CN119900919A - Tank manufacturing method and hydrogen tank - Google Patents

Abstract

The present invention relates to a method for manufacturing a tank and a hydrogen tank. The method for manufacturing the can includes a preparation step of preparing a preform having a cylindrical main body, a mold, and a sheet made of three-dimensional mesh-like fibers, a winding step of winding the sheet around the outer surface of the preform in the circumferential direction of the main body of the preform for at least one revolution, an injection step of injecting resin into the mold in a state where the preform around which the sheet is wound is placed in the mold, and an impregnation step of impregnating the sheet and the fiber bundle with the resin. In the winding step, the sheet is wound around at least a part of the body, and the preform around which the sheet is wound has a void extending in a direction different from the direction in which the fibers of the fiber bundles extend on the outer surface of the preform.

Description

Method for manufacturing tank and hydrogen tank

Technical Field

The present disclosure relates to a method of manufacturing a tank and a hydrogen tank.

Background

Conventionally, as shown in japanese patent application laid-open No. 2020-118288, a technique of forming a fiber-reinforced resin layer and a resin layer on the outer periphery of a liner by an RTM (RESIN TRANSFER Molding) method has been known.

As a can during production, the shape of an intermediate product formed by winding fibers around the outer surface of a liner is likely to vary. Therefore, in the resin impregnation step, when the mold is in contact with the intermediate product, the fibers at the contact portion may not sufficiently impregnate the resin.

The inventors studied a method of securing a flow path of a resin by providing irregularities on a surface of a mold. However, the resistance when the can is released from the rugged mold is greater than the resistance when the can is released from the mold with a flat surface. The can is pushed out by the ejector pin when it is released from the mold. When the resistance at the time of demolding is large, the resin layer of the can may be damaged by receiving an excessive load from the ejector pin. Therefore, in the production of a can, it is an issue to achieve both sufficient impregnation of the resin and securing of the quality of the can.

Disclosure of Invention

The present disclosure can be implemented as follows.

(1) According to one aspect of the present disclosure, a method of manufacturing a can is provided. The manufacturing method includes a preparation step of preparing a preform, a mold, and a sheet made of three-dimensional mesh-like fibers, wherein the preform is wound with a cylindrical body portion having a plurality of layers of fiber bundles around an outer surface of a liner defining an inner space of the tank, a winding step of winding the sheet around the outer surface of the preform in a circumferential direction of the body portion for at least one revolution, an injection step of injecting a resin into the mold in a state where the preform around which the sheet is wound is placed in the mold, and an impregnation step of impregnating the sheet and the fiber bundles with the resin, wherein the sheet is wound around at least a part of the body portion, and wherein the preform around which the sheet is wound has a void extending in a direction different from a direction in which fibers of the fiber bundles extend on the outer surface of the preform.

In this way, in the impregnation step, the resin can be impregnated with the sheet and the fiber bundle. The sheet material is overlapped with the fiber bundle to function as a flow path of the resin between the die and the fiber bundle. More specifically, the sheet and the preform are divided by a void extending in a direction different from the direction of the fiber bundles. Therefore, the resin easily flows between the die and the fiber bundle, and therefore, it is difficult to generate an un-impregnated portion of the fiber bundle. Further, since the method for manufacturing a can of the present disclosure does not require a special mold structure, impregnation can be facilitated even with a conventional mold structure. That is, the can manufacturing method of the present disclosure can manufacture a can while ensuring the quality of the can by using the same mold as in the related art. Thus, the method for manufacturing a can according to the present disclosure can achieve both sufficient impregnation of the resin and ensuring of the quality of the can.

(2) In the method of manufacturing a can according to the above aspect, in the winding step, the sheet may be wound around all of the main body portion.

In this way, when the sheet is in contact with the mold, the load caused by the mold clamping is difficult to concentrate on a part of the main body. For example, when the sheet is wound around a part of the main body, a load due to clamping of the mold tends to be concentrated on the part of the main body. Therefore, in the impregnation step, non-impregnated portions may be generated. By winding the sheet around the entire main body, the load caused by the clamping of the mold can be dispersed to the entire main body. Thus, the method for manufacturing a can of the present disclosure can reduce the possibility of non-impregnated sites in the body portion.

(3) In the method for manufacturing a can according to the above aspect, the impregnating step may include a step of forming a layer of the resin on the sheet.

In this way, the method of manufacturing the can of the present disclosure can protect the main body portion by covering the entire main body portion with the layer of resin.

(4) In the method for manufacturing a can according to the above aspect, the winding of the sheet may be performed a plurality of times in the winding step.

The outer diameter of the preform varies depending on the precision of winding the fiber bundle. In this way, the manufacturing method of the can of the present disclosure can easily adjust the outer diameter of the preform including the sheet by matching the size of the mold through adjustment of the number of winding turns of the sheet. Thus, the method for manufacturing a can of the present disclosure can make impregnation of the resin more appropriate.

(5) According to other aspects of the present disclosure, a hydrogen tank is provided. The hydrogen tank includes a cylindrical main body portion, and the hydrogen tank includes an outer layer including a resin and covering the main body portion, the outer layer including a lower layer including a plurality of layers of fiber bundles, and an upper layer overlapping the lower layer and including a three-dimensional mesh-shaped sheet having voids extending in a direction different from a direction in which fibers of the fiber bundles extend.

In this way, in the case of producing the outer layer of the hydrogen tank by the RTM method, the hydrogen tank of the present disclosure can flow the resin into the fiber bundle via the sheet. Therefore, since the fiber bundle is not in contact with the die, the hydrogen tank of the present disclosure is difficult to generate an un-impregnated site. In addition, the hydrogen tank of the present disclosure can facilitate impregnation even in a conventional mold structure by using a sheet. That is, the hydrogen tank of the present disclosure can facilitate the production of the hydrogen tank while ensuring the quality of the hydrogen tank.

Drawings

Features, advantages, technical and industrial importance of the exemplary embodiments of the present invention are described below with reference to the accompanying drawings, in which like reference numerals refer to like elements, and in which:

fig. 1 is a cross-sectional view showing a schematic configuration of a tank.

Fig. 2 is a cross-sectional view showing a schematic configuration of the preform.

Fig. 3 is a plan view showing a preform wound with a flow medium.

Fig. 4 is a plan view showing the construction of the flow medium.

Fig. 5 is a cross-sectional view showing the V-V section of fig. 4.

Fig. 6 is a schematic view schematically showing a schematic configuration of a tank manufacturing apparatus.

Fig. 7 is an explanatory diagram showing the ejector pin.

FIG. 8 is a cross-sectional view showing the section VIII-VIII of FIG. 7.

Fig. 9 is a flowchart showing a method of manufacturing a can.

Fig. 10 is a graph showing a range of variation in the outer diameter of the can.

Detailed Description

A. embodiment 1:

a-1, constitution of preform and can:

Fig. 1 is a cross-sectional view showing a schematic configuration of a tank 100. Fig. 2 is a cross-sectional view showing a schematic configuration of the preform P100. The can 100 shown in fig. 1 is manufactured by processing the preform P100 shown in fig. 2.

In fig. 1 and 2, a cross-sectional view perpendicular to the central axis O is illustrated for each of the preform P100 and the can 100. The X-axis, Y-axis, and Z-axis are depicted in fig. 1 and 2 as mutually orthogonal axes. The directions of the arrows of the X axis, the Y axis, and the Z axis represent the positive directions along the X axis, the Y axis, and the Z axis, respectively. Positive directions along the X-axis, Y-axis, and Z-axis are respectively +x-direction, +y-direction, and +z-direction. The directions opposite to the directions of the arrows of the X axis, the Y axis and the Z axis are negative directions along the X axis, the Y axis and the Z axis. Negative directions along the X-axis, Y-axis and Z-axis are respectively defined as-X direction, -Y direction and-Z direction. The case where the directions along the X-axis, Y-axis, and Z-axis are not positive or negative is referred to as X-direction, Y-direction, and Z-direction, respectively.

In the present embodiment, the X direction is a direction along the central axis O of the can 100. The direction parallel to the central axis O is also referred to as the axial direction OD. The Y direction is a direction along the gravity direction in a posture in which the tank 100 is arranged, which will be described later. The Y direction coincides with the direction of gravity in the configuration posture. The direction perpendicular to the central axis O is referred to as the radial direction CD. The direction parallel to the circumference with the center as the center axis O is referred to as the circumferential direction LD. In the radial direction CD of the can 100, the side closer to the center axis O is set as the inner side, and the side farther from the center axis O is set as the outer side.

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 the fuel cell in a high-pressure state. Tank 100 is provided with liner 110, reinforcement layer 120, joint 130, and flow medium 140.

In the production of the tank 100, the tank 100 is produced by impregnating a fiber layer P121 described later with a 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 can 100. The preform P100 will be described later. Here, impregnation is expressed in the present specification as impregnating the fiber bundles with a resin and containing the resin.

The liner 110 is a hollow vessel defining an interior space 110p of the tank 100 for storing fluid. The liner 110 is formed of, for example, a polyamide resin having gas barrier properties. The central axis O of the liner 110 is the same as the central axis O of the can 100.

Joints 130 are provided at both ends of the can 100. As one joint 130, the joint 130 at the right end in fig. 1 communicates the space inside the liner 110 with the external space. That is, one of the joints 130 has a cylindrical through hole. As the other joint 130, the joint 130 at the left end in fig. 1 has a cylindrical external shape, but does not have a through hole.

The reinforcing layer 120 is a layer for reinforcing the liner 110. The reinforcing layer 120 covers the outer circumference of the liner 110. The reinforcing layer 120 includes a fiber-reinforced resin layer 121 and a resin layer 122.

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: carbon fiber-reinforced resin). CFRP is formed by thermally curing carbon fibers after impregnating the thermosetting resin with an epoxy resin. Accordingly, the fiber reinforced resin layer 121 includes a plurality of fiber bundles formed by being wound around the outer surface 110o of the liner 110. That is, the fiber-reinforced resin layer 121 is formed by impregnating the multilayer fiber bundles with resin on the outer surface 110o of the liner 110. The layer formed by the fiber bundles before impregnation with the resin is referred to as a fiber layer P121.

The resin layer 122 covers the outer surface 121o of the fiber-reinforced resin layer 121. The resin layer 122 is formed of the same resin as the resin impregnating the fibers in the process of forming the fiber-reinforced resin layer 121. More specifically, the resin layer 122 is a layer formed by thermally curing the outside of the fiber bundles in the fiber-reinforced resin layer 121. In the present embodiment, the fiber-reinforced resin layer 121 and the resin layer 122 are formed by a resin injection Molding (RTM: RESIN TRANSFER Molding) method using a tank-manufacturing mold 21 shown in fig. 6, which will be described later. In the following description, the resin injection molding method is referred to as RTM method, and the can-manufacturing mold 21 is simply referred to as mold 21. The details of the method for forming the fiber-reinforced resin layer 121 and the resin layer 122 by the RTM method will be described later.

The flow medium 140 is a sheet made of three-dimensional mesh-like fibers. The flow medium 140 is disposed inside the resin layer 122. As for the flow medium 140, it will be described in detail later. In addition, the flow medium 140 is also referred to as a sheet 140.

A preform P100 as an intermediate product in the manufacturing process of the can 100 will be described. As shown in fig. 2, preform P100 is composed of liner 110, fibrous layer P121, and joint 130. In fig. 2, the flow medium 140 is illustrated for easy understanding of the technique. Liner 110 and tab 130 are identical in construction to can 100. As for the fiber layer P121, description will be made later.

The shape of the preform P100 is explained. The preform P100 includes a cylindrical body portion 100b and hemispherical spherical portions 100e located at both ends of the body portion 100 b.

More specifically, the body portion 100b is a range of the axial OD defined by a portion of the outer surface 110o of the liner 110 parallel to the axial OD. As in the case of the can 100 and the preform P100, the body portion 100b is defined similarly in a state where the fiber layer P121, the resin layer 122, and the like are laminated on the surface of the liner 110.

The spherical surface portion 100e is a portion of the liner 110 other than the main body portion 100 b. In the same manner as the main body 100b, the spherical surface 100e is defined in the same manner as in the case where the fiber layer P121, the resin layer 122, and the like are laminated on the surface of the backing 110. The spherical portions 100e are provided at both ends of the body portion 100 b. More specifically, the spherical portion 100e is provided to be continuous with the end portion 100be in the axial direction OD in the main body portion 100 b. The spherical portion 100e has a hemispherical shape protruding from the end portion 100be of the body portion 100b toward the joint 130. The spherical portion 100e has a diameter that decreases as it moves away from the main body portion 100 b.

Here, the reinforcing layer 120 covering the main body portion 100b is also referred to as an "outer layer". In the outer layer, the fiber-reinforced resin layer 121 composed of a plurality of fiber bundles is also referred to as a "lower layer", and the resin layer 122 that overlaps the lower layer and includes the flow medium 140 is also referred to as an "upper layer".

The fiber layer P121 is explained. The fiber layer P121 is a fiber-reinforced resin layer 121 before resin impregnation, and is made of fiber bundles of carbon fibers. The fiber bundle is formed, for example, by winding a plurality of layers in such a manner as to cover the outer surface 110o of the liner 110 using spiral winding and hoop winding. The term "fiber bundle" as used herein means an aggregate of a large number of filaments having diameters of about several micrometers. The fiber-reinforced resin layer 121 is formed by impregnating the fiber layer P121 with a thermosetting resin and then thermally curing it.

"Spiral winding" refers to a method of winding a fiber bundle around the liner 110 in such a manner that the winding angle of the fiber bundle with respect to the central axis O is greater than 0 degrees and less than 90 degrees. In the spiral winding, for example, the fiber bundle is wound so as to pass from one spherical surface portion 100e of the liner 110 to the other spherical surface portion 100e through the body portion 100b. The "hoop winding" refers to a method of winding the fiber bundle around the liner 110 such that the winding angle of the fiber bundle with respect to the central axis O is substantially 90 degrees. In hoop winding, the fiber bundle is wound around the main body 100b while moving the winding position parallel to the central axis O. That is, the innermost layer P121i of the fibrous 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.

That is, the preform P100 is wound with a multi-layered fiber bundle on the outer surface 110o of the liner 110 defining the inner space 110P of the can 100.

However, the outer diameter P100r of the preform P100 in the radial direction CD may vary in each portion of the preform P100 in the axial direction OD due to the formation of the fiber layer P121. Accordingly, when the preform P100 is arranged in the mold 21 described later, the gap S2 between the preform P100 and the mold 21 is deviated. Regarding the gap S2, description will be made later.

A-2, regarding the flow medium:

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

Fig. 3 is a top view showing the preform P100 wound with the flow medium 140. The flow medium 140 is wound around the preform P100 in a winding step S110 of manufacturing the can 100, which will be described later. More specifically, the flow medium 140 is wound around the entire body 100 b. The flow medium 140 in fig. 1 to 3 is wound around the body portion 100b of the preform P100. Accordingly, the flow medium 140 is impregnated with the resin together with the preform P100, and thus is disposed inside the resin layer 122 as in the tank 100 shown in fig. 1.

Fig. 4 is a plan view showing the configuration of the flow medium 140. More specifically, the flow medium 140 is wound multiple times along the circumferential direction LD of the body portion 100b of the preform P100 toward the outer surface P121o of the preform P100. That is, the flow medium 140 expands in a direction perpendicular to the radial direction CD. In fig. 4, a configuration of the flow medium 140 that can be confirmed in a case where the flow medium 140 is observed from the outside of the preform P100 along the radial direction CD is illustrated.

The flow medium 140 is composed of the 1 st fiber 140OD extending toward the axial direction OD and the 2 nd fiber 140LD extending toward the circumferential direction LD. More specifically, the flow medium 140 is formed by disposing a space between fibers that face in the same direction and are adjacent to each other and weaving the 1 st fiber 140OD and the 2 nd fiber 140 LD. Thus, a space S1 extending in the radial direction CD is defined in the flow medium 140. Wherein the interval between adjacent fibers of the flow medium 140 is set to be wider than the interval between carbon fibers of the fiber layer P121 of the preform P100.

Fig. 5 is a cross-sectional view showing the V-V section of fig. 4. In fig. 5, in order to facilitate the understanding of the technique, a mold 21 and a fiber layer P121 of a preform P100, which will be described later, are illustrated. As shown in fig. 5, the fibers are woven, whereby the space S1 is defined when the cross section of the flow medium 140 is viewed along the circumferential direction LD. As shown in fig. 4, the 1 st fiber 140OD crosses the 2 nd fiber 140LD at an angle of 90 degrees. Therefore, the gap S1 is also defined when the cross section of the flow medium 140 is viewed along the axial direction OD. The preform P100 is arranged in the mold 21 in a state where the flow medium 140 is wound. Therefore, when the flow medium 140 contacts the mold 21, the preform P100 around which the flow medium 140 is wound also includes a space S1 between the mold 21 and the fiber layer P121.

Accordingly, the preform P100 around which the flow medium 140 is wound has a void S1 extending in each of the circumferential direction LD, the axial direction OD, and the radial direction CD at the outer surface P121o of the preform P100. That is, the preform P100 around which the flow medium 140 is wound has a void S1 extending in a direction different from the direction in which the fibers of the fiber bundle extend on the outer surface P121 o. In this way, the flow medium 140 overlaps the fiber bundle of the preform P100, and thus functions as a flow path of the resin between the die 21 and the fiber bundle in the impregnation step S150 of the tank 100, which will be described later. Thus, the resin easily flows between the die 21 and the fiber bundle, and thus it is difficult to generate an un-impregnated portion of the fiber bundle.

On this basis, the flow medium 140 can reduce warpage of the can 100. The resin layer 122 may have a non-uniform thickness due to stagnation of the flow of the resin. For example, in fig. 1, when 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 is greatly contracted by curing the resin. Therefore, the can 100 may warp inward in the-Y direction. The flow medium 140 can reduce warpage of the can 100 by preventing the thickness of the resin layer 122 from being non-uniform. That is, the unevenness of the resin layer 122 is reduced by the flow medium 140, and the resin layer 122 is easily formed to be thinner than a case where the flow medium 140 is not provided.

A-3. Structure of the can manufacturing apparatus:

Fig. 6 is a schematic diagram schematically showing the configuration of the manufacturing apparatus 2 for the tank 100. Fig. 6 illustrates a state in which the preform P100 is disposed in the mold 21. The manufacturing apparatus 2 is an apparatus for manufacturing the can 100 of fig. 1 from the preform P100 of fig. 2 by the RTM method. Specifically, the manufacturing apparatus 2 manufactures the tank 100 in which the reinforcing layer 120 is formed on the outer peripheral side of the liner 110 by impregnating the fiber layer P121 of the preform P100 with a resin and then curing the resin by the RTM method. In the present embodiment, thermosetting resin is used for forming the reinforcing layer 120.

The manufacturing apparatus 2 includes a mold 21, a support mechanism 22, a temperature control device 23, a vacuum pump 24, a resin reservoir 25, a pressurizing device 26, a valve 27, a control device 28, a driving mechanism 29, and a thimble 30. Fig. 7 and 8, which will be described later, illustrate the ejector pin 30.

The support mechanism 22 supports the preform P100 from both ends where the joint 130 is located in the arrangement state of the preform P100.

The temperature regulating device 23 controls the temperature of the mold 21. The thermostat 23 is illustrated in the center of the left side of fig. 6. The temperature control device 23 sets the temperature of the mold 21 to be less than the curing temperature of the resin, for example, in a period before the impregnation of the resin into the fiber layer P121 is completed, in accordance with an instruction from the control device 28. After the completion of the impregnation of the resin into the fiber layer P121, the temperature adjusting device 23 sets the temperature of the mold 21 to a temperature equal to or higher than the curing temperature of the resin.

The vacuum pump 24 is a deaerator for deaerating by vacuum in the arrangement chamber 210 in the arrangement state of the preform P100 and the mold 21 in the mold-closed state. A vacuum pump 24 is illustrated in the lower left part of fig. 6. The arrangement state and the mold clamping state will be described later.

The resin storage 25 is a storage chamber for storing the resin supplied to the arrangement chamber 210. The resin reservoir 25 is illustrated in the upper right-hand side of fig. 6. The resin reservoir 25 is connected to the 2 nd die pipe portion 212c via a valve 27. The resin reservoir 25 is connected to a pressurizing device 26.

The pressurizing device 26 pressurizes the resin stored in the resin storage portion 25 to circulate the resin from the resin storage portion 25 to the arrangement chamber 210 side. The pressurizing means 26 is illustrated in the upper right-hand part of fig. 6. The pressurizing device 26 is disposed upstream of the resin storage portion 25 in the flow direction indicated by the arrow.

The valve 27 is an on-off valve for switching between a flow state in which the resin is allowed to flow from the resin storage portion 25 to the 2 nd die pipe portion 212c and a non-flow state in which the resin is not allowed to flow from the resin storage portion 25 to the 2 nd die pipe portion 212 c. The valve 27 is illustrated in the center of the left side of fig. 6. The valve 27 is disposed downstream of the resin reservoir 25 in the flow direction indicated by the arrow. The opening and closing of the valve 27 is controlled by a control device 28.

The driving mechanism 29 is a device for moving the 1 st die 211 and the 2 nd die 212. The drive mechanism 29 is illustrated in the upper central part of fig. 6. The driving mechanism 29 is a lifting device for lifting and lowering the 1 st die 211 and the 2 nd die 212 to open and close the die 21. When the mold 21 is closed, the driving mechanism 29 brings the 2 nd mold 212 and the 1 st mold 211 close to each other in the Y direction according to an instruction of the control device 28. In the case of demolding, the driving mechanism 29 moves the 2 nd die 212 and the 1 st die 211 away from each other in the Y direction according to an instruction of the control device 28. In the present specification, "mold closing" means closing the mold 21.

The control device 28 controls the manufacturing device 2. The control device 28 includes a processor, ROM, and RAM, not shown, and performs processing necessary for controlling the respective components of the manufacturing apparatus 2. In fig. 6, the electrical connection is schematically illustrated by a broken line for each component of the manufacturing apparatus 2 that is electrically connected to and controlled by the control apparatus 28.

The mold 21 includes a pair of 1 st and 2 nd molds 211 and 212 and an arrangement chamber 210 in which the preform P100 is arranged.

The 1 st die 211 is opposed to the 2 nd die 212. The 1 st die 211 is disposed on the-Y direction side in the gravity direction with respect to the 2 nd die 212.

The 1 st die 211 has a1 st die opposing wall 211a, a1 st die recess 211b, a1 st die tube portion 211c, and a1 st gate 211d. The 1 st die opposing wall 211a is a wall surface opposing the 2 nd die 212. The 1 st die recess 211b is a recess in which a part of the 1 st die opposing wall 211a is recessed inward of the 1 st die 211. The 1 st die concave portion 211b has a1 st die bottom surface 211bb and a1 st die connecting surface 211be, and is formed in a shape of an opening on the +y direction side where the 2 nd die 212 is located. The 1 st die connecting surfaces 211be are located on both end sides of the 1 st die bottom surface 211bb, respectively. The 1 st die tube portion 211c is a flow path of gas formed in the 1 st die 211 for degassing the arrangement chamber 210 by the vacuum pump 24. The 1 st gate 211d is an opening formed in the 1 st die bottom surface 211bb of the 1 st die recess 211 b. That is, the degassing by the vacuum pump 24 is performed from the 1 st gate 211d through the 1 st die pipe portion 211 c.

The 2 nd die 212 has a2 nd die opposing wall 212a, a2 nd die recess 212b, a2 nd die tube portion 212c, and a2 nd gate 212d. The 2 nd die opposing wall 212a is a wall surface opposing the 1 st die opposing wall 211 a. The 2 nd die recess 212b is a recess in which a part of the 2 nd die opposing wall 212a is recessed inward of the 2 nd die 212. The 2 nd die concave portion 212b has a2 nd die top surface 212bb and a2 nd die connecting surface 212be, and is shaped to be open on the-Y direction side where the 1 st die 211 is located. The 2 nd die connecting surface 212be is located at both end sides of the 2 nd die top surface 212 bb. That is, the inner surface 21a of the die 21 is formed by the 1 st die bottom surface 211bb and the 1 st die connecting surface 211be of the 1 st die concave portion 211b and the 2 nd die top surface 212bb and the 2 nd die connecting surface 212be of the 2 nd die concave portion 212 b. The 2 nd die pipe portion 212c is a flow path formed inside the 2 nd die 212 for flowing the resin supplied from the resin storage portion 25 to the arrangement chamber 210. The 2 nd gate 212d is an opening formed in the 2 nd die top surface 212bb of the 2 nd die recess 212 b. That is, the 2 nd die pipe portion 212c communicates the valve 27 and the resin reservoir portion 25 side with the arrangement chamber 210 side via the 2 nd gate 212d. In fig. 6, the direction of resin flow is shown with arrows.

The disposition chamber 210 is a space for disposing the preform P100 between the 1 st die 211 and the 2 nd die 212. The placement chamber 210 is an internal space 110p of the mold 21 defined by the 1 st mold concave portion 211b and the 2 nd mold concave portion 212b in a state where the 1 st mold 211 and the 2 nd mold 212 are clamped. The clamped state is referred to as a clamped state. That is, the arrangement chamber 210 is defined in the mold 21 in the mold-closed state of the mold 21.

More specifically, the arrangement chamber 210 is an internal space 110P larger than the outer shape of the preform P100, and is an internal space 110P conforming to the outer shape of the can 100. As described above, the preform P100 is supported at both ends by the support mechanism 22. Therefore, the gap S2 is generated between the preform P100 placed in the placement chamber 210 and the inner surface 21a of the placement chamber 210.

The 1 st die concave portion 211b and the 2 nd die concave portion 212b are formed in shapes along the shape of the preform P100, respectively. Specifically, the mold 21 includes a cylindrical mold body portion 210b and 2 mold spherical portions 210e provided at both ends of the mold body portion 210b and having diameters that decrease with distance from the mold body portion 210 b.

The mold main body 210b houses the main body 100b of the preform P100. The mold main body portion 210b is a portion of the mold 21 including a1 st mold bottom surface 211bb and a2 nd mold top surface 212 bb. Thus, in the state where the preform P100 is arranged in the arrangement chamber 210 and the mold 21 is in the mold-closed state, the 1 st mold bottom surface 211bb and the 2 nd mold top surface 212bb are opposed to the body portion 100b of the preform P100. Here, the state in which the preform P100 is arranged in the arrangement chamber 210 is referred to as an arrangement state.

The mold spherical surface portion 210e accommodates the spherical surface portion 100e of the preform P100. The mold spherical surface portion 210e is a portion of the mold 21 including the 1 st mold connecting surface 211be and the 2 nd mold connecting surface 212 be. Therefore, in the arranged state of the preform P100 and in the clamped state of the mold 21, the 1 st mold connecting surface 211be and the 2 nd mold connecting surface 212be are opposed to the spherical surface portion 100e of the preform P100.

Fig. 7 is an explanatory diagram showing the ejector pin 30. In fig. 7, the arrangement state of the preform P100 and the mold 21 clamping state are expressed. The ejector pins 30 separate the can 100 bonded to the mold 21 from the mold 21. The ejector pin 30 is a columnar pin provided in each of the 1 st die 211 and the 2 nd die 212.

FIG. 8 is a cross-sectional view showing the section VIII-VIII of FIG. 7. In the clamped state of the mold 21, the surface of one end of the ejector pin 30 is aligned with the 1 st mold bottom surface 211bb or the 2 nd mold top surface 212 bb. The other end is supported outside a mold 21, not shown, and does not operate even when the 1 st mold 211 and the 2 nd mold 212 are lifted by the driving mechanism 29.

As shown in fig. 7 and 8, a gap S2 exists between the preform P100 and the inner surface 21a of the mold 21. By the manufacturing method described later, the can 100 forms the resin layer 122 to the inner surface 21a of the mold 21 so as to fill the gap S2 in order to impregnate the preform P100 with the resin. At this time, the resin layer 122 is adhered to the inner surface 21a of the mold 21. The ejector pins 30 stop at the inner surface 21a of the mold 21 even when the 1 st mold 211 and the 2 nd mold 212 are lifted by the demolding, and therefore the can 100 adhered to the inner surface 21a of the mold 21 is separated from the inner surface 21a.

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 also a case where the body portion 100b provided with the flow medium 140 is in contact with the inner surface 21a of the die 21. With the flow medium 140 in contact with the inner surface 21a, the preform P100 receives a load toward the preform P100 in the Y direction due to the clamping of the mold 21.

A-4, manufacturing method of the tank:

fig. 9 is a flowchart showing a method of manufacturing the can 100. The manufacture of the can 100 is started as step S100 from the preparation of the components required for the can 100 by the operator. In the following description, the names of the respective steps are given with step numbers.

In the preparation step S100 shown in fig. 9, the worker prepares the preform P100, the mold 21, and the flow medium 140. The winding process S110 is performed after the preparation process S100.

In the winding step S110 shown in fig. 9, the operator winds the flow medium 140 a plurality of times along the circumferential direction LD of the body portion 100b of the preform P100 toward the outer surface P121o of the preform P100 shown in fig. 2. Regarding the number of windings of the flow medium 140, the operator determines the number of windings of the flow medium 140 so that the outer diameter of the preform P100 including the flow medium 140 is accommodated in the space of the disposition chamber 210 according to the deviation of the outer diameter P100r of the preform P100. The operator fixes the wound flow medium 140 to the fiber layer P121 by a heat-resistant tape. Thus, in the manufacture of the tank 100, the flow medium 140 is prevented from being deviated. The disposing step S120 is performed after the winding step S110.

In the disposing step S120 shown in fig. 9, the worker disposes the preform P100 in the disposing chamber 210 of the mold 21, and closes the 1 st mold 211 and the 2 nd mold 212 by the manufacturing apparatus 2. That is, as shown in fig. 6, the 1 st die 211 and the 2 nd die 212 are clamped, and the preform P100 is accommodated in the disposition chamber 210. The degassing process S130 is performed after the disposing process S120.

In the degassing step S130 shown in fig. 9, the manufacturing apparatus 2 performs degassing in the placement chamber 210. Specifically, the vacuum pump 24 starts degassing according to the instruction of the control device 28. The vacuum pump 24 continues the deaeration until the completion time of the injection of the resin in the injection step S140.

In the injection step S140 shown in fig. 9, the manufacturing apparatus 2 injects the resin stored in the resin storage 25 toward the placement chamber 210 side so as to impregnate the fiber layer P121 of the preform P100 with the resin. Specifically, the valve 27 is opened in accordance with an instruction of the control device 28, and pressurization of the resin reservoir 25 by the pressurization device 26 is started. Thus, the resin flows through the 2 nd die pipe portion 212c provided in the 2 nd die 212, and the resin is ejected from the 2 nd gate 212d toward the preform P100. At this time, the temperature of the mold 21 is adjusted by the temperature adjusting device 23 so that the temperature of the mold 21 is less than the curing temperature of the resin.

In the injection step S140, the manufacturing apparatus 2 injects the resin into the mold 21 in a state where the preform P100 around which the flow medium 140 is wound is placed in the mold 21. More specifically, the manufacturing apparatus 2 is injected onto the flow medium 140 by filling the inner surface 21a of the mold 21 with resin. That is, the gap S2 between the preform P100 and the mold 21 is filled with resin. The impregnation step S150 is performed after the injection step S140.

In the impregnation step S150 shown in fig. 9, the manufacturing apparatus 2 impregnates the resin with the flow medium 140 and the fiber bundles forming the fiber layer P121 of the preform P100. Through the impregnation step S150, the resin injected toward 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 into the body portion 100b in the circumferential direction LD, the axial direction OD, and the radial direction CD through the space S1 of the flow medium 140. Thus, even when the gap S2 is small, the resin can be spread over the entire body 100b by the flow medium 140 shown in fig. 2. The resin is impregnated from the outermost layer P121o side toward the innermost layer P121i side of the fiber layer P121. Thereby, the fiber-reinforced resin layer 121 is formed through the subsequent curing step S160. At a time point after the start of the injection step S140, a part of the impregnation step S150 is performed in parallel with the injection step S140.

In the impregnation step S150, a part of the resin is impregnated into the fiber layer P121, while the remaining resin flows through the gap S2 between the preform P100 and the inner surface 21a of the mold 21. Accordingly, in the subsequent curing step S160, the resin that does not impregnate the fiber layer P121 is cured outside the fiber-reinforced resin layer 121. More specifically, as shown in fig. 1, a resin layer 122 made of a resin that does not include fiber bundles is formed outside the fiber-reinforced resin layer 121 in the radial direction CD. That is, in the main body portion 100b, the resin layer 122 including the flow medium 140 is formed, thereby forming a layer of resin on the flow medium 140. The curing step S160 is performed after the impregnating step S150.

In the curing step S160 shown in fig. 9, the manufacturing apparatus 2 cures the resin impregnated in the fiber bundle. In this embodiment, a thermosetting resin is used as the resin forming the reinforcing layer 120. Accordingly, the manufacturing apparatus 2 cures the resin by heating in the curing step S160. Specifically, the temperature control device 23 controls the temperature of the mold 21 to be equal to or higher than the curing temperature of the resin. Thereby, the resin is cured to form the fiber reinforced resin layer 121. The demolding process S170 is performed after the curing process S160.

In the demolding step S170 shown in fig. 9, the manufacturing apparatus 2 releases the can 100 from the mold 21 by separating the 1 st mold 211 from the 2 nd mold 212. Specifically, the driving mechanism 29 lowers the 1 st die 211 from the 2 nd die 212 in the-Y direction and raises the 2 nd die 212 from the 1 st die 211 in the +y direction in response to a command from the control device 28. This brings about a state in which only the ejector pins 30 are in contact with the can 100. After the curing step S160, the can 100 is adhered to the inner surface 21a, and thus pulled to both sides in the Y axis direction by the release. 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, and therefore the can 100 is separated from the inner surface 21 a. Thus, the 1 st die 211 and the 2 nd die 212 are separated from each other, so that the can 100 shown in fig. 1 can be removed from the die 21. The manufacturing of the can 100 is completed by the execution of the steps up to the demolding step S170 shown in fig. 8.

Fig. 10 is a graph showing a range of variation of the outer diameter 100r of the can 100. In fig. 10, a range of variation of the outer diameter 100r of the manufactured tank 100 is shown according to different conditions related to the flow medium 140. As shown in fig. 1, the outer diameter 100r of the can 100 is the outer diameter 100r of the radial direction CD at the main body portion 100 b. The fluctuation range of the outer diameter 100r indicates the difference between the design value and the measured value of the outer diameter 100r for each condition. Fig. 10 illustrates average, maximum, and minimum values of the outer diameter 100r measured at a plurality of positions of the body portion 100 b. The conditions of the can 100 are classified into a case where the flow medium 140 is not wound as the condition a, a case where the flow medium 140 is wound around the entire main body portion 100B as the condition B, and a case where the flow medium 140 is wound around a part of the main body portion 100B as the condition C. In the case described with reference to fig. 3, the total length 100s of the can 100 used in the embodiment of fig. 10 is 1270mm, and the main body 100b is 800mm. The width of the flow medium 140 under condition a is 800mm which is the same as the main body portion 100 b. The width of the flow medium 140 under condition B is 100mm shorter than the main body portion 100B.

As shown in fig. 10, by winding the flow medium 140, the variation range of the outer diameter 100r is reduced. That is, the thickness of the resin layer 122 is not uniform due to stagnation of the resin flow, and warpage of the can 100 is reduced by the flow medium 140. Further, regarding the comparison of the condition B with the condition C, description will be made in other embodiments of B.

As described above, in the impregnation step S150, resin is impregnated through the flow medium 140 and the fiber bundles. The flow medium 140 overlaps the fiber bundle and functions as a flow path for the resin between the die 21 and the fiber bundle. More specifically, the flow medium 140 partitions the space S1 extending in a direction different from the fiber bundle from the preform P100. Therefore, the resin easily flows between the die 21 and the fiber bundle, and therefore, it is difficult to generate an un-impregnated portion of the fiber bundle. Further, since the method for manufacturing the can 100 of the present disclosure does not require a special mold structure, impregnation can be facilitated even with a conventional mold structure. That is, the method of manufacturing the can 100 of the present disclosure can manufacture the can 100 while ensuring the quality of the can 100 by using the same mold 21 as in the related art. Thus, the method for manufacturing the can 100 of the present disclosure can satisfy both sufficient impregnation of the resin and ensuring of the quality of the can 100.

Regarding the resistance when the can 100 is released from the mold 21, the method of manufacturing the can 100 of the present disclosure can be made to be equal to the resistance when the flow medium 140 is not used by using the flow medium 140. Therefore, for example, the strength of the resin layer 122 in relation to the load of the ejector pins 30, the strength in relation to scratches on the surface of the resin layer 122, and the like are not deteriorated.

In addition, by using the flow medium 140, the thickness unevenness of the resin layer 122 and the warpage of the can 100 due to the stagnation of the resin flow can be reduced. By reducing the unevenness of the resin layer 122, the resin layer 122 is easily formed to be thinner than in a manner in which the flow medium 140 is not provided.

In the winding step S110, the flow medium 140 is wound around the entire body 100 b. In this way, when the flow medium 140 contacts the mold 21, the load caused by the mold 21 clamping is less likely to be concentrated on a part of the main body 100 b. For example, when the flow medium 140 is wound around a part of the main body 100b, the load due to the clamping of the mold 21 tends to be concentrated on a part of the main body 100 b. Therefore, in the impregnation step S150, an un-impregnated portion may be generated. By winding the sheet around the entire main body 100b, the load caused by the clamping of the mold 21 is dispersed to the entire main body 100 b. Thus, the method of manufacturing the can 100 of the present disclosure can reduce the possibility of non-impregnated portions in the body portion 100 b.

The impregnation step S150 includes a step of forming a resin layer on the flow medium 140. In this way, the method of manufacturing the can 100 of the present disclosure can protect the body portion 100b by covering the entire body portion 100b with the layer of resin.

In the winding step S110, the winding of the flow medium 140 is performed a plurality of times. As described above, the outer diameter P100r of the preform P100 varies depending on the winding accuracy of the fiber bundle. In this way, the manufacturing method of the can 100 of the present disclosure can easily adjust the outer diameter of the preform P100 including the flow medium 140 by adjusting the number of windings of the flow medium 140 to conform to the size of the mold 21. Thus, the method of manufacturing the can 100 of the present disclosure can make impregnation of the resin more appropriate.

B. other embodiments:

In the above embodiment, the flow medium 140 is wound around the entire body portion 100b of the preform P100, but may be wound around a part of the body portion 100 b. For example, the flow medium 140 may be wound around only a central portion in the axial direction OD inside the main body portion 100 b. That is, the flow medium 140 may be wound around at least a portion thereof.

In fig. 10, the result of condition C is illustrated as a range of variation in the outer diameter 100r of the tank 100 in the case where only a part of the main body portion 100b is wound with the flow medium 140. The condition C has a larger fluctuation range than the condition B, but has a smaller average value and fluctuation range than the condition a. Thus, the can manufacturing method of the present disclosure can allow the resin to be impregnated with the flow medium 140 more easily than in a manner in which the flow medium 140 is not provided. In addition, in the method for manufacturing the tank 100 of the present disclosure, the amount of the flow medium 140 can be reduced as compared with the method in which the flow medium 140 is wound around the entire body portion 100b as in embodiment 1, and therefore, the cost required for manufacturing the tank 100 can be reduced.

C. other embodiments:

(1) In the above embodiment, the flow medium 140 is constituted by the 1 st fiber 140OD extending toward the axial direction OD and the 2 nd fiber 140LD extending toward the circumferential direction LD as a web-formed sheet. However, the direction in which the 1 st fiber 140OD extends may be inclined with respect to the central axis O. In this case, the flow medium 140 is configured to be a mesh by extending the 2 nd fiber 140LD in a direction perpendicular to the direction in which the 1 st fiber 140OD extends.

(2) In the above embodiment, the flow medium 140 is a sheet formed into a mesh shape. However, the flow medium 140 may be a sheet made of three-dimensional mesh-like fibers. For example, the flow medium 140 may have a structure in which fibers are irregularly extended, not a structure in which fibers are regularly extended like a mesh.

(3) In the above embodiment, the flow medium 140 is wound around the preform P100 a plurality of times. However, the flow medium 140 may be wound around the preform P100 only for one revolution. The flow medium 140 may be wound for more than one revolution.

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

(5) In the above embodiment, carbon fibers are used as the material of the fiber bundles of the fiber layer P121. The material of the fiber bundles of the fiber layer P121 is not limited to carbon fibers. For example, the material of the fiber bundles of the fiber layer P121 may be glass fibers, or glass fibers and carbon fibers may be combined.

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

The present disclosure is not limited to the above-described embodiments, and can be implemented in various configurations within a range not departing from the gist thereof. For example, the technical features of the embodiments corresponding to the technical features of the embodiments described in the summary of the invention can be replaced or combined as appropriate to solve part or all of the above-described problems or to achieve part or all of the above-described effects. In addition, the technical features may be appropriately deleted unless they are described as essential in the present specification.

Claims (5)

1. A method of manufacturing a can, comprising:

A preparation step of preparing a preform, a mold, and a sheet composed of three-dimensional mesh-like fibers, wherein the preform is provided with a cylindrical main body portion having a plurality of layers of fiber bundles wound around an outer surface of a liner defining an inner space of the tank;

a winding step of winding the sheet material around the outer surface of the preform for at least one revolution in the circumferential direction of the body portion;

An injection step of injecting a resin into the mold in a state where the preform around which the sheet is wound is placed in the mold, and

An impregnation step of impregnating the sheet and the fiber bundles with the resin,

In the course of the winding process,

The sheet is wound around at least a portion of the main body portion,

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,

Comprises a main body part in the shape of a cylinder,

The hydrogen tank is provided with an outer layer which contains resin and covers the main body part,

The outer layer includes a lower layer composed of a plurality of layers of fiber bundles, and an upper layer overlapped with the lower layer and including a sheet composed of a three-dimensional mesh-like material,

The sheet has voids extending in a direction different from the direction in which the fibers of the fiber bundle extend.