CN1182385A - Pressure vessel and method of manufacturing same - Google Patents

Abstract

A pressure vessel according to the invention has a feature comprising an inner shell having a gas barrier property and a pressure outer shell provided in a manner to cover the inner shell, the outer shell being composed of FRP containing a reinforming fiber and a resin and having a tensile elastic modulus of 35 CPa or more and a tensile rupture strain of 1.5% or more. Also, a method of manufacturing a pressure vessel, according to the invention, has a feature comprising forming a pressure out shell around an inner shell by means of a filament winding method or a tape winding method.

Description

Pressure vessel and manufacturing method thereof

technical field

The present invention relates to various pressure vessels, especially pressure vessels suitable for mounting on automobiles.

technical background

In recent years, in the United States and other countries, attention has been paid to natural gas-fueled vehicles as low-pollution vehicles. Such a car is generally equipped with a pressure vessel called a CNG tank (Compressed Natural Gas Tank) as a fuel tank.

Such pressure vessels for automobiles are conventionally made of metal such as steel or aluminum alloy. However, metal products are heavy, so that the vehicle travel distance per unit weight of fuel supplied to the vehicle is shortened. Moreover, the calorific value of natural gas per unit weight is less than half that of gasoline. Therefore, in the case of no recharge, the distance that can be driven is the same as that of a gasoline car, and the amount of natural gas that is about twice the amount of gasoline must be loaded. The total weight of the car, so the above-mentioned driving distance of the car will be shortened. Therefore, one way to increase the range of the vehicle is to reduce the weight of the pressure vessel.

Japanese Patent Publication No. 5-88665 describes a pressure vessel in which a pressure-resistant FRP (Fiber Reinforced Plastic) outer shell surrounds a gas-barrier plastic inner shell. Since the pressure vessel is actually made of plastic, it is much lighter than metal products. If it is used as a natural (gas) pressure vessel for automobiles, it is expected to increase the driving distance of the above-mentioned automobiles. However, on the one hand, FRP is more brittle than metals. Therefore, in the event of a collision accident or impact due to other reasons, there are fears of instantaneous rupture, fragments that may injure human bodies, or fires caused by natural gas leakage. In addition, if we look at the development of automobile damage in collision accidents, etc., we can see that when the same part receives several impacts as the damage progresses, even if the initial impact does not lead to rupture, the same part is subjected to secondary damage. When impacting, even a relatively low impact energy can easily rupture the FRP pressure vessel. As a result, the same situation as the rupture caused by a single impact occurs. In this way, the pressure vessel, especially the fuel pressure used in automobiles Of course, the container is required not to break when subjected to a single impact, and it is also required to continue to maintain its pressure resistance when subjected to repeated impacts. The prevention of the rupture and the maintenance of the pressure resistance performance can of course be solved by improving the safety factor. However, such an increase in weight destroys the advantage of light weight, which is the greatest advantage of FRP, and increases the manufacturing cost.

In addition, U.S. Patent No. 5,253,778 and U.S. Patent No. 4,925,044 describe a pressure vessel in which a metal joint is bonded to the opening of the plastic inner shell with an adhesive, and the edge of the metal joint is embedded in the shape of the plastic inner shell. Connect, and then outsource the pressure-resistant FRP shell.

This pressure vessel is also considerably lighter than metal products, and if used as a pressure vessel for automobiles, it is expected to increase the driving distance of automobiles. However, such a metal joint and the plastic inner shell are not mechanically connected, so when the metal joint or its surroundings are impacted, the tight connection between the metal joint and the plastic inner shell may be destroyed, causing the gas inside the pressure vessel to leak out. .

Contents of the invention

The object of the present invention is to provide a pressure vessel which solves the above-mentioned disadvantages of the conventional pressure vessel, is of course a light-weight product, and has good pressure resistance even when subjected to repeated shocks, and is a highly reliable pressure vessel.

Another object of the present invention is to provide a method of manufacturing such a pressure vessel.

In order to achieve the above object, the pressure vessel provided by the present invention is provided with an inner shell and an outer shell, wherein the inner shell has gas barrier properties, and the outer shell has pressure resistance and encloses the inner shell; it is characterized in that the outer shell is made of reinforced fiber It is composed of FRP and resin, and the tensile elastic modulus is above 35Gpa, and the tensile breaking strain is above 1.5%.

In addition, the present invention provides a method of manufacturing a pressure vessel as a method of manufacturing such a pressure vessel. It is characterized in that: On the inner shell with gas barrier property, a pressure-resistant outer shell is formed by filament winding method or tape winding method, the outer shell is made of FRP containing reinforced fiber and resin, and the elastic mold is stretched The weight is above 35Gpa, and the tensile strain at break is above 1.5%.

The pressure vessel of the present invention is provided with an outer shell made of FRP containing reinforcing fibers and resin, with a tensile modulus of more than 35 Gpa and a tensile fracture strain of more than 1.5%, and an inner shell with gas barrier properties. Therefore, it has good pressure resistance, high reliability, and light weight even when subjected to repeated impacts. Therefore, the pressure vessel of the present invention is particularly suitable as a CNG gas storage tank for automobiles that requires light weight and particularly high reliability.

By using the manufacturing method of the pressure vessel of the present invention, a pressure vessel with good pressure resistance, high reliability and light weight can be manufactured at low cost.

A brief description of the graphics

Fig. 1 is a schematic longitudinal sectional view of an embodiment of the pressure vessel of the present invention.

Fig. 2 is a longitudinal sectional view of main parts of still another embodiment of the pressure vessel of the present invention.

Figure 3 is an enlarged sectional view of part C of the pressure vessel shown in Figure 2.

Fig. 4 is a schematic flowchart of an example of a pressure vessel manufacturing method of the present invention.

Fig. 5 is a schematic cross-sectional view of an example of a straight roll used in an example of the pressure vessel manufacturing method of the present invention.

Fig. 6 is a schematic sectional view of another example of straight rolls used in an example of the pressure vessel manufacturing method of the present invention.

Fig. 7 is a schematic flowchart of still another example of a pressure vessel manufacturing method of the present invention.

Fig. 8 is a sectional view of an example of a reinforcing fiber bundle.

Fig. 9 is a partial longitudinal sectional view of the shell section of another embodiment of the pressure vessel of the present invention.

Fig. 10 is a schematic flow chart of still another example of a pressure vessel manufacturing method of the present invention.

Fig. 11 is a partial longitudinal sectional view of one shoulder of another embodiment of the pressure vessel of the present invention.

Fig. 12 is a partial longitudinal sectional view of another shoulder of another embodiment of the pressure vessel of the present invention.

Fig. 13 is a partial longitudinal sectional view of one shoulder of another embodiment of the pressure vessel of the present invention.

Fig. 14, Fig. 16, Fig. 17, Fig. 22. Fig. 28 to Fig. 35 are partial vertical cross-sectional views of the periphery of various joints in yet another embodiment of the pressure vessel of the present invention.

Fig. 15 is an enlarged partial longitudinal sectional view of a pressure vessel in a modified example of the structure shown in Fig. 14 .

Figures 18 to 20 show examples of the cross-sectional shape of the seal ring, and are partial cross-sectional views of the seal ring.

Fig. 21 is an enlarged partial longitudinal sectional view of the pressure vessel in another modified example of the structure shown in Fig. 14 .

23 to 27 show various examples of the concavo-convex structure of the joint in FIG. 22, and are partial perspective views of the joint.

In addition, the symbols in the figure represent as follows: 1. Pressure vessel. 2. Inner shell. 3. Shell. 4. Joint for nozzle installation. 5. Nozzle. 6. Raised part. A. Cylinder body. B. To seal the head. E. Enhancement layer. 101, creel. 102, bobbin. 103. Reinforcing fiber filaments. 104. Reinforcing fiber bundles (before impregnated with resin). 105. A guide roller for reinforcing fibers. 106a, 106b, 107a, 107b, 108, separation rollers. 109. Resin impregnation tank. 110. Resin. 111a, 111b, 111c, rollers. 112. Resin-impregnated reinforcing fiber bundles. 113, 113a, 113b, 113c, guide rollers. 114, 114a, 114b, feeding rollers. 115. Rubber ring for resin extrusion. 116, bracket. 117, spinning wheel support. 118, drum. 118a, the hollow part. 119, inner shell. 119a the axis of rotation of the core. 120, rotating driving device. 121. Shell.

Best form of invention practice

The present invention will be described in detail with reference to one of the embodiments. In FIG. 1 , a pressure vessel 1 is provided with a gas-barrier inner shell 2 and a pressure-resistant FRP outer shell 3 , and the outer shell 3 covers the inner shell 2 . The pressure vessel 1 is provided as a whole with a cylindrical body A, a cap portion B connecting the cylindrical body A, a joint 4 for attaching a nozzle, a nozzle 5 attached thereto, and a boss 6 provided on the opposite side.

According to the above description, the inner shell has the function of preventing air leakage. Furthermore, as will be described later, it can also be used as a core when forming a pressure-resistant casing.

For the inner shell, metals such as light alloys such as aluminum alloys or magnesium alloys, or polyethylene resins, polypropylene resins, polyamide resins, ABS resins, polybutylene terephthalate resins, polyacetal resins, Made of resin such as polycarbonate resin. In terms of excellent impact resistance, ABS resin is the best. Such a resin-made inner case can be manufactured, for example, by blow molding. In addition, a composite blow molding method can also be used to form a multi-layer structure: a layer of good airtightness such as polyamide resin layer is sandwiched between a layer of good rigidity such as high-density polyethylene resin. Furthermore, the inner shell can also be made of FRP. Such an inner shell made of FRP can be radially formed using, for example, a resin containing short fibers composed of reinforcing fibers and having a fiber length of 2 to 10 mm as described later.

In order to improve the performance of preventing air leakage of the inner shell, it is preferable to adopt the form of forming an air barrier layer on the inner surface and/or the outer surface. For example, in blow molding, if nitrogen gas containing fluorine is used as the blowing gas, a gas barrier layer composed of a fluororesin film can be formed on the inner surface of the inner case. In addition, on the outer surface, a metal plating film such as copper, nickel, chromium, etc. may be formed as a gas barrier layer. The formation of metal coating can adopt electrolytic coating method and non-electrolytic coating method. When the inner shell is manufactured by composite blow molding, a polyamide resin layer with good gas barrier properties can also be provided on the inside, and an ABS resin layer that is easy to coat, such as ABS resin, can be provided on the outside to facilitate the formation of a metal coating.

In addition, annular ribs extending along the circumferential direction can be designed on the inner or outer surface at intervals of 2.5-5 cm. Such an inner shell can be obtained, for example, by first manufacturing a ribbed inner shell that is vertically divided into two halves made of plastic and then joining them together to form a single piece. The ribs can increase the strength of the inner shell, prevent the inner shell from being deformed when forming the outer shell described later, and help prevent the decrease in the strength of the outer shell or the unevenness of the strength due to the bending or bias of the reinforcing fibers, resulting in a loss of pressure resistance. reduce.

Referring to Fig. 1 again, on the cylindrical part A of the inner shell, a layer of rings and the like composed of reinforcing fiber filaments described later are provided, and an FRP compound made of such a fabric of reinforcing fiber filaments and resin is arranged. The strengthening layer E. This reinforcing layer E may continue to a part of the head portion B. As shown in FIG. However, the reinforcing layer may not be provided in the present invention.

The shell is made of FRP containing reinforced fiber and resin, its tensile elastic modulus is above 35Gpa, and its tensile breaking strain is above 1.5%. By constituting the shell made of FRP with a tensile elastic modulus of more than 35Gpa and a tensile fracture strain of more than 1.5%, the pressure vessel can maintain good pressure resistance even in the face of repeated impacts, and become reliable. High performance products. The tensile modulus of elasticity should be above 37Gpa, more preferably above 40Gpa. When the tensile modulus of elasticity is less than 35Gpa, the amount of deformation is too large when impacted, which may cause damage to the inner shell and gas leakage. And, under repeated impact (strength) weakens. In terms of tensile fracture strain, at least 1.5% is required, and it should be more than 1.7%, preferably more than 2.0%. If it is less than 1.5%, the damage and fracture of the reinforcing fiber will be obvious when the impact is received. When the impact is repeated, even if the damage caused by the initial impact is small, when the same part is impacted again, it may cause gas leakage. rupture.

Such an outer shell can be formed, for example, by using the above-mentioned inner shell as a rotating cylinder, forming a winding layer of reinforcing fiber filaments containing a resin on its circumference by a well-known filament winding method or a long tape winding method, and reshaping.

Hereinafter, an example of a specific method of manufacturing the casing by the filament winding method will be described. That is, the reinforcing fibers 103 spun from the respective bobbins 102 of the creel 101 are collected in a certain number to form a reinforcing fiber bundle 104 and sent to the guide roller 105 . The guide roller 105, in this embodiment, consists of a pair of freely rotating rollers 106a, 106b extending substantially in the horizontal direction, a pair of freely rotating rollers 107a, 107b extending substantially in the up-down direction on the downstream side thereof, and Free-rotating rollers 108 extending substantially in the horizontal direction are constituted. The reinforcing fiber bundle 104 assembled into a substantially predetermined cross-sectional shape is introduced into a resin impregnation tank 109 by the guide roller 105 .

The reinforcing fiber bundle 104 is impregnated with a resin 110 in a resin impregnating tank 109, and the outer shell 121 can be formed by winding the reinforcing fiber bundle 112 impregnated with the resin around the rotating inner shell 119 at a predetermined angle. As a method of impregnating the reinforcing fiber bundle 104 with a resin, the impregnation method shown in FIG. 4 or the roller method can be used. In addition, when designing the reinforcement layer between the inner shell and the outer shell, if the outer surface of the inner shell including its surface is formed with a rough surface with an average roughness of 10 μm to 200 μm, it can prevent the reinforcement of the fiber filaments during winding. Slipping reduces disorder in the distribution of reinforcing fibers.

In this filament winding method, generally between the resin impregnating tank 109 and the inner shell 119, a guide device such as a guide roller 113 for guiding the resin-impregnated reinforcing fiber bundle 112, and an inner shell directly in front of the inner shell are provided. A feed roll 114 is wound with a resin-impregnated reinforcing fiber bundle at a predetermined position on the shell at a predetermined angle.

The guide rollers 105, 113 are constituted by rotating rollers or fixed rollers. In addition, pear skin rollers, electroplated rollers, etc. can also be used as guide rollers. If rollers with a small friction coefficient such as these rollers are used, damage to the reinforcing fiber bundle can be almost completely eliminated.

Although usually the feeding roller is made of a straight roller with flanges at both ends in order to prevent the guided reinforcing fiber bundle from falling off the surface of the roller, but in order to make the width of the guided reinforcing fiber bundle constant, it can also be used in the feeding roller. On the material roll, design as shown in Figure 5 grooves with a certain interval, or set a concave portion with a certain width as shown in Figure 6.

In this way, the molded body obtained by laminating the resin-impregnated reinforcing fiber bundles 112 on the surface of the inner shell 119 is heat-cured for a certain period of time depending on the curing conditions of the resin. In addition, during curing, it is preferable to place the molded body horizontally and rotate it in the circumferential direction, so that uneven curing of the resin can be reduced.

In addition, if the molded product is processed at the final curing temperature in a short period of time, the heat generated by curing inside the casing 121 is high and cracks are generated in the inner layer of the casing, and because the resin is extruded rapidly, voids are easily generated in the inner layer of the casing. , Therefore, the hardening temperature is best controlled by the following method. That is, it is best to perform a long-term pre-curing treatment at a temperature range of 50°C to 90°C in the initial stage of hardening, depending on the resin used, so as to prevent cracks caused by the heat generation of the inner layer of the shell. The resin can be slowly extruded to reduce the voids, and then the temperature is raised to the final hardening temperature for hardening.

The reinforcing fiber filaments can be carbon fiber filaments, glass fiber filaments, or high-strength and high-elasticity fiber filaments such as organic high-elasticity fiber filaments such as polyaramid fibers. These reinforcing fiber filaments have less stress concentration during bending and fewer voids. In this sense, untwisted fiber filaments with good openability are the best. In addition, these reinforcing fiber filaments may be used in combination. Among them, even if glass fiber yarns and carbon fiber yarns with low elastic modulus are mixed, the production cost can be reduced. As a combined method, glass fibers may be used for the helical layer, carbon fiber filaments may be used for the hoop layer, or a mixture of glass fibers and carbon fiber filaments may be impregnated with resin on the shell.

Even in such reinforcing fiber filaments, the relative strength (ratio of strength to specific gravity) and relative elastic modulus are excellent, and there is almost no occurrence of broken filaments or fluff during winding, and the improvement of production performance is fundamental, and it is possible to prevent damage due to splicing or fluff of the filaments. If the incorporation of grains causes a decline in strength characteristics or a decline in impact resistance, the tensile strength of the strands should be above 4.5Gpa, preferably above 5.5Gpa, and the tensile breaking strain of the strands should be above 2%, preferably above 2%. Some are carbon fiber filaments above 2.2%. The tensile strength referred to here is a value measured in JIS-R7601, and the tensile strain at break is a value obtained by dividing the tensile modulus of elasticity of a strand measured in JIS-R7601 by the tensile strength.

In addition, it is better to use this kind of carbon fiber filament, that is, on the basis of the above-mentioned strand tensile strength and tensile fracture strain characteristics, the surface relative oxygen concentration (O/C) is below 0.30, the surface relative nitrogen concentration (N /C) carbon fiber filaments below 0.02. The surface relative oxygen concentration and the surface relative nitrogen concentration referred to here are values measured by X-ray photoelectron spectroscopy as described below.

Surface relative oxygen concentration (O/C), first, cut the carbon fiber filament after removing the surface treatment agent in the solvent, and after expanding and arranging on the stainless steel sample support platform, the photoelectric beam is emitted at a fixed angle. 90°, use MgKα _1.2 as the X light source, and maintain a vacuum of 1×10 ^-8 Torr in the inner cavity of the sample. As a peak correction accompanying charging during measurement, first, the binding energy value of the main peak of C _1S coincides with 284.6 eV. The C _1S peak area is obtained by making a straight reference line in the range of 282-296eV; the O _1S peak area is obtained by making a straight reference line in the range of 528-540eV. The surface relative oxygen concentration (O/C) is represented by the atomic number ratio calculated by dividing the ratio of the O _1S peak area to the C _1S peak area by the device-specific sensitivity correction value. In addition, the values in Example 2 described later were obtained using ESCA-750 manufactured by Shimadzu Corporation, and the inherent sensitivity correction value of the above-mentioned device was 2.85.

The surface relative nitrogen concentration (N/C), first, cut the carbon fiber filaments after removing the surface treatment agent in the solvent, and after expanding the arrangement on the stainless steel sample support table, the photoelectric beam is emitted at a fixed angle. 90°, use MgKα _1.2 as the X light source, and maintain a vacuum of 1×10 ^-8 Torr in the inner cavity of the sample. As a peak correction accompanying charging during measurement, first, the binding energy value of the main peak of C _1S coincides with 284.6 eV. The C _1S peak area is obtained by making a straight reference line in the range of 282-296eV; the N _1S peak area is obtained by making a straight reference line in the range of 398-410eV. The surface relative nitrogen concentration (N/C) is represented by an atomic number ratio calculated by dividing the ratio of the N _1S peak area to the C _1S peak area by the device-specific sensitivity correction value. In addition, the values in Example 2 described later were obtained using ESCA-750 manufactured by Shimadzu Corporation, and the inherent sensitivity correction value of the above-mentioned device was 1.7.

Carbon fiber filaments with a surface relative oxygen concentration (O/C) of 0.30 or less and a surface relative nitrogen concentration (N/C) of 0.02 or more are expected to increase the reactivity of the resin and carbon fiber filaments that make up the shell. Fiber filaments for the compressive strength of the shell. Therefore, when the casing is made of such carbon fiber filaments, the pressure vessel becomes a pressure vessel that is light in weight, extremely excellent in impact resistance, and highly reliable.

The carbon fiber filaments whose surface relative oxygen concentration (O/C) and surface relative nitrogen concentration (N/C) measured by X-ray photoelectric spectroscopy as described above are set in the above range can be obtained by electrolytic oxidation treatment, gas phase Or liquid phase oxidation treatment etc. to obtain. Hereinafter, a method of manufacturing by the electrolytic oxidation treatment method will be described.

At this time, any of acidic and alkaline aqueous solutions can be used, and the electrolyte of the acidic aqueous solution can be specifically sulfuric acid, nitric acid, hydrochloric acid, and the like. It should be an aqueous solution containing ammonium ions as an alkaline aqueous solution. Specifically, ammonium bicarbonate, ammonium carbonate, hydrogenated tetraalkylammonium salt, or a mixture thereof can be used. It should be ammonium bicarbonate and ammonium carbonate, which can especially increase the relative nitrogen concentration (N/C) of the surface.

The treatment power should be suitable for the degree of carbonization of the treated carbon fiber filaments, but from the viewpoint of preventing the decrease of the tensile strength of the carbon fiber filament matrix and reducing the crystallinity of the surface layer, it is best to use a small amount of electricity for repeated electrolytic treatment. The method of processing. Specifically, the amount of conduction [coulomb number] per electrolytic cell per 1 g of carbon fiber filaments should be at least 1 [coulomb/g·cell] and not more than 40 [coulomb/g·cell].

As the method of electrification, any one of direct electrification in which carbon fiber filaments are directly in contact with electrode rods or indirect electrification through electrolyte solution electrification between carbon fiber filaments and electrode rods can be used, but in order to obtain high tensile strength, It is preferable to use indirect power supply that can suppress the bristling of hairs and electronic sparks during electrolytic treatment.

In addition, after the electrolytic treatment, it is preferable to wash with water and then dry. At this time, in order to improve the affinity or cohesiveness with the resin described later, so that the functional groups present on the outermost surface of the carbon fiber filaments will not be thermally decomposed, it is desirable to dry at as low a temperature as possible, specifically In other words, it is desirable to dry at a drying temperature below 250°C, more preferably below 210°C.

Then the resin that constitutes the pressure vessel shell of the present invention can adopt thermosetting resins such as epoxy resin, unsaturated polyester resin, vinyl resin, carbonic acid resin, or polyamide resin, polybutylene terephthalate resin , ABS resin, polyetherketone resin, polyphenylene sulfide resin, poly-4-methylbenzene-1 resin, polypropylene resin and other thermoplastic resins. Especially in order to increase the impact absorption energy during deformation, it is best to use a resin with a large tensile fracture strain, that is, a resin with a tensile fracture strain of more than 3%, preferably more than 5%.

The ratio of the tensile tension in the axial direction of the pressure vessel generated by the internal pressure to the tensile tension in the circumferential direction is approximately 1:2. Therefore, in order to achieve both light weight and high strength or tensile modulus of elasticity, and improve pressure resistance, it is better to use such a composition for the reinforcing fiber: on the outer shell, there are 0° relative to the axial direction of the pressure vessel in sequence from the inner side Reinforcing fiber layers arranged at an angle of ±15°, preferably 0° to ±5°, reinforcing fiber layers arranged at an angle of ±75° to ±105°, preferably ±85° to ±100°, and The reinforcing fiber layers are arranged at an angle of ±30° to ±60°, preferably ±40° to ±50°. In addition, the reinforcement of the reinforcing fiber layer arranged at an angle of 0° to ±15°, the reinforcing fiber layer arranged at an angle of ±75° to ±105°, and the reinforcing fiber layer arranged at an angle of ±30° to ±60° The fiber volume ratio can be set in the range of 1:1.5-2.5:0.2-1.2. The pressure resistance performance is mainly improved with 0°～±15° and ±75°～±105° layers, and the impact resistance performance is improved with ±30°～±60° layers. That is, in order to increase the residual strength after impact, it is preferable to arrange the layers of ±30° to ±60° on the outside.

In addition, in order to prevent the rupture of the pressure vessel when a hole appears instantaneously when it is impacted, it is preferable to adopt the following structure for the reinforcement fiber on the shell to improve the in-plane isotropy, that is, from the inner side, there are in order from the inside relative to the axial direction of the pressure vessel. The reinforcing fiber layer is arranged at an angle of ±5° to ±50°, which should be 25° to ±40°, and the reinforcing fiber layer is arranged at an angle of ±75° to ±105°, which should be ±85° to ±100° . In addition, the reinforcing fiber volume ratio of the reinforcing fiber layers arranged at an angle of ±5° to ±50° and the reinforcing fiber layer arranged at an angle of ±75° to ±105° is preferably in the range of 1.0:1.0 to 2.0.

In addition, since the interface between the cylindrical body and the head is subjected to bending stress caused by internal pressure, it is better to design it slightly thicker. In addition, an overlay of the above-mentioned resin or an FRP layer made of nonwoven fabric and resin is provided between the layers. If the same FRP layer is used to form the outermost layer, the impact energy can be dispersed to further improve the impact resistance. Similarly, the outermost layer can also be made of glass fiber with good impact resistance or an FRP layer made of organic fiber and resin, and a resin layer made of polyethylene resin, polyamide resin, urethane resin, etc. can also be used to form the outermost layer. .

The gas contained in the pressure vessel of the present invention is not particularly limited, and there are nitrogen, oxygen, helium and the like in addition to the above-mentioned natural gas.

In the pressure vessel of the present invention, the shell of the cylindrical part of the pressure vessel has a layered structure of more than five layers, and when the relationship between the total thickness T (mm) and the number of layers N satisfies the condition of 0.5≤T/N≤6 , can greatly improve the pressure resistance of the cylinder part and the relative strength from external impact force. It is more preferable to alternately arrange layers with hoop-wrapped layers of reinforced fibers and layers with helically-wound layers of reinforced fibers on the cylindrical body portion along the thickness direction of the casing.

For such a pressure vessel, when a pressure-resistant FRP outer shell is formed by filament winding on the circumference of the gas-barrier inner shell to form a pressure vessel, the cylindrical part of the pressure vessel shell can be used to form a 5 It is manufactured in such a way that the relationship between the total thickness T (mm) and the number of layers N satisfies the condition of 0.5≤T/N≤6.

In such a manufacturing method, for example, when the shell is formed by the filament winding method, it is preferable to use untwisted reinforcing fiber bundles in which the ratio D/t of the filament web D before resin impregnation to the thickness t is 5 or more.

In the pressure vessel according to this embodiment, the FRP casing 3 is formed as shown in FIGS. 2 and 3 . That is, the casing 3 has a cylindrical body having a layered structure having five or more layers. In this embodiment, the casing 3 is composed of ten layers in total on the cylindrical portion. Each layer is basically distinguished by the arrangement angles of reinforcing fibers that are different from each other between adjacent layers. However, a layer having an arrangement angle of ±, for example, a layer having a fiber arrangement angle of ±30°, ±45°, ±75°, or ±85° is a layer of ±θ°.

Although the sealing portion of the casing 3 is composed of five layers in this embodiment, it is not necessary to have a layered structure of more than five layers. The cylindrical part may have a layered structure of 5 or more layers.

On the cylinder portion of the shell 3, the layer 7a with a reinforced fiber spirally wound layer is arranged as the innermost layer, and the layer 8a with a reinforced fiber hoop layer is arranged on it, and then the layers with a reinforced fiber spirally wound layer are alternately arranged thereon. Layers 7b, 7c, 7d, 7e and layers 8b, 8c, 8d, 8e with reinforced fiber hoop layers. Regarding the configuration of each layer, the innermost layer may also be a layer with a reinforced fiber hoop layer, on which a layer with a reinforced fiber spiral layer is arranged, and then the hoop layer and the spiral layer are alternately arranged on it. layer.

For the hoop layer, when the axial direction of the air tank is 0°, the reinforcing fiber is actually a layer wound along the circumferential direction, and the 90° is of course hooped in the range of ±75°～±105° layer function. A spiral wrap is a wrap in a range other than a hoop wrap.

In this embodiment, as shown in FIG. 3, the layers 8a-8e of each hooped layer extend to the terminal portion of the cylindrical body of the shell 3, and the sealing portion of the shell 3 is formed by the layer 7a with the spirally wound layer. ～7e are formed by extending from the cylinder part. The layers 8a-8e of the above-mentioned hooped layers may also extend to the sealing portion.

In this embodiment, assuming that the overall thickness of the cylindrical part of the casing 3 is T (mm), and the total number of layers 7a-7e and 8a-8e constituting the casing 3 is N, then (between T and N) satisfies 0.5≤T/N≤6, in this case, the thickness of each layer is small, and the overall thickness of the case 3 can also be made small, and at the same time, a multilayer structure of 5 or more layers can be ensured.

By designing the casing 3, particularly the cylindrical body, to have such a multi-layer structure, the following operations and effects can be obtained.

First, even if local damage occurs due to a large impact force from the outside, the damage is contained in the outermost layer 8e or its adjacent layers, and the inner layer is protected so that there is no fatal damage as a whole. That is, by designing a multilayer structure, it is possible to disperse stress caused when a local impact load is applied, and prevent damage to the inner layer. The dispersion of this stress can not only prevent damage to the inner layer, but also absorb impact energy. Therefore, compared with when it is composed of a single layer or a small number of layers, the outermost layer itself is less likely to be damaged. Can also be alleviated.

In particular, as in this embodiment, the layers of the hooped layer are divided into multiple layers such as layers 8a to 8e, so that the interlayers are less prone to breakage and can maintain extremely high strength against external impact.

In addition, the above-mentioned multilayer structure increases the fiber volume content of the entire casing 3 and decreases the porosity. For example, when the shell 3 is formed by a filament winding method, the layers stacked in sequence are used to wind the next layer in turn, so the resin in the next layer is extruded sequentially to increase the fiber volume content. , and the porosity is reduced by pressing out the voids. Due to its high fiber volume content and low porosity, the overall strength of the shell 3 is greatly improved, and its quality is also greatly improved.

The casing 3 having the above five or more layers and having a T/N in the range of 0.5 to 6 can be formed, for example, by the method shown in FIG. 7 .

Figure 7 illustrates the method of forming an outer shell by filament winding on a pre-formed inner shell. The reinforcing fiber filaments 212 (such as carbon fiber filaments) pulled out from each cluster frame 211 are collected into reinforcing fiber bundles 213, and after being impregnated with resin in a resin bath (tank) 214, they are flattened with a pair of pressing rollers 215. shape, and then rolled onto the inner shell 220. By controlling the winding angle, the hoop coil layer and the spiral coil layer are sequentially formed respectively.

As mentioned above, although it is necessary to have a multilayer structure of a thin layer, the thin layer specified in the present invention, for example, as shown in FIG. 8, can use the ratio D A non-twisted reinforcing fiber bundle 216 (for example, a non-twisted carbon fiber bundle) having a /t of 5 or more is formed. In order to promote flattening, it is best to have good fiber openability, and that good fiber openability can be obtained, for example, by the method shown in Japanese Patent Publication No. 5-29688, that is, on the reinforcing fiber bundle, containing polyglycidol The surface treatment agent is mainly composed of ethers, cyclic resinous polyepoxides, or mixtures thereof, and satisfies the above-mentioned D/t condition. The surface treatment agent can be applied, for example, by using a surface treatment agent applicator as shown in FIG. 7, and dried and fixed by a drying device such as a heating plate 218, a heating roller, or a hot air drying chamber.

The reinforcing fiber bundle 216 satisfying these conditions is impregnated with a resin, shaped into a predetermined flat shape by a press roller 215, and then wound around the peripheral surface of the inner shell 220 to realize the multilayer structure of the present invention.

This method only needs to add extremely simple devices such as the surface treatment agent application device and the pressure roller 215, and mainly uses the existing filament winding device, so the desired multilayer structure can be obtained very easily and at low cost. .

In the pressure vessel of the present invention, the shell contains reinforcing fiber bundles [X], thermosetting resin [Y], synthetic resin and/or thermoplastic resin [Z] as constituent elements, and if the constituent elements [Z] Installed on the outer periphery of the component [X] that appears on the cross section of the shell, it can make the shell tough and maintain high pressure resistance, and can control the expansion of cracks or damage to the reinforcing fibers, and improve impact resistance and fatigue resistance.

In addition, in the pressure vessel of this embodiment, the outer shell of the pressure vessel can be formed using the prepreg strand. On the other hand, the prepreg contains the above-mentioned constituent elements [X], [Y], and [Z], the constituent element [Y] is impregnated on the constituent element [X], and the constituent element [Z] is present near the surface.

In this embodiment, the casing is composed of components [X], [Y], and [Z] as shown in FIG. 9 .

The number of single fibers constituting the reinforcing fiber bundle as the constituent element [X] should be in the range of 1,000 to 500,000 single fibers, more preferably 3,000 to 50,000 single fibers. In addition, in order to obtain thick fiber bundles, multiple fiber bundles can also be combined; on the contrary, in order to obtain thin fiber bundles, the thick fiber bundles can also be divided into fibers.

As the thermosetting resin of the constituent [Y], an epoxy resin is particularly exemplified, and generally a curing agent and a curing catalyst are used in combination. Among them, the epoxy resins with amino groups, phenols, and carbon-carbon double structure compounds as precursors are the best. Specifically, examples of epoxy resins having amino groups as precursors include tetra-glycidyldiaminodiphenylmethane, tris-glycidyl-p-aminophenol, tris-glycidyl-m-aminophenol , tri-glycidylmethylphenol, etc.; as the epoxy resin with phenols as precursors, biphenol A type epoxy resin, biphenol F type epoxy resin, biphenol S type epoxy resin, etc. Oxygen resin, novolac type epoxy resin, cresol novolak type epoxy resin, etc.; as the epoxy resin whose precursor is a compound containing a carbon-carbon double structure, cycloaliphatic type epoxy resin, etc. are mentioned. But not limited to these. In addition, brominated epoxy resins after bromination of these epoxy resins can also be used.

Hardeners, acid anhydrides (anhydrous toluene sic acid), amino series hardeners (methylenediamine, methyl dihydronaphthalene, ethylmethylimidazole, isophoronediamine, etc.), polyaminoamide series hardeners can be used Agents, phenol series hardeners (di-p-hydroxyphenyl sulfone), polythiol series hardeners, potential series hardeners (dicyandiamide, etc.). In addition, these curing agents can also be used in combination with boron trifluoride amine complexes or imidazole compounds, which are called curing catalysts. It can also be used in combination with the urea compound obtained by the additional reaction of isocyanate and dimethylamine

In addition, as the component [Y], maleimide resin, resin with acetylene end, resin with acid end, resin with cyanate ester, resin with vinyl end, resin with acryl end can also be used. . These resins are also suitable for use in blends with epoxy or other resins. In addition, reactive diluents can also be used by mixing modifiers such as thermoplastic resins and elastomers to such an extent that the heat resistance does not deteriorate too much.

Furthermore, as the component [Y], thermosetting resins widely known in the industry such as phenol resins, resorcinol resins, unsaturated polyethylene resins, and vinyl resins can also be used.

The component [Z] is an elastomer and/or a thermoplastic resin.

As a thermoplastic resin, representative ones are ester amide bonds, imide bonds, ester bonds, ether bonds, carbonate bonds, urethane bonds, sulfide bonds, sulfone bonds, imidazole bonds, and hydroxyl bonds. Bonded Thermoplastic Trees. Especially since polyesters, polyamides, polycarbonates, polyacetals, polyphenylene oxides, polyphenylene sulfides, polyarylates, polyesters, polyamide-imides, polyimides Amine, polyetherimide, polysulfone, polyethersulfone, polyether ether ketone, polyaramid, polybenzimidazole, polyethylene, polypropylene, cellulose acetate, good impact resistance, so suitable for As a thermoplastic tree of the present invention. Among them, polyamide, polyimide, polyamide-imide, polyetherimide, polyethersulfone, and polysulfone have high toughness and good heat resistance, and therefore are particularly suitable for the present invention. Among them, polyamide is particularly excellent in toughness and is most suitable for the present invention.

Various materials such as synthetic rubber can also be used as the elastomer, but thermoplastic elastomers are particularly suitable for the present invention. Examples of thermoplastic elastomers include thermoplastic elastomers such as polystyrene series, polyolefin series, polyester series, and polyamide series.

When epoxy resin is used as the constituent element [Y], polystyrene-based or polyolefin-based thermoplastic elastomers have low solubility in epoxy resins, while polyester-based and polyamide-based thermoplastic elastomers have the required resin solubility. Therefore, the bond between the constituent element [Y] and the constituent element [Z] has sufficient strength, and the two do not separate when stress occurs, and a good composite material can be obtained, which is very suitable.

Here, the so-called polyester-based or polyamide-based thermoplastic elastomers are block copolymer-type thermoplastic elastomers composed of a hard segment part and a soft segment part, wherein the hard segment part is Made of polyester or polyamide.

In this embodiment, the components [X], [Y], and [Z] are as shown in FIG. 9 in the cross section of the case.

That is, the outer periphery of the constituent element [X] formed of a reinforcing fiber bundle integrally formed with the constituent element [Y] is the constituent element [Z], and between adjacent constituent elements [X], it is clearly shown that actually only the Parts made of resin that do not contain reinforcing fibers.

On such a section, assuming that the length of a straight line connecting the geometric centers of two adjacent constituent elements [X] is L ₁ , the constituent elements [Z], That is, when the length of the part actually consisting of only resin is _L2 , it is hoped that its ratio _L2 / _L1 satisfies:

1/100≤L ₂ /L ₁ ≤1/2

should be:

1/50≤L ₂ /L ₁ ≤1/4

When L ₂ /L ₁ is less than 1/100, it cannot prevent cracks from expanding; and when L ₂ /L ₁ is greater than 1/2, the amount of resin increases, which increases the weight of the gas storage tank.

The part of component [X] shown in Fig. 9 is a cured product of thermosetting resin, that is, it is integrally molded with component [Y], and around the integrally formed part in this way, component [Z] is clearly shown Only the part made of resin.

In such a cross-sectional structure, since the part composed of the constituent element [Z] is composed of a resin mainly composed of elastomer and/or thermoplastic resin, it is different from the constituent element [X] and the constituent element [Y]. ] Integral molded parts compared to show high toughness. Therefore, this portion can be used to prevent the increase of cracks or the increase of damage of reinforcing fibers, thereby preventing them from expanding. In this way, it is possible to suppress the decrease in the pressure resistance and strength of the outer shell due to cracks or damage to the reinforcing fibers, and maintain good pressure resistance and strength of the entire shell.

Moreover, since the above-mentioned high-toughness portion itself has an excellent function of absorbing impact energy, the impact resistance of the outer shell is greatly improved, thereby improving the impact resistance of the pressure vessel.

Moreover, even when the same part of the shell is subjected to repeated impacts, damage to the reinforcing fibers or increase and expansion of cracks can be prevented, so fatal damage will not develop.

The outer shell 3 of the above-mentioned pressure vessel is formed around a pre-formed inner shell with gas barrier properties by, for example, filament winding with a prepreg, and the prepreg contains constituent elements [X], [ Y], [Z], impregnating the constituent element [Y] on the constituent element [X] so that the constituent element [Z] is near the surface. Here, component [Y] is a material before curing.

The prepreg constituent element [Z] should be a particle-like object made of the above-mentioned materials.

As the particle, its shape is not limited to a spherical shape. Needless to say, the spherical shape is preferable, but it is also possible to use fine powders obtained by pulverizing resin lumps, or various materials such as fine particles obtained by spray drying or reprecipitation methods. In addition, soft fibers, as well as acicular and single crystal fibers can also be used. Especially when spherical particles are used, products obtained by suspension polymerization can be used as they are.

The particle size is represented by a particle diameter, and the particle diameter in this case is a volume average particle diameter obtained by a centrifugal sedimentation velocity method or the like.

The particle size of the particles used in the present invention is suitably in the range of 2 μm to 150 μm, more preferably in the range of 5 μm to 100 μm. When the particle size is smaller than 2 μm, the particles are arranged on the outer periphery of the reinforcing fiber bundle. At this time, the particles also penetrate into the gaps between the single fibers of the reinforcing fiber together with the component [Y]. Therefore, the particles do not exist only on the surface of the prepreg strand. When it is more than 2 μm, the matrix resin containing particles penetrates into the reinforcing fiber bundle. At this time, the particles are discharged from the gaps between the single fibers of the reinforcing fibers, that is, they are filtered by the reinforcing fibers, so they only exist on the surface of the prepreg strand superior.

However, when the shape of the particles has a large degree of anisotropy such as soft fibers, needles, and single crystal fibers, even if the particle size is small, it is difficult to penetrate between the filaments, and there is a possibility of being excluded on the surface of the prepreg strand. tendency. In addition, even if the particle size is smaller than 2 μm, since the component [Y] is mixed with the component [Y], the component [Y] immerses in the particle and expands, and the particle size of the outer shape becomes larger. At this time, the above-mentioned particle size concept is applicable to shape of the particle size.

When the particle size exceeds 150 μm, the arrangement of the reinforcing fibers is disordered, and the distance between the fiber bundles or the interlayer thickness on the molded FRP shell becomes more than necessary, so the physical properties of the FRP shell may be degraded. However, even if the particles have a particle size exceeding 150 μm, there are materials in which the particles of the material become small due to partial dissolution in the constituent element [Y] during molding, or are deformed by heating during molding, and the filaments may be separated from each other. The material between the layers of the FRP shell is narrower than that before forming, which is also suitable for this case.

In addition, the optimum value of the particle size may vary depending on the outer diameter of the reinforcing fiber single fiber or the number of single fibers to be used.

In addition, a fibrous material can also be used as the constituent element [Z]. The fibers may be long fibers or short fibers. Here, the long fiber refers to a fiber having a length of 5 cm or more, and the short fiber refers to a fiber having a length of 5 cm or less. When the constituent element [Z] is a fiber, if the single fiber fineness is too large, the distance between the fiber bundles on the FRP shell or the part without the constituent element [X] between layers will have unnecessary thickness, reinforcing fiber Disorder in the arrangement of [X] may degrade the physical properties of the molded article, so it should be 15 denier or less, preferably 5 denier or less.

In addition, when the constituent element [Z] is a fiber, the degree of crystallinity of the fiber should be 40% or more due to operations such as stretching. When the degree of crystallinity is low, heat and humidity resistance may be lowered.

As for the component [Z], it is fine to maintain the original shape after molding, and it does not matter if the shape disappears.

The prepreg strands in this embodiment preferably have a flat longitudinal cross-section, so that a cross-sectional structure as shown in Figure 9 can be easily obtained, and a shell with a small thickness that meets the requirements of light weight can be easily obtained. . In such a flat cross-sectional shape, the length of the long axis is preferably not less than 2 mm and not more than 5 mm.

In the pressure vessel casing of the present embodiment, the component [Z] is preferably in the matrix resin surrounding the clustered component [X]. If such conditions are not satisfied, for example, there are a large number of constituent elements [Z] deep inside the constituent element [X], at this time, the energy absorption in the boundary area is insufficient, and the impact resistance and durability of the FRP constituting the casing The effect of improving the fracture toughness is not obvious, and the arrangement of the reinforcing fibers is disordered, and the distribution rate of the matrix resin near the reinforcing fibers is reduced, which may impair the strength and heat resistance.

From this point of view, the distribution of the component [Z] in the prepreg before molding is preferably such that most of the component [Z] is distributed near the surface of the prepreg. When the casing is formed from such prepreg strands, since the constituent element [Z] exists in the region between the prepreg strands, FRP with good impact resistance can be obtained. Here, distribution near the surface specifically means that 90% or more of the constituent element [Z] is distributed from the outer peripheral surface of the prepreg to 30% of the minimum thickness of the prepreg. When 90% or more of the component [Z] is distributed from the outer peripheral surface of the prepreg to 30% of the minimum thickness of the prepreg, the effect of the present invention is more remarkable, so it is more preferable.

Using such a prepreg strand, the shell of the pressure vessel according to the present invention can be formed, for example, by the method shown in FIG. 10 .

In the method shown in FIG. 10 , the reinforcing fiber filaments 312 drawn out from a plurality of cluster racks 311 are assembled into a reinforcing fiber bundle 313, and the reinforcing fiber bundle 313 passes through a first resin bath 314 and is impregnated with a thermosetting resin. Consists of matrix resin 315 . The resin-impregnated reinforcing fiber bundle 316 then passes through the tank 318 containing the particulate or powdery constituent [Z] 317, and the resin-impregnated reinforcing fiber bundle 316 is mainly attached to the constituent [Z] 317 near the surface. Then, the reinforcing fiber bundle 319 to which the constituent element [Z] 317 is attached passes through the second resin bath 320, and the matrix resin 321 made of a thermosetting resin adheres to the surface or penetrates from the surface. In addition, the second resin bath 320 may be omitted.

The resin-impregnated reinforcing fiber bundle 322 that comes out of the second resin bath 320 and has the constituent element [Z] attached near the surface is wound around the inner shell 2 at a predetermined winding angle by a filament winding method to form the outer shell 302. . After winding, the resin is heated and cured to form the desired shell 302 .

In such a manufacturing method, since the second resin bath 320 can be omitted, in fact, it is only necessary to add an attachment device for the component [Z] on the conventional filament winding device, and it can be formed in a simple and low-cost The casing with excellent pressure resistance is aimed at.

In addition, in the pressure vessel of the present invention, when the innermost layer of the shell shoulder portion is a hoop wrap layer with reinforcing fibers, the pressure resistance of the shoulder portion can be sufficiently improved.

This pressure vessel can be manufactured by such a method: on the outer peripheral surface of the shoulder portion of the inner shell with gas barrier properties, a reinforcing layer composed of reinforcing fiber and resin is arranged with a hoop layer of reinforcing fiber, and on the reinforcing layer And around the inner shell, a pressure-resistant FRP shell is formed.

On this type of pressure vessel, the shoulder of the outer shell is provided with an innermost layer with a hoop wrap of reinforcing fibers which function as a reinforcing layer. The innermost layer, which is the reinforcement layer, can be formed by filament winding or by disposing a unidirectional prepreg. Especially when forming by the filament winding method, if the outer peripheral surface of the shoulder portion of the inner shell is formed in a stepped shape extending in the circumferential direction and having a step in the axial direction, it is possible to prevent the reinforcing fiber filaments from being entangled in the circumferential direction. , or resin-impregnated reinforced filament sliding.

As shown in Fig. 11, the innermost layer 9a of the shoulder 3a of the shell 3 forms a layer with a hoop wrap of reinforced fibers. In this embodiment, the innermost layer 9a is composed of an FRP layer formed by a filament winding method. In this embodiment, since the reinforcing layer E is provided on the outer periphery of the cylindrical portion of the inner casing 2, the innermost layer 9a is formed just from the end of the reinforcing layer E to the middle of the sealing portion B. The hoop layer of the innermost layer 9a may be formed as an extension layer when forming the reinforcement layer E by the filament winding method, or may be formed alone. The innermost layer 9a also functions as a shoulder reinforcement layer, that is, a reinforcement layer that exhibits high tensile strength in the circumferential direction and high pressure resistance against radial internal pressure.

In this embodiment, a stepped portion 10a extending in the circumferential direction and having steps in the axial direction is formed on the outer peripheral surface of the shoulder of the inner casing 2 . The stepped portion 10a may be formed at a position corresponding to the innermost layer 9a. For the step a and the width b of each step shape, for example, a is suitably in the range of 0.5-2 mm, and b is suitably in the range of 1-5 mm.

By designing such a stepped portion 10a, when the innermost layer 9a is formed by the filament winding method, it is possible to prevent the reinforcing fiber yarn or the resin-impregnated reinforcing fiber yarn from slipping, so that the desired hoop-wound layer can be precisely positioned at the desired location. The desired position is formed. On the upper surface of the innermost layer 9a, other parts of the housing 3 are formed except the innermost layer 9a. This casing 3 is also desirably formed of FRP.

In the present embodiment, the shoulder 3b on the side of the boss 6 has substantially the same configuration. That is, as shown in FIG. 12, the layer 9b with the hoop layer of reinforced fiber is designed as the innermost layer 9b of the shell 3 on which other parts of the shell 3 are formed. On the shoulder of the inner case 2 is formed the same stepped portion 10b as above.

In the method for manufacturing a pressure vessel according to this embodiment, for example, when the inner shell 2 is made of plastic, first, when the inner shell 2 is blow-molded, the molded inner shell 2 and the joint 6 are integrated. . After the inner shell 2 is formed, the outer shell 3 with pressure resistance is formed to wrap the inner shell 2; but first, the innermost layers 9a, 9b as shoulder reinforcement layers must be formed, or the cylinder portion reinforcement layer should be formed on them e. The innermost layers 9a, 9b can be formed by using the inner shell 2 as the core, that is, by filament winding or tape winding. Especially when forming by the filament winding method, the stepped parts 10a, 10b provided on the outer peripheral surface of the shoulder of the inner shell 2 can be used to prevent the rolled-up reinforcing fiber filaments or resin-impregnated reinforcing fiber filaments from slipping. .

After the innermost layers 9a, 9b have been formed, the remainder of the housing 3 is formed. In the case where the case 3 is made of FRP, the remaining portion can also be formed by a filament winding method or a tape winding method.

The outer casing 3 formed in this way, on its shoulder, because its innermost layer is made of a layer with a reinforced fiber hoop layer, so the high tension in the circumferential direction can be effectively exerted on the shoulder, and can effectively The pressure resistance against radial internal pressure is greatly improved.

Figure 13 shows another embodiment. In addition, only the shoulder on the joint 4 side is shown in FIG. 13 , and the shoulder on the boss 6 side also adopts the same structure. In this embodiment, the innermost layer 9c of the shoulder of the shell 3 is formed of a unidirectional preform, that is, the unidirectional preform is arranged at a predetermined position of the shoulder, and the arrangement direction of the reinforcing fiber filaments is aligned with the circumferential direction. Consistently, in the temporarily fixed state, the remaining part of the shell 3 is formed on it. Since the pre-formed cover-shaped unidirectional preform is arranged, it is not necessary to have an inner shell as shown in Figure 11 or Figure 12. The stepped portion of the shell shoulder. Even with such a configuration, since the innermost layer 9c has a reinforced fiber hoop wrap, the pressure resistance against the radial internal pressure of the shoulder of the outer casing 3 and even the shoulder of the pressure vessel can be effectively improved. Furthermore, since only the preformed unidirectional prepreg can be arranged at a predetermined position, it can be easily formed as a whole of the housing.

On the pressure vessel of the present invention, a nozzle installation joint installed on the head of the inner shell is provided, and a sealing ring is embedded in the nozzle installation joint on the end face of the head, and the sealing ring is provided The airtightness of the junction between the inner case and the nozzle attachment joint can be sufficiently improved when the press-fitting device is press-fitted toward the end face of the head.

Such a pressure vessel can be manufactured by combining a gas-barrier inner shell and a mouth fitting, forming a pressure-resistant outer shell around the inner shell, and forming a pressure-resistant outer shell in the inner shell before forming the outer shell. A sealing ring is embedded on the joint of the end face of the shell head, and a pressing device is provided to press the sealing ring in the direction of the end face of the head, and the sealing ring is elastically deformed by using the pressing device, and the deformed The sealing ring is tightly connected with at least the end surface of the head and the outer peripheral surface of the joint.

In this embodiment, as shown in FIG. 14, the joint 4 is provided with a joint 4a, and the joint 4a expands toward its axial bottom into a trumpet shape; the head 2a of the inner shell 2 extends from the joint 4a to the joint 4 peripheral part. The inner peripheral surface of the inner shell 2 including the head portion 2 a is joined to the outer peripheral surface of the joint 4 . When the joint 4 is made of metal, for example, and the inner shell 2 is made of plastic, for example, the joint 4 and the inner shell 2 can be combined into one body when the inner shell 2 is blow-molded.

On the inner side of the joint 4, a gas passage is formed, and a nozzle connection screw 4c is formed; on the outer peripheral surface of the joint 4, a ring-shaped protrusion 4d is formed.

The joint surface 15 between the joint 4 and the inner casing 2, more specifically, is the joint surface between the outer peripheral surface of the joint 4a of the joint 4a and the inner peripheral surface of the head portion 2a of the inner casing 2, and is a surface that combines both surfaces into one body. , Therefore, it has a fairly high airtightness. However, when airtightness is required to withstand high-pressure gas exceeding 200kg/cm2, such as a CNG storage tank mounted on a car, the internal gas may leak from the joint surface.

This implementation form can effectively prevent gas from leaking out from the joint surface.

On the end face of the inner shell 2, more precisely the end face (upper end face) 2b of the head portion 2a of the inner shell 2, and on the outer periphery of the joint 4, a sealing ring 11 elastically deformed after being pressurized is arranged. The material of the seal ring 11 can be, for example, resins such as natural rubber, silicone rubber, fluororubber, ethylene fluoride, polyamide, polyethylene, polyester, etc., and metals such as stainless steel, aluminum, copper, titanium, etc. can also be used.

The cross-sectional shape (cross-sectional shape in the thickness direction) of the seal ring 11 may be a solid circular shape as shown in FIG. 18 , a hollow circular shape as shown in FIG. 19 , or a flat plate shape as shown in FIG. 20 . With the embodiment shown in FIG. 14, a synthetic rubber O-ring having a hollow circular shape as shown in FIG. 19 can be used as the seal ring 11. As shown in FIG.

A pressing member 12 is disposed adjacent to the sealing ring 11, and the pressing member 12 constitutes a part of a pressing device for pressing the sealing ring 11 toward the end surface 2b of the inner housing 2. In this embodiment, the pressing member 12 is located on the radially outer side of the sealing ring 11,

It is composed of a cylindrical portion 12a that extends to the outer periphery of the head portion 2a of the inner housing 2 and fits thereon, and an edge portion 12b into which the seal ring 11 is directly pressed.

A seat 13 is provided on the edge portion 12b of the pressing member 12, on which a connecting member 14 (for example, a connecting nut) is arranged,

The connecting piece 14 is screwed on the outer periphery of the joint 4, and the pressing piece 12 is moved to the sealing ring pressing direction through the seat 13. The above-mentioned seat 13 may also have a sealing function to prevent the intrusion of foreign matter from the outside and the leakage of gas inside.

In the above-mentioned gas sealing mechanism, for example, when the inner shell 2 is made of plastic and the joint 4 is made of metal, when the inner shell 2 is blow-molded, the formed inner shell 2 and the joint 4 can be combined into a In one piece, a predetermined seal is performed before the casing 3 is formed.

A sealing ring 11 is arranged on the end surface of the inner shell 2 and the outer periphery of the joint 4 , and a pressing member 12 is covered thereon. After the seat 13 is configured, the connecting piece 14 is installed, and the sealing ring 11 is pressed into the sealing ring 11 through the seat 13 and the edge 12b of the pressing piece 12 to make it elastically deformed. Through such compression and elastic deformation, the sealing ring 11 is tightly bonded to the end surface 2b of the inner shell 2 and the edge 12b of the pressing member 12, and these surfaces are sealed with the sealing ring 11. At the same time, since the sealing ring 11 is Elastic deformation also occurs in the radial direction, so it is also tightly bonded to the outer peripheral surface of the joint 4 to seal between the outer peripheral surface and the seal ring 11 . After the set installation is completed, the casing 3 made of FRP is formed by a well-known filament winding method or long tape winding method, and the casing 3 is formed to a position covering the outer peripheral surface of the pressing member 12 .

After sealing as described above, even if the gas in the gas storage tank may leak from the joint surface 15, the leaked gas should first pass between the sealing ring 11 and the end face 2b of the inner shell 2 and between the sealing ring 11 and the joint 4 Between the outer peripheral surfaces, since these parts are sealed as described above, gas leakage can be completely prevented in fact.

Such gas sealing is particularly effective between the sealing ring 11 and the end face 2b of the inner shell 2 and between the sealing ring 11 and the outer peripheral surface of the joint 4, so the shape of the pressing member 21 may not be provided with the cylindrical portion 12a, Can be in the shape of a circular plate. However, from the viewpoint of limiting the amount of deformation of the sealing ring 11 radially outward, making the sealing force between the sealing ring 11 and the outer peripheral surface of the joint 4 stronger, and that the pressing member can be strongly fixed by the housing 3 after the housing 3 is formed, It is preferable to use a pressing member provided with a cylindrical portion 12a as in this embodiment.

Here, when the cylindrical portion 12a is designed in a stepped shape as shown in FIG. 21, when the pressing member 12 is mounted with the mounting member 14, the required compression amount M of the seal ring can be easily and reliably ensured.

In order to further improve the sealing strength of the sealing surface, for example, as shown in FIG. 15 , an annularly extending groove 2c can be designed on the end surface 2b of the head portion 2a of the inner shell 2, and the compressed and deformed sealing ring 11 can be inserted into the groove 2c. middle. Such an annular groove may also be provided on the lower surface of the edge portion 12b of the pressing member 12. As shown in FIG. The cross-sectional shape of the groove is not particularly limited, but an arc-shaped groove as shown in the figure is suitable for enhancing the sealing performance.

Fig. 16 and Fig. 17 show yet another form of the gas-tight structure of the junction between the inner shell of the pressure vessel and the joint in this embodiment.

In the embodiment shown in Figure 16, the connecting piece 14 as shown in Figure 14 is not designed, but a thread is designed on the inner peripheral surface of the edge 21a of the pressing piece 21, and the pressing piece 21 is directly threaded on the On the thread on the outer peripheral surface of the joint 22. In such a configuration, which is also the same as shown in FIG. 14 , the sealing ring 11 is compressed and deformed elastically, so that the gas that may leak from the joint surface 15 of the inner shell 2 and the joint 22 is completely sealed.

In addition, in the embodiment shown in FIG. 16 , the housing 23 is preferably formed to cover the entire pressing member 21 . In this way, the fixing strength of the pressing member 21 can be further increased, and the rotation of the pressing member 21 can also be completely prevented.

In the embodiment shown in Figure 17, threads are provided on the outer peripheral surface of the head portion 31a of the inner shell 31, and threads are also provided on the inner peripheral surface of the cylindrical portion 32a of the pressing member 32, so that the pressing member 32 is screwed together. on the periphery of the head 31a. The sealing ring 11 is pressed between the edge portion 32b of the pressing member 32 and the end surface of the head portion 31a of the inner casing 31 to generate elastic deformation. Even in such a configuration, the gas that may leak from the joint surface 15 between the inner case 31 and the joint 33 is completely sealed by the arrangement portion of the seal ring 11 . Also, in such a case, the housing 34 is preferably formed to completely cover the pressing member 32 .

Moreover, if the sealing mechanism using the sealing ring in this embodiment is adopted, the gas-tight performance of the joint portion of the inner shell and the joint can be fully maintained, but in order to be safer, it is preferable to seal the seal on each sealing surface, such as the above-mentioned pressing member. Adhesive is applied between the inner peripheral surface and the outer peripheral surface of the mouth of the inner case, and between the sealing ring and the surface that is pressed into the sealing ring, so as to enhance the sealing performance. Such adhesives include thermosetting adhesives such as epoxy series, acrylic series, polyurethane series and polyester series, among which anaerobic adhesives which are reactive acrylic series adhesives are most preferable. Such anaerobic adhesives include polyether type and fat type, the representative of polyether type is tetraethylene glycol dimethacrylate, the representative of fat type is trimethylolpropane trimethacrylate, butanediol 1, 4-dimethacrylate, 2,2,4-trimethyl-1,3-pentanediol dimethacrylate, polyester acrylate, etc.

In addition, the pressure vessel of the present invention is constituted by providing a nozzle attachment joint installed in the head portion of the inner shell, and when the joint surface of the head portion of the nozzle attachment joint is concave-convex, the pressure can be improved sufficiently. The airtightness of the joint between the inner shell and the nozzle installation joint.

Alternatively, the pressure vessel of the present invention is configured such that a nozzle attachment fitting is installed in the head portion of the inner shell, and a ridge extending in the circumferential direction is formed on a joint surface of the head portion of the nozzle attachment fitting. In this case, the airtightness of the junction between the inner case and the nozzle mounting joint can be sufficiently improved.

For such a pressure vessel, for example, when forming a specific air-tight inner shell, the head of the inner shell is integrated with the outer peripheral surface of the nozzle installation joint, and the above-mentioned joint coupled to the head is used as the rotation axis, which can The outer shell is formed while rotating the formed outer shell, and the inner shell is covered.

In this embodiment, as shown in FIG. 22, the joint 4 is provided with a joint 4a, and the joint 4a expands toward its axial bottom into a trumpet shape; the head 2a of the inner shell 2 extends from the joint 4a to the joint 4 peripheral part. The inner peripheral surface of the inner shell 2 including the head portion 2 a is joined to the outer peripheral surface of the joint 4 . When the joint 4 is made of metal, for example, and the inner shell 2 is made of plastic, for example, the joint 4 and the inner shell 2 can be combined into one body when the inner shell 2 is blow-molded. On the inner side of the joint 4, a gas passage is formed, and at the same time, a thread 4c for connecting a nozzle is formed. Although the material of the joint 4 is not particularly limited, it is preferable to use metal products such as iron, aluminum, stainless steel, and titanium in terms of twisting the nozzle 7 .

The joint surface 15 on the outer peripheral surface of the joint 4 and the inner shell 2, more specifically, is the joint surface on the outer circumferential surface of the joint cylindrical portion 4d and the inner circumferential surface of the head portion 2a of the inner shell 2, along the joint cylindrical portion 4d. Concavities and convexities 41 are formed on the entire peripheral surface. The unevenness 41 is formed substantially along the entire length in the axial direction of the joint cylindrical portion 4d such that both ends of the cylindrical portion 4d are slightly exposed.

In this embodiment, the unevenness 41 is formed by processing with a knurl 41a as shown in FIG. 23 . However, the unevenness is not limited to the knurling process, but at least the outer peripheral surface of the joint cylindrical portion 4d has unevenness in the circumferential direction, preferably also in the axial direction. Therefore, it is also possible to adopt a plurality of grooves or hollow groove shapes 41b extending in the axial direction as shown in FIG. 24, a plurality of spline shapes 41c extending in the axial direction as shown in FIG. As shown in FIG. 26 , a plurality of protrusion shapes 41 d having a substantially flat front end are provided, and a plurality of protrusion shapes 41 e having a spherical front end are provided as shown in FIG. 27 .

Through the design of such concavo-convex 41 , especially when the joint 4 and the inner shell 2 are subjected to a counter-rotational torque, there will be no rotation between the two due to the large resistance. That is, when such a torque is applied, loosening of the joint 4 relative to the inner casing 2 in the circumferential direction can be reliably prevented.

In addition, when the unevenness 41 has a shape as shown in Fig. 23, Fig. 26, and Fig. 27, it has a large resistance to the above-mentioned torque, and also has a large resistance to the axial thrust in the axial direction of the joint 4, Therefore, when the joint 4 is subjected to an axial external force, the relative axial displacement of the joint 4 relative to the inner shell 2 can be reliably prevented. For example, when the joint 4 is subjected to the impact force from above in FIG. 22 , the joint 4 will not be pulled out from the head 2 a of the inner shell 2 downward.

Of course, the concavo-convex shape shown in Fig. 24 and Fig. 25 increases the joint area with the inner casing 2, so the resistance to the external force in the direction of the axial force as described above also increases.

In this way, the bonding strength of the joint 4 to the inner case 2 is remarkably improved by the formation of the unevenness 41 . The improvement of the bonding strength is firstly effective when the case 3 is molded.

That is, the pressure vessel of this embodiment can be manufactured as follows: for example, when the inner shell 2 is made of plastic and the joint 4 is made of metal, first, when the inner shell 2 is blow-molded, the formed inner shell 2 can be combined with Joint 4 is integrated into one body. Since the concavo-convex 41 is formed on the outer peripheral surface of the joint 4, in the state where the inner shell 2 and the joint 4 are integrated, the joint 4 has a high bonding strength relative to the inner shell 2, especially in the circumferential direction, and at the same time, it also improves the joint strength. The bonding strength between the two in the axial direction (that is, the direction in which the joint 4 is subjected to axial thrust).

In this state, an outer shell 3 covering the inner shell 2 and having pressure resistance is formed on the inner shell 2 . When the outer shell 3 is formed of FRP, the inner shell 2 is used as a core, a so-called mandrel, and the outer shell 3 is formed by a filament winding method or a tape winding method. At this time, while rotating the inner shell 2, the reinforcing fiber yarn wrap layer containing the above-mentioned resin is formed, but in order to rotate the inner shell 2, the joint 4 can be used as a rotating shaft (rotating shaft body). For example, in the structure shown in Figure 1, the boss 6 on the bottom side is clamped to make it rotate, and on the joint 4 side, the tool is screwed into the threaded hole 4c for nozzle installation, so that the inner shell 2 can be easily The two ends of the structure are supported by rotating shafts.

When performing such a turning action, the coupling surface 15 of the joint 4 and the inner shell 2 is subjected to a large reverse torque and an axial thrust in the direction of pulling the joint 4 into the air storage tank.

However, in this embodiment, due to the formation of the concave-convex 41 as mentioned above, the bonding strength on the bonding surface of the joint 4 and the inner shell 2 is significantly improved in both the torque direction and the axial thrust direction. Effectively prevent the joint 4 from being loosened and pulled out relative to the inner shell 2 (or, to be displaced in the direction of pulling out).

In addition, the improvement of the above-mentioned bonding strength can also play a role after the pressure vessel is completed. Especially when subjected to an external force in the axial thrust direction or an impact external force, it can effectively prevent the joint 4 from being pulled out from the inner shell 2 or be axially displaced relative to the inner shell 2 .

Fig. 28 is a schematic diagram showing the structure of the peripheral part of the joint of the pressure vessel in another embodiment of the present invention.

In this embodiment, the joint 51 is constituted by a member provided with a joint cylindrical portion 51a and a connecting portion 51b, wherein the connecting portion 51b is provided at the lower end of the joint cylindrical portion 51a and has a flared diameter. On the joint surface 53 between the outer peripheral surface of the joint cylindrical portion 51a and the inner case 52, there is formed a protrusion 54 extending in the circumferential direction and covering the entire circumference in the present embodiment. This protrusion 54 is formed on the outer peripheral surface of the joint cylindrical portion 51 a, and is clearly distinguished from the edge-shaped joint portion 51 b formed on the lower end portion of the joint 51 .

Such protrusions 54 can greatly improve the bonding strength between the joint 51 and the inner shell 52 , especially the bonding strength relative to the axial thrust applied to the joint 51 . Therefore, it is possible to reliably prevent the joint 51 from moving or falling off in the direction of pulling out of the gas tank due to the thrust force during the forming of the shell or the impact thrust applied to the joint 51 after the pressure vessel is completed.

Certainly, because the protruding strip 54 is designed, the joint area between the joint 51 and the inner shell 52 is enlarged, so the bonding strength for preventing the joint 51 from loosening in the circumferential direction is also improved.

The protrusions extend in the circumferential direction, and may be formed as two (protrusions 61a, 61b) as shown in FIG. 29, or three or more. As the number increases, the bonding strength between the inner shell 62 and the joint 61 tends to increase.

In addition, the configurations shown in FIG. 22 or FIG. 28 can also be used in any combination.

For example, as shown in FIG. 30, protrusions 72 extending in the circumferential direction may be formed on the lower portion of the outer peripheral surface of the cylindrical portion 71a of the joint 71, and unevenness 73 (for example, knurled as shown in FIG. 23 ) may be formed on the upper portion thereof. Bump).

In this way, by combining the protruding strip 72 and the concave-convex 73 together, the resistance against the axial thrust is mainly generated on the protruding strip 72, and the resistance mainly preventing the movement in the circumferential direction is generated on the concave-convex 73. There is also extreme strength in moving and loosening. That is, the bonding strength between the inner case 74 and the joint 71 in all directions can be significantly improved.

In addition, the joint structure provided with concavo-convex and protrusions in the present invention can also exert functions and effects other than those described above by utilizing the combined structure of the inner shell and the joint.

For example, in the structure shown in Figure 31, in order to completely prevent gas from leaking from the joint surface of the joint 81 and the inner shell 82, an elastically deformable sealing ring 83 is arranged on the end face of the inner shell 82, and it is fixed by a pressing member 84. Use connecting piece 85 (such as connecting nut) to install and connect, make it elastically deformed by compression, and be tightly connected to the outer peripheral surface of joint 81 and the end surface of inner shell 82, etc., so that these parts can be completely sealed.

In such a structure, by forming the concave-convex 86 and/or the protrusion 87 on the outer circumference of the cylindrical part of the joint 81, the above-mentioned bonding strength can be significantly improved. Looseness due to co-rotation, etc.

And, in the structure shown in Figure 31, when also wanting to improve the fixing strength of connector 85, or when wanting to further improve the gas sealing function at the same time, also can be between the inner peripheral surface of pressing member 84 and the outer peripheral surface of inner case 82. Between, and by sealing ring 83 sealing surface smear adhesive. As the adhesive, the aforementioned products can be used.

Furthermore, in the pressure vessel of the present invention, it is constructed that a nozzle mounting joint is installed in the head of the inner shell, and a cylindrical member is provided on the outside of the head, and the cylindrical member is provided with a rim and is connected to the The cylindrical portion on the edge portion and the flange portion extending from the outer peripheral surface of the cylindrical portion into the outer shell can also sufficiently improve the gas-tight shape of the junction between the inner shell and the nozzle mounting joint.

In this embodiment, as shown in FIG. 32 , the joint 4 is provided with a joint 4a, and the joint 4a expands toward its axial bottom into a trumpet shape; the head 92a of the inner shell 92 extends from the joint 4a to the joint 4 peripheral part. The inner peripheral surface of the inner shell 92 including the head portion 92 a is integrated with the outer peripheral surface of the joint 4 . When the joint 4 is made of metal, for example, and the inner shell 92 is made of plastic, for example, the joint 4 and the inner shell 92 can be combined into one body when the inner shell 92 is blow-molded. On the inner side of the joint 4, a nozzle connection thread 4c may be formed simultaneously with the formation of the gas passage 4b. And on the outer peripheral surface of the joint 4, a protrusion 4d extending in a ring shape is formed.

Although the material of the joint 4 is not particularly limited, since the nozzle 5 is to be screwed on, it is preferable to use metal products such as iron, aluminum, stainless steel, and titanium.

On the outer peripheral side of the head 4 and the outer side of the head 92a of the inner shell 92, a cylindrical member 90 is provided. A cylindrical portion 90b covering the outer periphery of the cylindrical portion 92a and an annular flange portion 90c extending into the housing 3 from the outer peripheral surface of the cylindrical portion 90b are constituted. In this embodiment, the flange portion 90c is vertically erected from the outer peripheral surface of the cylindrical portion 90b, but it may be slightly inclined to any one of the vertical directions in FIG. 32 . In addition, the shape of the front end of the flange portion 90c may be sharp, spherical, or the like in addition to the flat shape as shown in the figure. In addition, although in this embodiment, the flange portion 90c extends continuously in a ring shape in the entire circumferential direction, it may also be arranged intermittently in the circumferential direction, that is, it may also be arranged in a plurality of circular arcs in the circumferential direction. The construction form of an extended protrusion-like nosing.

On the axially outer side of the edge portion 90a of the cylindrical member 90, a connecting member 91 (such as a connecting nut) screwed on the outer peripheral surface of the joint 4 is provided. With this connection of the connecting piece 91, the edge portion 90a of the cylindrical member 90 is press-fixed between the connecting piece 91 and the end surface of the inner housing head portion 92a. Therefore, the edge portion 90 a of the fixed cylindrical member 90 is actually joined to the outer peripheral surface of the joint 6 by the connecting piece 91 screwed on the joint 4 .

In the manufacture of the pressure vessel as described above, for example, when the inner shell 92 is made of plastic and the joint 4 is made of metal, when the inner shell 92 is blow-molded, the formed inner shell 92 can be combined with the joint 4 After being integrally formed and blow-molded, the cylindrical member 90 is mounted on the head portion 92a of the shell 92, and the cylindrical member 90 is fixed at a predetermined position by installing the connector 91 thereon. In this state, the outer shell 3 is formed by using the nozzle mounting joint 4 and the boss 6 on the bottom side as a rotation axis, and the inner shell 92 as a core, and the outer shell 3 wraps the inner shell 92 . The outer shell 3 can be formed around the inner shell 92 by a filament winding method or a tape winding method. At this time, the casing 3 is formed by embedding at least the flange portion 90 c of the cylindrical member 90 in the casing 3 .

In the pressure vessel constructed as above, when the joint 4 is subjected to a load from the outside, such as impact force, etc., the load is of course applied to the joint surface between the joint 4 and the inner shell head 92a, and is screwed together. The connecting piece 91 on the joint 4 is added to the cylindrical member 90 . Because the flange portion 90c of the cylindrical member 90 is embedded in the casing 3, and the casing 3 is made of a pressure-resistant material, under the cooperation of the casing 3 and the cylindrical member 90, most of the above-mentioned load is caused by The cylindrical member 90 receives it. That is, the cylindrical member 90 functions as a pillar. As a result, the load component applied to the joint 4 itself is greatly reduced, and it is possible to reliably prevent the joint 4 from coming off from the head portion 92a of the inner case 92 toward the inside of the gas tank. That is, the bonding strength between the joint 4 and the inner case 92 is greatly improved.

In the embodiment shown in Figure 33, in order to improve the airtightness of the joint between the joint 4 and the inner shell 92, the end surface of the head 92a of the inner shell 92 and the outer peripheral surface of the joint will be embedded due to pressure. The elastically deformable annular seal ring 11 described above. In such a configuration, since the flange portion 90c of the cylindrical member 90 is fixedly supported by the housing 3, most of the external load applied to the joint 4 is received by the cylindrical member 90 through the connector 91. Therefore, it is possible to reliably prevent the connector 4 from coming off.

Figure 34 shows yet another embodiment. In this embodiment, the cylindrical member 95 is provided with an edge portion 95a, a cylindrical portion 95b, and a flange portion 95c, and the inner peripheral surface of the cylindrical member 95 edge portion 95a is directly threaded. On the outer peripheral surface of the joint 4. Therefore, there is no need to design the connecting piece 91 as shown in FIG. 33 . Other configurations are the same as those shown in FIG. 33 . However, in this embodiment, it is preferable that the casing 3 is formed up to a portion that completely covers the cylindrical member 95 .

In such a configuration, since the flange portion 95c of the cylindrical member 95 is fixedly supported by the housing 3, most of the external load applied to the joint 4 is also directly received by the cylindrical member 95. Pulling out of the connector 4 and the like can be reliably prevented. Moreover, the bonding strength between the inner casing and the cylindrical member is also improved. In order to further increase the fixing strength of the cylindrical member, it is also possible to press the sealing ring between the cylindrical member and the outer peripheral surface of the head of the inner casing, and between the sealing ring and the sealing ring. Applying adhesive between the attached surfaces can also increase the joint strength. As the adhesive, the aforementioned products can be used.

On the other hand, the pressure vessel of the present invention has a structure in which a nozzle mounting joint is installed in the head portion of the inner shell, and the outer diameter of the flange portion of the nozzle mounting joint is larger than the outer diameter of the nozzle mounting joint cylindrical portion. The diameter is 20mm-25mm larger, and the contact surface between the outer diameter of the nozzle installation joint and the inner shell head is designed to be tapered. In this case, the joint part of the inner shell and the nozzle installation joint can also be fully improved air tightness.

That is, by designing the joint for installing the nozzle into a shape as shown in Fig. 35, the joint is pressed against the inner shell by the action of pressure on the inner shell, thereby tightening the joint and preventing gas leakage in the pressure vessel. Example Example 1

A blow-molded high-density polyethylene resin inner shell (outer diameter: 200mm, total length excluding the nozzle mounting part: 1,000mm, wall thickness: 2mm) is used as a so-called mandrel, and a filament is wound on the inner shell. The wrapping method forms the shell. When using the filament winding method, carbon fiber filaments (single fiber diameter: 7μm, number of single fibers: 12,00, tensile strength: 4.6) impregnated with epoxy resin (tensile breaking strain: 4%) Gpa, tensile strain at break: 2.2%), relative to the axial direction of the pressure vessel, layers of ±3°, layers of 88°, layers of ±45°, layers of ±3°, layers of 88°, layers of ±45° are sequentially formed The volume ratio of the carbon fiber filaments in the layer of ° was 1:2:2, wound up, and heated in an oven at 130° C. for 6 hours to make the main body of the pressure vessel. The shell thus obtained was measured by the Nourling test method as a tensile elastic modulus of 47 GPa and a tensile breaking strain of 2.0%. The outer diameter of the main body is 216 mm, and the volume is about 30 liters. In addition, the tensile elastic modulus and the tensile breaking strain were measured by the Nourling test method on a sample cut out from the cylindrical portion of the pressure vessel in a ring.

Then, with a drop weight testing machine, a hammer with a curvature radius of 8 mm and a weight of 2 kg at the front end of the head hits the same part of the center of the body 50 times at a speed of 2 m/sec, and then uses an ultrasonic flaw detector to measure the damage area (in The projected area in the vertical direction) was 1.0 cm ² . Furthermore, the withstand voltage ratio before and after the pressurization test using water as a pressurization source was 1.00, and it can be considered that the withstand voltage performance did not decrease after repeated impacts. Comparative example 1

A body was obtained in the same manner as in Example 1, except that the carbon fiber filaments had a single fiber diameter of 7 μm, a single fiber number of 12,000, a tensile strength of 3.0 GPa, and a tensile breaking strain of 1.3%. The tensile elastic modulus of the shell was 51 GPa, and the tensile breaking strain was 1.2%.

The body was subjected to the same experiment as in the example, and the measured damage area was 7.2 cm ² , and the pressure resistance ratio before and after impact was 0.55. Comparative example 2

Using a carbon fiber filament with a single fiber diameter of 7 μm, a number of single fibers of 12,000, a tensile strength of 2.4 GPa, and a tensile strain at break of 1.6%, and a single fiber diameter of 9 μm, a tensile strength of 3.5 GPa, a tensile E glass fiber filaments with a breaking strain of 4.8%, relative to the axial direction of the pressure vessel, carbon fiber filaments are used to form a ±3° layer, carbon fiber filaments and E glass fiber filaments are mixed to form an 88° layer, and carbon fiber filaments are used to form a layer of 88°. The plain fiber filament forms a layer of ±45°, and the fiber volume ratio of the layer of ±3°, the layer of 88°, and the layer of ±45° is carbon fiber filament: {carbon fiber filament: E glass fiber filament}: carbon The main body of the pressure vessel was formed in the same manner as in Example 1 except that the vegan filaments=1:{1:1}:2 were wound. The shell thus obtained was measured by the Nourling test method as a tensile elastic modulus of 30 GPa and a tensile breaking strain of 1.6%.

The body was subjected to the same experiment as in Example 1, and the measured damage area was 6.5 cm ² , and the pressure resistance ratio before and after impact was 0.62. Example 2

A 20% dimethyl sulfoxide solution of a propylene-based copolymer composed of 99.5% by weight of acrylonitrile and 0.5% by weight of methylene succinic acid (a polymer with a solution viscosity of 600 poise at 45°C) , once sprayed into the air through the spinneret, after passing through a space of 3 mm, it is introduced into a static coagulation bath filled with a coagulation bath liquid of 3% dimethyl sulfoxide and a temperature of 5° C. to obtain coagulated fibers. Then washed with water, stretched in hot water, coated with amino-modified silicone oil, dried and encrypted, then stretched in pressurized warm steam, stretched to a full magnification of 10 times, and then wound to obtain a single A precursor having a fiber degree of 1.0 denier and a number of single fibers of 12,000 (1.55% by weight of spread oil). Then, continue to introduce it into the air with temperature limitation (231/260°C) for refractory treatment, and then introduce it into a carbonization furnace with a maximum temperature of 1,300°C, and carry out carbonization treatment under the following conditions in nitrogen to obtain carbon fiber filaments, The conditions are to raise the temperature at a rate of about 300°C/min in the temperature range of 300°C to 700°C, and to raise the temperature at a rate of about 400°C/min in the temperature range of 1,000°C to 1,200°C. The above refractory treatment and carbonization treatment are carried out in the atmosphere after the dust is filtered out with a filter. In an electrolytic cell with an aqueous solution of sulfuric acid at a concentration of 0.05 mol/L as the electrolyte, electrolytic treatment is performed for 1 minute under the condition of a flow rate of 5 coulomb/g (electricity per cell: 1.25 coulomb/g·cell) , then washed with water, and dried at 150°C to obtain a single fiber diameter of 7 μm, a single fiber number of 12,000, a tensile strength of 5.8 GPa, a tensile modulus of elasticity of 254 GPa, a specific gravity of 1.80, and a relative surface A carbon fiber filament with an oxygen concentration O/C of 0.18 and a surface relative nitrogen concentration N/C of 0.04. The fiber is impregnated with epoxy resin (bisphenol type epoxy resin, hardener is acid anhydride, catalyst is 2E4MZ series) while passing through the resin tank and roller guide. The inner shell made of density polyethylene resin (300mm in outer diameter, 500mm in total length except for the nozzle mounting part, and 5mm in wall thickness) is used as a so-called mandrel, and the inner shell is wound on the inner shell. The amount of fibers in the axial and circumferential directions of the shell (correctly θ=±3° and 90°) is 1:2; then heated in an oven at a temperature of 130° C. for 6 hours to obtain the body of the pressure vessel. The shell thus obtained was measured by the Nourling test method as a tensile elastic modulus of 80 GPa and a tensile breaking strain of 2.3%. The outer diameter and weight of the body are 310mm and 9kg, respectively.

Then, with a drop weight testing machine, a hammer with a curvature radius of 8 mm and a weight of 2 kg at the front end of the head hits the same part of the center of the body 50 times at a speed of 2 m/sec, and then uses an ultrasonic flaw detector to measure the damage area (in The projected area in the vertical direction) was 1.0 cm ² . Furthermore, the withstand voltage ratio before and after the pressurization test using water as a pressurization source was 1.00, and it can be considered that the withstand voltage performance did not decrease after repeated impacts.

Example 3

With the structure shown in Fig. 1 and Fig. 14, it is the same as embodiment 1 to form a pressure vessel. In this pressure vessel, be filled with the helium that pressure is 20MPa, then this pressure vessel is put into airtight container 1 hour, measure the helium amount in airtight container with gas chromatograph afterwards, the gas amount that records is 0. That is, the amount of gas leaked from the pressure vessel is zero.

Example 4

With the structure shown in Fig. 1 and Fig. 32, it is the same as embodiment 1 to form a pressure vessel. The cylindrical member 90 provided with the flange part 90c is used. Apply an external axial static pressure load on the joint 4, and gradually increase the external load, which can withstand a load of up to 1 ton. Example 5

A blow-molded inner shell made of high-density polyethylene resin (outer diameter: 100 mm, total length excluding the nozzle mounting part: 300 mm, wall thickness: 1 mm) is used as a mandrel, and a filament is used on the inner shell. The wrapping method forms the shell. When using the filament winding method, carbon fiber filaments (single fiber diameter: 7μm, number of single fibers: 12,000, tensile strength: 5.0Gpa, Tensile fracture strain: 2.2%), relative to the axial direction of the pressure vessel, layers of ±30° and layers of 88° are sequentially formed, and the volume ratio of carbon fiber filaments of layers of ±3° and layer of 88° is 1:1.5 Winding was performed, and heating was carried out at 130° C. in an oven for 6 hours to obtain the main body of the pressure vessel. The tensile modulus of elasticity of the casing thus obtained was 73 GPa, and the tensile strain at break was 2.0%. The outer diameter of the main body is 104mm. In addition, the tensile elastic modulus and the tensile breaking strain are obtained by measuring a sample cut out from the cylindrical part of the pressure vessel in a circular manner by the Norring test method.

Then, in the above-mentioned main body, a hydraulic testing machine was used to carry out a load test with a hydraulic pressure of 30 MPa. Afterwards, a drop hammer testing machine was used to test a hammer with a curvature radius of 3 mm at the front end of the head and a weight of 20 kg at a speed of 7 m/sec. When the above-mentioned main body was hit, a hole appeared only at the position where the front end of the head hit, and no damage to the pressure vessel as a whole was seen. Possibility of industrial use

Although the pressure vessel of the present invention can be used in various applications, it is particularly suitable as a CNG tank for automobiles that requires light weight and high reliability.

Claims (57)

1. A pressure vessel. It is characterized in that: an inner shell and an outer shell are provided, wherein the inner shell has gas barrier properties, and the outer shell has pressure resistance and encloses the inner shell; the outer shell is made of FRP containing reinforced fiber and resin, and is stretchable The modulus is above 35Gpa, and the tensile strain at break is above 1.5%. 2. The pressure vessel of claim 1. It is characterized in that the above-mentioned inner shell is made of metal, resin or FRP. 3. The pressure vessel of claim 1. It is characterized in that an air barrier layer is formed on the inner surface and/or outer surface of the inner shell. 4. The pressure vessel of claim 1. It is characterized in that: the above-mentioned inner shell is provided with a cylindrical body, and an FRP reinforced layer is formed on the cylindrical body. 5. The pressure vessel of claim 1. It is characterized in that: the tensile modulus of elasticity of the above shell is above 35Gpa, and the tensile breaking strain is above 1.7%. 6. The pressure vessel of claim 1. It is characterized in that the tensile elastic modulus of the above shell is above 35Gpa, and the tensile breaking strain is above 2.0%. 7. The pressure vessel of claim 1. It is characterized in that: the above-mentioned reinforcing fiber contains carbon fiber whose strand tensile strength is above 4.5Gpa and tensile breaking strain is above 2.0%. 8. The pressure vessel of claim 1. It is characterized in that: the above-mentioned reinforcing fiber contains carbon fiber whose strand tensile strength is more than 5.5Gpa and the tensile breaking strain is more than 2.0%. 9. A pressure vessel as claimed in claim 7 or 8. It is characterized in that: the above-mentioned reinforcing fiber contains carbon fibers with a surface relative oxygen concentration of 0.30 or less and a surface relative nitrogen concentration of 0.02 or more. 10. A pressure vessel as claimed in claim 1, 5 or 6. It is characterized in that: the above-mentioned shell includes reinforcing fiber layers arranged at an angle of ±5°-±50° relative to the axial direction of the pressure vessel, and reinforcing fiber layers arranged at an angle of ±75°-±105°. 11. A pressure vessel as claimed in claim 1, 5 or 6. It is characterized in that: the above-mentioned outer casing contains reinforcing fiber layers arranged at an angle of ±0° to ±15° relative to the axial direction of the pressure vessel, reinforcing fiber layers arranged at an angle of ±75° to ±105°, and reinforced fiber layers arranged at an angle of ±30° to ±105° The reinforcing fiber layer is arranged at an angle of 60°. 12. The pressure vessel of claim 10. It is characterized in that the reinforcing fiber volume ratio of the reinforcing fiber layer arranged at an angle of ±5° to ±50° relative to the axial direction of the pressure vessel and the reinforcing fiber layer arranged at an angle of ±75° to ±105° is set at 1.0: The range of 1.0 to 2.0. 13. The pressure vessel of claim 11. It is characterized in that: relative to the axial direction of the pressure vessel, the reinforcing fiber layer is arranged at an angle of ±0° to ±15°, the reinforcing fiber layer is arranged at an angle of ±30° to ±60°, and the reinforcing fiber layer is arranged at an angle of ±30° to ±60° The reinforcing fiber volume ratio of the reinforcing fiber layer arranged at an angle of 1:1.5 to 2.5:0.2 to 1.2 is set in the range. 14. A method of manufacturing a pressure vessel. It is characterized in that: On the inner shell with gas barrier property, a pressure-resistant outer shell is formed by filament winding method or tape winding method, the outer shell is made of FRP containing reinforced fiber and resin, and the elastic mold is stretched The weight is above 35Gpa, and the tensile strain at break is above 1.5%. 15. A method of manufacturing a pressure vessel as claimed in claim 14. It is characterized in that a rough surface is formed on the surface of the inner casing before the filament winding or tape winding. 16. A method of manufacturing a pressure vessel as claimed in claim 14. It is characterized in that the shell is formed by reinforcing fiber layers arranged at an angle of ±5°-±50° relative to the axial direction of the pressure vessel, and reinforcing fiber layers arranged at an angle of ±75°-±105°. 17. A method of manufacturing a pressure vessel as claimed in claim 14. It is characterized in that: the outer shell is composed of reinforcing fiber layers arranged at an angle of ±0°-15° relative to the axial direction of the pressure vessel, reinforcing fiber layers arranged at an angle of ±75°-±105°, and reinforced fiber layers arranged at an angle of ±30°-± The reinforcing fiber layers are formed at an angle of 60°. 18. A method of manufacturing a pressure vessel as claimed in claim 16. It is characterized in that the reinforcing fiber volume ratio of the reinforcing fiber layer arranged at an angle of ±5° to ±50° relative to the axial direction of the pressure vessel and the reinforcing fiber layer arranged at an angle of ±75° to ±105° is set at 1.0: The range of 1.0 to 2.0. 19. A method of manufacturing a pressure vessel as claimed in claim 17. It is characterized in that: relative to the axial direction of the pressure vessel, the reinforcing fiber layer is arranged at an angle of ±0°-15°, the reinforcing fiber layer is arranged at an angle of ±75°-±105°, and the reinforcing fiber layer is arranged at an angle of ±30°-±60° The reinforcing fiber volume ratio of the reinforcing fiber layer arranged at an angle is set in the range of 1:1.5-2.5:0.2-1.2. 20. A method of manufacturing a pressure vessel as claimed in claim 14. It is characterized in that it forms a pressure-resistant shell with a tensile elastic modulus of more than 35Gpa and a tensile breaking strain of more than 1.7%. 21. A method of manufacturing a pressure vessel as claimed in claim 14. It is characterized in that it forms a pressure-resistant shell with a tensile elastic modulus of more than 35Gpa and a tensile breaking strain of more than 2.0%. 22. A method of manufacturing a pressure vessel as claimed in claim 14. It is characterized in that: the reinforced fiber uses carbon fiber with strand tensile strength above 4.5Gpa and tensile breaking strain above 2.0%. 23. A method of manufacturing a pressure vessel as claimed in claim 14. It is characterized in that: the reinforcing fiber uses carbon fiber with strand tensile strength above 5.5Gpa and tensile breaking strain above 2.0%. 24. The pressure vessel of claim 1. It is characterized in that: the pressure vessel is provided with a cylindrical body, and the shell has a layered structure of more than 5 layers in the cylindrical body, and the relationship between the total thickness T (mm) and the number of layers N satisfies 0.5≤T/N≤ 6. 25. The pressure vessel of claim 24. It is characterized in that: on the above-mentioned cylinder part, along the thickness direction of the casing, layers with hoop-wrapped layers of reinforced fiber and layers with helical-wound layers of reinforced fiber are arranged alternately. 26. A method of manufacturing a pressure vessel as claimed in claim 14. It is characterized in that: a layered structure with more than 5 layers is formed on the outer periphery of the cylindrical part of the inner shell provided with the cylindrical part, and the relationship between the total thickness T (mm) and the number of layers N satisfies 0.5≤T/ The above shell with N≤6. 27. A method of manufacturing a pressure vessel as claimed in claim 26. It is characterized in that: on the above-mentioned cylinder part, along the thickness direction of the casing, layers with hoop-wrapped layers of reinforced fiber and layers with helical-wound layers of reinforced fiber are arranged alternately. 28. A method of manufacturing a pressure vessel as claimed in claim 26. It is characterized in that: as the reinforcing fiber, the untwisted reinforcing fiber bundle whose ratio D/t of silk web D to thickness t before resin impregnation can be 5 or more can be used. 29. The pressure vessel of claim 1. It is characterized in that the above-mentioned casing contains the following constituent elements [X], [Y], [Z], and the outer periphery of the constituent element [X] shown on the cross-section of the above-mentioned casing is filled with the constituent element [Z]. [X]: Reinforcing Fiber Bundle [Y]: Thermosetting resin [Z]: Elastomer and/or thermoplastic resin 30. The pressure vessel of claim 29. It is characterized in that it is between the length _L1 of a straight line connecting the geometric centers of two adjacent constituent elements [X] and the length _L2 of a constituent element [Z] existing between the two adjacent constituent elements [X] connected by the straight line. The ratio L ₂ /L ₁ satisfies: 1/100≤L ₂ /L ₁ ≤1/2 31. The pressure vessel of claim 29. It is characterized in that the constituent element [Z] is any one selected from the following materials: polyethyl acetate, polyamide, polycarbonate, polyacetal, polyphenylene oxide, polyphenylene sulfide , polyarylate, polyester, polyamide-imide, polyimide, polyetherimide, polysulfone, polyethersulfone, polyetheretherketone, polyaramid, polybenzimidazole, poly Ethylene, polypropylene, cellulose acetate, tyrophenol cellulose, polyester series thermoplastic elastomers or polyamide series thermoplastic elastomers. 32. A method of manufacturing a pressure vessel as claimed in claim 14. It is characterized in that it contains the following constituent elements [X], [Y], [Z], impregnates the constituent element [Y] on the constituent element [X], and has the constituent element [Z] near its surface. The strands form a pressure-resistant shell. [X]: Reinforcing Fiber Bundle [Y]: Thermosetting resin [Z]: Elastomer and/or thermoplastic resin 33. A method of manufacturing a pressure vessel as claimed in claim 32. It is characterized in that a prepreg strand in which the particulate component [Z] is adhered to the component [X] containing the component [Y] is used. 34. The pressure vessel of claim 1. It is characterized in that: the above-mentioned shell is provided with a shoulder, and the innermost layer on the shoulder contains a hoop roll layer of reinforcing fiber. 35. The pressure vessel of claim 34. It is characterized in that the above-mentioned innermost layer is formed by filament winding method. 36. The pressure vessel of claim 34. It is characterized in that: the outer peripheral surface of the shoulder of the housing forms a stepped shape extending along the circumferential direction and having steps in the axial direction. 37. A method of manufacturing a pressure vessel as claimed in claim 14. It is characterized in that: on the outer peripheral surface of the shoulder of the inner shell provided with the cylindrical part and the shoulder, a reinforced layer with a reinforced fiber hoop layer, which is composed of reinforced fibers and resin, is arranged, and the reinforced layer and the above-mentioned The outer periphery of the inner shell forms a pressure-resistant outer shell. 38. A method of manufacturing a pressure vessel as claimed in claim 37. It is characterized in that the reinforcing layer is formed by filament winding method. 39. A method of manufacturing a pressure vessel as claimed in claim 37. It is characterized in that the above-mentioned reinforcing layer is formed as an extension layer of the innermost layer of the outer shell on the outer peripheral surface of the cylindrical body of the inner shell by a filament winding method. 40. The pressure vessel of claim 1. It is characterized in that: the above-mentioned inner shell is provided with a head, and the nozzle installation joint is installed in the head, and the sealing ring is embedded in the end surface of the head and the nozzle installation joint, and the sealing ring is provided to the head. A compression device that compresses the direction of the end face of the head. 41. The pressure vessel of claim 40. It is characterized in that the pressing device includes a pressing part of the sealing ring and a connecting part of the pressing part. 42. The pressure vessel of claim 40. It is characterized in that: the pressing device is provided with a pressing piece that is threadedly connected to the joint for installing the nozzle. 43. The pressure vessel of claim 40. It is characterized in that the pressing device includes a pressing piece, and the pressing piece is provided with a cylindrical portion screwed to the head and an edge connected to the sealing ring. 44. The pressure vessel of claim 40. It is characterized in that: the above-mentioned joint for installing the nozzle is provided with a flange portion, and the outer diameter of the above-mentioned pressing device is 1-10 mm smaller than the outer diameter of the above-mentioned flange portion. 45. The pressure vessel of claim 40. It is characterized in that: an annular groove for inserting the sealing ring is provided on the end surface of the head. 46. The pressure vessel of claim 42. It is characterized in that the above-mentioned shell extends to a position covering the above-mentioned pressing member. 47. The pressure vessel of claim 43. It is characterized in that the above-mentioned cylindrical portion is stepped. 48. The pressure vessel of claim 1. It is characterized in that: the above-mentioned inner shell is provided with a head, and the head is equipped with a joint for installing the nozzle, and concave and convex are formed on the joint surface of the joint for installing the nozzle and the head. 49. The pressure vessel of claim 1. It is characterized in that: the above-mentioned inner shell is provided with a head, the head is equipped with a joint for nozzle installation, and a protruding strip extending along the circumferential direction is formed on the joint surface of the joint for nozzle installation and the head. 50. The pressure vessel of claim 49. It is characterized in that unevenness is also formed on the above-mentioned joint surface. 51. A pressure vessel as claimed in claim 48 or 49. It is characterized in that: on the end surface of the above-mentioned head, a sealing ring is embedded in the joint for installing the nozzle, and at the same time, a pressing device is provided to press the sealing ring to the direction of the end surface of the above-mentioned head. 52. The pressure vessel of claim 1. It is characterized in that: the above-mentioned inner shell is provided with a head, the head is equipped with a joint for nozzle installation, and a cylindrical member is provided outside the above-mentioned head, and the cylindrical member is provided with an edge, and a cylindrical member connected to the edge. part, and a flange part extending from the outer periphery of the cylindrical part into the housing. 53. The pressure vessel of claim 52. It is characterized in that the above-mentioned flange part extends in a ring shape. 54. The pressure vessel of claim 52. It is characterized in that a seal ring is embedded on the end face of the head at the joint for installing the nozzle, and the edge portion presses the seal ring toward the end face of the head. 55. The pressure vessel of claim 52. It is characterized in that on the outer side of the edge of the cylindrical member, there is provided a connecting piece of the cylindrical member screwed to the joint for installing the nozzle. 56. The pressure vessel of claim 52. It is characterized in that the above-mentioned edge is screwed on the above-mentioned joint for installing the nozzle. 57. The pressure vessel of claim 1. It is characterized in that: the above-mentioned inner shell is provided with a head, and a nozzle installation joint with a flange and a cylindrical portion is installed in the head, and the outer diameter of the flange is 20mm to 25mm larger than the outer diameter of the cylindrical portion , and there is a slope on the contact surface between the cylindrical portion and the head portion.

Images