Manufacturing method for high-pressure tanks

Abstract

To provide manufacturing method for high-pressure tanks that allows easy adjustment of the amount of resin.SOLUTION: A method for manufacturing a high-pressure tank, comprises the steps of winding a laminate having a laminated structure consisting of a fiber layer and a solid thermosetting resin layer around a hollow liner, and melting and then curing the thermosetting resin layer by heating.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present application relates to a method of manufacturing a high pressure tank, for example a container for storing a high pressure gas, such as hydrogen. [Background technology]

[0002] Regarding a method for manufacturing a high-pressure tank, Patent Document 1 describes a method for manufacturing a high-pressure tank in which a fiber-reinforced composite material impregnated with a thermosetting resin is wound around the outer periphery of a hollow liner, and then the thermosetting resin is hardened by heating. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2008-286297 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the invention described in Patent Document 1, it was difficult to adjust the amount of resin impregnated into the fibers.

[0005] The present invention provides a method for manufacturing a high-pressure tank, which makes it possible to easily adjust the amount of resin in a fiber-reinforced resin. [Means for solving the problem]

[0006] The present invention includes the following embodiment [1]. [1] A method for manufacturing a high-pressure tank, comprising: A step of winding a laminate having a structure in which a fiber layer and a solid thermosetting resin layer are laminated around a hollow liner; melting and then curing the thermosetting resin layer by heating; A method for manufacturing a high-pressure tank, comprising: Effect of the Invention

[0007] According to the manufacturing method of the high-pressure tank of the present invention, since the laminated material has a laminated structure of a fiber layer and a solid thermosetting resin layer, it is possible to easily adjust the amount of resin in the fiber reinforced resin by changing the number of thermosetting resin layers contained in the laminated material. [Brief description of the drawings]

[0008] [Figure 1] Fig. 1(A) is a flowchart illustrating a manufacturing method S100 of a high-pressure tank according to one embodiment. Fig. 1(B) is a flowchart illustrating a winding step S10 according to one embodiment. [Diagram 2] Fig. 2(A) is a diagram for explaining step S11. Fig. 2(B) is a cross-sectional view taken along the line BB in Fig. 2(A). Fig. 2(C) is a diagram for explaining step S12. Fig. 2(D) is a cross-sectional view taken along the line DD in Fig. 2(C). [Diagram 3] Fig. 3(A) is a cross-sectional view that typically illustrates a high-pressure tank 100 manufactured by the manufacturing method S100. Fig. 3(B) is a cross-sectional view that typically illustrates a portion of the fiber reinforced resin layer 40 in Fig. 3(A) at a lead wire B. Fig. 3(C) is a cross-sectional view that typically illustrates a portion of the fiber reinforced resin layer 40 in Fig. 3(A) at a lead wire C. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to these embodiments. The drawings do not necessarily reflect accurate dimensions. In addition, some symbols may be omitted in the drawings. In this specification, unless otherwise specified, the expression "A to B" for numerical values ​​A and B means "A or more and B or less." In such an expression, when a unit is added only to numerical value B, the unit is also applied to numerical value A. Furthermore, the words "or" and "or" mean a logical sum unless otherwise specified. Furthermore, the expression "E1 and / or E2" for elements E1 and E2 means "E1 or E2, or a combination thereof," and the expression "E1 and / or E2" for elements E1, ..., E N (N is an integer of 3 or more) for E1, ..., E N-1 , and / or E N " is written as "E1, ..., E N-1 , or E N ", or a combination thereof."

[0010] <Manufacturing method of high pressure tank> Fig. 1(A) is a flow chart for explaining a manufacturing method S100 of a high-pressure tank according to one embodiment (hereinafter, sometimes simply referred to as "manufacturing method S100"). A high-pressure tank is a container capable of holding gas or liquid at high pressure, and is also called a pressure-resistant tank or pressure vessel. The manufacturing method S100 includes a winding step S10 and a hardening step S20. Each step will be explained in order below.

[0011] (1. Winding process S10) The winding step S10 (hereinafter sometimes simply referred to as "step S10") is a step of winding a laminated material having a structure in which a fiber layer and a solid thermosetting resin layer are laminated around a hollow liner. FIG. 1(B) is a flow chart explaining the winding step S10 according to one embodiment. The winding step S10 includes a first winding step S11, a second winding step S12, and a determination step S13.

[0012] (1.1 First Winding Step S11) The first winding step S11 (hereinafter sometimes referred to as "step S11") is a step of winding (filament winding (FW) molding) the first laminate material 2 around the body portion 1a of the hollow liner 1. Fig. 2(A) is a diagram for explaining step S11 in schematic form.

[0013] The liner 1 is a hollow member that defines the internal space of the high-pressure tank, and is cylindrical in this embodiment. The liner 1 has a body 1a with a generally constant diameter, dome-shaped side ends 1b, 1b (hereinafter sometimes simply referred to as "side ends 1b" or "dome-shaped parts 1b") provided at both ends of the body 1a, and openings 1c, 1c (hereinafter sometimes simply referred to as "openings 1c") provided at the ends (tops) of the side ends 1b, 1b. A cap (not shown) is usually placed in the opening 1c. The liner 1 is made of a material that can hold what is contained in the internal space (e.g., hydrogen gas) without leaking, and known materials can be used as the material. Examples of materials that make up the liner 1 include synthetic resins such as polyamide resins (e.g., nylon (registered trademark), etc.), polyethylene-based resins, and metals such as stainless steel and aluminum. Among these, from the viewpoint of reducing the weight of the high-pressure tank, it is preferable that the material that makes up the liner 1 is synthetic resin. The thickness of the liner 1 is not particularly limited, but may be, for example, 0.5 mm to 3.0 mm. The inner diameter of the body portion 1a of the liner 1 is not particularly limited, but may be, for example, about 300 mm to 800 mm.

[0014] Fig. 2(B) is a cross-sectional view taken along the line BB in Fig. 2(A). Fig. 2(B) shows a cross section of the first laminated material 2. The first laminated material 2 has a structure in which a first fiber layer 21 and a solid first resin layer 22 are laminated. The ratio of the number of layers of the first fiber layer 21 to the first resin layer 22 in the first laminated material 2 is first fiber layer:first resin layer=1:1 in Fig. 2(B).

[0015] As a winding method in the first winding step S11, for example, hoop winding can be preferably adopted. Hoop winding is a winding method in which the first laminate 2 is set almost perpendicular to the central axis of the liner 1, and the winding point is gradually shifted, as shown in Fig. 2(A).

[0016] (1.2 First Winding Process S12) The second winding step S12 (hereinafter sometimes referred to as "step S12") is a step of winding (filament winding (FW) molding) the second laminated material 3 around at least the dome-shaped portion 1b of the liner 1 that has been subjected to step S11. FIG. 2(C) is a diagram for explaining step S12 in a schematic manner, and FIG. 2(D) is a cross-sectional view taken along the line DD in FIG. 2(C). The second laminated material 3 has a structure in which a second fiber layer 31 and second resin layers 32, 32 (hereinafter sometimes simply referred to as "second resin layer 32") are laminated. The ratio of the number of layers of the second fiber layer 31 and the second resin layer 32 in the second laminated material 3 is second fiber layer:second resin layer=1:2 in FIG. 2(D). According to the present invention, it is possible to change the amount of resin depending on the location in this manner. For example, as in this embodiment, by increasing the ratio of the amount of the second resin layer 32 to the amount of the second fiber layer 31 contained in the second laminate 3 covering the dome-shaped portion 1b to be greater than the ratio of the amount of the first resin layer 22 to the amount of the first fiber layer 21 contained in the first laminate 2, it becomes possible to selectively increase the toughness of the fiber-reinforced resin layer in the portion covering the dome-shaped portion 1b.

[0017] As the winding method in the second winding step S12, from the viewpoint of increasing the area covered by the dome-shaped portion 1b with one winding, for example, helical winding is preferably adopted. As shown in Fig. 2(C), helical winding is a winding method in which the second laminate 3 is set at an angle to the central axis of the liner 1 and the winding point is largely shifted.

[0018] The first fiber layer 21 and the second fiber layer 31 are each a band-shaped member formed by a fiber bundle in which a plurality of fibers are bundled together, so as to have a predetermined cross-sectional shape (for example, a rectangular cross-section). The fiber bundle may be a simple collection of a plurality of fibers, or may be a woven bundle of a plurality of fibers. The fibers constituting the fiber bundle may be continuous (uninterrupted from one end to the other end where the fibers are wound) or may be discontinuous. Examples of the fibers include carbon fiber, glass fiber, and aramid fiber. In this embodiment, an example in which carbon fiber is used as the fiber will be mainly described. The first fiber layer 21 and the second fiber layer 31 may be the same fiber layer or may be different from each other. For example, the first fiber layer 21 and the second fiber layer 31 may have the same thickness or may have different thicknesses from each other. The dimensions of the first fiber layer 21 and the second fiber layer 31 may be, for example, several mm to several tens of mm in the width direction and about 0.01 mm to several mm in the thickness direction.

[0019] The first resin layer 22 and the second resin layer 32 are each made of a thermosetting resin. Examples of the thermosetting resin constituting the first resin layer 22 and the second resin layer 32 include epoxy resin, polyurethane resin, diallyl phthalate resin, phenol resin, polyester resin, etc. Among these, epoxy resin can be particularly preferably used. The resin may be added with an imparting agent (e.g., a curing agent, a flexibility imparting agent, etc.) for controlling the curing temperature, etc. Thermosetting resins having a melting point higher than room temperature (e.g., 25°C) can be preferably used. The thermosetting resin constituting the first resin layers 22, 22, ... is in a solid state during the winding step S10, but melts when heated in the curing step S20 and penetrates between the fibers of the first fiber layers 21, 21, ..., and then cures to form an integral fiber reinforced resin layer (e.g., a carbon fiber reinforced plastic (CFRP) layer) together with the first fiber layers 21, 21, .... Similarly, the thermosetting resin constituting the second resin layers 32, 32, ... is in a solid state during the winding step S10, but melts when heated in the curing step S20 and penetrates between the fibers of the second fiber layers 31, 31, ..., and then hardens to form an integrated fiber reinforced resin layer (e.g., a carbon fiber reinforced plastic (CFRP) layer) together with the second fiber layers 31, 31, .... The first resin layer 22 and the second resin layer 32 may be the same resin layer or may be different from each other. For example, the first resin layer 22 and the second resin layer 32 may have the same thickness or may have different thicknesses from each other. The thickness of the first resin layer 22 and the second resin layer 32 may be, for example, about 0.01 mm to several mm.

[0020] (1.3 Judgment step S13) The judgment step S13 (hereinafter sometimes referred to as "step S13") is a step for judging whether the first winding step S11 and the second winding step S12 have been performed a predetermined number of times. If the judgment result of step S13 is positive, the winding step S10 is terminated. If the judgment result of step S13 is negative, the process returns to the first winding step S11, and the first and second winding steps S11, S12 are performed again. The number of times (repetition number) of the first and second winding steps S11, S12 is two or more, and can be, for example, two to several tens of times.

[0021] (2.Curing process S20) The curing step S20 (hereinafter sometimes simply referred to as "step S2") is a step of melting the solid thermosetting resin layer by heating and then curing it. In the curing step S20, the first resin layer 22 and the second resin layer 32 are melted by heating, permeate the first fiber layer 21 and the second fiber layer 31, respectively, and then cured to form a fiber reinforced resin layer. As the processing conditions in the curing step S20, conventionally known heating conditions can be adopted. As the heating temperature, for example, a temperature that is equal to or higher than the melting point of the thermosetting resin constituting the first and second resin layers 22, 32 and at which the thermosetting resin is cured can be adopted. Also, for example, after heating for a certain period of time at a temperature that is equal to or higher than the melting point of the thermosetting resin constituting the first and second resin layers 22, 32 and lower than the temperature at which the thermosetting resin is cured, the temperature may be raised to a temperature at which the thermosetting resin is cured. By going through steps S10 to S20, the manufacturing method S100 is completed.

[0022] (3. High-pressure tank) Fig. 3(A) is a cross-sectional view that typically explains a high-pressure tank 100 manufactured by the manufacturing method S100. The high-pressure tank 100 includes a hollow liner 1 and a fiber-reinforced resin layer 40 that covers the outer surface of the liner 1. Fig. 3(B) is a cross-sectional view that typically explains a portion (lead line B) of the fiber-reinforced resin layer 40 that covers the body portion 1a of the liner 1 in Fig. 3(A). Fig. 3(C) is a cross-sectional view that typically explains a portion (lead line C) of the fiber-reinforced resin layer 40 that covers the dome-shaped portion 1b of the liner 1 in Fig. 3(A).

[0023] As shown in FIG. 3(B), in the portion covering the body portion 1a of the liner 1 (see FIG. 2(A)), the fiber reinforced resin layer 40 has a laminated structure in which the first fiber reinforced resin layers 41, 41, ... and the second fiber reinforced resin layers 42, 42, ... are alternately laminated. Also, as shown in FIG. 3(C), in the portion covering the dome-shaped portion 1b of the liner 1 (see FIG. 2(A)), the fiber reinforced resin layer 40 has a laminated structure in which only the second fiber reinforced resin layers 42, 42, ... are laminated. The first fiber reinforced resin layer 41 is a fiber reinforced resin layer derived from the first laminate material 2, and the second fiber reinforced resin layer 42 is a fiber reinforced resin layer derived from the second laminate material 3. The first fiber reinforced resin layer 41 includes a fiber bundle 21' derived from the first fiber layer 21, and the second fiber reinforced resin layer 42 includes a fiber bundle 31' derived from the second fiber layer 31. Since the amount of resin contained in the second laminate 3 (per unit fiber amount) is greater than the amount of resin contained in the first laminate 2 (per unit fiber amount) (the second laminate 3 has the second resin layers 32 on both sides of the second fiber layer 31), a resin-rich layer 43 is formed between each pair of adjacent fiber bundles 31', 31' of the second fiber-reinforced resin layers 42, 42 in Fig. 3(C) . As a result, the fiber-reinforced resin layer 40 has improved interlaminar shear strength in the portion covering the dome-shaped portion 1b.

[0024] In the conventional method using a tow prepreg (TPP) in which a fiber bundle is pre-impregnated with resin, a roller for applying the resin to the fiber bundle and a bath for storing the resin are required for impregnation with the resin, which results in costs for impregnation. In addition, in the conventional manufacturing method using the wet method in which resin is impregnated into the fiber bundle immediately before filament winding (FW) molding of the TPP or FW molding, it was difficult to control the amount of resin impregnated into the fiber bundle and the interlayer resin thickness. In contrast, according to the manufacturing method of the present invention, impregnation and curing can be performed simultaneously in the curing process after the winding process by winding a laminated material formed by laminating a solid resin layer (resin film) and a fiber layer on a liner. This makes it possible to omit impregnation equipment, thereby reducing manufacturing costs. In addition, the amount of resin in the fiber reinforced resin layer can be controlled by changing the number of layers of the solid resin layer (resin film). For example, it is possible to improve the interlayer shear strength by increasing the amount of resin in the fiber reinforced resin layer. By improving the interlayer shear strength, it is also possible to reduce the amount of fiber reinforced resin used and reduce manufacturing costs.

[0025] In the above description of the present invention, the manufacturing method S100 of a high-pressure tank in which the first laminate 2 includes one first fiber layer 21 and one first resin layer 22, and the second laminate 3 includes one second fiber layer 31 and two second resin layers 32, is given as an example, but the present invention is not limited to this form. The number of fiber layers and resin layers included in each laminate, as well as their thicknesses and stacking order, can be appropriately adjusted to obtain a desired fiber:resin ratio.

[0026] In the above description of the present invention, the manufacturing method S100 is described as an example in which the first laminated material 2 is wound around the body 1a of the liner 1, and then the second laminated material 3 is wound around the dome-shaped portion 1b, but the present invention is not limited to this embodiment. For example, it is also possible to wind the first laminated material 2 around the body 1a after winding the second laminated material 3 around the dome-shaped portion 1b of the liner 1. [Explanation of symbols]

[0027] 1: (hollow) liner, 1a: body, 1b: dome-shaped side end (dome-shaped portion), 1c: opening, 2: first laminate, 3: second laminate, 21: first fiber layer, 22: (solid) first resin layer, 31: second fiber layer, 32: (solid) second resin layer, 100: high-pressure tank, 40: fiber-reinforced resin layer, 41: first fiber-reinforced resin layer, 42: second fiber-reinforced resin layer, 21': first fiber bundle, 31': second fiber bundle, 43: resin-rich layer

Claims

[Claim 1] A method for manufacturing a high-pressure tank, comprising the steps of: A step of winding a laminate having a structure in which a fiber layer and a solid thermosetting resin layer are laminated around a hollow liner; melting and then curing the thermosetting resin layer by heating; A method for manufacturing a high-pressure tank, comprising:

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