JP2011144860A - High-pressure tank - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin high-pressure tank that prevents a surface resin layer from breaking by a simple device. <P>SOLUTION: The high-pressure tank 10 includes: a resin-made liner 11 that forms a storage space 17 for high pressure gas; a fiber reinforced resin layer 12 that covers an outer surface of the liner 11; and a surface foaming resin layer 13 that is made to be porous by applying a solvent to the surface resin layer that is a part of the fiber reinforced resin layer 12 and foaming it. The surface foaming resin layer 13 regulates porous structure formation without reducing the burst strength of the tank by, for instance, properly regulating the application amount of a solvent, thereby improving gas permeability. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a high pressure tank, and more particularly to a resin high pressure tank in which a resin liner is covered with a fiber reinforced resin layer.

  In recent years, the development of fuel cells has been actively carried out, and the opportunity to mount a high-pressure tank filled with hydrogen gas on a vehicle or the like has increased. Thus, weight reduction of the high-pressure tank is strongly demanded. Resin-made high-pressure tanks have been developed as light-weight high-pressure tanks. As shown in FIG. 4A, the resin high-pressure tank includes a resin liner 11, and has a structure reinforced by providing a fiber reinforced resin layer 12 on the outer surface thereof. Here, FIG. 4 is a view showing a laminated structure of a conventional high-pressure tank, and corresponds to FIG. 2 described later.

  As shown in FIG. 4A, a surface resin layer 18 is usually formed on the surface of the fiber reinforced resin layer 12. The surface resin layer 18 is a dense layer made only of a resin formed by bleeding the resin impregnated around the liner 11 to form the fiber reinforced resin layer 12 with excess resin bleeding outward. is there. That is, the fiber reinforced resin layer 12 and the surface resin layer 18 are an integrated continuous layer.

  As a technique related to the present invention, Patent Document 1 discloses a high-pressure tank that includes a liner made of an aluminum alloy and a fiber reinforced resin layer that covers the liner, and the outer surface of the fiber reinforced resin layer is covered with a heat-shrinkable tube. It is disclosed. Further, in Patent Document 1, the heat-shrinkable tube has a plurality of vent holes, and the gas present inside the resin-impregnated fiber bundle layer is caused to shrink outside the resin-impregnated fiber bundle layer by thermally shrinking the heat-shrink tube. It is described that the gas that has reached the outer surface of the resin-impregnated fiber bundle layer can be discharged to the outside of the heat-shrinkable tube through the vent hole during extrusion.

JP 2008-309219 A

  As described above, the surface resin layer 18 is formed in the high-pressure tank including the fiber reinforced resin layer 12. As shown in FIG. 4B, the surface resin layer 18 has a function of blocking gas (gas barrier property). In the high-pressure tank made of resin, there is no liner 11 that completely shuts off the gas, so the gas filled in the tank permeates the liner 11 over time. And the gas which permeate | transmitted the liner 11 is interrupted | blocked by the precise | minute surface resin layer 18 which consists only of resin.

  As shown in FIG. 4C, when the gas that has passed through the liner 11 is blocked by the surface resin layer 18 and the accumulated amount of gas reaches the limit point, the surface resin layer 18 is destroyed and the gas is released at once. Can happen. At this time, the amount of released gas is not a problem for safety, but noise is generated due to the destruction of the surface resin layer 18. Further, since the surface resin layer 18 has a role as a protective layer for imparting damage resistance to the tank, the damage resistance or the like may be reduced when it is destroyed.

  On the other hand, in a tank including a metal liner made of an aluminum alloy like the high-pressure tank described in Patent Document 1, there is no problem that the surface resin layer is destroyed because the gas is completely blocked by the liner. Therefore, Patent Document 1 does not include a description regarding the surface resin layer of the fiber reinforced resin layer. As described above, in the prior art including the technique of Patent Document 1, it is difficult to prevent the surface resin layer from being destroyed in the high-pressure tank made of resin.

  An object of the present invention is to provide a resin-made high-pressure tank capable of preventing the surface resin layer from being destroyed. Another object of the present invention is to provide a production method capable of producing the high-pressure tank only by adding a simple operation without changing the conventional basic process.

  A high-pressure tank according to the present invention is a high-pressure tank comprising a resin liner, a fiber-reinforced resin layer covering an outer surface of the liner, and a surface resin layer provided outside the fiber-reinforced resin layer. A surface porous resin layer having a porous structure is formed by subjecting to a porous treatment. That is, the high-pressure tank according to the present invention includes a resin liner, a fiber reinforced resin layer, and a surface porous resin layer that is a surface resin layer having a porous structure. Here, the porous treatment is preferably a treatment for foaming the surface resin layer to make it porous.

  The surface resin layer may be a layer separately provided outside the fiber reinforced resin layer, but is usually formed by bleeding an excess resin component to the outside in the process of forming the fiber reinforced resin layer. In that case, the surface resin layer constitutes a part of the fiber reinforced resin layer. That is, a high-pressure tank according to the present invention comprises a resin liner and a fiber-reinforced resin layer that covers the outer surface of the liner and that has a resin component bleed outwardly to form a surface resin layer. The surface porous resin layer having a porous structure is formed by subjecting the surface resin layer to a porous treatment.

  According to the said structure, since gas permeability improves with a porous structure, it can suppress that the gas which permeate | transmitted the liner is interrupted | blocked on the outer side of a liner. That is, the surface porous resin layer, which is a surface resin layer having a porous structure, is not destroyed by the accumulation of gas that has passed through the liner.

  A method for producing a high-pressure tank according to the present invention is a method for producing a high-pressure tank comprising a step of wrapping a fiber containing an uncured resin component around an outer surface of a resin liner to form an uncured fiber reinforced resin layer. A solvent application step of applying and infiltrating a solvent into an uncured surface resin layer formed by bleeding the uncured resin component of the cured fiber reinforced resin layer outward, and curing the resin component of the uncured fiber reinforced resin layer And a heat treatment step of evaporating and removing the solvent to foam the surface resin layer to make it porous.

  According to the said structure, a surface porous resin layer can be formed by foaming a surface resin layer only by adding operation which applies a solvent to an uncured surface resin layer. Here, as the solvent, it is preferable to use a solvent that penetrates into the uncured resin component and is well mixed (compatibilized), and can be easily removed by evaporation in the heat treatment step. Further, the amount of the solvent used is adjusted to an appropriate range in order to increase the gas permeability and prevent the destruction of the surface resin layer (surface porous resin layer) while maintaining the burst strength of the tank.

  According to the high-pressure tank according to the present invention, the surface resin layer can be prevented from being destroyed by making the surface resin layer porous (that is, forming the surface porous resin layer). Moreover, according to the method for manufacturing a high-pressure tank according to the present invention, it is possible to manufacture a high-pressure tank capable of preventing the surface resin layer from being destroyed only by adding a simple operation without changing the conventional basic process. .

It is a figure which shows the structure of the high pressure tank which is embodiment which concerns on this invention. It is the figure which expanded the laminated structure cross section (A section) of the high-pressure tank shown in FIG. It is a flowchart which shows the manufacture procedure of the high pressure tank which is embodiment which concerns on this invention. It is a figure for demonstrating the subject of a prior art.

  Embodiments of a high-pressure tank according to the present invention will be described below in detail with reference to the drawings. In the following description, the high-pressure tank is described as a tank filled with high-pressure hydrogen gas mounted on a fuel cell vehicle, but it can also be applied to other uses. The gas that can be filled in the high-pressure tank is not limited to high-pressure hydrogen gas.

  The configuration of the high-pressure tank 10 will be described with reference to FIGS. 1 and 2. As shown in FIG. 1, the high-pressure tank 10 is a substantially cylindrical hydrogen gas storage container whose both ends are rounded in a dome shape. The high-pressure tank 10 includes a liner 11 having a gas barrier property and a fiber reinforced resin layer 12 including a surface foamed resin layer 13. The high-pressure tank 10 has openings at both ends, and a base 14 is attached to one opening, and an end boss 16 is attached to the other opening.

  The liner 11 is a resin member that forms a housing space 17 filled with high-pressure hydrogen gas. Generally, the liner 11 is made of a thermoplastic resin that can be processed into a substantially cylindrical shape or the like. The resin that constitutes the liner 11 is preferably a resin that has good processability and good performance for holding hydrogen gas in the accommodation space 17, that is, good gas barrier properties. Examples of such a resin include thermoplastic resins such as polyester, polyamide, polyethylene, and ethylene-vinyl alcohol copolymer resin (EVOH).

  As described above, the liner 11 has a substantially cylindrical shape having dome portions at both ends. Each dome portion of the liner 11 is formed with an opening, and a base 14 and an end boss 16 are provided in each opening. As will be described in detail later, since the fiber reinforced resin layer 12 is formed along the outer surface of the liner 11, the shape of the liner 11 determines the shape of the high-pressure tank 10.

  The base 14 is an outlet for taking out hydrogen gas filled in the accommodation space 17. In the base 14, for example, a valve 15 can be installed, and a groove or the like (not shown) that fits the valve 15 is formed. As the base 14, a metal material such as an aluminum alloy processed into a predetermined shape can be used.

  The end boss 16 is a member provided in the dome portion on the opposite side to the base 14 and is a member for attaching a shaft for rotating the liner 11 when the fiber reinforced resin layer 12 is formed. The shaft is attached not only to the end boss 16 but also to the base 14. The end boss 16 can be made of a metal material such as an aluminum alloy, like the base 14.

  The fiber reinforced resin layer 12 is a layer that covers the outer surface of the liner 11 and has a function of reinforcing the liner 11 and improving mechanical strength such as rigidity and pressure resistance of the high-pressure tank 10. Generally, the fiber reinforced resin layer 12 is comprised from a thermosetting resin and a reinforced fiber. Here, as the thermosetting resin, it is preferable to use a thermosetting resin such as a phenol resin, a melamine resin, a urea resin, and an epoxy resin, and it is particularly preferable to use an epoxy resin from the viewpoint of mechanical strength and the like. . As the reinforcing fiber, glass fiber, aramid fiber, boron fiber, carbon fiber, and the like can be used. In particular, it is preferable to use carbon fiber from the viewpoints of lightness and mechanical strength.

  In general, an epoxy resin is a resin obtained by mixing a prepolymer such as a copolymer of bisphenol A and epichlorohydrin and a curing agent such as polyamine and thermosetting the mixture. The epoxy resin is fluid in an uncured state and forms a tough crosslinked structure after thermosetting and becomes insoluble in a solvent such as methyl ethyl ketone (MEK).

  The fiber reinforced resin layer 12 is formed by winding fibers (for example, carbon fibers) impregnated with uncured resin (for example, epoxy resin) around the outer surface of the liner 11 and curing the resin. For example, a shaft is attached to the base 14 and the end boss 16 of the liner 11 so as to be rotatably supported, and the resin-impregnated fiber is wound using both helical winding and hoop winding while rotating. Then, the resin component is cured by heating at the curing temperature of the resin. By using the helical winding and the hoop winding together, mechanical strength such as pressure resistance can be secured in the axial direction (longitudinal direction) and the radial direction of the high-pressure tank 10.

  The surface foamed resin layer 13 is a layer obtained by foaming a surface resin layer formed by bleeding the uncured epoxy resin of the fiber reinforced resin layer 12 outward. That is, the surface foamed resin layer 13 is a surface resin layer having a porous structure. Here, the surface resin layer (non-porous structure) is a layer formed only of a resin formed by the process of forming the fiber reinforced resin layer 12, that is, an extra resin component is pushed outward when the resin-impregnated fiber is wound. is there. That is, the surface resin layer and the surface foamed resin layer 13 obtained by making this porous are part of the fiber reinforced resin layer 12. By appropriately adjusting the amount of resin impregnated in the fibers, the surface foamed resin layer 13 can be adjusted to an appropriate thickness, and the mechanical strength of the tank can be ensured. For example, in order to ensure the mechanical strength of the tank, a resin component that normally forms a surface resin layer of 1 to 2 mm is necessary.

  The surface foamed resin layer 13 functions as a protective layer that imparts damage resistance and the like to the tank. For example, since the surface foamed resin layer 13 made of an epoxy resin is a tough resin, it functions as a protective layer excellent in damage resistance, impact resistance, and the like.

  As described above, the surface foamed resin layer 13 has a porous structure obtained by making the surface resin layer porous. In the present embodiment, the porous structure is a structure including a large number of pores, and is a structure (foamed structure) obtained by foaming the surface resin layer to make it porous. Generally, the foam structure includes both a closed cell structure and an open cell structure. Here, the closed cell structure is a structure in which the holes are independent and adjacent holes are not connected to each other, and the open cell structure means a structure in which the holes are connected and communicated with each other. From the viewpoint of improving gas permeability, it is preferable to increase the open cell structure.

  As shown in FIG. 2, since the surface foamed resin layer 13 has high gas permeability, the hydrogen gas that has passed through the liner 11 can be released to the outside without being shielded. Therefore, the surface foamed resin layer 13 is not destroyed by the increase in internal pressure. The surface foamed resin layer 13 having such a function can be formed by adding a step of applying a solvent to the uncured surface resin layer in a conventional high-pressure tank manufacturing process. The form of the foam structure (closed cell structure, open cell structure), the size of the pores, and the like can be arbitrarily adjusted depending on, for example, the type and amount of the solvent used.

  As the solvent, those having good compatibility with the uncured resin and having a boiling point lower than the heating temperature in the heat treatment step described later are preferable. When the resin constituting the fiber reinforced resin layer 12 (surface foamed resin layer 13) is an epoxy resin, methyl ethyl ketone (MEK), toluene, dimethylacetamide, acetone, etc. can be applied, and in particular, MEK is used. Is preferred. Two or more kinds of solvents can be mixed to adjust the compatibility and the evaporation temperature.

  Taking the epoxy resin and MEK as an example, the amount of the solvent used may be, for example, 1% (1% by weight) with respect to the epoxy resin weight of the uncured surface resin layer. When the solvent is applied at about 1% by weight, a good porous structure can be formed, and the surface foamed resin layer 13 can be prevented from being destroyed without lowering the burst strength of the tank. In addition, when there is too much usage-amount of a solvent, a solvent osmose | permeates to the fiber reinforced resin layer 12, and the burst strength of a tank falls. On the other hand, if the amount of the solvent is too small, the gas permeability cannot be sufficiently improved and the surface foamed resin layer 13 may be destroyed.

  A manufacturing procedure of the high-pressure tank 10 having the above configuration will be described below with reference to FIG. FIG. 3 is a flowchart showing the manufacturing procedure of the high-pressure tank 10 and shows the procedure after the procedure of covering the liner 11 to which the cap 14 and the end boss 16 are attached with the fiber reinforced resin layer 12.

  First, a shaft is attached to the base 14 and the end boss 16 of the liner 11 and is supported rotatably. Then, the fiber impregnated with the uncured resin is wound so as to cover the outer surface of the liner 11 while rotating the liner 11 (S10). As the winding method, there are so-called helical winding that winds along a substantially axial direction and so-called loop winding that winds along a substantially radial direction, and both are preferably performed alternately. By this step, an uncured fiber reinforced resin layer is formed on the outer surface of the liner 11.

  Further, in the fiber winding step of S10, the uncured surface resin layer made of only the uncured resin is formed on the outer surface of the uncured fiber reinforced resin layer by bleeding the excess uncured resin impregnated into the fiber to the outside. It is formed. For example, the thickness of the uncured fiber reinforced resin layer is 2 to 3 mm, and the thickness of the surface resin layer is 1 to 2 mm.

  Next, a solvent such as MEK is applied to the uncured surface resin layer and penetrated (S11). Specifically, the solvent is uniformly sprayed on the entire uncured surface resin layer using an applicator such as a spray. As described above, the solvent is preferably a solvent having good miscibility (compatibility) with the uncured resin and penetrating into the inside and having a boiling point lower than the heating temperature in the heat treatment step described later. Moreover, it is preferable that the usage-amount of a solvent is about 1 weight% with respect to the resin weight which comprises an uncured surface resin layer, for example.

  Next, a heat treatment for curing the uncured resin is performed (S12). The heat treatment process is also a process for forming a porous structure by foaming the surface resin layer. For example, when the resin is an epoxy resin, the curing temperature is 140 ° C to 150 ° C. Since the solvent applied to the uncured surface resin layer is removed by evaporation at a high temperature of 140 ° C. to 150 ° C., the portion where the solvent is present becomes pores and a porous structure is obtained. In this way, the resin component is cured to form the fiber reinforced resin layer 12, and the surface foamed resin layer 13 having a porous structure is formed.

  As described above, the resin liner 11, the fiber reinforced resin layer 12 covering the outer surface of the liner 11, and the surface of the fiber reinforced resin layer 12 simply by adding an operation of applying a solvent to the conventional manufacturing process. The high-pressure tank 10 provided with the surface foamed resin layer 13 formed on is obtained. The high-pressure tank 10 is a surface foamed resin layer 13 in which the surface resin layer is foamed and made porous, so that the gas permeability is high, and the gas that has permeated the liner 11 is prevented from being blocked outside the liner 11. it can. That is, the surface foamed resin layer 13, which is a surface resin layer having a porous structure, is not destroyed by the accumulation of gas that has passed through the liner 11.

  The porous structure of the surface foamed resin layer 13 can be adjusted to a good form by appropriately adjusting the amount of solvent to be applied. That is, according to the high-pressure tank 10, only the surface resin layer can be made porous by appropriately adjusting the amount of solvent to be applied, and the surface resin layer (surface foamed resin layer 13 is maintained while maintaining high burst strength. ) Gas permeability can be improved and destruction can be prevented.

  In addition, if the fiber reinforced resin layer can be formed by suppressing the bleed of the resin component without reducing the burst strength of the tank, a surface porous resin layer different from the fiber reinforced resin layer should be provided as a protective layer. You can also. In that case, the surface porous resin layer needs to have a porous structure similar to that of the surface foamed resin layer 13 in order to prevent destruction due to gas blocking.

  DESCRIPTION OF SYMBOLS 10 High pressure tank, 11 Liner, 12 Fiber reinforced resin layer, 13 Surface foamed resin layer, 14 Base, 15 Valve | bulb, 16 End boss | hub, 17 Storage space, 18 Surface resin layer.

Claims (3)

A resin liner,
A fiber reinforced resin layer covering the outer surface of the liner;
A surface resin layer provided outside the fiber-reinforced resin layer;
In a high pressure tank comprising:
A high-pressure tank in which a surface porous resin layer having a porous structure is formed by subjecting a surface resin layer to a porous treatment. A resin liner,
A fiber reinforced resin layer that coats the outer surface of the liner and has a resin component bleed outwardly to form a surface resin layer;
In a high pressure tank comprising:
A high-pressure tank in which a surface porous resin layer having a porous structure is formed by subjecting a surface resin layer to a porous treatment. In a method for producing a high-pressure tank comprising a step of wrapping a fiber containing an uncured resin component around an outer surface of a resin liner to form an uncured fiber reinforced resin layer,
Applying and infiltrating a solvent to the uncured surface resin layer formed by bleeding the uncured resin component of the uncured fiber reinforced resin layer to the outside; and
A heat treatment step of curing the resin component of the uncured fiber reinforced resin layer, evaporating and removing the solvent to foam the surface resin layer, and making it porous;
A method for manufacturing a high-pressure tank, further comprising:

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