JP2012052588A - Method for manufacturing pressure vessel, and pressure vessel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a pressure vessel that prevents a minute crack from occurring to a reinforced resin and enables speed production in good work environment, and also to provide a pressure vessel manufactured thereby.SOLUTION: The method includes: a step of winding a reinforced fiber 2 on a side of a metal liner 1; a step of expanding a diameter of the metal liner 1 on which the reinforced fiber 2 is wound and impregnating the reinforced fiber 2 with a resin 4 while the diameter being expanded; and a step of stopping the diameter expansion after the impregnated resin 4 is hardened.

Description

  The present invention relates to a pressure vessel manufacturing method and a pressure vessel, and more particularly to a fiber reinforced pressure vessel manufacturing method and a pressure vessel manufactured by the manufacturing method.

Conventionally, containers equipped in transportation devices such as automobiles and ships and various plant devices, particularly pressure vessels for storing fuel (for example, natural gas, hydrogen, etc.) at a high pressure are required to be lighter and higher in pressure resistance. The fiber is reinforced to meet the requirements.
And the pressure vessel which is excellent in the fatigue characteristic with the sufficient fracture characteristic with respect to an internal pressure, and is lightweight, and its manufacturing method are disclosed (for example, refer patent document 1).

International Publication No. 2004/051138 A1 (Page 5-6, FIG. 2)

  The invention disclosed in Patent Document 1 wraps around a container body (same as a metal liner) while immersing and impregnating reinforcing fibers in a matrix resin housed in a storage tank (same as resin impregnation treatment). (Same as the filament winding (hereinafter referred to as “FW”) treatment), and the intermediate container is cured at room temperature or heat treatment to cure the fiber reinforced resin layer (same as the container body wrapped with the fiber resin) ( (Same as resin layer curing process), and after applying internal pressure to the intermediate container to plastically deform the container body, lowering the internal pressure and applying compressive residual stress to the container body (same as self-adhesive process) The process which consists of. For this reason, there were the following problems.

(A) Since the self-adhesive treatment is performed after the reinforced resin is cured, a tensile force acts on the cured reinforced resin. For this reason, a fine crack may arise in the reinforced resin which has hardened | cured, and the performance (high intensity | strength) of a reinforced fiber cannot fully be exhibited.
(Ii) In addition, since the impregnation treatment and the FW treatment are executed continuously, the time required for resin impregnation and curing becomes a constraint condition (rate-limiting condition), and high-speed production cannot be performed. Production efficiency is poor.
(U) Furthermore, in FW molding, an uncured resin that generates organic volatilization is an open mold that is exposed and exposed to the entire molded product, so the working environment is poor, and installation of ventilation equipment or wearing a gas mask is required. Necessary.

  The present invention solves such a problem, and suppresses the occurrence of fine cracks in the reinforced resin, and a method of manufacturing a pressure vessel that enables high-speed manufacturing in a favorable working environment, and manufacturing by the manufacturing method An object of the present invention is to provide a pressure vessel.

(1) A method for producing a pressure vessel according to the present invention includes:
Winding the reinforcing fiber around the side of the container body;
Expanding the diameter of the container body around which the reinforcing fibers are wound, and impregnating the reinforcing fibers with a resin in the expanded diameter;
After the impregnated resin is cured, the step of stopping the diameter expansion.
(2) In the above (1), the step of impregnating the resin is performed by a vacuum assisted resin impregnation method.
(3) In the above (2), a covering material for airtightly covering at least a side surface of the container body is disposed, the container body is disposed substantially vertically, and the resin is injected into a lower portion of the covering material. A resin injection port is provided, and a degassing port for evacuation is provided above the covering material.
(4) In any one of (1) to (3), the pressure vessel is made of metal.
(5) In any one of (1) to (4), the reinforcing fiber is one or both of carbon fiber and glass fiber.
(6) Furthermore, the pressure vessel according to the present invention is manufactured by the method for manufacturing a pressure vessel according to any one of (1) to (5).

According to the pressure vessel manufacturing method of the present invention, the following effects can be obtained.
(I) In a state where the diameter of the container body around which the reinforcing fibers are wound is expanded, the reinforcing fibers wound around the container body are impregnated with resin, and after the impregnated resin is cured, the diameter expansion is stopped. Since a compressive residual stress acts on the container body, a tensile residual stress acts on the reinforcing fiber, and a compressive residual stress acts on the resin, occurrence of fine cracks in the resin is suppressed. For this reason, since a stronger self-binding process becomes possible, the value of the compressive residual stress of the container body can be increased, and the pressure resistance of the container body can be increased.

  (Ii) Further, when expanding the diameter of the container body, the reinforcing fibers wound around the container body are in a dry state (a state in which the resin is not impregnated). Since generation | occurrence | production is accept | permitted, the tensile stress which generate | occur | produces in a reinforced fiber distributes more uniformly over the whole (full length). Therefore, since the tightening effect is improved, the pressure resistance strength of the container body can be increased. In addition, when the reinforcing fibers are impregnated with resin as in the past, since “slip” between the reinforcing fibers is difficult, when expanding the diameter of the container body, the reinforcing fibers in the layer close to the container body and the container body The tensile stress generated in the reinforcing fibers in the separated layers became non-uniform, and the fastening effect was not sufficiently exhibited.

(Iii) In addition, since the step of winding the reinforcing fiber around the container body and the step of impregnating the reinforcing fiber with the resin in the expanded state are independent, one does not rate-limit the other. Occupancy time does not increase and manufacturing efficiency does not deteriorate.
(Iv) Further, in the step of winding the reinforcing fiber around the container body (same as FW molding), the reinforcing fiber is in a dry state, so that high-speed winding is possible, and a limited FW device can be operated efficiently. .

  (V) Further, in the step of winding the reinforcing fiber around the container body (same as FW molding), since the reinforcing fiber is in a dry state, organic volatilization is not generated, and thus it is exposed to the entire molded product. Even if it is an open mold, the working environment will not deteriorate. Therefore, it is not necessary to install a ventilation facility or wear a gas mask.

(Vi) Furthermore, when the step of impregnating the resin is a vacuum assisted resin impregnation method (Vacuum Assisted Resin Transfer Molding, hereinafter referred to as “VARTM molding”), a large number of container bodies (with reinforcing fibers wound) are arranged side by side. Productivity is improved because it can be performed simultaneously or processed in a flow production process.
(Vii) Furthermore, since the VARTM molding is a closed mold molding in which a resin is injected while covered with a film or bag, it is possible to suppress scattering of volatilized substances from the resin, and the working environment is clean. In addition, there is little mixing of voids during impregnation. Therefore, a high quality container can be produced stably.
(Viii) Further, in the VARTM molding, if the container body is arranged substantially vertically, a resin injection port is provided at the lower part of the covering material, and a deaeration port is provided at the upper part of the covering material, the resin is uniform on the side surface of the container body. Since it is impregnated toward the upper direction of the container main body, it can be uniformly impregnated over a wide range of side surfaces. In addition, even if the bubbles contained in the resin expand due to reduced pressure, the expanded bubbles (same as the voids) rise and are removed from the deaeration port provided at the top. Quality containers can be produced stably.

The flowchart explaining the manufacturing method of the pressure vessel which concerns on Embodiment 1 of this invention. Sectional drawing which shows typically the predetermined | prescribed process explaining the manufacturing method of the pressure vessel shown in FIG. The perspective view which shows typically the pressure vessel which concerns on Embodiment 2 of this invention.

[Embodiment 1]
1 and 2 are diagrams for explaining a method of manufacturing a pressure vessel according to Embodiment 1 of the present invention. FIG. 1 is a flowchart, and FIG. 2 is a cross-sectional view schematically showing a predetermined process.
In FIG. 1, a pressure vessel manufacturing method 100 is to manufacture a pressure vessel 7 in which a metal liner 1 (same as the vessel body) is reinforced using CFRP (Carbon fiber reinforced plastics) 6. And has the following steps. Hereinafter, the number of a process (step) is described as Sj (j = 1-9).

First, the metal liner 1 is manufactured (S1).
Then, the base 1k is attached to the metal liner 1 (S2).
Then, the reinforcing fiber 2 in a dry state is wound around the side surface of the metal liner 1 (S3, referred to as “FW reinforcement”).
Then, a high pressure is applied to the inside of the metal liner 1 around which the reinforcing fiber 2 is wound to expand the diameter of the metal liner 1 (S4, referred to as “self-tightening pressure load”). The reinforcing fiber 2 wound around the main body is impregnated with the resin 4 by vacuum auxiliary resin impregnation (VARTM) (S5), and further, the impregnated resin 4 is cured under a self-tightening pressure load (S6).
Then, after the impregnated resin 4 is cured, the inside of the metal liner 1 is gradually pressurized (S7, referred to as “self-tightening pressure unloading”).
Furthermore, equipment (not shown) is adjusted to manufacture the pressure vessel 7 (S8).
If necessary, the process proceeds to the inspection process (S9).

(Container body)
The reason why the metal liner 1 is used as the container body is that the permeation blocking ability (gas barrier property) of the gas filled in the inside and the plastic properties when performing the self-tightening treatment are secured, and in particular, aluminum such as A6061 If it is made of an alloy, the weight can be reduced. Note that the present invention is not limited to the metal liner 1 and may be any (such as polyethylene) as long as it has gas barrier properties and plastic properties. Further, a member having a gas barrier property (first container) and a member having a plastic property (second container) may be combined.
Moreover, the manufacturing method of the metal liner 1 is not limited, and the cylindrical portion and the end plate portion that closes both ends of the cylindrical portion may be manufactured integrally, or each may be separately manufactured. You may join after manufacturing. Further, the cylindrical portion may have a constricted portion or a bulging portion, and the outer diameter (inner diameter) may be non-uniform.
Furthermore, the pressure vessel manufacturing method 100 according to the first embodiment is not limited to literally “a pressure vessel (a tubular portion and end plates are installed at both ends of the tubular portion)”. A method of manufacturing a part of a container (having no end plate) or a part of a pressure vessel, for example, a method of manufacturing a pipe body (pipe, line pipe, etc.) in which high-pressure fluid is enclosed Is included.

(Reinforced fiber)
Reinforcing fiber 2 shows what uses carbon fiber (Carbon fiber), but this invention is not limited to this, It is glass fiber or metal fiber (piano wire or shape memory alloy wire), Also good. At this time, if carbon fiber or glass fiber is used, weight reduction of the pressure vessel 7 can be further promoted. Further, like the material, the size of the outer diameter of the fiber is not limited.

(Sudden treatment)
The self-tightening process is a process in which a pressure about twice the working pressure is applied in the manufacturing process, a predetermined portion on the inner surface side of the metal liner 1 is yielded, and the pressure is returned to compress the residual stress on the inner portion of the plate thickness. The part is a process for generating a tensile residual stress. In the case of the pressure vessel 7, the reinforcing fiber 2 (for example, carbon fiber) is wound around the metal liner 1 and reinforced with CFRP 6, thereby compressing residual stress in the metal liner 1 and tensile residual in CFRP 6. Generate stress. By performing the self-tightening treatment, the fatigue strength due to repeated use is improved, and the weight can be reduced by reducing the thickness of the metal liner 1.
In addition, the yield range of the metal liner 1 in the self-tightening pressure load state and the magnitude of the residual stress of each member in the self-tightening pressure unloading state are determined based on the material characteristics of each member. is there.
Moreover, although the above has applied the high voltage | pressure inside the metal liner 1 and expanded the diameter, this invention does not limit the point of diameter expansion. For example, when one or both of the cylindrical portions have no end plate, a mechanical diameter expanding device (a so-called expander) may be inserted inside the cylindrical portion to increase the diameter.

(FW method)
In the FW method, the reinforcing fiber is wound around the metal liner 1 while being rotated as an embedded mold, and the wound form (winding shape) is not limited. For example, the distance between the reinforcing fibers (winding density) may be changed in the axial direction of the metal liner 1, or the number of windings (the thickness of the wound layer) may be changed. Further, the rotating direction of the reinforcing fiber may be changed by variously changing the rotation axis of the metal liner 1 and the orientation direction of the reinforcing fiber. At this time, a predetermined layer is formed by winding in a direction (+ α) inclined to one side with respect to the axis of the metal liner 1, and inclined to the other side with respect to the axis of the metal liner 1 on the layer. A layer wound in the direction (−α) may be formed. Such winding allows an optimum design to make the pressure vessel 7 light and have the required functions.

  In addition, when the diameter of the metal liner 1 is increased, the reinforcing fiber 2 wound around the metal liner 1 is in a dry state, so that “slip” is allowed to occur between the reinforcing fibers 2. The tensile stress to be distributed is more evenly distributed over the entire length (full length). Therefore, since the tightening effect is improved, the pressure resistance of the metal liner 1 can be increased. Further, high-speed winding is possible, and a limited FW device can be operated efficiently.

(Reinforced resin)
By the above process, since a compressive residual stress is generated in the resin 4, occurrence of fine cracks is suppressed.
The resin 4 fixes the reinforcing fibers 2 wound around the outer periphery of the metal liner 1 to disperse stress while preventing the occurrence of displacement between the reinforcing fibers 2 and to suppress moisture intrusion and deterioration over time. Is. In the present invention, the type of the resin is not limited, but a thermosetting epoxy resin having high adhesive strength with the reinforcing fiber is often used.

(VARTM molding method)
The VARTM molding method is a production method of FRP (fiber reinforced plastic) that has begun to become popular in recent years. The outer periphery of the metal liner 1 is covered with a covering material such as a vacuum film or a rubber sheet, and the inside of the covering material. The reinforced resin is supplied to a vacuum state by reducing the pressure.
Therefore, since organic volatiles from the resin 4 are captured, emission of the organic volatiles to the surroundings (in the factory) can be suppressed. Further, if the reinforced resin is supplied while continuing the evacuation, even if the bubbles are contained in the resin 4, it expands due to the reduced pressure, and the expanded bubbles (same as the voids) are removed by evacuation. Therefore, it is possible to stably produce a high-quality pressure vessel 7 with little mixing of voids.

As shown in FIG. 2, the metal liner 1 is arranged substantially vertically, a resin injection port 5 a is provided at the lower part of the vacuum film (same as the covering material) 5, and a deaeration port 5 b is provided at the upper part of the vacuum film 5. It is preferable to execute the VARTM molding method.
At this time, the resin 4 is impregnated toward the upper side of the metal liner 1 while being uniformly distributed on the side surface of the metal liner 1, so that uniform impregnation can be performed over a wide range of the side surface. Further, even when the bubbles contained in the resin 4 expand due to the reduced pressure, the expanded bubbles (same as the voids) float and are removed from the deaeration port 5b provided at the upper portion, so that the inclusion of voids is further increased. A small number of high-quality containers can be stably produced.
Large-scale VARTM molding methods often use low-viscosity vinyl ester resins, but recently, epoxy resins that can be made VARTM molding with reduced viscosity have also emerged, and VARTM molding methods that require fluidity It has come to be used.

[Embodiment 2]
FIG. 3 illustrates a pressure vessel according to Embodiment 2 of the present invention, and is a perspective view schematically showing a part in cross section. The same parts as those in the first embodiment are denoted by the same reference numerals, and a part of the description is omitted.
In FIG. 2, the pressure vessel 200 is manufactured by the pressure vessel manufacturing method 100 described in the first embodiment.
That is, the pressure vessel 200 (same as the pressure vessel 7 in the first embodiment) winds the reinforcing fiber 2 around the metal liner 1 in a dry state, and executes the effect of the VARTM treatment and the resin in a self-tight pressure load state. Since the resin is unloaded after the effect of the resin, it is produced stably and has high quality.

  According to the present invention, the generation of fine cracks in the reinforced resin is suppressed, and high-speed production is possible in a favorable working environment. Therefore, a pressure vessel made of various materials of various sizes and shapes, and part of the pressure vessel In addition, it can be widely used as various pressure vessels.

1 Metal liner (container body)
1k Base 2 Reinforcing Fiber 3 Peel Ply 4 Resin 5 Vacuum Film 5a Resin Injection Port 5b Degassing Port 6 CFRP
7 Pressure Vessel 100 Pressure Vessel Manufacturing Method (Embodiment 1)
200 Pressure vessel (Embodiment 2)

Claims (6)

Winding the reinforcing fiber around the side of the container body;
Expanding the diameter of the container body around which the reinforcing fibers are wound, and impregnating the reinforcing fibers with a resin in the expanded diameter;
And a step of stopping the diameter expansion after the impregnated resin is cured.   The method for producing a pressure vessel according to claim 1, wherein the step of impregnating the resin is performed by a vacuum auxiliary resin impregnation method.   A covering material that airtightly covers at least a side surface of the container body is disposed, the container body is disposed substantially vertically, and a resin injection port for injecting the resin is provided below the covering material, and the covering material A method for producing a pressure vessel according to claim 1 or 2, wherein a deaeration port for evacuation is provided in an upper part of the container.   The method of manufacturing a pressure vessel according to any one of claims 1 to 3, wherein the pressure vessel is made of metal.   The method for producing a pressure vessel according to any one of claims 1 to 4, wherein the reinforcing fiber is one or both of carbon fiber and glass fiber.   A pressure vessel manufactured by the method for manufacturing a pressure vessel according to claim 1.

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