Gas tank and method of manufacturing the same

Abstract

To provide a technique capable of improving strength of a fiber layer formed on an outer periphery of a liner of a gas tank and capable of improving an impregnation property of a resin material with respect to the fiber layer.SOLUTION: A gas tank includes: a liner having a cylindrical trunk and domes provided on both ends of the trunk; and a reinforcement layer covering an outer periphery of the liner. The reinforcement layer includes at least one first fiber layer having a first reinforcement in which fibers are wound in such a manner of being alternately woven on an outer periphery of the trunk, and at least one second fiber layer having a second reinforcement in which the fibers are wound at a predetermined angle with respect to a center axis of the liner on the outer periphery of the trunk.SELECTED DRAWING: Figure 11

Description

[Technical field]

[0001] The present disclosure relates to a gas tank and a method for manufacturing the same. [Background technology]

[0002] There is known a gas tank in which a fiber layer having a first reinforcing part in which reinforcing fibers are wound so as to be woven alternately and a second reinforcing part in which reinforcing fibers are wound helically so as to be continuous with the first reinforcing part is laminated on the outer circumferential surface of a container body (for example, Patent Document 1). The gas tank is obtained by impregnating the laminated fiber layer with a thermosetting resin and heating and curing it. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-026817 A Summary of the Invention [Problem to be solved by the invention]

[0004] The second reinforcing portion in which the reinforcing fibers are wound in a helical shape may not be sufficiently impregnated with the thermosetting resin due to the high fiber density. [Means for solving the problem]

[0005] The present disclosure can be realized in the following forms.

[0006] (1) According to one embodiment of the present disclosure, there is provided a gas tank comprising a liner having a cylindrical body and dome portions provided at both ends of the body, and a reinforcing layer covering an outer periphery of the liner. The reinforcing layer comprises at least one first fiber layer comprising a first reinforcing portion wound around the outer periphery of the body in a staggered weaving of fibers, and at least one second fiber layer comprising a second reinforcing portion wound around the outer periphery of the body at a predetermined angle with respect to a central axis of the liner. According to this form of gas tank, the strength of the fiber layer is improved by providing the second fiber layer, thereby improving the strength of the gas tank, and the impregnation performance of the resin material into the fiber layer is improved by providing the first fiber layer. (2) In the gas tank of the above aspect, the outermost layer of the reinforcing layer may be the first fiber layer. According to the gas tank of this embodiment, it is possible to suppress or prevent the arrangement of the fiber material on the outer surface of the fiber layer from becoming disordered. (3) In the gas tank of the above aspect, the innermost layer of the reinforcing layer may be the first fiber layer. According to the gas tank of this configuration, it is possible to suppress or prevent insufficient impregnation of the resin material in the innermost layer, which is difficult to impregnate with the resin material. (4) In the gas tank of the above aspect, the reinforcing layer may include an alternating laminate portion in which the first fiber layer and the second fiber layer are laminated alternately. According to this form of gas tank, by alternately arranging fiber layers with different winding methods of fiber material, shape variation throughout the reinforcing layer can be suppressed, and a decrease in the strength of the gas tank can be suppressed or prevented. (5) In the gas tank of the above embodiment, the reinforcing layer may include a first continuous laminate portion in which a plurality of the first fiber layers are continuously laminated, and a second continuous laminate portion in which a plurality of the second fiber layers are continuously laminated. According to this type of gas tank, the number of times the winding method of the fiber material needs to be changed can be reduced, thereby improving the productivity of the gas tank. (6) In the gas tank of the above aspect, the first continuous laminate portion may be disposed on an inner layer side of the second continuous laminate portion in the reinforcing layer. According to the gas tank of this embodiment, the first fiber layer, which is easily impregnated with the resin material, is concentrated on the inner layer side, thereby improving the impregnation performance of the inner layer side, which is more difficult to impregnate with the resin material than the outer layer side. (7) In the gas tank of the above embodiment, the number of layers of the first fiber layers included in the middle of the reinforcing layer and on the inner layer side of the middle may be greater than the number of layers of the first fiber layers included on the outer layer side of the middle. In the gas tank of this embodiment, by disposing a larger number of the first fiber layers on the inner layer side, which is less easily impregnated with the resin material than the outer layer side, the resin material can be more reliably impregnated into the innermost layer. (8) In the gas tank of the above aspect, the second fiber layer may have a total thickness of 5 millimeters or less. According to the gas tank of this configuration, when the resin material is filled under pressure, the resin material can be more reliably impregnated up to the innermost layer. (9) In the gas tank of the above aspect, the number of layers of the first fiber layer may be greater than the number of layers of the second fiber layer. According to the gas tank of this configuration, the fiber layer can be more reliably impregnated with the resin material. (10) In the gas tank of the above aspect, the first fiber layer and the second fiber layer may include the first reinforcing portion on an outer periphery of the dome portion. With this type of gas tank, by forming a first reinforcing portion on the outer periphery of the dome portion having a curvature, the problem of the fiber material shifting from its intended position can be suppressed compared to the case where a second reinforcing portion is formed on the outer periphery of the dome portion. The present disclosure can also be realized in various forms other than the gas tank or the manufacturing method of the gas tank, for example, in the form of a method for forming a fiber reinforced resin layer, a manufacturing method for fiber reinforced plastic, a manufacturing device for fiber reinforced plastic, a control method for a manufacturing device for a gas tank or a manufacturing device for fiber reinforced plastic, a computer program for implementing the control method, a non-transitory recording medium on which the computer program is recorded, etc. [Brief description of the drawings]

[0007] [Figure 1] 1 is a cross-sectional view illustrating a configuration of a gas tank according to a first embodiment of the present disclosure. [Diagram 2] FIG. 4 is an explanatory diagram showing a substrate having a first fiber layer on the outer periphery of a body portion. [Diagram 3] FIG. 4 is an explanatory diagram showing an enlarged view of a portion of a first reinforcing portion. [Figure 4] FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. [Diagram 5] FIG. 4 is an explanatory diagram showing a substrate having a second fiber layer on the outer periphery of a body portion. [Figure 6] FIG. 4 is an explanatory diagram showing an enlarged view of a portion of a second reinforcing portion. [Figure 7] FIG. 7 is a cross-sectional view taken along the line VII-VII in FIG. 6 . [Figure 8] FIG. 2 is an explanatory diagram showing a schematic configuration of a gas tank manufacturing apparatus. [Figure 9] FIG. 11 is an explanatory diagram showing the movement paths of the first supply section and the second supply section when performing helical winding. [Figure 10] FIG. 11 is an explanatory diagram showing the movement paths of the first supply section and the second supply section when performing braiding winding. [Figure 11] FIG. 2 is an explanatory diagram illustrating a schematic configuration of a fiber-reinforced resin layer of the gas tank according to the first embodiment of the present disclosure. [Figure 12] FIG. 11 is an explanatory diagram illustrating a schematic configuration of a fiber-reinforced resin layer of a gas tank according to a second embodiment of the present disclosure. [Figure 13] FIG. 11 is an explanatory diagram showing another embodiment of the first reinforcing portion. [Figure 14] FIG. 14 is a cross-sectional view taken along the line XIV-XIV in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] A. First embodiment: Fig. 1 is an explanatory diagram showing a cross-sectional view of a configuration of a gas tank 100 according to a first embodiment of the present disclosure. The gas tank 100 is a storage container for storing a high-pressure fluid of 10 to 70 MPa. The gas tank 100 can be formed in any shape, and in the example of Fig. 1, the gas tank 100 has an external shape of a long, approximately cylindrical cylinder along a central axis AX.

[0009] The gas tank 100 is used to store hydrogen gas to be supplied to, for example, a fuel cell for a vehicle or a fuel cell for a stationary use. The gas tank 100 includes a liner 10, nozzles 16 and 17 disposed on 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 nozzles 16 and 17. The gas tank 100 may store various fluids such as oxygen, natural gas, and the like, in addition to hydrogen gas.

[0010] The liner 10 is a container having an internal space for sealing a fluid. The liner 10 is formed of a resin having gas barrier properties, such as nylon, polyamide, ethylene vinyl alcohol copolymer (EVOH), polyethylene, polypropylene, epoxy, polystyrene, etc. The liner 10 includes a cylindrical body 12 and two hemispherical dome portions 14 arranged at both ends of the body 12 along the central axis AX. An opening is provided at the top of the dome portion 14. The boundary BD shown in FIG. 1 is a connection portion between the dome portion 14 and the body 12 of the liner 10, and is a position where the curvature of the outer shape of the liner 10 is zero. The liner 10 may be formed of a metal instead of a resin. The body 12 is not limited to a cylindrical shape, and may be any cylindrical shape having a polygonal cross-sectional shape.

[0011] The nozzles 16 and 17 are attached to openings provided at the top of each dome portion 14 of the liner 10. The nozzle 16 is used, for example, to fill the gas tank 100 with gas or to release gas from the gas tank 100. The nozzle 17 is sealed and is used for centering during manufacturing, etc.

[0012] The fiber reinforced resin layer 20 is a reinforcing layer for reinforcing the liner 10. The fiber reinforced resin layer 20 is formed to cover the outer periphery of the liner 10 using fiber reinforced plastics (FRP). In this embodiment, the fiber reinforced resin layer 20 is formed by a so-called RTM (Resin Transfer Molding) method. Specifically, a base body (also called a "fiber preform") on which a fiber layer is formed on the outer periphery of the liner 10 is prepared and placed in a mold. The "fiber layer" means a layer formed by winding a fiber material. As described later, the fiber layer has a structure in which two types of fiber layers, a first fiber layer L1 and a second fiber layer L2, are laminated in a predetermined order in the thickness direction. The fiber material may be wound on the outer surfaces of the nozzles 16 and 17 in addition to the liner 10.

[0013] In this embodiment, carbon fiber is used as the fiber material. In addition to carbon fiber, glass fiber, aramid fiber, boron fiber, high-strength polyethylene fiber, etc. may be used as the fiber material, and a combination of a plurality of types of fibers may be used. The number of fiber layers is, for example, about 10 to 20 layers, and can be set arbitrarily depending on the size and shape of the gas tank 100. In this embodiment, the number of fiber layers is 11 layers.

[0014] The mold with the base placed therein is closed, and the resin material is pressurized and filled into the closed mold at high speed and high pressure, thereby impregnating the fiber layer with the resin material. When the resin material is impregnated, the inside of the base placed in the mold, i.e., the inside of the liner 10, is filled with, for example, nitrogen gas to impart internal pressure to withstand the external pressure imparted by the resin material during impregnation. The gas tank 100 is completed by hardening the resin material impregnated into the fiber layer.

[0015] 2 is an explanatory diagram showing the appearance of a substrate having a first fiber layer L1 on the outer periphery of the body portion 12. The "first fiber layer" refers to a fiber layer having a first reinforcing portion 210 in an area RG2 that forms the outer periphery of the body portion 12. The "first reinforcing portion" refers to a portion of the fiber layer that is formed by so-called braiding winding. "Braiding winding" refers to a method of winding fiber material so as to weave it alternately.

[0016] 2, in this embodiment, the first fiber layer L1 includes a first reinforcing portion 210 not only in the range RG2 but also in the range RG1 that is the outer periphery of the dome portion 14 of the liner 10. That is, the first fiber layer L1 includes the first reinforcing portion 210 continuously formed across the ranges RG1 and RG2, thereby including the first reinforcing portion 210 on the entire outer periphery of the liner 10. The first fiber layer L1 is also called a "braiding wound layer" because it is formed by braiding winding on the entire outer periphery of the liner 10.

[0017] FIG. 3 is an explanatory diagram showing an enlarged view of a range AR1 of a part of the first reinforcing portion 210. FIG. 4 is a cross-sectional view showing the IV-IV position in FIG. 3. As shown in FIGS. 3 and 4, the fiber material has a strip-like external shape having a predetermined width WF of, for example, about several millimeters. However, the fiber material may have any shape, such as a thread shape or a flat plate shape. The thickness of each sheet of the fiber material can be set to any thickness, for example, 0.5 millimeters or less. In this embodiment, the thickness of each sheet of the fiber material is 0.3 millimeters.

[0018] As shown in FIG. 3, the fiber material 211 is wound at an angle θ1 which is an elevation angle with respect to the central axis AX of the liner 10. The fiber materials 212 to 215 are wound at an angle θ2 which is a depression angle with respect to the central axis AX of the liner 10. The angles θ1 and θ2 can be set arbitrarily. It is preferable that the angles θ1 and θ2 are set in consideration of, for example, the stress acting on the body portion 12 of the liner 10. In this embodiment, in order to obtain a gas tank 100 with sufficient strength, the angle θ1 is set, for example, near +54.7 degrees with respect to the central axis AX, and the angle θ2 is set, for example, at -54.7 degrees with respect to the central axis AX.

[0019] As shown in FIG. 4, the first reinforcing portion 210 is formed by interchanging the positions of the fiber material 211 and the fiber materials 212 to 215 on the inside and outside along the stacking direction and weaving them in a staggered manner. In this embodiment, the fiber material 211 is interchanged every two fiber materials. The first reinforcing portion 210 includes a layer L11 having a thickness of one fiber material arranged on the outside of the gas tank 100 and a layer L12 having a thickness of one fiber material arranged on the inside of the gas tank 100, and the thickness of each layer of the first reinforcing portion 210 is the thickness of two fiber materials. In the following description, the number of layers of the first fiber layer L1 is counted as "one layer" when the layer L11 and the layer L12 are combined. In this embodiment, the thickness of the first reinforcing portion 210 is 0.6 millimeters.

[0020] 3, the first reinforcing portion 210 is formed by alternately weaving a plurality of fiber materials, and therefore the binding force between the fiber materials is stronger than in helical winding. Therefore, for example, compared to the second reinforcing portion 220, the first reinforcing portion 210 can suppress problems such as the arrangement of the fiber materials being disordered and the fiber materials slipping when wound and shifting from the intended arrangement position.

[0021] 3, in the first reinforcing portion 210, gaps GP may occur between the woven fiber materials due to the fact that a plurality of fiber materials are woven alternately. Therefore, the first reinforcing portion 210 may be more easily impregnated with the resin material than a fiber layer formed by closely adhering the fiber materials to each other, such as helical winding.

[0022] 5 is an explanatory diagram showing the appearance of a substrate having a second fiber layer L2 on the outer periphery of the body portion 12. The "second fiber layer" refers to a fiber layer having a second reinforcing portion 220 in the range RG2. The "second reinforcing portion" refers to a portion of the fiber layer formed by so-called helical winding. "Helical winding" refers to a method in which a fiber material is wound around the outer periphery of the body portion 12 at a predetermined angle with respect to the central axis AX of the liner 10, and then further wound at another predetermined angle with respect to the central axis AX.

[0023] As shown in Fig. 5, in this embodiment, the second fiber layer L2 has a first reinforcing portion 210 in the range RG1. According to the gas tank 100 of this embodiment, by forming the first reinforcing portion 210 on the outer periphery of the dome portion 14 having a curvature, it is possible to suppress the problem of the fiber material slipping and shifting from the intended arrangement position compared to helical winding. Note that, on the premise that a gas tank 100 with sufficient strength is obtained, the second fiber layer L2 may have the second reinforcing portion 220 formed in the range RG1, or the fiber layer in the range RG1 may be omitted and the first reinforcing portion 210 may be formed only on the outer periphery of the body portion 12.

[0024] In the second fiber layer L2, the first reinforcing portion 210 in the range RG1 and the second reinforcing portion 220 in the range RG2 are formed continuously. Specifically, after forming the first reinforcing portion 210 in one range RG1, the winding method of the fiber material is switched to form the second reinforcing portion 220 in the range RG2 continuously from the first reinforcing portion 210. After forming the second reinforcing portion 220, the first reinforcing portion 210 is formed in the other range RG1 to complete the second fiber layer L2. The second fiber layer L2 is also called a "switched winding layer" because it is formed by switching the winding method of the fiber material between the range RG1 and the range RG2.

[0025] As shown in the vicinity of the boundary BD in FIG. 5, a predetermined width may occur in the axial direction from the start position of the switching of the winding method to the end position of the switching of the winding method in terms of arranging the fiber material regularly. Here, the "switching position of the winding method of the fiber material in the axial direction" means a position in the axial direction between the start position of the switching of the winding method of the fiber material and the end position of the switching of the winding method. In the example of FIG. 5, the switching position of the winding method from the first reinforcing part 210 to the second reinforcing part 220 is approximately coincident with the boundary BD. In addition, a predetermined width may be set to the "switching position of the winding method of the fiber material in the axial direction" to allow for manufacturing errors, machine errors, and the like. In this embodiment, the "switching position of the winding method of the fiber material in the axial direction" is further set to be included in the boundary part BR that allows a distance LW of two fiber material widths WF before and after the axial direction as an error.

[0026] FIG. 6 is an explanatory diagram showing an enlarged appearance of the second reinforcing portion 220. In FIG. 6, a part of the range AR2 in FIG. 5 is shown enlarged. As shown in FIG. 6, the fiber material 221 is wound at an angle θ3 which is an elevation angle with respect to the central axis AX of the liner 10. The fiber materials 222 to 225 are wound in parallel with each other at an angle θ4 which is a depression angle with respect to the central axis AX. The angles θ3 and θ4 can be set arbitrarily, for example, taking into consideration the stress acting on the body portion 12 of the liner 10. In this embodiment, the angles θ3 and θ4 are configured similarly to the angles θ1 and θ2 described above.

[0027] Fig. 7 is a cross-sectional view showing the position VII-VII in Fig. 6. As shown in Fig. 7, the second reinforcing part 220 has a layer L21 arranged on the outside of the gas tank 100 as the fiber material 221, and a layer L22 arranged on the inside of the gas tank 100 as the fiber materials 222-225. In the following description, the number of layers of the second fiber layer L2 is counted as "one layer" including the layer L21 and the layer L22. In this embodiment, the thickness of the second reinforcing part 220 is 0.6 millimeters.

[0028] 6 and 7, the second reinforcing portion 220 is wound in a helical manner, with multiple fiber materials arranged parallel to each other and tightly wrapped around each other. This results in a higher density of the fiber material than in braiding, and increases the strength of the gas tank 100. Since the fiber material is tightly wrapped around the second reinforcing portion 220, it may be more difficult for the resin material to penetrate than the first reinforcing portion 210 when the resin material is pressurized and filled by, for example, the RTM method.

[0029] Fig. 8 is an explanatory diagram showing a schematic configuration of a manufacturing apparatus 300 for the gas tank 100. The manufacturing apparatus 300 is an apparatus for winding a fiber material around the liner 10. The manufacturing apparatus 300 includes a first supply section 42 and a second supply section 44 for supplying the fiber material, and a moving mechanism (not shown) for moving the liner 10 in the direction DRT. Note that, for convenience of illustration, two first supply sections 42 and two second supply sections 44 are shown in Fig. 8, but in reality, the number of first supply sections 42 and second supply sections 44 corresponds to the number of fiber material to be wound.

[0030] The manufacturing apparatus 300 rotates a first supply unit 42 that feeds out the fibrous material 22A and a second supply unit 44 that feeds out the fibrous material 22B on movement paths OR1 and OR2 around the liner 10. The manufacturing apparatus 300 winds the fibrous materials 22A and 22B around the outer periphery of one dome portion 14 of the liner 10, the outer periphery of the trunk portion 12, and the outer periphery of the other dome portion 14 in this order while moving the liner 10 in a direction DRT along the axial direction.

[0031] The manufacturing apparatus 300 can switch the movement paths OR1 and OR2 between different paths when performing helical winding and when performing braiding winding. In the example of Fig. 8, the movement paths OR1 and OR2 when performing helical winding are shown.

[0032] FIG. 9 is an explanatory diagram showing the movement paths OR1 and OR2 of the first supply unit 42 and the second supply unit 44 when performing helical winding. The movement path OR1 of the first supply unit 42 is shown by a solid line, and the movement path OR2 of the second supply unit 44 is shown by a dashed line. The first supply unit 42 and the second supply unit 44 are arranged, for example, on two concentric movement paths OR1 and OR2 surrounding the central axis AX. The movement path OR1 is disposed at a position farther away from the central axis AX than the movement path OR2, that is, on the outer side in the radial direction. Note that the movement paths OR1 and OR2 are not limited to concentric circles, and may be any shape of orbit that can rotate around the central axis AX.

[0033] As shown in Fig. 9, the moving direction DR1 of the first supply unit 42 on the moving path OR1 and the moving direction DR2 of the second supply unit 44 on the moving path OR2 are opposite to each other. As shown in Fig. 8, the second supply unit 44 rotating in the moving direction DR2 winds a plurality of fiber materials 22B around the outer periphery of the liner 10 at an angle θ4 that is a depression angle with respect to the central axis AX. The first supply unit 42 rotating in the moving direction DR1 winds a plurality of fiber materials 22A around the outer side of the fiber materials 22B at an angle θ3 that is an elevation angle with respect to the central axis AX. As a result, a second reinforcing part 220 having a layer L21 on the outer side and a layer L22 on the inner side is formed around the outer periphery of the body part 12.

[0034] Fig. 10 is an explanatory diagram showing the movement paths OR1b, OR2b of the first supply unit 42 and the second supply unit 44 when performing braiding winding. To facilitate understanding of the technique, in Fig. 10, the movement path OR1b of the first supply unit 42 is shown by a solid line, and the movement path OR2b of the second supply unit 44 is shown by a dashed line.

[0035] As shown in FIG. 10, 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. On the moving paths OR1b and OR2b, a state in which the first supply section 42 is on the radial inside and the second supply section 44 is on the radial outside alternates with a state in which the second supply section 44 is on the radial inside and the first supply section 42 is on the radial outside. As a result, the fiber material 22B supplied at an angle θ2 that is a depression angle with respect to the central axis AX and the fiber material 22A supplied at an angle θ1 that is an elevation angle with respect to the central axis AX are wound around the outer periphery of the liner 10 so as to be woven in a staggered manner. As a result, a first reinforcing section 210 having a layer L11 on the outer side and a layer L12 on the inner side is formed on the outer periphery of the body section 12.

[0036] The manufacturing apparatus 300 can switch between the moving paths OR1, OR2 and the moving paths OR1b, OR2b at any timing for the liner 10 moving in the direction DRT. In this embodiment, when forming the second fiber layer L2, the manufacturing apparatus 300 performs braiding winding on the outer periphery of one dome portion 14 with the moving paths OR1b, OR2b, and then switches the moving paths OR1b, OR2b to the moving paths OR1, OR2 at the boundary portion BR shown in FIG. 2 to perform helical winding on the trunk portion 12. At the boundary portion BR between the trunk portion 12 and the other dome portion 14, the manufacturing apparatus 300 switches from the moving paths OR1, OR2 to the moving paths OR1b, OR2b to perform braiding winding on the other dome portion 14. When forming the first fiber layer L1, the manufacturing apparatus 300 performs braiding winding on the entire liner 10 without switching the moving paths OR1, OR2.

[0037] FIG. 11 is an explanatory diagram showing a schematic configuration of the fiber reinforced resin layer 20 of the gas tank 100 according to the first embodiment of the present disclosure. Table TB1 shown in FIG. 11 corresponds to a cross-sectional view of the fiber reinforced resin layer 20 in the range RG2, and shows the arrangement relationship in the stacking direction of the first fiber layer L1 and the second fiber layer L2 on the outer periphery of the body 12 of the liner 10. The bottom row of table TB1 is the liner 10, and the lower side shows the inside of the gas tank 100. The top row of table TB1 is the 11th layer of the fiber reinforced resin layer 20, which is the outermost layer. The fiber layer stacked on the outer surface of the liner 10 is also called the "innermost layer". When the innermost layer is the first layer, the second to tenth layers are also called the "inner layers".

[0038] As shown in Fig. 11, in the gas tank 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 winding, and a second fiber layer L2 having a second reinforcing portion 220 formed by helical winding. The provision of the second fiber layer L2 improves the strength of the gas tank 100, and the provision of the first fiber layer L1 makes it easier for the resin material to be impregnated into the fiber layer. Therefore, it is possible to obtain a gas tank 100 that has a good balance between preventing insufficient impregnation of the resin material and improving strength.

[0039] 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. When a resin material is pressurized and filled into a mold by the RTM method, the high-speed and high-pressure resin material collides with the fiber layer, which may cause problems such as disturbance of the fiber material arrangement and peeling or floating of the fiber material. By disposing the first fiber layer L1, which has a high binding force between the fiber materials, on the outermost layer, it is possible to suppress or prevent problems such as disturbance of the fiber material arrangement on the outer surface of the fiber layer and peeling of the fiber material due to collision of the resin material when the fiber layer is impregnated with the resin material.

[0040] 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 the deformation of the liner 10, and the density of the fiber material is likely to be high compared to the fiber layer of the inner layer. Therefore, the innermost layer of the fiber reinforced resin layer 20 may be more difficult to impregnate with the resin material than other layers. This characteristic is particularly noticeable when the liner 10 is made of resin. In this embodiment, by disposing the first fiber layer L1, which is easily impregnated with the resin material, in the innermost layer of the fiber reinforced resin layer 20, it is possible to suppress or prevent insufficient impregnation of the resin material in the innermost layer.

[0041] In the gas tank 100 of this embodiment, the fiber reinforced resin layer 20 includes an alternating laminated portion. The "alternating laminated portion" refers to a fiber layer having a plurality of first fiber layers L1 and a plurality of second fiber layers L2, in which the first fiber layers L1 and the second fiber layers L2 are alternately laminated. In this embodiment, the first fiber layers L1 and the second fiber layers L2 are alternately laminated for each layer. However, this is not limited to this, and the first fiber layers L1 and the second fiber layers L2 may be alternately laminated for a predetermined number of layers of two or more layers. The alternating laminated portion may be included in any part of the fiber reinforced resin layer 20, for example, may be provided only in the inner layer, or may include at least one of the innermost layer and the outermost layer. In this embodiment, the alternating laminated portion is formed over all layers from the innermost layer to the outermost layer. According to the gas tank 100 of this embodiment, by alternately arranging fiber layers having different winding methods of the fiber material, it is possible to suppress the variation in the shape of the entire fiber reinforced resin layer 20 and suppress or prevent a decrease in the strength of the gas tank 100.

[0042] In the gas tank 100 of this embodiment, the fiber reinforced resin layer 20 is set so that the total thickness of the second fiber layer L2 is 5 millimeters or less. This is a value experimentally obtained by the inventors using a manufacturing device for the gas tank 100 that utilizes the RTM method to determine the relationship between the thickness of the second fiber layer L2 included in the fiber reinforced resin layer 20 and the impregnation of the resin material. Specifically, a plurality of samples of substrates having different thicknesses of the second fiber layer L2 were prepared. The samples were placed in a mold of the manufacturing device, and the fiber layers of each sample were impregnated with a two-component epoxy resin as a resin material by pressurized filling at about 5 to 10 MPa. As a result, the maximum thickness of the second fiber layer L2 in the sample in which the resin material was impregnated up to the innermost layer of the fiber layer was 5 millimeters. However, in order to more reliably impregnate the resin material, in this embodiment, the number of layers of the second fiber layer L2 is set to 5 layers or less in total, and as a result, the total thickness of the second fiber layer L2 is 3.0 millimeters or less. According to the gas tank 100 of the present embodiment, when the resin material is pressurized and filled using the RTM method, the resin material can be more reliably impregnated up to the innermost layer.

[0043] In the gas tank 100 of this embodiment, as shown in Fig. 11, the fiber reinforced resin layer 20 has six first fiber layers L1 and five second fiber layers L2. That is, the number of first fiber layers L1 in the fiber reinforced resin layer 20 is set to be greater than the number of second fiber layers L2. This makes it possible to more reliably impregnate the fiber layers with the resin material.

[0044] B. Second embodiment: Fig. 12 is an explanatory diagram showing a schematic configuration of the fiber reinforced resin layer 20 of the gas tank 100 according to the second embodiment of the present disclosure. The configuration of table TB2 shown in Fig. 12 is similar to the configuration of table TB1 shown in Fig. 11, so the description will be omitted.

[0045] In the gas tank 100 of the second embodiment, as in the first embodiment, the fiber reinforced resin layer 20 has a first fiber layer L1 and a second fiber layer L2, and a gas tank 100 can be obtained that balances the suppression of insufficient impregnation of the resin material and strength. In addition, the total thickness of the second fiber layer L2 is 3.0 millimeters or less, and the resin material can be more reliably impregnated up to the innermost layer. In addition, in order to suppress or prevent the occurrence of insufficient impregnation of the resin material in the innermost layer, the first fiber layer L1 is arranged in the innermost layer of the fiber reinforced resin layer 20, and in order to increase the strength of the outer surface of the fiber layer, the first fiber layer L1 is arranged in the outermost layer of the fiber reinforced resin layer 20.

[0046] As shown in Table TB2, in this embodiment, the fiber reinforced resin layer 20 includes a first continuous laminate portion ST1 in which a plurality of first fiber layers L1 are continuously laminated, and a second continuous laminate portion ST2 in which a plurality of second fiber layers L2 are continuously laminated. By continuously arranging fiber layers having different winding methods of the fiber material, the number of times the winding method of the fiber material needs to be switched can be reduced, and the productivity of the gas tank 100 can be improved.

[0047] As shown in Table TB2, in the gas tank 100 of the second embodiment, the first continuous laminate portion ST1 is formed by a first fiber layer L1 that is continuously laminated from the innermost layer to the fifth layer, and the second continuous laminate portion ST2 is formed by a second fiber layer L2 that is continuously laminated from the sixth layer to the tenth layer. In this embodiment, in the fiber reinforced resin layer 20, the first continuous laminate portion ST1 is disposed on the inner layer side of the second continuous laminate portion ST2. By concentrating the first fiber layer L1 that is easily impregnated with the resin material on the inner layer side, it is possible to improve the impregnation performance of the inner layer side, which is more difficult to impregnate with the resin material than the outer layer side.

[0048] C. Other embodiments: (C1) In the above first embodiment, the first fiber layer L1 has the first reinforcing portion 210 in both ranges RG1 and RG2 which form the outer periphery of the dome portion 14 and the trunk portion 12 of the liner 10. In contrast, the first fiber layer L1 may have a fiber layer formed by a method other than the first reinforcing portion 210, such as a second reinforcing portion 220, in the range RG1, provided that the first fiber layer L1 has the first reinforcing portion 210 in the range RG2.

[0049] (C2) In the first embodiment, as shown in FIG. 11, the number of layers of the first fiber layer L1 included in the middle of the fiber reinforced resin layer 20 and on the inner side of the middle is equal to the number of layers of the first fiber layer L1 included on the outer side of the middle. "Middle of the fiber reinforced resin layer 20" means a middle position in the lamination direction of the fiber reinforced resin layer 20. When the fiber reinforced resin layer 20 has an odd number of fiber layers, "middle of the fiber reinforced resin layer 20" includes a middle fiber layer based on the number of laminations of the fiber reinforced resin layer 20, and when the fiber reinforced resin layer 20 has an even number of fiber layers, it means a boundary between two fiber layers located in the middle based on the number of laminations of the fiber reinforced resin layer 20. In the example of FIG. 12, the middle of the fiber reinforced resin layer 20 is the sixth layer. When the fiber reinforced resin layer 20 has, for example, 12 fiber layers, the middle layer is the boundary between the 6th layer and the 7th layer.

[0050] In contrast, the number of first fiber layers L1 included in the intermediate layer and on the inner side of the intermediate layer of the fiber reinforced resin layer 20 may be greater than the number of first fiber layers L1 included on the outer layer side. According to the gas tank 100 of this embodiment, by arranging more first fiber layers L1 on the inner layer side, which is less easily impregnated with the resin material than the outer layer side, the resin material can be more reliably impregnated up to the innermost layer.

[0051] (C3) Fig. 13 is an explanatory diagram showing another embodiment of the first reinforcing portion 210. Fig. 14 is a cross-sectional view showing the XIV-XIV position in Fig. 13. In each of the above embodiments, the first reinforcing portion 210 is formed by weaving the fiber material so that every two fiber strands are alternately arranged. In contrast to this, as shown in Figs. 13 and 14, the first reinforcing portion 210 may be formed by weaving the fiber material so that every one fiber strand is alternately arranged.

[0052] (C4) In the second embodiment, the first continuous laminate portion ST1 is disposed on the inner side of the second continuous laminate portion ST2. In contrast, the second continuous laminate portion ST2 may be disposed on the inner side of the first continuous laminate portion ST1. According to the gas tank 100 of this embodiment, the strength of the gas tank 100 can be improved by providing a large amount of the second fiber layer L2 on the inner side.

[0053] The present disclosure is not limited to the above-mentioned embodiment, and can be realized in various configurations without departing from the spirit of the present disclosure. For example, the technical features in the embodiments corresponding to the technical features in each aspect described in the Summary of the Invention column can be appropriately replaced or combined to solve some or all of the above-mentioned problems or to achieve some or all of the above-mentioned effects. Furthermore, if the technical feature is not described as essential in this specification, it can be appropriately deleted. [Explanation of symbols]

[0054] 10...liner, 12...body portion, 14...dome portion, 16, 17...mouthpiece, 20...fiber reinforced resin layer, 22A, 22B...fiber material, 42...first supply portion, 44...second supply portion, 100...gas tank, 210...first reinforcing portion, 211-215, 221-225...fiber material, 220...second reinforcing portion, 300...manufacturing device, AX...center axis, BD...boundary, BR...boundary portion, GP...gap, L1...first fiber layer, L11, L12...layer, L2...second fiber layer, L21, L22...layer, OR1, OR1b, OR2, OR2b...movement path, ST1...first continuous layer portion, ST2...second continuous layer portion, TB1, TB2...surface

Claims

1. A gas tank, a liner having a cylindrical body portion and dome portions provided on both ends of the body portion; a reinforcing layer covering an outer periphery of the liner; The reinforcing layer is At least one first fiber layer having a first reinforcing portion around an outer periphery of the body portion, the first fiber layer being formed by winding fibers in a staggered manner; and at least one second fiber layer having a second reinforcing portion on an outer periphery of the barrel portion, the second reinforcing portion being formed by winding fibers at a predetermined angle with respect to the central axis of the liner. Gas tank.

2. 2. The gas tank according to claim 1, wherein the outermost layer of the reinforcing layer is the first fiber layer.

3. 2. The gas tank according to claim 1, wherein the innermost layer of the reinforcing layer is the first fiber layer.

4. 2. The gas tank according to claim 1, The reinforcing layer includes an alternating laminate portion in which the first fiber layer and the second fiber layer are alternately laminated. Gas tank.

5. 2. The gas tank according to claim 1, The reinforcing layer is a first continuous laminate portion in which a plurality of the first fiber layers are continuously laminated; and a second continuous laminate portion in which a plurality of the second fiber layers are continuously laminated. Gas tank.

6. 6. The gas tank according to claim 5, The first continuous laminate portion is disposed on an inner layer side of the second continuous laminate portion in the reinforcing layer. Gas tank.

7. 2. The gas tank according to claim 1, the number of the first fiber layers included in the middle of the reinforcing layer and on the inner layer side of the middle is greater than the number of the first fiber layers included on the outer layer side of the middle. Gas tank.

8. 2. The gas tank of claim 1, wherein the total thickness of the second fibrous layer is less than or equal to 5 millimeters.

9. 2. The gas tank according to claim 1, The number of layers of the first fiber layer is greater than the number of layers of the second fiber layer. Gas tank.

10. 2. The gas tank according to claim 1, The first fiber layer and the second fiber layer include the first reinforcing portion on an outer periphery of the dome portion. Gas tank.

11. A method for manufacturing a gas tank, comprising the steps of: preparing a liner having a cylindrical body and dome portions provided at both ends of the body; forming a substrate having a fiber layer on an outer periphery of the liner; The step of forming the substrate comprises: forming at least one first fiber layer having a first reinforcing portion around an outer periphery of the body portion, the first reinforcing portion being wound in a staggered manner with fibers; and forming at least one second fiber layer having a second reinforcing portion around an outer periphery of the barrel portion, the second reinforcing portion being formed by winding fibers at a predetermined angle with respect to a central axis of the liner. A method for manufacturing a gas tank.

12. A method for manufacturing the gas tank according to claim 11, comprising the steps of: placing the formed substrate within a mold and closing the mold; and filling the closed mold with a resin material to impregnate the fiber layer of the base with the resin material. A method for manufacturing a gas tank.

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