JPH10332083A - Pressure-resisting container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a double structure, to make it light and to improve a pressure-resisting tight property by fitting an inner base part on the inside of a base part, providing a disc shape one end side of which is enlarged along the inside of a shoulder part of an inside shell on this inner base part and interpolating the other end side in a cylindrical head part of the base part. SOLUTION: A pressure-resisting container is constituted by fitting an inner base part 7 on the inside of a base part 6. One end side of the inner base part 7 has a disc type part 7a enlarged along the inside of a shoulder part 3a of an inside shell, the other end side is to be an inner base part head part 7b closely interpolated on a base part head part 6b. A female screw is engraved on an inwall surface of the base part head part 6b, a male screw is engraved on an external wall part of the inner base part head part 7b, and both of them are structured to be screwed on each other. Additionally, the inner base part head part 7b closely interpolated on the base part head part 6b has a gas passage 7c communicated to a gas passage 3c. Furthermore, a head end inside of the base part head part 6b is free to continuously provide a nozzle and an orifice at the time of using injected gas as well as an injection port to inject gas in the pressure-resisting container.

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 gas internal pressure is directly applied to the end of the base, even if there is no gas leakage immediately after the pressure vessel is manufactured, the product 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, As with the pressure vessel described above, the plastic of the inner shell may creep and shrink, causing 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]

Under such circumstances, the present invention has been completed as a result of intensive studies to provide a pressure vessel which can solve 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 has excellent pressure resistance. 2. Excellent gas sealing at the interface between the inner shell and the base,
To provide a pressure-resistant container that can easily cope with a case where the inner shell material contracts due to creep or the like. 3. To provide a pressure-resistant container that can be manufactured at a low cost with a simple manufacturing process.

[0011]

In order to solve the above-mentioned problems, 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 is attached to at least one pole part of the configured container, one end of the base is buried in the shape of a disc on the shoulder of the inner shell,
The other end is formed as a cylindrical neck portion and protrudes outwardly from the opening of the outer shell along the central axis thereof. An inner base is fitted inside the base, and the inner base is formed. The part has a disk-shaped part whose one end side is enlarged along the inside of the shoulder of the inner shell, and the other end side is provided inside a cylindrical neck part of a base part, and a nozzle and an orifice are provided in this base part. A pressure container characterized by being capable of being tightened in combination.

[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 conventionally known 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 about 2 to 10 mm. Short fibers are preferred. If the material is a resin material, compression molding, blow molding,
It can be manufactured by molding methods such as injection molding,
Among them, the rotational molding method is preferred.

The wall surface of the inner shell needs to have gas barrier properties. However, when 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. When 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 be used.

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 plating film of a metal such as aluminum, copper, nickel, and 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 is in a suitable range suitable for the purpose by variously combining the type of reinforcing fiber yarn forming the winding layer, the winding form, the winding thickness, the resin type, the resin thickness, etc. Things.

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. These reinforcing fiber yarns may be non-twisted fiber yarns that are excellent in opening property in the sense that stress concentration due to bending can be reduced and generation of voids can be reduced. Among such reinforcing fiber yarns, excellent in specific strength and specific elastic modulus, there is almost no occurrence of yarn breakage or fluff during winding, and in addition to improvement in productivity, strength characteristics due to yarn seams and fluff mixing. Carbon fiber yarns are particularly preferred from the viewpoints of prevention of reduction and prevention of reduction in impact resistance.

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

At least one of the poles of the container constituted by the inner shell and the outer shell is provided with a base having one end formed in a disk shape and embedded in the shoulder of the inner shell. As will be apparent from FIG. 2 described later, the base portion has a disk-shaped end, and both disk-shaped surfaces are embedded in the thick portion of the hemispherical shoulder of the inner shell. The embedding means that the disc-shaped portion is partially or substantially equivalently covered on both sides by the shoulder portion of the inner shell (hereinafter, this portion is referred to as “embedded portion”). The buried portion is not limited to a flat plate shape, but may be a convex shape, a concave shape, or the like. The other end side of the base portion (meaning a side away from the shoulder portion of the inner shell) is formed as a cylindrical neck portion and protrudes outward from the opening portion of the outer shell along the central axis thereof.

An inner base portion is fitted inside the base portion, and the inner base portion is formed as a disk-shaped portion whose one end side is enlarged along the inside of the shoulder portion of the inner shell. The disk-shaped part is in close contact with the shoulder covering the embedded part of the base. The other end side of the inner base is tightly fitted inside the cylindrical neck of the base.

Materials for manufacturing the base and inner base include alloys such as aluminum, copper, nickel and titanium, composite materials thereof, metals such as chromium-molybdenum alloy, nylon 6, nylon 66, nylon 12, polyethylene terephthalate, polybutylene terephthalate, polymethylpentene, polycarbonate, modified polyphenylene oxide, polyethersulfone, polyphenylene sulfide, polyarylate, polyetherimide, polyetheretherketone, polyimide, polyamideimide, polyoxybenzylene, polysulfone, etc. Resins. The material for the base and inner base is
It is not limited to these examples. Metals and resins are preferably metal materials.

Hereinafter, the pressure-resistant container according to the present invention will be described in detail with reference to the drawings, but the present invention is not limited to the following description unless it departs from 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 attached to 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 has a cylindrical body as a whole, hemispherical shoulders 4 at both ends thereof, and a base 6 attached to at least one of the tips (poles) of the hemispherical shoulders.

FIG. 2 is a partially enlarged longitudinal sectional view of the vicinity of the shoulder and the base of an example of the pressure-resistant container. The pressure vessel 1 has an inner shell 3
The pole of the shoulder 3a is formed as a cylindrical neck 3b, and is projected outward from the pole opening 2a of the outer shell 2 along the central axis of the cylindrical neck 3b. The inside of the cylindrical neck 3b is hollow and serves as a gas passage 3c.

The base 6 supports the shoulder 3a and the cylindrical neck 3b from outside, and the disc-shaped buried portion 6a at one end (shoulder side of the pressure-resistant container) has shoulders 3a, 3a 'of the inner shell. And the base neck 6b is held by the pole opening 2a of the shoulder 4 of the outer shell 2. The other end of the base 6 (the side remote from the shoulder of the inner shell) has the base neck 6b and the inner shell 2
Projecting outward along the central axis of

In the pressure-resistant container according to the present invention, an inner base 7 is fitted inside the base 6, and one end of the inner base 7 is enlarged along the inside of the shoulder 3a of the inner shell. The other end side is an inner base neck part 7b closely fitted to the base neck part 6b. It is preferable to form a female screw on the inner wall surface of the base neck portion 6b and a male screw on the outer wall surface of the inner base neck portion 7b, and to screw them together.

FIG. 2 shows that the inner base 7b closely fitted to the base 6b has a gas passage 7 communicating with the gas passage 3c.
An example is shown in which a screw 7d is arranged inside the tip of the inner neck portion 7b, and the inner neck portion 7b is pressed and adhered to the inner neck portion 6b. A female screw 6e is engraved on the inside of the tip of the base neck portion 6b, and it is possible to connect devices and parts such as a filling port for filling the pressure-resistant container with gas and a nozzle and orifice when using the gas filled in the pressure-resistant container. And A male screw is engraved on the outside of the tip of the inner base neck portion 7b, and can be used to screw a female screw of a cap nut for tightening a nozzle or an orifice connected to the female screw 7e.

When the inner shell 3 is manufactured by the rotational molding method, the base part 6 and the inner base part 7 constituting the base 5 are combined and integrated, and the combined body is previously placed at a predetermined position of the forming die. The inner shell 3 is fixed by insert molding method.
Can be integrally joined. In addition, when manufacturing by the insert rotational molding method, the shoulder 3 of the inner shell is used.
a, 3a 'are filled in advance with resin powder, and after heating and melting, the disk-shaped portion 7a of the inner die is moved toward the disk-shaped buried portion 6a of the die and pressed. By continuing the rotary molding, the members can be integrally joined. When manufacturing by the blow molding method or the injection molding method, it is possible to fix the base part 6 constituting the base 5 in a predetermined position of the forming die in advance, form the inner shell 3 and integrally connect the both. it can.

Next, as described above, a reinforcing fiber yarn is wound around the outer peripheral surface of the inner shell 3, 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 portion 4 of the outer shell 2 is formed on the disc-shaped buried portion 6a of the base 6, and the opening 2a of the shoulder 4 is brought into close contact with the neck 6b of the base. As described above, the shoulder portion 4 and the opening portion 2a are tightened by the tightening nut 8 to the disc-shaped buried portion 6a side.

When the high-pressure gas filled in the inner shell 3 leaks, there may be a case where the interface between the inner shell 3 and the disc-shaped buried portion 6a of the base 6 is partially separated to form a leak passage. Many. In order to improve the adhesive strength of the interface portion and prevent peeling, (1) the base neck portion 6b
The end face of the cylindrical neck portion 3b of the inner shell 3 is formed in a groove shape. (2) A plurality of dovetail-shaped projections 6f having a dovetail shape in vertical section are provided on the surface of the disc-shaped buried portion 6a. (3) It is also possible to adopt a combination of methods such as forming a plurality of holes 6g penetrating from one surface to the other surface in the disc-shaped buried portion 6a, and (4) providing an adhesive layer at an interface portion.

As an example of the above (1), a modified example in which the end face 3d of the cylindrical neck 3b is formed in a groove shape is shown in FIGS. 3 (a), (b) and (c) as a partially enlarged longitudinal sectional view. Indicated. FIG. 3 shows an annular portion having a circular or polygonal vertical section with the inside tip 3d of a portion sandwiched between the cylindrical neck portion 6b of the base portion and the neck portion of the inner base portion extending outward. The cylindrical neck 7b of the base
An example is shown below. As an example of the above (2), FIG. 4 shows a partially enlarged longitudinal sectional view, and as an example of the above (3), FIG. 5 shows a partially enlarged longitudinal sectional view.

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.

FIG. 6 shows another example of a pressure-resistant container according to the present invention. An inner base neck portion 7b closely attached to a base neck portion 6b has a gas passage 7c communicating with a gas passage 3c. An example is shown in which the tip of the mouthpiece neck 7b is longer than the tip of the mouthpiece neck 6b. The tip of the inner neck 7b is screwed with a fastening nut 9 at the tip of the neck 6b. By tightening the tightening nut 9, the nut 9
The shoulders 3a, 3a 'of the inner shell and the buried portion 6a arranged between the inner shell and the disk-shaped portion 7a of the inner base portion can be pressed so that the mutual interface does not peel off. By filling the female screw 7e inside the tip of the inner base neck portion 7b, a device or part such as a filling port for filling the pressure-resistant container with gas, a nozzle or an orifice for using the gas filled in the pressure-resistant container is provided. Can be connected.

FIG. 7 shows still another example of the pressure-resistant container according to the present invention, in which the diameter of the disc-shaped portion 7a of the inner mouth portion is smaller than that of the example shown in FIG. .

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 A pressure-resistant container having the structure shown in FIGS. 1 and 2 and having a capacity of 76 liters was manufactured.
The pressure vessel was filled with helium gas so as to have an internal pressure of 25 MPa. The pressure vessel was placed in a closed vessel and allowed to stand for 1 hour, and the amount of helium gas in the closed vessel was measured by gas chromatography. No detection was found, indicating no gas leakage.

[Comparative Example 1] A pressure-resistant container was prepared in the same manner as in Test Example 1 except that the inner die portion was not arranged at the die portion in the example described in Test Example 1. As in Test Example 1, when the amount of helium gas in the closed container was measured,
It was 20 cc (gas permeability: 0.26 cc / hour / liter). Therefore, it is understood that the pressure vessel cannot completely prevent gas leakage of the high-pressure gas.

[0039]

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. The pressure-resistant container of the present invention has a structure in which the disk-shaped buried portion of the base portion is embedded in the shoulder portion of the inner shell. Further, the disk-shaped portion 15a of the inner base portion and the neck portion of the inner base portion 15b form the inner shell. Since the interface with the base is covered or tightened with bolts, the interface has excellent gas sealing properties.

3. Even if the inner shell material contracts due to creep, it can be easily coped with by tightening the tightening bolts of the inner base portion, and can be used for a long time. 4. 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 flange of an example of a pressure-resistant container.

FIG. 3 is a partial longitudinal sectional view showing a modification of the end face of the cylindrical neck portion of the inner shell.

FIG. 4 is a partially enlarged longitudinal sectional view of the vicinity of a shoulder and a flange of another example of the pressure-resistant container according to the present invention.

FIG. 5 is a partially enlarged longitudinal sectional view showing the vicinity of a shoulder and a flange of another example of the pressure-resistant container according to the present invention.

FIG. 6 is a partial longitudinal sectional view showing an example of a modification of the disc-shaped buried portion.

FIG. 7 is a partial longitudinal sectional view showing another example of the deformation of the disc-shaped buried portion.

[Explanation of symbols]

 1: Pressure vessel 2: Outer shell 3: Inner shell 4: Outer shell shoulder 5: Base 6: Base 7: Inner base 8: Tightening nut 9: Tightening nut for inner base

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-resistant container, one end of the base is formed in a disk shape and embedded in the shoulder of the inner shell, and the other end is formed as a cylindrical neck along the central axis from the opening of the outer shell. The inner base portion is fitted inside the base portion, and the inner base portion is a disc-shaped portion whose one end side is enlarged along the inside of the shoulder portion of the inner shell. A pressure-resistant container characterized in that the other end side is tightly fitted inside a cylindrical neck portion of the base portion, and the base portion can be tightened by combining a nozzle and an orifice. 2. The tip of an inner mouth part provided inside a cylindrical neck part of a mouth part reaches an internal thread carved in an opening part of a cylindrical neck part, and is tightened to an inner wall of the cylindrical neck part with a bolt having a hole. The pressure-resistant container according to claim 1, which is formed. 3. An inner end of a portion sandwiched between the cylindrical neck portion of the mouth portion and the inner mouth portion is formed into an annular portion having a circular or polygonal vertical section, and is formed on the cylindrical neck portion of the mouth portion. The pressure-resistant container according to claim 1, which is buried. 4. 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. 5. The ferrule and the inner ferrule 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 item 4
Pressure-resistant container according to the item. 6. A tip of an inner mouth part provided inside a cylindrical neck part of a mouth part is made to project outward beyond an opening part of a cylindrical neck part, and a male screw is engraved on an outer peripheral surface of the projecting part. The pressure-resistant container according to claim 1, wherein the container is fixed by screwing a tightening nut thereto.