Gas cylinder and method of manufacturing the same

Abstract

The present disclosure relates to a gas tank and a manufacturing method thereof. The present invention provides a technology capable of improving the strength of a fiber layer formed on the outer periphery of a liner of a gas tank and improving the impregnation performance of a resin material with respect to the fiber layer. The gas tank is provided with: a liner having a cylindrical body portion and dome portions provided at both ends of the body portion; and a reinforcing layer covering the outer periphery of the liner. The reinforcing layer has: at least one first fiber layer provided with a first reinforcing portion in which fibers are wound in an interlaced manner on the outer periphery of the body portion; and at least one second fiber layer provided with a second reinforcing portion in which fibers are wound at a predetermined angle with respect to the central axis of the liner on the outer periphery of the body portion.

Description

Technical Field

[0001] This disclosure relates to gas cylinders and methods of manufacturing them. Background Technology

[0002] It is known that gas canisters have fiber layers stacked on the outer periphery of a container body. These fiber layers include: a first reinforcing portion in which reinforcing fibers are wound in an interlaced weave; and a second reinforcing portion in which reinforcing fibers are wound in a spiral shape, continuous with the first reinforcing portion (e.g., Patent Document 1). The gas canister is obtained by impregnating the stacked fiber layers with a thermosetting resin and then heating and curing them.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2020-026817

[0004] In the second reinforcing section where the reinforcing fibers are wound into a spiral shape, due to the high fiber density, there is a situation where the thermosetting resin is not sufficiently impregnated. Summary of the Invention

[0005] This disclosure can be implemented in the following forms.

[0006] (1) According to one aspect of the present disclosure, a gas canister is provided. The gas canister comprises: a liner having a cylindrical body portion and rounded tops disposed at both ends of the cylindrical body portion; and a reinforcing layer covering the outer periphery of the liner. The reinforcing layer comprises: at least one first fiber layer having a first reinforcing portion on the outer periphery of the cylindrical body portion having fibers wound in an interlaced manner; and at least one second fiber layer having a second reinforcing portion on the outer periphery of the cylindrical body portion having fibers wound at a predetermined angle relative to the central axis of the liner.

[0007] According to this type of gas canister, the strength of the gas canister can be improved by having a second fiber layer, thereby increasing the strength of the fiber layer, and the impregnation performance of the resin material relative to the fiber layer can be improved by having a first fiber layer.

[0008] (2) It can also be configured such that, based on the gas tank of the above form, the first fiber layer is the outermost layer of the above reinforcing layer.

[0009] According to this type of gas cylinder, it is possible to suppress or prevent the disorder of the arrangement of fibrous material on the outer surface of the fiber layer.

[0010] (3) It can also be configured such that, based on the gas tank of the above form, the first fiber layer is the innermost layer of the above reinforcing layer.

[0011] According to this type of gas canister, it is possible to suppress or prevent insufficient impregnation of resin material in the innermost layer, which is difficult to impregnate with resin material.

[0012] (4) It can also be configured such that, based on the gas tank of the above form, the reinforcing layer has an alternating stacked portion in which the first fiber layer and the second fiber layer are alternately stacked.

[0013] According to this type of gas canister, by alternately configuring different fiber layers with different winding methods, the shape deviation in the overall reinforcing layer can be suppressed, thereby suppressing or preventing the reduction of the gas canister's strength.

[0014] (5) It can also be configured such that, based on the gas tank of the above form, the reinforcing layer includes: a first continuous stacked portion, on which a plurality of the first fiber layers are continuously stacked; and a second continuous stacked portion, on which a plurality of the second fiber layers are continuously stacked.

[0015] Based on this type of gas canister, the number of times the winding method for switching fiber materials can be reduced, thereby increasing the productivity of the gas canister.

[0016] (6) It can also be configured such that, based on the gas tank of the above form, the first continuous layer stack is disposed in the reinforcing layer at a position on the inner side than the second continuous layer stack.

[0017] According to this type of gas canister, by centrally arranging a first fiber layer that is easy to impregnate with resin material on the inner layer side, the impregnation performance of the inner layer side, which is difficult to impregnate with resin material compared to the outer layer side, can be improved.

[0018] (7) It can also be configured such that, based on the gas tank of the above form, the number of the first fiber layers contained in the middle of the reinforcing layer and in the position of the inner layer side of the middle layer is greater than the number of the first fiber layers contained in the position of the outer layer side of the middle layer.

[0019] According to this type of gas canister, by providing more of the first fiber layer on the inner layer side, which is more difficult to impregnate with resin material compared to the outer layer side, it is possible to more reliably impregnate the innermost layer with resin material.

[0020] (8) It can also be configured such that, based on the gas tank of the above form, the total thickness of the second fiber layer is 5 mm or less.

[0021] According to this type of gas canister, when the resin material is pressurized and filled, the resin material can be more reliably impregnated to the innermost layer.

[0022] (9) It can also be configured such that, based on the above-described gas tank, the number of layers of the first fiber layer is greater than the number of layers of the second fiber layer.

[0023] According to this type of gas canister, resin material can be impregnated into the fiber layer more reliably.

[0024] (10) It can also be configured such that, based on the gas tank of the above-described form, the first fiber layer further has the first reinforcing portion on the outer periphery of the dome. It can also be configured such that, the second fiber layer further has the first reinforcing portion on the outer periphery of the dome.

[0025] According to this type of gas cylinder, by forming a first reinforcing portion on the outer periphery of a curved dome, compared to forming a second reinforcing portion on the outer periphery of the dome, it is possible to suppress the undesirable situation of the fiber material deviating from the predetermined configuration position.

[0026] This disclosure can also be implemented in various forms other than gas canisters and gas canister manufacturing methods. For example, it can be implemented in the form of a method for forming a fiber-reinforced resin layer, a method for manufacturing fiber-reinforced plastics, an apparatus for manufacturing fiber-reinforced plastics, an apparatus for manufacturing gas canisters, a control method for the apparatus for manufacturing fiber-reinforced plastics, a computer program for implementing the control method, and a non-transitory recording medium recording the computer program. Attached Figure Description

[0027] Figure 1 This is an explanatory diagram showing the structure of the gas tank according to the first embodiment of this disclosure from a cross-sectional perspective.

[0028] Figure 2 This is an explanatory diagram showing a substrate having a first fiber layer on the outer periphery of the cylindrical part.

[0029] Figure 3 This is an explanatory diagram showing an enlarged view of a portion of the first reinforcing section.

[0030] Figure 4 It means Figure 3 A cross-sectional view at position IV-IV.

[0031] Figure 5 This is an explanatory diagram showing a matrix having a second fiber layer on the outer periphery of the cylindrical part.

[0032] Figure 6 This is an explanatory diagram showing an enlarged view of a portion of the second reinforcing section.

[0033] Figure 7 It means Figure 6 A sectional view at position VII-VII.

[0034] Figure 8 This is an explanatory diagram showing the simplified structure of a gas cylinder manufacturing apparatus.

[0035] Figure 9 This is an explanatory diagram showing the movement paths of the first and second supply units when spiral winding is performed.

[0036] Figure 10This is an explanatory diagram showing the movement paths of the first and second supply units during the weaving and winding process.

[0037] Figure 11 This is an explanatory diagram schematically showing the structure of the fiber-reinforced resin layer of the gas tank according to the first embodiment of this disclosure.

[0038] Figure 12 This is an explanatory diagram schematically showing the structure of the fiber-reinforced resin layer of the gas tank according to the second embodiment of this disclosure.

[0039] Figure 13 This is an explanatory diagram showing another form of the first reinforcing section.

[0040] Figure 14 It means Figure 13 A cross-sectional view at position XIV-XIV.

[0041] Explanation of reference numerals in the attached figures

[0042] 10…lining; 12…cylinder section; 14…dome; 16, 17…joints; 20…fiber-reinforced resin layer; 22A, 22B…fiber material; 42…first supply section; 44…second supply section; 100…gas tank; 210…first reinforcement section; 211-215, 221-225…fiber material; 220…second reinforcement section; 300…manufacturing apparatus; AX…central shaft; BD…boundary; BR…boundary section; GP…gap; L1…first fiber layer; L11, L12…layers; L2…second fiber layer; L21, L22…layers; OR1, OR1b, OR2, OR2b…movement path; ST1…first continuous laminate; ST2…second continuous laminate; TB1, TB2…tables. Detailed Implementation

[0043] A. Implementation Method 1:

[0044] Figure 1 This is an explanatory diagram showing the structure of the gas tank 100 according to the first embodiment of this disclosure from a cross-sectional perspective. The gas tank 100 is a storage container for containing fluids with high pressures of 10 to 70 MPa. The gas tank 100 can be formed in any shape. Figure 1 In the example, the gas tank 100 has a long, roughly cylindrical shape along the central axis AX.

[0045] The gas tank 100 is used, for example, to store hydrogen supplied to fuel cells for vehicles or stationary fuel cells. The gas tank 100 includes a liner 10, connectors 16 and 17 disposed at both ends of the liner 10, and a fiber-reinforced resin layer 20 formed on the outer peripheral surfaces of the liner 10 and the connectors 16 and 17. Not limited to hydrogen, the gas tank 100 can also store various fluids such as oxygen and natural gas.

[0046] Liner 10 is a container having an internal space for sealing fluid. Liner 10 is formed, for example, from a gas-barrier resin such as nylon, polyamide, ethylene-vinyl alcohol copolymer (EVOH), polyethylene, polypropylene, epoxy resin, or polystyrene. Liner 10 has a cylindrical body portion 12 and two hemispherical domes 14 disposed at both ends of the cylindrical body portion 12 along a central axis AX. An opening is provided at the top of the domes 14. Figure 1 The boundary BD shown is the connection between the dome 14 of the liner 10 and the cylindrical portion 12, and is the position where the curvature of the liner 10 is zero. The liner 10 may also be made of metal instead of resin. The cylindrical portion 12 is not limited to a cylindrical shape, and may also be any cylindrical shape with a polygonal cross-section.

[0047] Connectors 16 and 17 are installed at the openings provided at the top of each dome 14 of the liner 10. Connector 16 is used, for example, for filling gas into or releasing gas from the gas tank 100. Connector 17 is sealed and used for centering during manufacturing, etc.

[0048] The fiber-reinforced resin layer 20 is a reinforcing layer used to reinforce the liner 10. The fiber-reinforced resin layer 20 is formed by covering the outer periphery of the liner 10 with fiber-reinforced plastic (FRP). In this embodiment, the fiber-reinforced resin layer 20 is formed by a so-called RTM (Resin Transfer Molding) method. Specifically, a substrate (also referred to as a "fiber preform") on which the fiber layer is to be formed on the outer periphery of the liner 10 is disposed within a mold. A "fiber layer" refers to a layer formed by winding fibrous material. As described later, the fiber layer has a structure in which multiple first fiber layers L1 and second fiber layers L2 are stacked in a predetermined order in the thickness direction. In addition to the liner 10, the fibrous material may also be wound onto the outer surfaces of the joints 16 and 17.

[0049] In this embodiment, carbon fiber is used as the fiber material. Besides carbon fiber, other fiber materials such as glass fiber, aramid fiber, boron fiber, and high-strength polyethylene fiber can also be used, or combinations of these types of fibers can be used. The number of fiber layers is, for example, about 10 to 20 layers, and can be arbitrarily set according to the size and shape of the gas canister 100. In this embodiment, the number of fiber layers is 11.

[0050] The mold containing the substrate is closed, and resin material is filled into the closed mold under high speed and pressure, thereby impregnating the fiber layer with the resin material. During the impregnation of the resin material, the interior of the substrate disposed within the mold, i.e., the interior of the lining 10, is pressurized to withstand the external pressure applied from the resin material during impregnation, for example, by filling it with nitrogen gas. By curing the resin material impregnated into the fiber layer, the gas cylinder 100 is completed.

[0051] Figure 2 This is an explanatory diagram showing the appearance of the substrate having a first fiber layer L1 on the outer periphery of the cylindrical portion 12. The "first fiber layer" refers to the fiber layer having a first reinforcing portion 210 in the area RG2 that forms the outer periphery of the cylindrical portion 12. The "first reinforcing portion" is a portion of the fiber layer formed by a so-called weaving and winding. "Weaving and winding" refers to a method of winding fibrous material in an interlaced weave.

[0052] like Figure 2 As shown, in this embodiment, the first fiber layer L1, in addition to the area RG2, also has a first reinforcing portion 210 on the outer periphery of the dome 14 that forms the lining 10. That is, the first fiber layer L1 has a first reinforcing portion 210 on the outer periphery of the entire lining 10 by continuously forming the first reinforcing portion 210 throughout the areas RG1 and RG2. Since the first fiber layer L1 is formed on the outer periphery of the entire lining 10 by weaving and winding, it is also referred to as a "woven and wound layer".

[0053] Figure 3 This is an explanatory diagram showing an enlarged view of the area AR1 of the first reinforcing section 210. Figure 4 It means Figure 3 A cross-sectional view at position IV-IV. (See attached image.) Figure 3 , 4 As shown, the fibrous material may have a strip-like shape, with a predetermined width WF of approximately several millimeters. However, the fibrous material can also be any shape, such as thread or sheet. The thickness of each piece of fibrous material can be set to any thickness, for example, less than 0.5 millimeters. In this embodiment, the thickness of each piece of fibrous material is 0.3 millimeters.

[0054] like Figure 3As shown, fiber material 211 is wound at an angle θ1 relative to the central axis AX of lining 10, forming an upward angle. Fiber materials 212 to 215 are wound at an angle θ2 relative to the central axis AX of lining 10, forming a downward angle. Angles θ1 and θ2 can be arbitrarily set. For example, it is preferable to set angles θ1 and θ2 considering the stress acting on the cylinder portion 12 of lining 10. In this embodiment, in order to obtain a gas cylinder 100 with sufficient strength, for example, angle θ1 is set at approximately +54.7 degrees relative to the central axis AX, and for example, angle θ2 is set at -54.7 degrees relative to the central axis AX.

[0055] like Figure 4 As shown, the first reinforcing portion 210 is formed by interlacing fiber materials 211 and 212-215, alternating their configurations on the inner and outer sides along the lamination direction. In this embodiment, the fiber materials 211 are arranged in units of two fibers. The first reinforcing portion 210 includes a layer L11, disposed on the outer side of the gas canister 100, having a thickness equivalent to one fiber material, and a layer L12, disposed on the inner side of the gas canister 100, having a thickness equivalent to one fiber material. The thickness of each layer of the first reinforcing portion 210 is equivalent to the thickness of two fibers. In the following description, the number of layers of the first fiber layer L1 is counted as "1 layer" when layers L11 and L12 are added together. Furthermore, in this embodiment, the thickness of the first reinforcing portion 210 is 0.6 mm.

[0056] like Figure 3 As shown, the first reinforcing portion 210 is formed by interlacing multiple fiber materials, thus increasing the mutual constraint between the fiber materials compared to spiral winding. Therefore, for example, compared to the second reinforcing portion 220, the first reinforcing portion 210 can suppress the undesirable situation of disordered fiber arrangement and the undesirable situation of fiber material slippage and deviation from the predetermined arrangement position during winding.

[0057] like Figure 3 As shown, the first reinforcing section 210 has gaps GP between the woven fibers due to the interlacing of multiple fiber materials. Therefore, in the first reinforcing section 210, the resin material can be easily impregnated compared to a fiber layer formed by tightly adhering fiber materials such as spiral winding.

[0058] Figure 5This is an explanatory diagram showing the appearance of the substrate having a second fiber layer L2 on the outer periphery of the cylindrical portion 12. The "second fiber layer" refers to the fiber layer having a second reinforcing portion 220 within the range RG2. The "second reinforcing portion" is a portion of the fiber layer formed by a so-called helical winding. "Helical winding" refers to a method in which, after winding the fiber material around the outer periphery of the cylindrical portion 12 at a predetermined angle relative to the central axis AX of the lining 10, it is further wound around the lining 10 at another predetermined angle relative to the central axis AX.

[0059] like Figure 5 As shown, in this embodiment, the second fiber layer L2 has a first reinforcing portion 210 in the area RG1. According to the gas cylinder 100 of this embodiment, by forming the first reinforcing portion 210 on the outer periphery of the curved dome 14, the occurrence of the defect of the fiber material slipping and deviating from the predetermined arrangement position can be suppressed compared to helical winding. Furthermore, provided that the gas cylinder 100 has sufficient strength, the second fiber layer L2 may have a second reinforcing portion 220 formed in the area RG1, or the fiber layer in the area RG1 may be omitted and the first reinforcing portion 210 may only be formed on the outer periphery of the cylinder portion 12.

[0060] In the second fiber layer L2, a first reinforcing portion 210 in range RG1 and a second reinforcing portion 220 in range RG2 are formed continuously. Specifically, after the first reinforcing portion 210 is formed in one range RG1, the winding method of the fiber material is switched, thereby forming the second reinforcing portion 220 in range RG2 continuously with the first reinforcing portion 210. After the second reinforcing portion 220 is formed, the first reinforcing portion 210 is formed in another range RG1, thus completing the second fiber layer L2. Because it is formed by switching the winding method of the fiber material in ranges RG1 and RG2, the second fiber layer L2 is also referred to as a "switched winding layer".

[0061] like Figure 5 As shown near the boundary BD, from the start position of the winding method switch to the completion position of the winding method switch, from the viewpoint of regularly arranging the fiber material, a predetermined width may be generated in the axial direction. Here, "the axial position of the fiber material winding method switch" refers to the position midway between the axial start position and the completion position of the winding method switch. Figure 5 In the example, the switching position of the winding method from the first reinforcing part 210 to the second reinforcing part 220 is approximately consistent with the boundary BD. Furthermore, a specified width can be set for the "switching position of the axial fiber material winding method" to allow for manufacturing errors, mechanical errors, etc. In this embodiment, the "switching position of the axial fiber material winding method" is also set to include the distance LW, which is the width WF of two fiber materials of different sizes allowed to be wound forward and backward in the axial direction, as the error boundary BR.

[0062] Figure 6 This is an enlarged explanatory diagram showing the appearance of the second reinforcing section 220. Figure 6 In the middle, magnification indicates Figure 5 A portion of the AR2 range. For example... Figure 6 As shown, fiber material 221 is wound at an angle θ3 relative to the central axis AX of lining 10, forming an elevation angle. Fiber materials 222 to 225 are wound parallel to each other at an angle θ4 relative to the central axis AX, forming a depression angle. Angles θ3 and θ4 can be arbitrarily set, for example, taking into account the stress acting on the cylindrical portion 12 of lining 10. In this embodiment, angles θ3 and θ4 are configured to be the same as the angles θ1 and θ2 described above.

[0063] Figure 7 It means Figure 6 A sectional view at position VII-VII. (See attached image.) Figure 7 As shown, the second reinforcing portion 220 has a layer L21 disposed on the outer side of the gas canister 100, such as fiber material 221, and a layer L22 disposed on the inner side of the gas canister 100, such as fiber materials 222 to 225. In the following description, the number of layers of the second fiber layer L2 is counted as "1 layer" when layers L21 and L22 are added together. Furthermore, in this embodiment, the thickness of the second reinforcing portion 220 is 0.6 mm.

[0064] like Figure 6 , 7 As shown, the second reinforcing section 220 is wound in a spiral manner, with multiple fiber materials arranged parallel to each other and tightly pressed together. Therefore, the density of the fiber material is higher than that of woven winding, resulting in higher strength of the gas canister 100. In the second reinforcing section 220, the fiber materials are tightly pressed together, making it more difficult to impregnate with resin material, for example, when resin material is pressurized and filled using the RTM method, compared to the first reinforcing section 210.

[0065] Figure 8 This is an explanatory diagram showing a simplified structure of the manufacturing apparatus 300 for the gas cylinder 100. The manufacturing apparatus 300 is a device for winding fibrous material onto the liner 10. The manufacturing apparatus 300 includes a first supply section 42 and a second supply section 44 for supplying the fibrous material, and a moving mechanism (not shown) for moving the liner 10 in the direction DRT. Furthermore, in Figure 8 For ease of illustration, two first supply sections 42 and a second supply section 44 are shown, but in reality, they have a number corresponding to the number of strands of wound fiber material.

[0066] The manufacturing apparatus 300 rotates the first supply section 42 for feeding fiber material 22A and the second supply section 44 for feeding fiber material 22B around the movement paths OR1 and OR2 of the lining 10, respectively. The manufacturing apparatus 300 moves the lining 10 along the axial direction DRT and sequentially winds the fiber materials 22A and 22B relative to the outer periphery of one dome 14, the outer periphery of the cylindrical portion 12, and the outer periphery of the other dome 14 of the lining 10.

[0067] In the case of spiral winding and braided winding, the manufacturing apparatus 300 can switch the movement paths OR1 and OR2 to different paths. Figure 8 In the example, the movement paths OR1 and OR2 are shown in the case of spiral winding.

[0068] Figure 9 This diagram illustrates the movement paths OR1 and OR2 of the first supply unit 42 and the second supply unit 44 in the case of spiral winding. The movement path OR1 of the first supply unit 42 is represented by a solid line, and the movement path OR2 of the second supply unit 44 is represented by a dashed line. The first supply unit 42 and the second supply unit 44 are arranged, for example, along movement paths OR1 and OR2, which are two concentric circles surrounding the central axis AX. Movement path OR1 is positioned further away from the central axis AX than movement path OR2, i.e., radially outward. Furthermore, movement paths OR1 and OR2 are not limited to concentric circles and can be tracks of any shape capable of rotating around the central axis AX.

[0069] like Figure 9 As shown, the moving direction DR1 of the first supply unit 42 on moving path OR1 and the moving direction DR2 of the second supply unit 44 on moving path OR2 are opposite to each other. Figure 8 As shown, a second supply section 44, rotating in the direction of movement DR2, winds multiple fiber materials 22B around the outer periphery of the lining 10 at an angle θ4 relative to the central axis AX, forming a downward angle. A first supply section 42, rotating in the direction of movement DR1, winds multiple fiber materials 22A around the outer side of the fiber materials 22B at an angle θ3 relative to the central axis AX, forming an upward angle. As a result, a second reinforcing section 220, with a layer L21 disposed on the outer side and a layer L22 disposed on the inner side, is formed on the outer periphery of the cylindrical section 12.

[0070] Figure 10 This is an explanatory diagram showing the movement paths OR1b and OR2b of the first supply unit 42 and the second supply unit 44 during the weaving and winding process. To facilitate understanding of the technology, in Figure 10 In the diagram, the movement path OR1b of the first supply unit 42 is represented by a solid line, and the movement path OR2b of the second supply unit 44 is represented by a dashed line.

[0071] like Figure 10 As shown, the moving direction DR1 of the first supply section 42 on the moving path OR1b and the moving direction DR2 of the second supply section 44 on the moving path OR2b are opposite to each other. In the moving paths OR1b and OR2b, the first supply section 42 is radially inner and the second supply section 44 is radially outer, and vice versa. This alternates between states where the second supply section 44 is radially inner and the first supply section 42 is radially outer. Consequently, fiber material 22B supplied at an angle θ2 relative to the central axis AX (a downward angle) and fiber material 22A supplied at an angle θ1 relative to the central axis AX (an upward angle) are wound in an interlaced manner around the outer periphery of the lining 10. As a result, a first reinforcing section 210, with a layer L11 disposed on the outer side and a layer L12 disposed on the inner side, is formed on the outer periphery of the cylindrical section 12.

[0072] The manufacturing apparatus 300 can switch movement paths OR1, OR2, and OR1b, OR2b at any time relative to the lining 10 moving in the direction DRT. In this embodiment, when forming the second fiber layer L2, after the manufacturing apparatus 300 weaves and winds the lining 10 relative to the outer periphery of a dome 14 using movement paths OR1b, OR2b, ... Figure 2 The boundary portion BR shown switches the movement paths OR1b and OR2b to OR1 and OR2 to spirally wind relative to the cylindrical portion 12. The manufacturing apparatus 300 switches the movement paths OR1 and OR2 to OR1b and OR2b at the boundary portion BR between the cylindrical portion 12 and the other dome 14 to weave and wind the other dome 14. When forming the first fiber layer L1, the manufacturing apparatus 300 does not switch the movement paths OR1 and OR2 and weaves and winds the entire lining 10.

[0073] Figure 11 This is an explanatory diagram schematically showing the structure of the fiber-reinforced resin layer 20 of the gas tank 100 according to the first embodiment of this disclosure. Figure 11 Table TB1, shown, corresponds to a cross-sectional view of the fiber-reinforced resin layer 20 within range RG2, illustrating the stacking direction arrangement of the first fiber layer L1 and the second fiber layer L2 in the outer periphery of the cylinder portion 12 of the liner 10. The bottom layer of Table TB1 is the liner 10, with its lower side representing the inner side of the gas tank 100. The top layer of Table TB1 is the 11th layer of the fiber-reinforced resin layer 20, which is also the outermost layer. The fiber layers stacked on the outer surface of the liner 10 are also referred to as the "innermost layer." When the innermost layer is considered as the first layer, layers 2 through 10 are also referred to as "inner layers."

[0074] like Figure 11As shown, in the gas canister 100 of this embodiment, the fiber-reinforced resin layer 20 has: a first fiber layer L1 having a first reinforcing portion 210 formed by braiding; and a second fiber layer L2 having a second reinforcing portion 220 formed by spiral winding. The strength of the gas canister 100 is increased by including the second fiber layer L2, and the resin material is less likely to be impregnated into the fiber layer by including the first fiber layer L1. Therefore, a gas canister 100 that achieves a balance between suppressing insufficient impregnation of the resin material and increasing strength can be obtained.

[0075] In the gas tank 100 of this embodiment, a first fiber layer L1 is disposed on the outermost layer of the fiber-reinforced resin layer 20. If resin material is filled into the mold under pressure using the RTM method, the high-speed, high-pressure resin material collides with the fiber layer, resulting in defects such as disordered fiber arrangement, fiber peeling, and floating. By disposing the first fiber layer L1, which has a higher binding force between the fiber materials, on the outermost layer, when the resin material is impregnated into the fiber layer, defects such as disordered fiber arrangement and fiber peeling on the outer surface of the fiber layer caused by the collision of the resin material can be suppressed or prevented.

[0076] In the gas tank 100 of this embodiment, a first fiber layer L1 is disposed in the innermost layer of the fiber-reinforced resin layer 20. The innermost layer of the fiber-reinforced resin layer 20 is easily affected by deformation of the lining 10, and the density of the fiber material tends to be higher compared to inner fiber layers. Therefore, the innermost layer of the fiber-reinforced resin layer 20 is difficult to impregnate with resin material compared to other layers. This characteristic becomes particularly pronounced when the lining 10 is made of resin. In this embodiment, by disposing a first fiber layer L1, which facilitates resin impregnation, inadequate impregnation of the resin material in the innermost layer of the fiber-reinforced resin layer 20, insufficient impregnation of the resin material in the innermost layer can be suppressed or prevented.

[0077] In the gas canister 100 of this embodiment, the fiber-reinforced resin layer 20 has an alternating laminated portion. An "alternating laminated portion" refers to a fiber layer having multiple first fiber layers L1 and multiple second fiber layers L2, with the first fiber layers L1 and the second fiber layers L2 alternately laminated. In this embodiment, the first fiber layers L1 and the second fiber layers L2 are alternately laminated every other layer. However, this is not a limitation; the first fiber layers L1 and the second fiber layers L2 may also be alternately laminated every two or more predetermined layers. The alternating laminated portion may be included in any part of the fiber-reinforced resin layer 20; for example, it may be present only in the inner layer, or it may be included in at least one of the innermost and outermost layers. In this embodiment, the alternating laminated portion is formed throughout all layers from the innermost to the outermost layer. According to the gas canister 100 of this embodiment, by alternately arranging fiber layers with different winding methods for the fiber materials, the overall shape deviation of the fiber-reinforced resin layer 20 can be suppressed, thereby suppressing or preventing a decrease in the strength of the gas canister 100.

[0078] In the gas cylinder 100 of this embodiment, the fiber-reinforced resin layer 20 is set such that the total thickness of the second fiber layer L2 is 5 mm or less. This value was obtained by the inventors through experiments using a manufacturing apparatus for the gas cylinder 100 employing the RTM method, determining the relationship between the thickness of the second fiber layer L2 contained in the fiber-reinforced resin layer 20 and the impregnation properties of the resin material. Specifically, samples of multiple substrates with different thicknesses of the second fiber layer L2 are prepared. The samples are placed in a mold of the manufacturing apparatus, and a two-component epoxy resin is used as the resin material. The resin is filled under pressure of approximately 5 to 10 MPa to impregnate the fiber layer of each sample. As a result, the maximum thickness of the second fiber layer L2 in the sample where the resin material can impregnate to the innermost layer of the fiber layer is 5 mm. However, in order to more reliably impregnate the resin material, in this embodiment, the total number of second fiber layer L2 layers is set to 5 or less, resulting in a total thickness of 3.0 mm or less for the second fiber layer L2. According to the gas tank 100 of this embodiment, when the resin material using the RTM method is pressurized and filled, the resin material can be more reliably impregnated to the innermost layer.

[0079] In the gas tank 100 of this embodiment, such as Figure 11 As shown, the fiber-reinforced resin layer 20 is configured such that the first fiber layer L1 has 6 layers and the second fiber layer L2 has 5 layers. That is, the first fiber layer L1 in the fiber-reinforced resin layer 20 is configured to have more layers than the second fiber layer L2. Therefore, the resin material can be more reliably impregnated into the fiber layers.

[0080] B. Second Implementation Method:

[0081] Figure 12This is an explanatory diagram schematically showing the structure of the fiber-reinforced resin layer 20 of the gas tank 100 according to the second embodiment of this disclosure. Figure 12 The structure of Table TB2 shown is similar to Figure 11 The structure of Table TB1 shown is the same, so the explanation is omitted.

[0082] The gas cylinder 100 in the second embodiment is the same as that in the first embodiment. The fiber-reinforced resin layer 20 has a first fiber layer L1 and a second fiber layer L2, which can achieve a gas cylinder 100 that balances the suppression of insufficient impregnation of the resin material and its strength. In addition, the total thickness of the second fiber layer L2 is 3.0 mm or less, which can more reliably impregnate the resin material to the innermost layer. Furthermore, in order to suppress or prevent insufficient impregnation of the resin material in the innermost layer, the first fiber layer L1 is disposed in the innermost layer of the fiber-reinforced resin layer 20, and in order to improve the strength of the outer surface of the fiber layer, the first fiber layer L1 is disposed in the outermost layer of the fiber-reinforced resin layer 20.

[0083] As shown in Table TB2, in this embodiment, the fiber-reinforced resin layer 20 has a first continuous stacked portion ST1 in which multiple first fiber layers L1 are continuously stacked, and a second continuous stacked portion ST2 in which multiple second fiber layers L2 are continuously stacked. By continuously arranging fiber layers with different winding methods for the fiber materials, the number of times the winding method of the fiber materials is switched can be reduced, thereby improving the productivity of the gas tank 100.

[0084] As shown in Table TB2, in the gas tank 100 of the second embodiment, the first continuous laminated portion ST1 is formed by a first fiber layer L1 continuously laminated from the innermost layer to the fifth layer, and the second continuous laminated portion ST2 is formed by a second fiber layer L2 continuously laminated from the sixth layer to the tenth layer. In this embodiment, in the fiber-reinforced resin layer 20, the first continuous laminated portion ST1 is positioned on the inner layer side compared to the second continuous laminated portion ST2. By concentrating the first fiber layer L1, which is easily impregnated with resin material, on the inner layer side, the impregnation performance of the inner layer side, which is difficult to impregnate with resin material compared to the outer layer side, can be improved.

[0085] C. Other implementation methods:

[0086] (C1) In the first embodiment described above, the first fiber layer L1 has a first reinforcing portion 210 on both sides of the area RG1 and RG2 that form the dome 14 of the lining 10 and the outer periphery of the cylindrical portion 12. In contrast, the first fiber layer L1 may also be configured as a fiber layer formed by a method other than the first reinforcing portion 210, on the premise that the first reinforcing portion 210 is provided in the area RG2. For example, a second reinforcing portion 220 is provided in the area RG1.

[0087] (C2) In the first embodiment described above, as Figure 11 As shown, the number of first fiber layers L1 contained in the middle and the innermost layer position of the fiber-reinforced resin layer 20 is equal to the number of first fiber layers L1 contained in the outermost layer position of the fiber-reinforced resin layer 20. "Middle of the fiber-reinforced resin layer 20" refers to the middle position in the stacking direction of the fiber-reinforced resin layer 20. "Middle of the fiber-reinforced resin layer 20" means, in the case where the fiber-reinforced resin layer 20 has an odd number of fiber layers, the middle fiber layer based on the stacking number of the fiber-reinforced resin layer 20; in the case where the fiber-reinforced resin layer 20 has an even number of fiber layers, it refers to the boundary between two fiber layers located in the middle based on the stacking number of the fiber-reinforced resin layer 20. Figure 12 In the example, the middle layer of the fiber-reinforced resin layer 20 is the 6th layer. In the case where the fiber-reinforced resin layer 20 has, for example, 12 fiber layers, the middle layer is the boundary between the 6th and 7th layers.

[0088] In contrast, the number of layers of the first fiber layer L1 contained in the intermediate layer of the fiber-reinforced resin layer 20 and the layer located on the inner side of the intermediate layer can be more than the number of layers of the first fiber layer L1 contained on the outer side. According to this configuration of the gas canister 100, by distributing more of the first fiber layer L1 on the inner side, which is more difficult for resin material to impregnate compared to the outer side, it is possible to more reliably impregnate the resin material to the innermost layer.

[0089] (C3) Figure 13 This is an explanatory diagram showing another form of the first reinforcing section 210. Figure 14 It means Figure 13 A cross-sectional view at position XIV-XIV. In the above embodiments, an example is shown where the first reinforcing portion 210 is formed by weaving fiber material in a manner different for each pair of fibers. In contrast, as... Figure 13 and Figure 14 As shown, the first reinforcing part 210 can also be formed by weaving the fiber material in a way that is different for each fiber material.

[0090] (C4) In the second embodiment described above, an example is shown where the first continuous laminate ST1 is positioned on the inner side of the second continuous laminate ST2. Conversely, the second continuous laminate ST2 may also be positioned on the inner side of the first continuous laminate ST1. According to this configuration of the gas canister 100, by having a greater number of second fiber layers L2 on the inner side, the strength of the gas canister 100 can be improved.

[0091] This disclosure is not limited to the embodiments described above, and can be implemented in various structures without departing from its spirit. For example, in order to solve some or all of the above-described problems, or to achieve some or all of the above-described effects, the technical features in the embodiments corresponding to the technical features in the various forms described in the summary section of the invention can be appropriately replaced or combined. In addition, any technical feature not specified as essential to this specification can be appropriately deleted.

Claims

1. A gas tank, wherein the gas tank comprises: a liner having a cylindrical cylinder portion and dome portions provided at both ends of the cylinder portion; and a reinforcement layer covering an outer periphery of the liner, the reinforcement layer comprises: at least one first fiber layer having a first reinforcing portion in which a fiber is wound in an interlaced weave at an outer periphery of the cylinder portion; and at least one second fiber layer having a second reinforcing portion in which a fiber is wound at a predetermined angle with respect to a central axis of the liner at the outer periphery of the cylinder portion, the reinforcement layer comprises: a first continuous layering portion in which a plurality of the first fiber layers are continuously layered; and a second continuous layering portion in which a plurality of the second fiber layers are continuously layered, the first continuous layering portion is disposed at a position closer to an inner layer side than the second continuous layering portion in the reinforcement layer.

2. A gas tank, wherein the gas tank comprises: a liner having a cylindrical cylinder portion and dome portions provided at both ends of the cylinder portion; and a reinforcement layer covering an outer periphery of the liner, the reinforcement layer comprises: at least one first fiber layer having a first reinforcing portion in which a fiber is wound in an interlaced weave at an outer periphery of the cylinder portion; and at least one second fiber layer having a second reinforcing portion in which a fiber is wound at a predetermined angle with respect to a central axis of the liner at the outer periphery of the cylinder portion, the reinforcement layer comprises: a first continuous layering portion in which a plurality of the first fiber layers are continuously layered; and a second continuous layering portion in which a plurality of the second fiber layers are continuously layered, a number of the first fiber layers contained in a position closer to an inner layer side than a middle of the reinforcement layer is larger than a number of the first fiber layers contained in a position closer to an outer layer side than the middle.

3. The gas tank according to claim 1 or 2, wherein the first fiber layer is an outermost layer of the reinforcement layer.

4. The gas tank according to claim 1 or 2, wherein the first fiber layer is an innermost layer of the reinforcement layer.

5. The gas tank according to claim 1 or 2, wherein the reinforcement layer comprises an alternate layering portion in which the first fiber layer and the second fiber layer are alternately layered.

6. The gas tank according to claim 1 or 2, wherein a total value of thicknesses of the second fiber layers is 5 mm or less.

7. The gas tank according to claim 1 or 2, wherein a number of the first fiber layers is larger than a number of the second fiber layers.

8. The gas tank according to claim 1 or 2, wherein the first fiber layer further has the first reinforcing portion at an outer periphery of the dome portion, the second fiber layer further has the first reinforcing portion at the outer periphery of the dome portion.

9. A method of manufacturing a gas tank, wherein the method of manufacturing the gas tank comprises: a step of preparing a liner having a cylindrical cylinder portion and dome portions provided at both ends of the cylinder portion; and a step of forming a base body having a reinforcement layer at an outer periphery of the liner, the step of forming the base body comprises: a step of forming at least one first fiber layer having a first reinforcing portion in which a fiber is wound in an interlaced weave at an outer periphery of the cylinder portion; and a step of forming at least one second fiber layer having a second reinforcing portion in which a fiber is wound at a predetermined angle with respect to a central axis of the liner at the outer periphery of the cylinder portion, the reinforcement layer comprises: a first continuous layer stack portion in which a plurality of the first fiber layers are continuously stacked; and a second continuous layer stack portion in which a plurality of the second fiber layers are continuously stacked, the first continuous layer stack portion is disposed at a position closer to an inner layer side than the second continuous layer stack portion in the reinforcement layer.

10. A method of manufacturing a gas tank, wherein the method of manufacturing the gas tank comprises: a step of preparing a liner having a cylindrical cylinder portion and dome portions provided at both ends of the cylinder portion; and a step of forming a base body having a reinforcement layer on an outer periphery of the liner, the step of forming the base body comprises: a step of forming at least one first fiber layer having a first reinforcement portion in which fibers are wound in an interlaced weave on an outer periphery of the cylinder portion; and a step of forming at least one second fiber layer having a second reinforcement portion in which fibers are wound at a predetermined angle with respect to a central axis of the liner on the outer periphery of the cylinder portion, the number of the first fiber layers contained at a position closer to an inner layer side than a middle of the reinforcement layer and the middle is greater than the number of the first fiber layers contained at a position closer to an outer layer side than the middle and the middle.

11. The method of manufacturing the gas tank according to claim 9 or 10, wherein the method further comprises: a step of disposing the formed base body in an interior of a mold and closing the mold; and a step of filling a resin material into the closed mold to impregnate the resin material into fiber layers of the base body.

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