an extending portion of the inner shell, and an upper flange is formed of an extending portion of the inner shell. A seal ring is disposed at least at one position between the extending portion and the upper flange, and both upper and lower flanges can be tightened by a plurality of bolts and nuts. 2. The pressure-resistant container according to 1. 3. The outer diameter of the neck support portion of the lower flange of the pair of flanges is slightly larger than the diameter of the extending portion of the inner shell, and a male screw is formed on the outer peripheral surface of the neck support portion. The upper flange is formed in a cap shape capable of covering the extending portion, and a female screw to be screwed into a male screw formed on the outer peripheral surface of the neck support portion is formed. 2. The pressure-resistant container according to claim 1, wherein a seal ring is arranged between the container and the female screw and the female screw is screwed into the seal ring so as to be able to be tightened. 4. A portion of the extension portion that contacts the upper flange,
The pressure-resistant container according to any one of claims 1 to 3, wherein an annular groove for arranging the seal ring is formed. 5. The pressure-resistant container according to claim 1, wherein an annular projection protruding toward the shoulder of the inner shell is formed on the outermost periphery of the extending portion. 6. A disk-shaped buried portion of a lower flange which is held by a shoulder of an inner shell and an opening of an outer shell,
The pressure-resistant container according to any one of claims 1 to 5, wherein a plurality of dovetail-like projections are formed on the upper and lower surfaces, or a plurality of holes penetrating vertically is formed. 7. 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. 8. The base according to claim 1, wherein the base is selected from the group consisting of alloys of aluminum, copper, nickel, titanium, etc., composite materials thereof, and chromium-molybdenum alloy. Or a pressure-resistant container according to claim 1.