Method for manufacturing tank and hydrogen tank

Abstract

The invention relates to a method for manufacturing a tank and a hydrogen tank. This can manufacturing method comprises: a preparation step for preparing a preform provided with a cylindrical main body, a mold, and a sheet comprising three-dimensional mesh-like fibers; a winding step for winding one or more circles of the sheet on the outer surface of the preform along the circumferential direction of the main body part of the preform; an injection step for injecting a resin into the mold in a state in which the preform on which the sheet has been wound is disposed in the mold; and an impregnation step in which the sheet and the fiber bundles are impregnated with a resin. In the winding step, the sheet is wound around at least a part of the main body, and the preform on which the sheet is wound is provided with, on the outer surface of the preform, a gap extending in a direction different from the direction in which the fibers of the fiber bundle extend.

Description

Technical Field

[0001] The present disclosure relates to a tank manufacturing method and a hydrogen tank. Background Art

[0002] Conventionally, as disclosed in Japanese Patent Application Laid-Open No. 2020-118288, there is known a technique for forming a fiber-reinforced resin layer and a resin layer on the outer periphery of a liner by an RTM (Resin Transfer Molding) method.

[0003] The shape of the intermediate product formed by winding the fiber around the outer surface of the liner of the tank in the process of manufacturing is easily deviated. Therefore, in the resin impregnation process, when the mold contacts the intermediate product, the fiber at the contacting portion may not be fully impregnated with the resin.

[0004] The inventors have studied a method of ensuring the flow path of the resin by providing unevenness on the surface of the mold. However, the resistance when the can is demolded from a mold with unevenness is greater than the resistance when the can is demolded from a mold with a flat surface. The can is pushed out by the ejector pin when it is demolded from the mold. When the resistance during demolding is large, the resin layer of the can is sometimes damaged due to excessive load from the ejector pin. Therefore, in the manufacture of the can, it is a problem to strike a balance between sufficient impregnation of the resin and ensuring the quality of the can. Summary of the invention

[0005] The present disclosure can be implemented as the following aspects.

[0006] (1) According to one embodiment of the present disclosure, a method for manufacturing a tank is provided. The method includes: a preparation step of preparing a preform, a mold, and a sheet made of three-dimensional mesh fibers, wherein the preform has a cylindrical main body with multiple layers of fiber bundles wound around the outer surface of a liner defining the inner space of the tank; a winding step of winding the sheet around the outer surface of the preform for more than one turn along the circumference of the main body; an injection step of injecting a resin into the mold in a state where the preform wound with the sheet is arranged in the mold; and an impregnation step of impregnating the sheet and the fiber bundle with the resin, wherein in the winding step, the sheet is wound around at least a portion of the main body, and the preform wound with the sheet has voids on the outer surface of the preform extending in a direction different from the direction in which the fibers of the fiber bundle extend.

[0007] By adopting such a mode, in the impregnation process, the resin can be impregnated with the help of the sheet and the fiber bundle. The sheet functions as a flow path for the resin between the mold and the fiber bundle by overlapping with the fiber bundle. More specifically, a gap extending in a direction different from the fiber bundle is defined between the sheet and the preform. Therefore, the resin can easily flow between the mold and the fiber bundle, and it is difficult to produce unimpregnated parts of the fiber bundle. In addition, since the manufacturing method of the tank disclosed in the present invention does not require a special mold structure, even the existing mold structure can make impregnation easy. That is, the manufacturing method of the tank disclosed in the present invention can manufacture the tank while ensuring the quality of the tank by using the same mold as in the past. Therefore, the manufacturing method of the tank disclosed in the present invention can take into account both sufficient impregnation of the resin and ensuring the quality of the tank.

[0008] (2) In the can manufacturing method of the above aspect, in the winding step, the sheet may be wound around the entire body portion.

[0009] By adopting such a mode, when the sheet is in contact with the mold, the load caused by the mold clamping is less likely to be concentrated on a part of the main body. For example, when the sheet is wound around a part of the main body, the load caused by the mold clamping is likely to be concentrated on a part of the main body. Therefore, in the impregnation process, unimpregnated areas are sometimes produced. By wrapping the sheet around the entire main body, the load caused by the mold clamping can be dispersed to the entire main body. Therefore, the manufacturing method of the tank disclosed in the present invention can reduce the possibility of unimpregnated areas being produced in the main body.

[0010] (3) In the can manufacturing method of the above aspect, the impregnation step may include a step of forming a layer of the resin on the sheet.

[0011] By adopting such a mode, the method for manufacturing a tank of the present disclosure can protect the main body by covering the entire main body with the resin layer.

[0012] (4) In the can manufacturing method of the above aspect, in the winding step, the sheet material may be wound a plurality of times.

[0013] The outer diameter of the preform varies due to the winding accuracy of the fiber bundle. By adopting such a mode, the method for manufacturing a tank disclosed in the present invention can easily adjust the outer diameter of the preform including the sheet material in accordance with the size of the mold by adjusting the number of windings of the sheet material. Therefore, the method for manufacturing a tank disclosed in the present invention can make the impregnation of the resin more appropriate.

[0014] (5) According to another aspect of the present disclosure, a hydrogen tank is provided. The hydrogen tank includes a cylindrical main body, the hydrogen tank includes an outer layer including a resin and covering the main body, the outer layer includes a lower layer including a plurality of fiber bundles, and an upper layer overlapping the lower layer and including a sheet material configured in a three-dimensional mesh shape, the sheet material including voids extending in a direction different from a direction in which fibers of the fiber bundles extend.

[0015] By adopting such a method, when the outer layer of the hydrogen tank is manufactured by the RTM method, the hydrogen tank disclosed in the present invention can make the resin flow into the fiber bundle with the help of the sheet. Therefore, since the fiber bundle is not in contact with the mold, it is difficult for the hydrogen tank disclosed in the present invention to have unimpregnated parts. In addition, the hydrogen tank disclosed in the present invention can facilitate impregnation even with the existing mold structure by using the sheet. That is, the hydrogen tank disclosed in the present invention can make the manufacture of the hydrogen tank easier while ensuring the quality of the hydrogen tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Hereinafter, features, advantages, technical and industrial significance of exemplary embodiments of the present invention will be described with reference to the accompanying drawings, in which like reference numerals represent like components, wherein:

[0017] Figure 1 It is a cross-sectional view showing a schematic structure of the tank.

[0018] Figure 2 It is a cross-sectional view showing a schematic structure of a preform.

[0019] Figure 3 FIG. 1 is a top view showing a preform wound with a flow media.

[0020] Figure 4 It is a top view showing the structure of the fluid medium.

[0021] Figure 5 Yes means Figure 4 Cross-sectional view of the V-V section.

[0022] Figure 6 This is a diagram schematically showing the general structure of a can manufacturing device.

[0023] Figure 7 This is an explanatory diagram showing an ejector pin.

[0024] Figure 8 Yes means Figure 7 Cross-sectional view of section VIII-VIII.

[0025] Fig. 9 1 is a flow chart showing a method for manufacturing a tank.

[0026] Fig.10This is a graph showing the variation range of the outer diameter of the tank. DETAILED DESCRIPTION

[0027] A. First Implementation Method:

[0028] A-1. Composition of prefabricated parts and tanks:

[0029] Figure 1 It is a cross-sectional view showing a schematic structure of the tank 100 . Figure 2 1 is a cross-sectional view showing the schematic structure of the preform P100. Figure 2 The preform P100 shown is manufactured Figure 1 The tank 100 is shown.

[0030] exist Figure 1 as well as Figure 2 In FIG. 1 , for each of the preform P100 and the tank 100 , a cross-sectional view perpendicular to the central axis O is illustrated. Figure 1 as well as Figure 2 The X-axis, Y-axis, and Z-axis are depicted as mutually orthogonal axes. The directions pointed by the arrows of the X-axis, Y-axis, and Z-axis represent the positive directions along the X-axis, Y-axis, and Z-axis, respectively. The positive directions along the X-axis, Y-axis, and Z-axis are respectively referred to as +X direction, +Y direction, and +Z direction. The direction opposite to the directions pointed by the arrows of the X-axis, Y-axis, and Z-axis is the negative direction along the X-axis, Y-axis, and Z-axis. The negative directions along the X-axis, Y-axis, and Z-axis are respectively referred to as -X direction, -Y direction, and -Z direction. The situation in which the directions along the X-axis, Y-axis, and Z-axis are not distinguished between positive and negative is referred to as the X-direction, the Y-direction, and the Z-direction, respectively.

[0031] In the present embodiment, the X direction is a direction along the center axis O of the tank 100. The direction parallel to the center axis O is also referred to as the axial direction OD. The Y direction is a direction along the direction of gravity in the configuration posture of the tank 100 described later. The -Y direction is consistent with the direction of gravity in the configuration posture. Furthermore, the direction perpendicular to the center axis O is referred to as the radial direction CD. The direction parallel to the circumference of the circle with the center axis O as the center is referred to as the circumferential direction LD. Furthermore, on the radial CD of the tank 100, the side close to the center axis O is referred to as the inner side, and the side away from the center axis O is referred to as the outer side.

[0032] The tank 100 is, for example, a hydrogen tank. The hydrogen tank as the tank 100 is mounted on a fuel cell vehicle and is used to store hydrogen gas supplied to a fuel cell in a high pressure state. The tank 100 includes a liner 110 , a reinforcement layer 120 , a joint 130 , and a fluid medium 140 .

[0033] In the manufacture of the tank 100, the tank 100 is manufactured by impregnating the fiber layer P121 described later with resin. The tank 100 before impregnation is referred to as a preform P100. That is, the preform P100 is an intermediate product in the manufacturing process of the tank 100. The preform P100 will be described later. In this specification, impregnation means that the fiber bundle is impregnated with resin to contain resin.

[0034] The liner 110 is a hollow container that defines an internal space 110p of the tank 100 for storing a fluid. The liner 110 is formed of a resin having a gas barrier property, such as a polyamide resin. The central axis O of the liner 110 is the same as the central axis O of the tank 100.

[0035] The joints 130 are provided at both ends of the tank 100. Figure 1 The joint 130 at the right end of the middle part connects the space inside the liner 110 with the external space. That is, one joint 130 has a cylindrical through hole. As the other joint 130, Figure 1 The joint 130 at the left end has a cylindrical appearance but does not have a through hole.

[0036] The reinforcement layer 120 is a layer for reinforcing the liner 110. The reinforcement layer 120 covers the outer periphery of the liner 110. The reinforcement layer 120 includes a fiber-reinforced resin layer 121 and a resin layer 122.

[0037] The fiber-reinforced resin layer 121 covers the outer surface 110o of the liner 110. The material constituting the fiber-reinforced resin layer 121 is, for example, a fiber-reinforced resin of CFRP (Carbon Fiber Reinforced Plastics). CFRP is formed by thermally curing carbon fibers after impregnating them with a thermosetting resin such as an epoxy resin. Therefore, the fiber-reinforced resin layer 121 includes a plurality of fiber bundles wound around the outer surface 110o of the liner 110. That is, the fiber-reinforced resin layer 121 is formed by impregnating the outer surface 110o of the liner 110 with a resin. The layer formed by the fiber bundles before being impregnated with the resin is referred to as a fiber layer P121.

[0038] The resin layer 122 covers the outer surface 121o of the fiber-reinforced resin layer 121. The resin layer 122 is formed from the same resin as the resin impregnated with the fiber in the process of forming the fiber-reinforced resin layer 121. More specifically, the resin layer 122 is formed by thermally curing the fiber bundles in the fiber-reinforced resin layer 121. In this embodiment, the resin layer 122 shown later is used. Figure 6The tank manufacturing mold 21 in the tank manufacturing mold 21 is used to form the fiber reinforced resin layer 121 and the resin layer 122 by the resin transfer molding (RTM) method. In the following description, the resin transfer molding method is referred to as the RTM method, and the tank manufacturing mold 21 is simply referred to as the mold 21. The details of the method for forming the fiber reinforced resin layer 121 and the resin layer 122 based on the RTM method will be described later.

[0039] The fluid medium 140 is a sheet material composed of three-dimensional mesh-shaped fibers. The fluid medium 140 is provided inside the resin layer 122. The fluid medium 140 will be described in detail later. In addition, the fluid medium 140 is also referred to as a sheet material 140.

[0040] The preform P100 as an intermediate product in the manufacturing process of the tank 100 will be described. Figure 2 As shown, the preform P100 is composed of a liner 110, a fiber layer P121 and a joint 130. Figure 2 In order to facilitate technical understanding, the fluid medium 140 is shown in the figure. The configurations of the liner 110 and the joint 130 are the same as those of the tank 100. The fiber layer P121 will be described later.

[0041] The shape of the preform P100 will be described. The preform P100 includes a cylindrical main body 100b and hemispherical spherical parts 100e located at both ends of the main body 100b.

[0042] More specifically, the main body 100b is a range of the axial direction OD defined by the portion of the outer surface 110o of the liner 110 parallel to the axial direction OD. When the fiber layer P121, the resin layer 122, etc. are stacked on the surface of the liner 110 as in the tank 100 or the preform P100, the main body 100b is similarly defined.

[0043] The spherical portion 100e is a portion of the lining 110 other than the main body 100b. Similar to the main body 100b, when the fiber layer P121, the resin layer 122, etc. are stacked on the surface of the lining 110, the spherical portion 100e is also defined in the same manner. The spherical portion 100e is provided at both ends of the main body 100b. More specifically, the spherical portion 100e is provided to be continuous with the end 100be in the axial direction OD of the main body 100b. The shape of the spherical portion 100e is a hemispherical shape protruding from the end 100be of the main body 100b toward the joint 130. For the spherical portion 100e, the diameter decreases as it moves away from the main body 100b.

[0044] The reinforcing layer 120 covering the main body 100b is also referred to as an "outer layer". In the outer layer, the fiber-reinforced resin layer 121 composed of multiple layers of fiber bundles is also referred to as a "lower layer", and the resin layer 122 overlapping the lower layer and including the fluid medium 140 is also referred to as an "upper layer".

[0045] The fiber layer P121 is described below. The fiber layer P121 is a fiber-reinforced resin layer 121 before being impregnated with resin, and is composed of a fiber bundle of carbon fibers. The fiber bundle is formed by winding multiple layers in a manner that covers the outer surface 110o of the liner 110 by spiral winding and hoop winding, for example. The "fiber bundle" mentioned here refers to an aggregate of fibers obtained by bundling a large number of single fibers having a diameter of about several microns. The fiber-reinforced resin layer 121 is formed by impregnating the fiber layer P121 with a thermosetting resin and then thermally curing it.

[0046] “Spiral winding” refers to a method of winding a fiber bundle around the liner 110 in such a manner that the fiber bundle has a winding angle greater than 0 degrees and less than 90 degrees relative to the central axis O. In spiral winding, for example, the fiber bundle is wound in such a manner that it passes through the main body 100b from the spherical portion 100e on one side of the liner 110 and spreads to the spherical portion 100e on the other side. In addition, “hoop winding” refers to a method of winding a fiber bundle around the liner 110 in such a manner that the fiber bundle has a winding angle of approximately 90 degrees relative to the central axis O. In hoop winding, the fiber bundle is wound around the main body 100b while moving the winding position in parallel with the central axis O. That is, the innermost layer P121i of the fiber layer P121 is in contact with the outer surface 110o of the liner 110. The outermost layer P121o of the fiber layer P121 forms the outer surface of the preform P100. Therefore, in the present specification, the outermost layer P121o of the fiber layer P121 is also referred to as the outer surface P121o of the preform P100.

[0047] That is, in the preform P100 , a plurality of fiber bundles are wound around the outer surface 110 o of the liner 110 defining the internal space 110 p of the tank 100 .

[0048] However, due to the formation of the fiber layer P121, the outer diameter P100r of the preform P100 in the radial direction CD may vary in each part of the preform P100 in the axial direction OD. Therefore, when the preform P100 is arranged in the mold 21 to be described later, the gap S2 between the preform P100 and the mold 21 varies. The gap S2 will be described later.

[0049] A-2. Regarding mobile media:

[0050] The flow medium 140 functions as a flow path of the resin by being provided in the preform P100. As described above, the flow medium 140 is a sheet material composed of three-dimensional mesh-shaped fibers. More specifically, the flow medium 140 is a sheet material formed into a mesh shape by weaving fibers composed of, for example, nylon as a resin.

[0051] Figure 3 1 is a plan view showing the preform P100 wound with the fluid medium 140. The fluid medium 140 is wound around the preform P100 in a winding step S110 of manufacturing the can 100 described later. More specifically, the fluid medium 140 is wound around the entire body portion 100b. Figure 1 to Figure 3 The fluid medium 140 in the preform P100 is in a state of being wound around the main body 100b of the preform P100. Therefore, the fluid medium 140 is impregnated with the resin together with the preform P100, so that Figure 1 The tank 100 is arranged inside the resin layer 122 .

[0052] Figure 4 1 is a top view showing the structure of the fluid medium 140. More specifically, the fluid medium 140 is wound multiple times along the circumferential direction LD of the main body 100b of the preform P100 on the outer surface P121o of the preform P100. That is, the fluid medium 140 extends in a direction perpendicular to the radial direction CD. Figure 4 , the structure of the fluid medium 140 that can be confirmed when the fluid medium 140 is observed from the outside of the preform P100 along the radial direction CD is shown.

[0053] The flow medium 140 is composed of first fibers 140OD extending in the axial direction OD and second fibers 140LD extending in the circumferential direction LD. More specifically, the flow medium 140 is formed by weaving the first fibers 140OD and the second fibers 140LD with intervals between adjacent fibers extending in the same direction. Therefore, a space S1 penetrating in the radial direction CD is defined in the flow medium 140. The intervals between adjacent fibers of the flow medium 140 are set wider than the intervals between carbon fibers of the fiber layer P121 of the preform P100.

[0054] Figure 5 Yes means Figure 4 The cross-sectional view of the V-V section. Figure 5 In order to facilitate the understanding of the technology, the mold 21 and the fiber layer P121 of the preform P100 which will be described later are shown. Figure 5 As shown, by weaving the fibers, a gap S1 is defined when observing a cross section of the flow medium 140 along the circumferential direction LD. Figure 4In this way, the first fiber 140OD and the second fiber 140LD intersect at an angle of 90 degrees. Therefore, when the cross section of the fluid medium 140 is observed along the axial direction OD, a gap S1 is defined. The preform P100 is arranged in the mold 21 in a state where the fluid medium 140 is wound. Therefore, when the fluid medium 140 is in contact with the mold 21, the preform P100 wound with the fluid medium 140 also has a gap S1 between the mold 21 and the fiber layer P121.

[0055] Therefore, the preform P100 around which the fluid medium 140 is wound has gaps S1 extending in the circumferential direction LD, the axial direction OD, and the radial direction CD on the outer surface P121o of the preform P100. That is, the preform P100 around which the fluid medium 140 is wound has gaps S1 extending in a direction different from the direction in which the fibers of the fiber bundle extend on the outer surface P121o. By adopting such a mode, the fluid medium 140 overlaps with the fiber bundle of the preform P100, and thus functions as a flow path for the resin between the mold 21 and the fiber bundle in the impregnation step S150 of the tank 100 described later. Therefore, the resin easily flows between the mold 21 and the fiber bundle, and thus it is difficult to produce a portion of the fiber bundle that is not impregnated.

[0056] On this basis, the flow medium 140 can reduce the warping of the can 100. The resin layer 122 may have uneven thickness due to the stagnation of the resin flow. Figure 1 In the case where the resin layer 122 on the -Y direction side is thicker than the resin layer 122 on the +Y direction side, the resin layer 122 on the -Y direction side shrinks significantly due to the solidification of the resin. Therefore, the can 100 may be warped with the -Y direction side as the inner side. The fluid medium 140 can reduce the warping of the can 100 by preventing the thickness of the resin layer 122 from being uneven. That is, the unevenness of the resin layer 122 is reduced by the fluid medium 140, and it is easier to form a thin resin layer 122 than in a method where the fluid medium 140 is not provided.

[0057] A-3. Structure of the tank manufacturing device:

[0058] Figure 6 1 is a diagram schematically showing a simplified structure of a manufacturing device 2 for a can 100. Figure 6 , the figure shows a state where a preform P100 is arranged in a mold 21. The manufacturing apparatus 2 is used to obtain a preform P100 by RTM method. Figure 2 Prefabricated P100 Figure 1Specifically, the manufacturing device 2 manufactures the tank 100 having the reinforcement layer 120 formed on the outer peripheral side of the liner 110 by impregnating the fiber layer P121 of the preform P100 with resin using the RTM method and then curing the resin. In this embodiment, the reinforcement layer 120 is formed using a thermosetting resin.

[0059] The manufacturing device 2 includes a mold 21, a support mechanism 22, a temperature control device 23, a vacuum pump 24, a resin storage unit 25, a pressurizing device 26, a valve 27, a control device 28, a drive mechanism 29, and an ejector pin 30. Figure 7 as well as Figure 8 The ejector pin 30 is shown.

[0060] The support mechanism 22 supports the preform P100 from both ends where the joints 130 are located in the arranged state of the preform P100.

[0061] The temperature regulating device 23 controls the temperature of the mold 21. Figure 6 The temperature control device 23 is shown in the center of the left side of the figure. The temperature control device 23 sets the temperature of the mold 21 to a temperature lower than the curing temperature of the resin, for example, before the impregnation of the fiber layer P121 with the resin is completed, according to the instruction of the control device 28. After the impregnation of the fiber layer P121 with the resin is completed, the temperature control device 23 sets the temperature of the mold 21 to a temperature higher than the curing temperature of the resin.

[0062] The vacuum pump 24 is a degassing device for degassing by making the arrangement chamber 210 evacuated when the preform P100 is arranged and the mold 21 is in a closed state. Figure 6 The vacuum pump 24 is shown in the lower left part of FIG. The configuration state and the mold closing state will be described later.

[0063] The resin storage section 25 is a storage chamber for storing the resin supplied to the arrangement chamber 210. Figure 6 The resin storage part 25 is shown in the upper right part of FIG. The resin storage part 25 is connected to the second mold tube part 212c via a valve 27. In addition, the resin storage part 25 is connected to a pressurizing device 26.

[0064] The pressurizing device 26 pressurizes the resin stored in the resin storage portion 25 to flow the resin from the resin storage portion 25 toward the arrangement chamber 210 side. Figure 6 The pressurizing device 26 is shown in the upper right part of FIG. The pressurizing device 26 is arranged on the upstream side of the resin storage part 25 in the flow direction indicated by the arrow.

[0065] The valve 27 is an on-off valve for switching between a flow state in which the resin flows from the resin storage portion 25 to the second mold tube portion 212c and a non-flow state in which the resin does not flow from the resin storage portion 25 to the second mold tube portion 212c. Figure 6 The valve 27 is shown in the center of the left side of FIG. The valve 27 is arranged on the downstream side of the flow direction indicated by the arrow of the resin storage part 25. The opening and closing of the valve 27 is controlled by the control device 28.

[0066] The driving mechanism 29 is a device that enables the first mold 211 and the second mold 212 to move. Figure 6 The driving mechanism 29 is illustrated in the upper center of the figure. The driving mechanism 29 is a lifting device that lifts and lowers the first mold 211 and the second mold 212 to open and close the mold 21. When closing the mold 21, the driving mechanism 29 brings the second mold 212 and the first mold 211 closer to each other in the Y direction according to the command of the control device 28. When demolding, the driving mechanism 29 moves the second mold 212 and the first mold 211 away from each other in the Y direction according to the command of the control device 28. In this specification, "mold closing" means closing the mold 21.

[0067] The control device 28 controls the manufacturing device 2. The control device 28 is provided with a processor, ROM, and RAM (not shown) to perform processing necessary for controlling each component of the manufacturing device 2. Figure 6 In FIG. 1 , the electrical connections of the components of the manufacturing apparatus 2 that are electrically connected to the control device 28 and controlled are schematically shown by dotted lines.

[0068] The mold 21 includes a pair of a first mold 211 and a second mold 212 , and an arrangement chamber 210 in which the preform P100 is arranged.

[0069] The first mold 211 faces the second mold 212. The first mold 211 is arranged on the −Y direction side of the second mold 212 in the gravity direction.

[0070] The first mold 211 has a first mold opposing wall 211a, a first mold recess 211b, a first mold tube portion 211c, and a first gate 211d. The first mold opposing wall 211a is a wall surface opposing the second mold 212. The first mold recess 211b is a recess formed by a portion of the first mold opposing wall 211a being recessed toward the inner side of the first mold 211. The first mold recess 211b has a first mold bottom surface 211bb and a first mold connecting surface 211be, and is a shape that is open on the +Y direction side where the second mold 212 is located. The first mold connecting surface 211be is located at both end sides of the first mold bottom surface 211bb. The first mold tube portion 211c is a gas flow path formed inside the first mold 211 in order to degas the configuration chamber 210 using the vacuum pump 24. The first gate 211d is an opening formed in the first mold bottom surface 211bb of the first mold recess 211b. That is, degassing is performed by the vacuum pump 24 from the first gate 211d through the first mold tube 211c.

[0071] The second mold 212 has a second mold opposing wall 212a, a second mold recess 212b, a second mold tube portion 212c, and a second gate 212d. The second mold opposing wall 212a is a wall surface opposing the first mold opposing wall 211a. The second mold recess 212b is a recess formed by a portion of the second mold opposing wall 212a being recessed toward the inner side of the second mold 212. The second mold recess 212b has a second mold top surface 212bb and a second mold connecting surface 212be, and is a shape that is open on the -Y direction side where the first mold 211 is located. The second mold connecting surface 212be is located at both end sides of the second mold top surface 212bb. That is, the inner surface 21a of the mold 21 is formed by the first mold bottom surface 211bb and the first mold connecting surface 211be of the first mold recess 211b and the second mold top surface 212bb and the second mold connecting surface 212be of the second mold recess 212b. The second mold tube portion 212c is a flow path formed inside the second mold 212 to allow the resin supplied from the resin retaining portion 25 to flow to the configuration chamber 210. The second gate 212d is an opening formed on the second mold top surface 212bb of the second mold recess 212b. That is, the second mold tube portion 212c connects the valve 27 and the resin retaining portion 25 side with the configuration chamber 210 side by means of the second gate 212d. Figure 6 In the figure, the direction of resin flow is shown by arrows.

[0072] The arrangement chamber 210 is a space for arranging the preform P100 between the first mold 211 and the second mold 212. The arrangement chamber 210 is an internal space 110p of the mold 21 defined by the first mold recess 211b and the second mold recess 212b when the first mold 211 and the second mold 212 are in a mold-clamped state. The mold-clamped state is referred to as a mold-clamped state. That is, the arrangement chamber 210 is defined in the mold 21 in the mold-clamped state.

[0073] More specifically, the arrangement chamber 210 is an internal space 110p that is larger than the outer shape of the preform P100 and is an internal space 110p that matches the outer shape of the tank 100. As described above, the preform P100 is supported at both ends by the support mechanism 22. Therefore, the above-mentioned gap S2 is generated between the preform P100 arranged in the arrangement chamber 210 and the inner surface 21a of the arrangement chamber 210.

[0074] The first mold recess 211b and the second mold recess 212b are each formed in a shape along the shape of the preform P100. Specifically, the mold 21 includes a cylindrical mold body 210b and two mold spherical parts 210e provided at both ends of the mold body 210b and having a diameter that decreases as it moves away from the mold body 210b.

[0075] The mold body 210b accommodates the main body 100b of the preform P100. The mold body 210b is a portion of the mold 21 including the first mold bottom surface 211bb and the second mold top surface 212bb. Therefore, when the preform P100 is arranged in the arrangement chamber 210 and the mold 21 is in the mold-clamping state, the first mold bottom surface 211bb and the second mold top surface 212bb are both opposite to the main body 100b of the preform P100. The state in which the preform P100 is arranged in the arrangement chamber 210 is referred to as the arrangement state.

[0076] The mold spherical portion 210e accommodates the spherical portion 100e of the preform P100. The mold spherical portion 210e is a portion including the first mold connection surface 211be and the second mold connection surface 212be in the mold 21. Therefore, in the configuration state of the preform P100 and the mold 21 is in the mold clamping state, the first mold connection surface 211be and the second mold connection surface 212be are both opposite to the spherical portion 100e of the preform P100.

[0077] Figure 7 30 is an explanatory diagram showing the ejector pin 30. Figure 7 , the arrangement state of the preform P100 and the clamping state of the mold 21 are expressed. The ejector pin 30 separates the can 100 bonded to the mold 21 from the mold 21. The ejector pin 30 is a cylindrical pin provided inside each of the first mold 211 and the second mold 212.

[0078] Figure 8 Yes means Figure 7 2 is a cross-sectional view of section VIII-VIII of FIG. In the mold-clamping state of the mold 21, the surface of one end of the ejector pin 30 is aligned with the first mold bottom surface 211bb or the second mold top surface 212bb. The other end is supported outside the mold 21 (not shown) and does not move even when the first mold 211 and the second mold 212 are raised or lowered by the drive mechanism 29.

[0079] like Figure 7 as well as Figure 8 As shown in FIG. 1 , there is a gap S2 between the preform P100 and the inner surface 21a of the mold 21. In order to impregnate the preform P100 with resin, the can 100 forms a resin layer 122 to the inner surface 21a of the mold 21 so as to fill the gap S2 by the manufacturing method described later. At this time, the resin layer 122 is in a state of being bonded to the inner surface 21a of the mold 21. Since the ejector pin 30 stops at the inner surface 21a of the mold 21 even when the first mold 211 and the second mold 212 are raised and lowered by demolding, the can 100 bonded to the inner surface 21a of the mold 21 is separated from the inner surface 21a.

[0080] Furthermore, as described above, the gap S2 is not constant due to the variation in the outer diameter P100r of the preform P100. Therefore, there is a case where the main body 100b provided with the fluid medium 140 contacts the inner surface 21a of the mold 21. When the fluid medium 140 contacts the inner surface 21a, the preform P100 receives a load in the Y direction toward the preform P100 due to the clamping of the mold 21.

[0081] A-4. Can manufacturing method:

[0082] Fig. 9 1 is a flowchart showing a method for manufacturing the tank 100. The manufacturing of the tank 100 starts with the worker preparing the parts necessary for the tank 100 as step S100. In the following description, the names of the processes are described by attaching step numbers.

[0083] exist Fig. 9 In the preparation step S100 shown, the operator prepares the preform P100, the mold 21, and the fluid medium 140. After the preparation step S100, the winding step S110 is performed.

[0084] exist Fig. 9 In the winding step S110 shown in FIG. Figure 2 The outer surface P121o of the preform P100 shown is wound with the fluid medium 140 multiple times along the circumferential direction LD of the main body 100b of the preform P100. The operator determines the number of windings of the fluid medium 140 according to the deviation of the outer diameter P100r of the preform P100 so that the outer diameter of the preform P100 including the fluid medium 140 is accommodated in the space of the arrangement chamber 210. The operator fixes the wound fluid medium 140 to the fiber layer P121 through the heat-resistant belt. In this way, the fluid medium 140 is prevented from shifting during the manufacture of the tank 100. The arrangement step S120 is performed after the winding step S110.

[0085] exist Fig. 9In the arrangement step S120 shown in FIG. 1 , the operator arranges the preform P100 in the arrangement chamber 210 of the mold 21, and closes the first mold 211 and the second mold 212 by the manufacturing device 2. Figure 6 As shown, the first mold 211 and the second mold 212 are clamped, and the preform P100 is stored in the arrangement chamber 210. After the arrangement step S120, a degassing step S130 is performed.

[0086] exist Fig. 9 In the degassing step S130 shown, the manufacturing apparatus 2 degasses the interior of the arrangement chamber 210. Specifically, the vacuum pump 24 starts degassing in accordance with the command of the control device 28. The vacuum pump 24 continues degassing until the injection of the resin is completed in the injection step S140.

[0087] exist Fig. 9 In the injection step S140 shown, the manufacturing device 2 injects the resin stored in the resin storage part 25 into the arrangement chamber 210 side in order to impregnate the fiber layer P121 of the preform P100 with resin. Specifically, the valve 27 is opened according to the command of the control device 28, and the pressurization of the resin storage part 25 by the pressurizing device 26 is started. As a result, the resin flows in the second mold tube part 212c provided in the second mold 212, and the resin is injected toward the preform P100 from the second gate 212d. At this time, the temperature of the mold 21 is adjusted by the temperature adjustment device 23 so that the temperature of the mold 21 is lower than the curing temperature of the resin.

[0088] In the injection step S140, the manufacturing device 2 injects the resin into the mold 21 in a state where the preform P100 wound with the fluid medium 140 is arranged in the mold 21. More specifically, the manufacturing device 2 injects the resin onto the fluid medium 140 by filling the resin up to the inner surface 21a of the mold 21. That is, the gap S2 between the preform P100 and the mold 21 is filled with the resin. After the injection step S140, the impregnation step S150 is performed.

[0089] exist Fig. 9 In the impregnation step S150 shown, the manufacturing device 2 impregnates the flow medium 140 and the fiber bundles forming the fiber layer P121 of the preform P100 with resin. Through the impregnation step S150, the resin injected into the preform P100 flows in the gap S2 between the preform P100 and the inner surface 21a of the mold 21. On this basis, the resin is impregnated in the main body 100b in the circumferential direction LD, the axial direction OD, and the radial direction CD through the gap S1 of the flow medium 140. Therefore, even if the gap S2 is small, the resin can pass through. Figure 2The fluid medium 140 shown in the figure extends to the entire body 100b. In addition, the resin is impregnated from the outermost layer P121o side of the fiber layer P121 toward the innermost layer P121i side. Thus, the fiber-reinforced resin layer 121 is formed through the subsequent curing step S160. At the moment after the injection step S140 is started, a part of the impregnation step S150 is performed simultaneously with the injection step S140.

[0090] In the impregnation step S150, part of the resin is impregnated into the fiber layer P121, while the remaining resin flows into the gap S2 between the preform P100 and the inner surface 21a of the mold 21. Therefore, in the subsequent curing step S160, the resin that is not impregnated into the fiber layer P121 is cured on the outside of the fiber-reinforced resin layer 121. More specifically, Figure 1 As shown, a resin layer 122 composed of a resin not including a fiber bundle is formed outside the fiber reinforced resin layer 121 in the radial direction CD. That is, in the main body 100b, the resin layer 122 including the fluid medium 140 is formed, thereby forming a resin layer on the fluid medium 140. After the impregnation step S150, the curing step S160 is performed.

[0091] exist Fig. 9 In the curing step S160 shown, the manufacturing device 2 cures the resin impregnated with the fiber bundle. In the present embodiment, a thermosetting resin is used as the resin forming the reinforcing layer 120. Therefore, the manufacturing device 2 cures the resin by heating in the curing step S160. Specifically, the temperature adjustment device 23 adjusts the temperature of the mold 21 to a temperature higher than the curing temperature of the resin. Thus, the resin is cured to form the fiber reinforced resin layer 121. After the curing step S160, the demolding step S170 is performed.

[0092] exist Fig. 9 In the demolding step S170 shown, the manufacturing device 2 demolds the can 100 from the mold 21 by separating the first mold 211 from the second mold 212. Specifically, the drive mechanism 29 lowers the first mold 211 from the second mold 212 in the -Y direction and raises the second mold 212 from the first mold 211 in the +Y direction according to the command of the control device 28. As a result, only the ejector pin 30 is in contact with the can 100. After the curing step S160, since the can 100 is bonded to the inner surface 21a, it is pulled to both sides in the Y-axis direction due to demolding. Since the ejector pin 30 also stops at the position of the inner surface 21a of the mold 21 in the curing step S160 in the demolding step S170, the can 100 is separated from the inner surface 21a. Therefore, by separating the first mold 211 from the second mold 212, Figure 1 The can 100 shown is in a state where it can be removed from the mold 21. Figure 8The production of the can 100 is completed by executing the steps up to the mold release step S170 shown.

[0093] Fig.10 100r is a graph showing the variation range of the outer diameter 100r of the tank 100. Fig.10 , the variation range of the outer diameter 100r of the manufactured tank 100 is shown according to different conditions related to the flowing medium 140. Figure 1 As shown in FIG. 1 , the outer diameter 100r of the tank 100 is the outer diameter 100r in the radial direction CD of the main body 100b. The variation range of the outer diameter 100r represents the difference between the design value and the measured value of the outer diameter 100r for each condition. Fig.10 , the average value, maximum value, and minimum value of the outer diameter 100r measured at multiple locations of the main body 100b are shown. The conditions of the tank 100 are divided into a condition A in which the fluid medium 140 is not wound, a condition B in which the fluid medium 140 is wound around the entire main body 100b, and a condition C in which the fluid medium 140 is wound around a portion of the main body 100b. Figure 3 In case of description, Fig.10 The total length 100s of the tank 100 used in the embodiment is 1270 mm, and the main body 100b is 800 mm. The width of the fluid medium 140 under condition A is 800 mm, which is the same as that of the main body 100b. The width of the fluid medium 140 under condition B is 100 mm shorter than that of the main body 100b.

[0094] like Fig.10 As shown, the variation range of the outer diameter 100r is reduced by winding the fluid medium 140. That is, the uneven thickness of the resin layer 122 and the warping of the tank 100 caused by the stagnation of the resin flow are reduced by the fluid medium 140. In addition, the comparison between condition B and condition C will be described in B. Other embodiments.

[0095] According to the above description, by adopting such a mode, in the impregnation step S150, the resin is impregnated through the fluid medium 140 and the fiber bundle. The fluid medium 140 functions as a flow path for the resin between the mold 21 and the fiber bundle by overlapping with the fiber bundle. More specifically, the fluid medium 140 defines a gap S1 extending in a direction different from that of the fiber bundle between the preform P100. Therefore, the resin easily flows between the mold 21 and the fiber bundle, and thus it is difficult to produce a portion where the fiber bundle is not impregnated. In addition, since the manufacturing method of the tank 100 disclosed in the present invention does not require a special mold structure, impregnation can be facilitated even with an existing mold structure. That is, the manufacturing method of the tank 100 disclosed in the present invention can manufacture the tank 100 while ensuring the quality of the tank 100 by using the same mold 21 as in the past. Therefore, the manufacturing method of the tank 100 disclosed in the present invention can take into account both sufficient impregnation of the resin and ensuring the quality of the tank 100.

[0096] The method for manufacturing the can 100 of the present disclosure can achieve the same resistance when releasing the can 100 from the mold 21 by using the fluid medium 140 as when the fluid medium 140 is not used. Therefore, for example, the strength of the resin layer 122 related to the load of the ejector pin 30 and the strength related to scratches on the surface of the resin layer 122 are not deteriorated.

[0097] In addition, the use of the fluidizing medium 140 can reduce uneven thickness of the resin layer 122 and warping of the can 100 caused by stagnant resin flow. By reducing uneven thickness of the resin layer 122, it is easier to form a thin resin layer 122 than in a method without the fluidizing medium 140.

[0098] Furthermore, in the winding step S110, the fluid medium 140 is wound around the entire body 100b. By adopting such a manner, when the fluid medium 140 is in contact with the mold 21, the load caused by the clamping of the mold 21 is less likely to be concentrated on a portion of the body 100b. For example, when the fluid medium 140 is wound around a portion of the body 100b, the load caused by the clamping of the mold 21 is easily concentrated on a portion of the body 100b. Therefore, in the impregnation step S150, unimpregnated portions may sometimes be generated. By winding the sheet around the entire body 100b, the load caused by the clamping of the mold 21 is dispersed over the entire body 100b. Therefore, the manufacturing method of the tank 100 disclosed in the present invention can reduce the possibility of unimpregnated portions being generated in the body 100b.

[0099] In addition, the impregnation step S150 includes a step of forming a resin layer on the fluid medium 140. In this manner, the method for manufacturing the can 100 of the present disclosure can protect the main body 100b by covering the entire main body 100b with the resin layer.

[0100] Furthermore, in the winding step S110, the fluid medium 140 is wound multiple times. As described above, the outer diameter P100r of the preform P100 varies due to the winding accuracy of the fiber bundle. By adopting such a mode, the method for manufacturing the tank 100 of the present disclosure can easily adjust the outer diameter of the preform P100 including the fluid medium 140 by adjusting the number of winding turns of the fluid medium 140 to match the size of the mold 21. Therefore, the method for manufacturing the tank 100 of the present disclosure can make the impregnation of the resin more appropriate.

[0101] B. Other implementations:

[0102] In the above embodiment, the fluid medium 140 is wound around the entire body 100b of the preform P100, but may be wound around a portion of the body 100b. For example, the fluid medium 140 may be wound around only the central portion in the axial direction OD inside the body 100b. That is, the fluid medium 140 only needs to be wound around at least a portion.

[0103] exist Fig.10 , the result of condition C is shown as the variation range of the outer diameter 100r of the tank 100 when the fluid medium 140 is wound around only a part of the main body 100b. Condition C has a larger variation range than condition B, but has a smaller average value and a smaller variation range than condition A. Therefore, the tank manufacturing method disclosed in the present invention can make it easier to impregnate the resin with the fluid medium 140 than in a method where the fluid medium 140 is not provided. In addition, the method for manufacturing the tank 100 disclosed in the present invention can reduce the amount of the fluid medium 140 compared to a method in which the fluid medium 140 is wound around the entire main body 100b as in the first embodiment, so that the cost required for manufacturing the tank 100 can be reduced.

[0104] C. Other implementations:

[0105] (1) In the above embodiment, the fluid medium 140 is a sheet material formed into a mesh shape and is composed of the first fibers 140OD extending in the axial direction OD and the second fibers 140LD extending in the circumferential direction LD. However, the direction in which the first fibers 140OD extend may be inclined with respect to the central axis O. In this case, the fluid medium 140 is formed into a mesh shape by the second fibers 140LD extending in a direction perpendicular to the direction in which the first fibers 140OD extend.

[0106] (2) In the above embodiment, the fluid medium 140 is a sheet material formed in a mesh shape. However, the fluid medium 140 may be a sheet material as long as it is composed of three-dimensional mesh-shaped fibers. For example, the fluid medium 140 may have a structure in which fibers extend irregularly instead of a mesh-shaped structure in which fibers extend regularly.

[0107] (3) In the above embodiment, the fluid medium 140 is wound around the preform P100 multiple times. However, the fluid medium 140 may be wound around the preform P100 only once. The fluid medium 140 only needs to be wound around the preform P100 once or more.

[0108] (4) In the above embodiment, the impregnation step S150 forms a resin layer on the fluid medium 140 . However, the impregnation step S150 may be formed in conformity with the surface of the fluid medium 140 facing the outside of the can 100 .

[0109] (5) In the above embodiment, carbon fiber is used as the material of the fiber bundle of the fiber layer P121. The material of the fiber bundle of the fiber layer P121 is not limited to carbon fiber. For example, the material of the fiber bundle of the fiber layer P121 may be glass fiber, or a combination of glass fiber and carbon fiber.

[0110] (6) In the above embodiment, nylon is used as the material of the fibers constituting the fluid medium 140. However, the material of the fibers constituting the fluid medium 140 is not limited to nylon. The material constituting the fluid medium 140 may be glass fiber, for example.

[0111] The present disclosure is not limited to the above-mentioned embodiments, and can be implemented in various configurations within the scope of the main purpose. For example, the technical features of the embodiments corresponding to the technical features in each method described in the invention content column can be appropriately replaced or combined in order to solve part or all of the above-mentioned problems, or to achieve part or all of the above-mentioned effects. In addition, as long as the technical feature is not described as a necessary technical feature in this specification, it can be appropriately deleted.

Claims

1. A method for manufacturing a can, wherein: include: A preparation step of preparing a preform, a mold, and a sheet made of three-dimensional mesh fibers, wherein the preform has a cylindrical main body portion in which a plurality of fiber bundles are wound around an outer surface of a liner defining an inner space of the tank; A winding step of winding the sheet material for more than one time along the circumference of the main body on the outer surface of the preform; An injection step of injecting resin into the mold in a state where the preform around which the sheet is wound is arranged in the mold; as well as an impregnation step of impregnating the sheet and the fiber bundle with the resin, In the winding process, The sheet is wound around at least a portion of the main body. The preform around which the sheet is wound has voids extending in a direction different from a direction in which the fibers of the fiber bundle extend on an outer surface of the preform.

2. The method for manufacturing a can according to claim 1, wherein: In the winding step, the sheet is wound around the entire body portion.

3. The method for manufacturing a can according to claim 2, wherein: The impregnation step includes a step of forming a layer of the resin on the sheet.

4. The method for manufacturing a can according to claim 3, wherein: In the winding step, the sheet is wound a plurality of times.

5. A hydrogen tank, wherein: A main body having a cylindrical shape, The hydrogen tank includes an outer layer containing resin and covering the main body. The outer layer includes a lower layer composed of a plurality of fiber bundles and an upper layer overlapped with the lower layer and including a sheet material formed in a three-dimensional mesh shape. The sheet includes voids extending in a direction different from a direction in which the fibers of the fiber bundle extend.

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