JP2018189178A - Pressure vessel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-cost pressure vessel in which corrosion of a base is suppressed. SOLUTION: A container main body 10 having a cylindrical straight body portion 14 and a dome portion 16 provided at both ends of the straight body portion 14 and narrowing as the distance from the straight body portion 14 increases, and a tip portion of the dome portion 16. The container body 10 is provided with a metal base 12 provided, and the container body 10 is provided with a resin liner 18 and a reinforcing layer 20 provided on the outside of the liner 18 and made of a fiber-reinforced resin material containing reinforcing fibers and a matrix resin. The fiber volume content of the reinforcing fibers in the reinforcing layer 20 in the dome portion 16 is 45% by volume or more and 55% by volume or less, and the fiber volume content of the reinforcing fibers in the reinforcing layer 20 in the straight body portion 14 is 55. Pressure vessel 1 which is more than 65% by volume and less than 65% by volume. [Selection diagram] Fig. 1

Description

  The present invention relates to a pressure vessel.

  Containers for using, transporting, and storing various gases, liquefied gases, etc., especially containers that involve transportation and movement, high-pressure specifications that can be filled with large amounts of gas, liquefied gas, etc. for efficient transportation or movement Pressure vessels are required. In addition, the pressure vessel is desired to be lightweight in order to reduce fuel consumption for transportation and movement.

  Conventionally, metal pressure vessels have been the mainstream. However, since a metal pressure vessel is very heavy, a pressure vessel having a resin liner and a reinforcing layer covering the outer surface of the liner has been proposed as a lightweight pressure vessel (Patent Documents 1 and 2). . Generally, in the liner, for the purpose of preventing leakage of gas to be filled, liquefied gas, etc., the resin, thickness, laminated structure and the like are selected so that their permeability is lowered. The reinforcing layer is a layer in which high-strength reinforcing fibers such as carbon fibers are hardened with a matrix resin such as a thermosetting resin or a thermoplastic resin. Excellent pressure resistance is obtained by the reinforcing layer.

  The pressure vessel is usually provided with a base as an installation part of a valve for taking in and out the contents. The base is also used as a support when forming the reinforcing layer. A screw structure is generally used for attaching a jig for supporting the base or a valve to the base. Therefore, for the purpose of ensuring the strength of the screw structure, the base is made of metal such as alloy steel or aluminum alloy.

Japanese Patent Laid-Open No. 10-332082 Japanese Patent No. 4457359

  However, since there is a potential difference between the carbon fiber used in the reinforcing layer and the base, if a metal base is provided on the container body formed of the liner and the reinforcing layer, the base corrodes due to the contact between the carbon fiber and the base. Cheap. Therefore, corrosion resistant titanium is used for the base of a pressure vessel such as an aircraft. However, since titanium materials are difficult to process and expensive, the cost increases. Moreover, in industrial use etc., passivation treatment such as insulation coating or oxidation is performed on the surface of the die. However, the method of performing insulation coating or passivation treatment increases the number of steps and makes the manufacturing complicated, and the cost also increases. In particular, in the passivation treatment, the treatment layer is fragile and easily damaged, so that the insulation may be unexpectedly broken, resulting in lack of reliability.

  An object of the present invention is to provide a low-cost pressure vessel in which corrosion of the die is suppressed.

The present invention has the following configuration.
[1] A cylindrical main body, and a container body provided at both ends of the main body, and having a dome that is narrowed away from the main body,
A metal base provided at the tip of the dome,
The container body includes a resin liner, and a reinforcing layer provided on the outside of the liner and made of a fiber reinforced resin material containing reinforcing fibers and a matrix resin.
The fiber volume content of the reinforcing fibers in the reinforcing layer in the dome is 45% by volume or more and 55% by volume or less,
The pressure vessel, wherein a fiber volume content of the reinforcing fiber in the reinforcing layer in the straight body portion is more than 55 volume% and 65 volume% or less.
[2] The pressure vessel according to [1], wherein the matrix resin has an electric resistance of 10 ⁶ to 10 ¹⁸ Ω.

  In the pressure vessel of the present invention, the corrosion of the base is suppressed, and the cost is low.

It is sectional drawing which showed an example of the pressure vessel of this invention. It is sectional drawing to which the nozzle | cap | die part of the pressure vessel of FIG. 1 was expanded. It is the front view which showed the nozzle | cap | die of the pressure vessel of FIG.

  Hereinafter, an example of the pressure vessel of the present invention will be shown and described. In addition, the dimension of the figure illustrated in the following description is an example, Comprising: This invention is not necessarily limited to them, It is possible to implement suitably changing in the range which does not change the summary. .

As shown in FIG. 1, the pressure vessel 1 of the present embodiment includes a vessel body 10 and a metal base 12. The container body 10 includes a cylindrical straight body portion 14 and dome portions 16 that are provided at both ends of the straight body portion 14 and narrow as they move away from the straight body portion 14. The base 12 is provided at the tip of one dome portion 16.
The dome portion 16 is provided so as to close both ends of the straight body portion 14, and is preferably in the form of an isotensoid. The tip of the dome portion 16 is located on the central axis of the straight body portion 14.

  The container body 10 includes a resin liner 18 and a reinforcing layer 20 provided on the outside of the liner 18 and made of a fiber reinforced resin material containing reinforcing fibers and a matrix resin.

  The thickness of the straight body portion 18a of the liner 18 is preferably 3 mm or greater and 12 mm or less. If the thickness of the straight body portion 18a of the liner 18 is equal to or greater than the lower limit of the above range, the liner suspended during molding can be easily held. If the thickness of the straight body portion 18a of the liner 18 is equal to or less than the upper limit of the above range, the pressure vessel can be easily reduced in weight.

  The outer diameter D of the straight body portion 18a of the liner 18 is preferably 300 mm or greater and 1000 mm or less. If the outer diameter D of the straight body portion 18a is equal to or greater than the lower limit of the above range, the productivity is high and economically advantageous as compared with the case where the liner is made of metal. If the outer diameter D of the straight body portion 18a is less than or equal to the upper limit of the above range, the reinforcing layer 20 does not become too thick, and therefore, when a curable resin is used for the matrix resin of the reinforcing layer 20, a long time is required for curing. It is easy to suppress.

  The ratio (L / D) of the axial length L of the liner 18 to the outer diameter D of the straight body portion 18a of the liner 18 is preferably 2 or more and 12 or less. If L / D is equal to or greater than the lower limit of the above range, the ratio of the dome portion 16 in the container body 10 is sufficiently small, so that it is easy to sufficiently increase the capacity per unit length. Moreover, it becomes easy to reduce the quantity of the reinforcement layer 20 required. If L / D is less than or equal to the upper limit of the above range, the liner 18 can be easily manufactured, it is easy to suppress the liner 18 from being bent, and the weight can be easily reduced.

  Examples of the resin forming the liner 18 include polyethylene resin, polypropylene resin, nylon resin, PPS resin, LCP resin, DCPD resin, and ethylene-vinyl alcohol copolymer (EVOH). A recycled material may be used as the resin forming the liner. As the resin forming the liner 18, one type may be used alone, or two or more types may be used in combination.

  The structure of the liner 18 is not particularly limited, and may be a single layer structure or a multilayer structure. As a multilayer structure, the multilayer of the gas barrier layer containing EVOH etc. and the layer containing resin mentioned previously is mentioned, for example. In this case, an adhesive layer for adhering the gas barrier layer and another layer may be provided between them.

  As the reinforcing fiber forming the reinforcing layer 20, one having high tensile strength is preferable. Further, when the tensile elastic modulus is high, deformation of the liner and the base at the time of high-pressure gas filling can be suppressed, which is effective against fatigue due to repeated filling and discharging. Specifically, carbon fibers, glass fibers, aramid fibers, and polyethylene fibers are preferable as the reinforcing fibers, and carbon fibers are particularly preferable from the viewpoint of high strength and high elasticity. As the reinforcing fiber, one kind may be used alone, or two or more kinds may be used in combination.

The tensile strength of the reinforcing fiber is preferably 4000 MPa or more, and more preferably 5000 MPa or more. The tensile strength of the reinforcing fiber is measured according to JIS R 7606 “Testing method for tensile properties of carbon fiber”.
The tensile elastic modulus of the reinforcing fiber is preferably 230 GPa or more, and more preferably 250 GPa or more. The tensile elastic modulus of the reinforcing fiber is measured according to JIS R 7606 “Testing method for tensile properties of carbon fiber”.

  The basis weight of the reinforcing fiber is preferably 0.2 g / m or more and 4 g / m or less, and more preferably 0.8 g / m or more and 2 g / m or less. If the basis weight of the reinforcing fibers is equal to or more than the lower limit of the above range, the amount of fibers that can be wound around the outer surface of the liner 18 at a time increases, and the productivity is excellent. If the basis weight of the reinforcing fiber is equal to or less than the upper limit of the above range, it is easy to wind around the liner 18 without causing meandering of the fiber due to the overlapping of the reinforcing fibers.

  Examples of the matrix resin that forms the reinforcing layer 20 include thermoplastic resins such as thermosetting resins such as epoxy resins, vinyl ester resins and unsaturated polyester resins, and polypropylene resins, nylon resins, PPS resins, LCP resins, and DCPD resins. Resin. As the matrix resin, a thermosetting resin is preferable because it has a lower viscosity than a thermoplastic resin and has good impregnation into reinforcing fibers. As the matrix resin, one kind may be used alone, or two or more kinds may be used in combination.

The electric resistance of the matrix resin is preferably 10 ⁶ to 10 ¹⁸ Ω, and more preferably 10 ¹⁰ to 10 ¹⁴ Ω. If the electric resistance of the matrix resin is equal to or greater than the lower limit of the above range, corrosion of the die can be easily suppressed. If the electric resistance of the matrix resin is not more than the upper limit of the above range, the deterioration of the matrix resin can be suppressed.
The electric resistance of the matrix resin is measured based on JIS C 2139 “Measurement method of volume resistivity and surface resistivity of solid electrically insulating material”.

In the pressure vessel 1, the fiber volume content (Vf _A ) of the reinforcing fiber in the reinforcing layer 20 in the dome portion 16 is 45% by volume or more and 55% by volume or less, and the reinforcing fiber in the reinforcing layer 20 in the straight body portion 14. The fiber volume content (Vf _B ) is more than 55% by volume and 65% by volume or less. Thus, the base 12 is coated with the matrix resin of the reinforcing layer 20 by making the reinforcing layer 20 in the dome portion 16 around the base 12 richer in resin than the reinforcing layer 20 in the straight body portion 14 far from the base 12. It will be in the state. Therefore, contact between the metal base 12 and the reinforcing fibers of the reinforcing layer 20 is suppressed, and thereby corrosion of the base 12 is suppressed.

The fiber volume content (Vf _A ) of the reinforcing fiber in the reinforcing layer 20 in the dome portion 16 is 45 volume% or more and 55 volume% or less, preferably 47 volume% or more and 53 volume% or less, and 49 volume% or more and 51 volume. % Or less is more preferable. If Vf _A is less than or equal to the upper limit of the above range, the periphery of the die becomes resin-rich, and contact between the die and the reinforcing fiber can be suppressed, so that corrosion of the die can be suppressed. If Vf _A is not less than the lower limit of the above range, sufficient pressure resistance can be easily obtained.

The fiber volume content (Vf _B ) of the reinforcing fiber in the reinforcing layer 20 in the straight body portion 14 is more than 55 volume% and 65 volume% or less, preferably 57 volume% or more and 63 volume% or less, and 59 volume% or more 61. Volume% or less is more preferable. If Vf _B is equal to or greater than the lower limit of the above range, sufficient pressure resistance is easily obtained. If Vf _B is equal to or lower than the upper limit of the above range, the reinforcing fiber can be cured while suppressing movement in the resin.

  As shown in FIGS. 2 and 3, the base 12 includes a cylindrical tube portion 22, a first flange portion 24 that protrudes from the outer surface of the rear end portion of the tube portion 22 over the entire circumference, and a tip end of the tube portion 22. And a second flange portion 26 extending from the outer surface of the portion between the first flange portion 24 and the entire circumference. The base 12 is attached to the distal end portion of the dome portion 16 so that the first flange portion 24 is sandwiched between the liner 18 and the reinforcing layer 20, and the reinforcing layer 20 is sandwiched between the first flange portion 24 and the second flange portion 26. ing. The central axis of the cylindrical portion 22 of the base 12 and the central axis of the straight body portion 14 of the container body 10 coincide with each other.

  The shape of the cylindrical portion 22a in contact with the container body 10 in the cylindrical portion 22 of the base 12 as viewed from the front end side of the central axis of the base 12 is such that each corner of the polygon is rounded in an arc shape. Thereby, sufficient tolerance is easily acquired with respect to the torque loaded at the time of the assembly | attachment or removal of a valve | bulb, and it is easy to suppress that the reinforcement layer 20 remove | deviates by this torque. Further, as in this example, it is preferable that the corner portion of the cylindrical portion 22a has a circular arc shape. Thereby, since it can suppress that the reinforcement fiber of the reinforcement layer 20 is bent sharply, a reinforcement fiber becomes difficult to damage.

  The number of corners of the cylindrical portion 22a in the base 12 is preferably 4 or more and 12 or less, and more preferably 6 or more and 12 or less. If the number of corners of the cylindrical portion 22a is equal to or greater than the lower limit of the above range, the reinforcing fibers of the reinforcing layer 20 can be prevented from being bent sharply, and thus the reinforcing fibers are hardly damaged. If the number of corners of the cylindrical portion 22a is equal to or less than the upper limit of the above range, it is easy to suppress the reinforcement layer 20 from being detached due to torque applied when the valve is assembled or removed.

  At the lower part of the base 12, a part of the liner 18 enters the through hole of the cylindrical part 22 a and covers the inner surface 12 a at the lower part of the base 12. A female screw for fastening to the liner 18 is formed on the lower inner surface 12a of the base 12 that is in contact with the liner 18. The screw shape of the female screw is not particularly limited, and a buttress screw having a larger angle in the central portion side of the container body 10 than in the distal end portion in the central axis direction of the base 12 is preferable from the viewpoint of preventing detachment. Specifically, in the cross section obtained by cutting the base 12 along the plane passing through the central axis, the angle formed by the central groove side of the central groove of the container body 10 is 90 ± 10 °, and the screw on the tip side A buttress screw in which the angle formed by the groove and the central axis direction is 45 ± 10 ° is preferable.

  From the viewpoint of adhesiveness with the liner 18 of the base 12, it is preferable that an adhesive is applied to the lower inner surface 12 a in contact with the liner 18 of the base 12. In this case, the primer 12 suitable for each member and the adhesive may be applied to the inner surface 12a of the base 12 before the adhesive is applied.

  As a material for forming the base 12, a known metal material usually used for the base can be used, and examples thereof include alloy steel, aluminum alloy, brass and the like.

  Various shock-absorbing materials may be installed on the outer surface of the pressure vessel 1 in order to impart impact resistance. As the material of the cushioning material, a material such as rubber, an elastomer, or a foam itself having an impact absorbing performance, or a material having a part that deforms or breaks into a shape can be used.

  The use of the pressure vessel 1 is not particularly limited, and examples thereof include a fuel vessel for automobiles and a vessel for transporting fuel gas for consumption in other places.

The manufacturing method of the pressure vessel 1 is not particularly limited.
Examples of the molding method of the liner 18 include a rotational molding method and a blow molding method. Among them, the blow molding method is preferable because it is excellent in productivity and physical properties of the resin after molding, and it is not necessary to join a plurality of members even in a large pressure vessel, and is convenient and economically advantageous.
The outer surface of the liner 18 may be coated with an adhesive resin or a reactive agent, if necessary, or oxidized with a flame such as a gas burner in order to enhance the adhesion with the base 12 or the reinforcing layer 20. Good.

  For forming the reinforcing layer 20, it is preferable to employ a filament winding (FW) method in which a long reinforcing fiber bundle is impregnated with a matrix resin composition, and the formed fiber reinforced resin material is wound around the liner 18 and laminated. . A fiber reinforced resin material obtained by impregnating a matrix resin composition into a long reinforcing fiber bundle was prepared in advance, and the fiber reinforced resin material was wound around the liner 18 or only the reinforcing fiber bundle was wound around the liner 18 and laminated. A method of impregnating the matrix resin composition later may be used.

  For example, in the FW method, when carbon fibers are used as the reinforcing fibers, one or more bundles of fiber bundles having a filament number of about 3000 to 60000 are drawn and impregnated with a matrix resin composition, and then formed into a band shape. The formed fiber reinforced resin material is wound around the liner 18. In the fiber reinforced resin material, it is preferable that the thickness is uniform in the width direction and there is no gap between the fiber bundles.

  As an aspect in which the reinforcing fiber bundle is impregnated with the matrix resin composition in the FW method, for example, an aspect in which a pickup roller is used. Specifically, the reinforcing fiber bundle passes through the surface of the pickup roller with a constant tension while the matrix resin composition is picked up on the surface of the pickup roller from the resin tank containing the matrix resin composition. Thus, the fiber reinforced resin material is formed by impregnating the reinforcing fiber bundle with the matrix resin composition. It is preferable to control the temperature of the resin tank from the viewpoint that a predetermined amount of the matrix resin composition is easily attached to the surface of the pickup roller.

  The bandwidth of the fiber reinforced resin material is preferably 1/15 or more and 1/10 or less with respect to the outer diameter of the liner. When the band width is equal to or greater than the lower limit of the above range, it becomes easy to wind the fiber reinforced resin material around the liner without a gap in a short time. When the band width is equal to or less than the upper limit of the above range, it is easy to suppress the occurrence of winding slip due to the tension applied to the fiber reinforced resin material during winding, and it becomes easy to wind the fiber reinforced resin material at a desired position. Therefore, it is easy to suppress deterioration of physical properties such as the burst strength of the pressure vessel.

  The tension applied to the fiber reinforced resin material at the time of winding is preferably 1 to 100 N and more preferably 10 to 50 N per fiber basis weight of all the reinforced fiber bundles included in the fiber reinforced resin material. If the tension is within the above range, voids in the reinforcing layer can be easily reduced, the reinforcing fibers can be easily prevented from meandering, and the liner can be easily prevented from being deformed.

  As a method for winding the fiber reinforced resin material in the FW method, for example, a method of repeating hoop winding and helical winding as appropriate can be given. In this case, the reinforcing layer includes a hoop layer formed by hoop winding of the fiber reinforced resin material and a helical layer formed by helical winding of the fiber reinforced resin material. The hoop layer is installed for the purpose of receiving stress in the radial direction of the straight body portion. The helical layer is installed for the purpose of receiving stress in the direction of the central axis of the straight body portion. In the pressure vessel, the reinforcing layer is composed of both a hoop layer and a helical layer in the straight body portion, and is composed of a helical layer in the dome portion.

First, the fiber reinforced resin material is wound around the straight body portion 18a of the liner 18 by FW hoop winding. The hoop layer formed in the lowermost layer in contact with the liner 18 has no entanglement of reinforcing fibers and has high adhesion to the liner, so that formation of voids is sufficiently suppressed. The winding start position of the lowermost hoop layer is preferably the boundary between the straight body portion 18a and the dome portion 18b of the liner 18.
The winding angle of the reinforcing fiber with respect to the central axis of the liner 18 in the hoop layer when the straight body portion 18a of the liner 18 is viewed from the side is preferably 85 to 90 °.

  When the hoop layer is close to the liner 18, the efficiency of using the strength of the reinforcing layer for the pressure resistance of the pressure vessel is increased. On the other hand, when the number of hoop layers laminated continuously is too large, the stepped portion of the end of the hoop layer that gets over when the helical layer is wound on the hoop layer becomes large, so that the reinforcing fibers are likely to meander. For this reason, it is preferable to divide the hoop layer into several hoop layer groups and to provide a helical layer between the hoop layer group and the hoop layer group from the viewpoint of easily suppressing the strength of the pressure vessel from decreasing.

The helical layer preferably includes an axial helical layer, a low angle helical layer, a medium angle helical layer, and a high angle helical layer.
The axial helical layer is basically installed for the purpose of receiving stress in the central axis direction of the straight body portion of the pressure vessel. Therefore, in the axial helical layer, the reinforcing fibers are oriented so that the fiber direction is as close to the axial direction as possible while exposing the base 12 provided at the tip of the dome portion 16.

  The low-angle helical layer is installed for the purpose of suppressing the excessive concentration of reinforcing fibers in the periphery of the base and reducing abnormal reactions when the fiber-reinforced resin material is cured. The winding angle of the reinforcing fiber with respect to the central axis of the liner 18 in the low-angle helical layer when the straight body portion 18a of the liner 18 is viewed from the side is preferably 5 ° to 15 ° larger than the fiber direction of the axial helical layer, 10 ° to 20 ° is preferable.

  The high-angle helical layer is a layer installed for the purpose of eliminating the stress load in the circumferential direction at the dome portion and the step difference of the hoop layer at the reinforced portion of the straight body portion and the dome portion. The winding angle of the reinforcing fiber with respect to the central axis of the liner 18 in the high-angle helical layer when the straight body portion 18a of the liner 18 is viewed from the side is preferably 65 ° to 85 °.

  The medium angle helical layer is installed to increase the strength of the dome. When the straight body portion 18a of the liner 18 is viewed from the side, the winding angle of the reinforcing fiber with respect to the central axis of the liner 18 in the medium angle helical layer is an angle between the winding angle of the low angle helical layer and the winding angle of the high angle helical layer. It is.

  In the helical layer, the reinforcing fiber winding angle is close to the axial direction of the straight body part, so the tension during winding does not work very effectively in the direction to hold the reinforcing fiber in the radial direction against the straight body part. Little action to expel resin and voids. By tightening the helical layer with the hoop layer, it is possible to suppress the excess resin of the lower helical layer from being driven out and sagging. A hoop layer is preferably disposed on the helical layer, particularly the low-angle helical layer.

In general, in helical winding to form a reinforcing layer in the dome, the entanglement of the fiber reinforced resin material around the base becomes exaggerated, so there is a possibility that a resin deficient part such as a void occurs and the base and the reinforcing fiber contact Is expensive. On the other hand, in the present invention, the fiber volume content of the fiber reinforced resin material forming the reinforcing layer of the dome part and the fiber volume content of the fiber reinforced resin material forming the reinforcing layer of the straight body part are respectively determined as the reinforcing layer. Vf _A is controlled to be in the range of 45% by volume to 55% by volume and Vf _{B in} the range of more than 55% by volume to 65% by volume. Thereby, since the reinforcement layer formed in a dome part becomes resin rich, it can suppress that a nozzle | cap | die and a reinforced fiber contact. For this reason, the base is prevented from corroding.

  When providing a label or the like on the container body, glass fiber is used as the reinforcing fiber of the fiber reinforced resin material forming the uppermost layer of the reinforcing layer, and the label or the like can be seen through from the outside by placing the label or the like directly under the uppermost layer. You may do it.

  When winding the fiber reinforced resin material by the FW method, it is preferable to pressurize the inside of the liner. Thereby, it is possible to suppress the deformation of the liner due to the winding tension, and it is possible to suppress the reinforced fibers in the already wound layer from being loosened and the burst strength from being lowered. The pressure inside the liner during winding may be increased as the winding amount increases.

  After the fiber reinforced resin material is wound around the liner, the resulting pressure vessel precursor is placed in a heating furnace and heated at a predetermined temperature suitable for the matrix resin composition for a predetermined time to cure the matrix resin and form a reinforcing layer. To do. The curing profile (time-temperature program) is temporarily held at a temperature lower than the curing temperature of the matrix resin composition, uniformizes the temperature of the uncured product, and lowers the viscosity of the matrix resin composition and is inside. It is preferable to expel the void. Thereafter, the liner is not deformed by heat and is cured at a temperature and a holding time at which the matrix resin composition is cured.

  During curing, it is preferable to pressurize and hold the inside of the liner. Further, at the time of curing, it is preferable to cure while rotating the precursor of the pressure vessel in order to prevent the uncured matrix resin from flowing and being unevenly distributed or dripping.

As described above, in the pressure vessel of the present invention, Vf _A of the reinforcing layer in the dome portion is 45% by volume or more and 55% by volume or less, and Vf _B of the reinforcing layer in the straight body portion is more than 55% by volume and 65% by volume or less. The range is controlled. Thereby, since the periphery of the base in the reinforcing layer becomes resin-rich, the contact between the base and the reinforcing fiber is suppressed, and the base is prevented from corroding.
Further, in the present invention, it is not necessary to use titanium for the die in order to suppress the corrosion of the die, and it is not necessary to perform passivation treatment such as insulation coating or oxidation on the die surface, which is advantageous in terms of cost. .

  The pressure vessel of the present invention is not limited to the pressure vessel 1 described above. For example, the pressure vessel of the present invention is not limited to one provided with a single base, but is provided with a base at each tip of two dome parts located at both ends of the straight body part. May be. Further, the pressure vessel may be provided with a support member having the same shape as the base except that there is no through hole at the tip of the dome on the opposite side to the dome where the base is provided. If it is a pressure vessel of this invention, when this support member is metal, corrosion of this support member can also be suppressed.

EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited by the following description.
[Example 1]
A pressure vessel having the same shape as the pressure vessel 1 illustrated in FIG. 1 was produced.
Specifically, high-density polyethylene (HDPE, 4261AGBD manufactured by Lyondellbasell) having a density of 0.945 g / cm ³ was used as the material of the liner. By blow molding, a liner having a straight barrel portion thickness of 7 mm, an outer diameter of the straight barrel portion of 720 mm, and an L / D of 2.7 was obtained.
Aluminum alloy A7075 was used as the base material. An acrylic adhesive (DP8005 manufactured by 3M) was applied to the surface of the base that contacts the liner.
As the fiber bundle of the reinforcing fiber, 37-800-WD 30K (tensile strength: 5520 MPa, tensile elastic modulus: 255 GPa, basis weight: 1.675 g / m) manufactured by Mitsubishi Rayon Carbon Fiber and Composites was used. As the matrix resin composition, a bisphenol A type epoxy resin, an acid anhydride curing agent, and a curing accelerator epoxy resin composition (LY1564 / 917 / 960-1 manufactured by Huntsman) were used.

Eight fiber bundles are aligned, and the fiber bundle is immersed in a resin tank containing the epoxy resin composition to form a fiber reinforced resin material. The width of the band made of the fiber reinforced resin material on the liner is 45 mm. In this way, a predetermined amount of hoop winding and helical winding was wound around the liner in the order shown in Table 1. The tension applied to the fiber bundle at the time of winding was 17 N per fiber basis weight of the fiber bundle. The pressure inside the liner was 0.1 MPa at the start of winding, and 0.3 MPa after each layer of hoop winding and helical winding was completed. After winding the fiber reinforced resin material, it was heated at 65 ° C. for 45 minutes with the pressure inside the liner maintained at 0.3 MPa. Subsequently, it heated for 6 hours with a 95 degreeC hardening furnace, and the pressure vessel in which the reinforcement layer was formed on the liner was obtained.
The angle in Table 1 is the winding angle of the reinforcing fiber (carbon fiber, CF) with respect to the central axis of the liner when the straight body portion of the liner is viewed from the side.

Using a salt spray device (Cass tester manufactured by Suga Test Instruments Co., Ltd. Model: CASSER-ISO-3) under conditions of spray pressure 70 to 167 kPa, spray amount 1.5 ± 0.5 mL / h, test bath temperature 35 ° C. The pressure vessel was kept for 31 days in an environment in which the spray solution (50 ± 5 g / L NaCl aqueous solution) was continuously sprayed. Thereafter, when the pressure vessel was observed, no corrosion was observed in the die.
Also, from the pressure vessel after the corrosion test, 8 sample pieces were cut out from the reinforcing layer in the dome portion around the base and the reinforcing layer in the straight body portion, and the fiber volume content Vf was calculated from the density of each sample piece. did. Table 2 shows the measurement results of Vf _A of the reinforcing layer in the dome part and Vf _B of the reinforcing layer in the straight body part.

As shown in Table 2, Vf _A was in the range of 45% to 55% by volume, and Vf _B was in the range of more than 55% to 65% by volume. Thus, it was confirmed that Vf _A and Vf _B satisfy the conditions of the present invention, and that the dome around the base is richer in resin than the straight body part, so that the corrosion of the base is controlled. .

  DESCRIPTION OF SYMBOLS 1 ... Pressure vessel, 10 ... Container body, 12 ... Base, 14 ... Straight body part, 16 ... Dome part, 18 ... Liner, 20 ... Reinforcement layer

Claims (2)

A cylindrical main body, and a container body provided at both ends of the main body, and having a dome portion that is narrowed away from the main body,
A metal base provided at the tip of the dome,
The container body includes a resin liner, and a reinforcing layer provided on the outside of the liner and made of a fiber reinforced resin material containing reinforcing fibers and a matrix resin.
The fiber volume content of the reinforcing fibers in the reinforcing layer in the dome is 45% by volume or more and 55% by volume or less,
The pressure vessel, wherein a fiber volume content of the reinforcing fiber in the reinforcing layer in the straight body portion is more than 55 volume% and 65 volume% or less. The pressure vessel according to claim 1, wherein the matrix resin has an electric resistance of 10 ⁶ to 10 ¹⁸ Ω.

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