Fiber-reinforced plastic manufacturing method and fiber-reinforced plastic manufacturing device

Abstract

To provide a manufacturing method of a fiber-reinforced plastic capable of detecting insufficient impregnation of a resin material into a fiber material of a substrate during a manufacturing process of the fiber-reinforced plastic.SOLUTION: The manufacturing method of the fiber-reinforced plastic includes a mold clamping step of placing the substrate made of the fiber material inside a mold to close the mold, a supply step of supplying the resin material inside the closed mold, and an impregnation step of impregnating the substrate the resin material supplied to the inside of the mold while pressurizing the resin material by using a pressurizing unit capable of pressurizing the resin material with its movement. In the impregnation step, it is determined that an impregnation of the resin material to the substrate is insufficient when a displacement of the pressurizing unit is detected from an impregnation completion timing at which the impregnation of the resin material to the substrate is expected to be completed till a cure shrinkage start timing at which the cure shrinkage of the resin material starts.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present disclosure relates to a method and an apparatus for producing fiber-reinforced plastics. [Background technology]

[0002] A resin impregnation molding die for manufacturing fiber reinforced plastics using the RTM (Resin Transfer Molding) method is known (for example, Patent Document 1). In this resin impregnation molding die, the resin material stored in the storage section is pushed toward the storage section by using a piston that utilizes air pressure. As a result, the fiber material on the surface of the liner stored in the storage section is impregnated with the resin material, and fiber reinforced plastic is formed on the surface of the liner. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-84317 Summary of the Invention [Problem to be solved by the invention]

[0004] If the fiber material is not sufficiently impregnated with the resin material, this may lead to a decrease in the strength of the fiber-reinforced plastic resin. Therefore, there has been a demand for a technology for determining whether the fiber material is sufficiently impregnated with the resin material during the manufacturing process of the fiber-reinforced plastic. [Means for solving the problem]

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

[0006] (1) According to one aspect of the present disclosure, a method for manufacturing a fiber-reinforced plastic is provided. The method for manufacturing a fiber-reinforced plastic includes a clamping step of placing a base using a fiber material inside a mold and closing the mold, a supplying step of supplying a resin material into the closed mold, and an impregnation step of impregnating the base with the resin material while applying pressure to the resin material using a pressurizing unit capable of applying pressure to the resin material supplied inside the mold by moving. In the impregnation step, if a displacement of the pressurizing unit is detected from an impregnation completion timing, which is predicted to be when the impregnation of the base with the resin material is completed, to a cure shrinkage start timing, which is when the resin material starts to cure and shrink, the impregnation of the base with the resin material is determined to be insufficient. According to the method for producing fiber-reinforced plastic of this aspect, it is possible to detect insufficient impregnation of the fiber material of the substrate with the resin material during the production process of the fiber-reinforced plastic. (2) In the method for producing a fiber-reinforced plastic of the above aspect, when displacement of the pressurizing part is detected at the timing when the cure shrinkage starts in the impregnation step, it is determined that the base body is not sufficiently impregnated with the resin material. According to this aspect of the manufacturing method for fiber reinforced plastic, the displacement of the pressure applying part can be confirmed at the critical timing when the resin material becomes difficult to impregnate into the fiber material, and insufficient impregnation of the resin material can be determined. (3) In the method for producing a fiber-reinforced plastic according to the above aspect, the impregnation step may further include acquiring an internal pressure of the mold, and detecting a maximum value at which a change in the internal pressure changes from a positive value to a negative value using the acquired internal pressure. If the internal pressure at a first timing, which is a predetermined time after a maximum value detection timing at which the maximum value was last detected, is lower than the internal pressure at the maximum value detection timing, the maximum value detection timing may be identified as the cure shrinkage start timing. According to this aspect of the method for producing fiber reinforced plastic, the timing at which cure shrinkage begins can be identified using the detection results of the internal pressure of the mold. (4) In the method for producing a fiber-reinforced plastic according to the above aspect, in the impregnation step, a second timing at which a predetermined time has elapsed since the start of movement of the pressurizing unit may be identified as the cure shrinkage start timing. According to this aspect of the manufacturing method for fiber reinforced plastic, impregnation can be judged without using the detection results of the internal pressure of the mold. (5) In the method for producing a fiber-reinforced plastic according to the above aspect, a third timing at which the viscosity of the resin material becomes equal to or greater than a predetermined threshold in the impregnation step may be identified as the cure shrinkage start timing. According to this aspect of the manufacturing method for fiber reinforced plastic, impregnation can be judged without using the detection results of the internal pressure of the mold. (6) In the method for producing a fiber-reinforced plastic according to the above aspect, in the impregnation step, the pressurizing unit may be moved so as to pressurize the resin material with a predetermined pressure. According to this aspect of the method for manufacturing fiber-reinforced plastic, it is possible to improve the detection accuracy of the displacement of the pressurizing portion, compared to a case in which pressurization by the pressurizing portion is not performed at a constant pressure. (7) In the method for producing a fiber-reinforced plastic according to the above aspect, the substrate may be formed by winding the fiber material on an outer surface of a liner. According to this aspect of the manufacturing method for fiber reinforced plastic, it is possible to determine whether or not the fiber material has been sufficiently impregnated with the resin material during the manufacturing process of a gas tank that uses a liner. (8) In the method for producing a fiber-reinforced plastic according to the above aspect, the resin material may be a two-component epoxy resin. According to this aspect of the method for producing fiber reinforced plastic, it becomes easier to adjust the timing at which curing starts, and it becomes easier to estimate the timing at which the curing of the resin material has progressed sufficiently. (9) According to another aspect of the present disclosure, there is provided a fiber-reinforced plastic manufacturing apparatus. The fiber-reinforced plastic manufacturing apparatus includes a mold capable of accommodating a base using a fiber material, a resin supply unit for supplying a resin material into the mold, a pressurizing unit that moves inside the mold to impregnate the base with the resin material, a pressurizing unit displacement detection unit for detecting displacement of the pressurizing unit, and a control unit for controlling the pressurizing unit. When the control unit controls the pressurizing unit to impregnate the base with the resin material, if the control unit detects displacement of the pressurizing unit from an impregnation completion timing that is predicted to complete the impregnation of the base with the resin material to a curing shrinkage start timing that the resin material starts curing shrinkage, the control unit determines that the base is insufficiently impregnated with the resin material. According to the fiber reinforced plastic manufacturing apparatus of this aspect, insufficient impregnation of the fiber material of the base with the resin material can be detected during the fiber reinforced plastic manufacturing process. The present disclosure can also be realized in various forms other than the manufacturing method for fiber-reinforced plastic and the manufacturing apparatus for fiber-reinforced plastic, for example, a method for forming a fiber-reinforced resin layer, a manufacturing method for a gas tank, a control method for a manufacturing apparatus for fiber-reinforced plastic, a computer program for implementing the control method, a non-transitory recording medium on which the computer program is recorded, etc. [Brief description of the drawings]

[0007] [Figure 1] FIG. 2 is an explanatory diagram showing the configuration of a gas tank. [Diagram 2] FIG. [Diagram 3] FIG. 1 is a schematic cross-sectional view showing an internal configuration of a fiber-reinforced plastic manufacturing apparatus. [Figure 4] FIG. [Diagram 5] FIG. 11 is an explanatory diagram illustrating a state in which a resin material is fed into a base body housing portion by a pin. [Figure 6] 1A to 1C are process diagrams showing a method for producing a fiber-reinforced plastic according to an embodiment of the present invention. [Figure 7]FIG. 4 is a process diagram showing details of an impregnation step in the method for producing a fiber-reinforced plastic according to the present embodiment. [Figure 8] 11 is a graph showing changes in the internal pressure of the substrate housing portion and the position of the pin when the control portion determines that there is no insufficient impregnation. [Figure 9] 11 is a graph showing changes in the internal pressure of the substrate housing portion and the position of the pin when the control portion determines that there is insufficient impregnation. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] A. First embodiment: Fig. 1 is an explanatory diagram showing the configuration of a gas tank 100. Fig. 1 shows a schematic external view and a cross-sectional view of the gas tank 100, with the central axis AX of the gas tank 100 as the boundary. The gas tank 100 includes a fiber reinforced resin layer 19 formed using fiber reinforced plastics (FRP) as a first embodiment of the present disclosure.

[0009] The gas tank 100 is a storage container for storing a high-pressure fluid of 10 to 70 MPa. The gas tank 100 can be formed in any shape, and in the example of FIG. 1, the gas tank 100 has an external shape of a long, approximately cylindrical shape. In FIG. 1, the axial direction DA of the gas tank 100 and the radial direction DR in the circular cross section of the gas tank 100 are indicated by arrows. The axial direction DA and the radial direction DR are common to the figures following FIG. 1.

[0010] In this embodiment, the gas tank 100 is used to store hydrogen gas to be supplied to, for example, a fuel cell for a vehicle or a fuel cell for a stationary use. The gas tank 100 may store oxygen, natural gas, or the like in addition to hydrogen gas. The gas tank 100 includes a liner 10, nozzles 16 and 17 disposed on both ends of the liner 10, and a fiber-reinforced resin layer 19 formed on the outer peripheral surfaces of the liner 10 and the nozzles 16 and 17.

[0011] The liner 10 is a container having an internal space for sealing a fluid. The liner 10 is formed of a resin having gas barrier properties, such as nylon, polyamide, ethylene vinyl alcohol copolymer (EVOH), polyethylene, polypropylene, epoxy, polystyrene, or the like. The liner 10 includes a cylindrical body 12 and two hemispherical dome portions 14 disposed on both ends of the body 12 along a central axis AX. An opening is provided at the top of the dome portion 14. The liner 10 may be formed of a metal instead of a resin.

[0012] The nozzles 16, 17 are attached to openings provided at the top of each dome portion 14 of the liner 10 so as to protrude from both ends of the liner 10. The nozzle 16 is used, for example, to fill the gas tank 100 with gas or to release gas from the gas tank 100. The nozzle 17 is sealed and is used for centering during manufacturing, etc.

[0013] The fiber reinforced resin layer 19 is a reinforcing layer for reinforcing the liner 10. The fiber reinforced resin layer 19 is formed using fiber reinforced plastic manufactured by the manufacturing method of fiber reinforced plastic of this embodiment. In this embodiment, the fiber reinforced resin layer 19 is formed by placing a base (also called a "fiber preform") in a mold, pressurizing and filling the mold with resin by the so-called RTM method to impregnate the fiber material, and thermally curing it.

[0014] FIG. 2 is an explanatory diagram that shows a schematic diagram of the base 20. As shown in FIG. 2, the base 20 is formed by winding a fiber bundle 18 on the outer surfaces of the liner 10 and the nozzles 16 and 17. The layer formed by winding the fiber bundle 18 around the liner 10 is also called a "fiber layer". In this embodiment, carbon fiber is used as the fiber material. In addition to carbon fiber, glass fiber, aramid fiber, boron fiber, high-strength polyethylene fiber, poly p-phenylenebenzobisoxazole fiber, etc. can be used as the fiber material, and a combination of multiple types of these fibers may be used.

[0015] In this embodiment, the fiber bundle 18 is wound around the outer circumferential surface of the trunk portion 12 by helical winding, and around the outer circumferential surface of the dome portion 14 by braiding winding. The fiber bundle 18 is wound to such an extent that a plurality of layers, for example, about 10 to 20 layers, can be formed. The helical winding means a method of winding the fiber bundle 18 around the entire outer circumferential surface of the trunk portion 12 at a predetermined winding angle θ1 with respect to the central axis AX of the liner 10, and then winding the fiber bundle 18 by crossing the central axis AX of the liner 10 at a predetermined winding angle θ2. The braiding winding means a method of winding the fiber bundle 18 so as to be woven alternately. In the example of FIG. 2, the fiber bundle 18 is wound around the central axis AX of the liner 10 at a winding angle θ1 and a winding angle θ2.

[0016] The winding angles θ1 and θ2 can be set arbitrarily. The winding angles θ1 and θ2 are preferably derived, for example, using the stress applied to the liner 10. In this embodiment, the winding angle θ1 is set, for example, near 54.7 degrees, and the winding angle θ2 is set, for example, at -54.7 degrees. The fiber bundle 18 may be wound around the trunk portion 12 by braiding winding, and around the dome portion 14 by helical winding. The fiber bundle 18 may be wound around the liner 10 using only one of helical winding and braiding winding.

[0017] The configuration of the fiber reinforced plastic manufacturing apparatus 200 (hereinafter, simply referred to as the "manufacturing apparatus 200") of this embodiment will be described with reference to FIG. 3 and FIG. 4. FIG. 3 is a schematic cross-sectional view showing the internal configuration of the fiber reinforced plastic manufacturing apparatus 200. FIG. 4 is a plan view showing the lower mold 52 in a top view. The manufacturing apparatus 200 impregnates the fiber layer of the base 20 with a resin material using the RTM method, and further hardens the impregnated resin material to form a fiber reinforced plastic. As a result, a gas tank 100 is manufactured in which a fiber reinforced resin layer 19 using the fiber reinforced plastic is formed on the outer peripheral surface of the liner 10. As shown in FIG. 3, the manufacturing apparatus 200 includes a mold 50, a resin supply unit 40, a pressurizing mechanism 60, and a control unit 80. In order to facilitate understanding of the technology, FIG. 3 shows a state in which the base 20 is arranged in the base accommodation unit 54, and FIG. 4 shows a state in which the base 20 is not arranged in the lower base accommodation unit 524. In addition, in FIG. 4, the upper surface of the lower die 52 is hatched to facilitate understanding of the technology.

[0018] The mold 50 is opened and closed by a drive device (not shown) under the control of the control unit 80. The mold 50 includes an upper mold 51, a lower mold 52, and a base accommodating section 54 for accommodating the base 20. The upper mold 51 includes a supply path 512 and an upper base accommodating section 514. The supply path 512 is a resin flow path connecting the resin supply section 40 and the internal space of the mold 50. The upper base accommodating section 514 is a recessed section provided on the surface of the upper mold 51 facing the lower mold 52.

[0019] The lower mold 52 includes a lower base accommodating portion 524, a resin storage portion 526, and a flow path 528. The lower base accommodating portion 524 is a recess provided on the surface of the lower mold 52 facing the upper mold 51. The base accommodating portion 54 is defined by the inner circumferential surface of the lower base accommodating portion 524 and the inner circumferential surface of the upper base accommodating portion 514. The base accommodating portion 54 includes a space having substantially the same shape as the outer shape of the base 20, and can accommodate the base 20.

[0020] In this embodiment, the base accommodating section 54 is provided with a pressure sensor 32. Specifically, the base accommodating section 54 is provided with a total of six pressure sensors 32, three on the inner wall surface of the upper base accommodating section 514 and three on the inner wall surface of the lower base accommodating section 524. The pressure sensor 32 functions as a part of the inner wall of the base accommodating section 54 and can detect the internal pressure of the resin material filled in the base accommodating section 54. The detection result of the internal pressure of the base accommodating section 54 by the pressure sensor 32 is transmitted to the control section 80. The number of pressure sensors 32 is not limited to six, and may be one, or may be any number of two or more. All of the multiple pressure sensors 32 may be provided in the upper mold 51, or all may be provided in the lower mold 52. The pressure sensor 32 may be arranged at any position in the internal space of the mold 50, not limited to the base accommodating section 54. Furthermore, for example, in cases where the pressurizing mechanism 60 includes a sensor for detecting the pressure with which the pressurizing portion presses against the resin material, the pressure sensor 32 may be omitted.

[0021] 4, the flow paths 528 are provided in the same number as the resin storage sections 526, and each of the flow paths 528 connects the base storage section 54 to each of the resin storage sections 526. Thus, the flow paths 528 function as a flow path for the resin material from the resin storage sections 526 to the base storage sections 54.

[0022] The resin reservoir 526 is a recess formed in the lower mold 52. The resin reservoir 526 accommodates a pin 62, which will be described later. As shown in FIG. 4, in this embodiment, the lower mold 52 is provided with a plurality of resin reservoirs 526 each having a substantially circular shape in a plan view. In the example of FIG. 4, the resin reservoirs 526 are arranged in three on each side along the axial direction of the base accommodating section 54, i.e., along the axial direction DA of the base 20 arranged in the base accommodating section 54. According to the manufacturing apparatus 200 configured in this manner, the plurality of resin reservoirs 526 are arranged at positions corresponding to the two dome sections 14 and the body section 12 of the liner 10, respectively. Therefore, the resin material can be individually pressed and fed to each part of the base 20, and the occurrence of insufficient impregnation of the resin material in each part of the base 20 can be reduced or prevented. The number of resin reservoirs 526 is not limited to six, and may be one when the manufacturing apparatus 20 can sufficiently impregnate the resin material, or any number of two or more may be provided. The resin reservoir 526 is not limited to a circular shape in a plan view, but may be any shape such as a rectangular shape or a polygonal shape.

[0023] The resin supply unit 40 supplies the resin material to the inside of the mold 50 through the supply path 512 under the control of the control unit 80. The resin supply unit 40 can be, for example, a device including a plunger (not shown) and a drive unit for driving the plunger. The resin material is supplied to the resin storage unit 526 through the supply path 512 as shown by the arrow D1 in FIG. 3, and is supplied to the base housing unit 54 housing the base 20 as shown by the arrow D2 in FIG. 3. The resin material supplied to the base housing unit 54 flows to another resin storage unit 526 as shown by the arrow D3 in FIG. 3, filling the inside of the mold 50.

[0024] In this embodiment, a two-component epoxy resin is used as the resin material. The resin supply unit 40 injects and mixes the epoxy resin and the curing agent. Therefore, in this embodiment, the resin material starts curing at the timing when it is supplied inside the mold 50. For the epoxy resin, any type of epoxy resin may be used, such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, multifunctional epoxy resin, flexible epoxy resin, glycidyl ester type epoxy resin, polymer type epoxy resin, and biphenyl type epoxy resin. For the curing agent, various curing agents such as amine type, acid anhydride type, and latent curing agent type may be used. However, the resin material is not limited to two-component epoxy resin, and may be one-component epoxy resin. In addition to the curing agent, a curing catalyst such as a tertiary amine, imidazole, phosphorus compound, or thermal base generator may be mixed into the epoxy resin. For the resin material, the resin is not limited to epoxy resin, and a thermosetting resin such as a phenol resin, a melamine resin, a urea resin, a polyester resin, or a polyimide resin may be used. In cases where the fiber reinforced plastic has sufficient strength, a thermoplastic resin such as polyolefin, polyamide, polycarbonate, or polyphenylene sulfide may be used in place of the thermosetting resin.

[0025] The pressurizing mechanism 60 is controlled by the control unit 80, and sends the resin material in the resin storage unit 526 toward the base storage unit 54. The pressurizing mechanism 60 includes a pin 62, a motor 64, and a shaft unit 66. The pin 62 is a so-called piston that is connected to the motor 64 via the shaft unit 66. As shown in FIG. 4, the pin 62 has a substantially circular external shape in a plan view, and substantially matches the external shape of the resin storage unit 526. As shown in FIG. 3, the pin 62 is accommodated in the resin storage unit 526. An upper surface 62T of the pin 62 that faces the upper mold 51 functions as a part of the inner wall of the resin storage unit 526 when the pin 62 is accommodated in the resin storage unit 526. FIG. 3 shows a schematic initial position P0 of the upper surface 62T of the pin 62 in the axial direction DP. A seal member for restricting the resin in the resin storage unit 526 from moving toward the motor 64 may be provided on the side of the pin 62.

[0026] In this embodiment, the pin 62 functions as a pressurizing unit capable of applying pressure to the resin material in the resin storage unit 526 by moving. The pin 62 can reciprocate within the resin storage unit 526 along the axial direction DP via the shaft unit 66 by being driven by the motor 64. By moving the pin 62 along the axial direction DP in a direction toward the upper mold 51, the resin material in the resin storage unit 526 can be sent to the base accommodation unit 54 while being pressurized.

[0027] In this embodiment, the pressure mechanism 60 further includes a displacement sensor 34 for detecting the displacement of the pin 62, and a torque sensor 36 for detecting the output torque of the motor 64. The detection results of the displacement sensor 34 and the torque sensor 36 are output to the control unit 80.

[0028] The displacement sensor 34 functions as a pressure unit displacement detection unit that acquires position information of the pin 62 in the axial direction DP and detects the displacement of the pin 62 from the position information of the pin 62. The position information of the pin 62 may be, for example, the position or coordinates of the pin 62, but is not limited to the position or coordinates of the pin 62 and includes various information that can detect the position and displacement of the pin 62, such as the position and movement amount of the shaft unit 66, the driving time, power consumption, rotation speed, and output torque of the motor 64. The displacement of the pin 62 can be acquired by the amount of change in the position of the pin 62 per unit time or a derivative using the position information of the pin 62.

[0029] The control unit 80 is a microcomputer having a central processing unit (CPU) and a storage device. The storage device is, for example, a RAM, a ROM, or a hard disk drive (HDD). Various programs for implementing the functions provided in this embodiment are stored in the HDD or ROM, and the various programs read from the HDD or ROM are deployed on the RAM and executed by the CPU. The storage device stores position information of the pin 62, which will be described later, and the acquired results of the internal pressure of the base body housing part 54. In this embodiment, the control unit 80 uses the detection results of the pressure sensor 32, the displacement sensor 34, and the torque sensor 36 to control the pressurizing mechanism 60 and to determine the impregnation of the resin material, which will be described later. The control unit 80 includes a timer (not shown) for counting the elapsed time. The timer may be configured as either hardware or software. Instead of the timer, the control unit 80 may acquire the elapsed time from a time server.

[0030] 5 is an explanatory diagram showing a schematic view of the resin material being sent into the base body accommodating section 54 by the pin 62. When the resin material is supplied into the mold 50 by the resin supply section 40, the motor 64 of the pressurizing mechanism 60 is driven by the control section 80, and the pin 62 moves toward the upper mold 51 along the axial direction DP, as shown by the direction DP1 in FIG. 5. As a result, the resin material in the resin reservoir 526 is pushed out of the resin reservoir 526 by the upper surface 62T of the pin 62, and sent into the base body accommodating section 54.

[0031] 5 shows a schematic diagram of a position P1 of the top surface 62T of the pin 62 after the pin 62 has moved in the axial direction DP. In this embodiment, the displacement sensor 34 acquires the position P1 of the pin 62 after the pin 62 has moved from the initial position P0, and acquires the distance L1 that the pin 62 has moved per unit time as the amount of displacement. The amount of displacement of the pin 62 may be calculated by the control unit 80 that has acquired the position information of the pin 62.

[0032] FIG. 6 is a process diagram showing the manufacturing method of fiber reinforced plastic of this embodiment. In step S10, the base body 20 is prepared. Specifically, the base body 20 is formed by winding the fiber bundle 18 around the outer peripheral surface of the liner 10 and forming a fiber layer on the outer peripheral surface of the liner 10. In step S20, the base body 20 is placed inside the mold 50 and the mold 50 is closed. Specifically, the control unit 80 controls the drive device of the mold 50 to close the upper mold 51, and further closes the mold 50. The mold closing of the mold 50 means a process of pressurizing the mold 50 in a direction to close the mold 50 with a pressure higher than the pressure at the time of mold closing after the mold 50 is closed. However, in step S20, only the mold closing may be performed.

[0033] In step S30, the control unit 80 controls the resin supply unit 40 to inject and mix the epoxy resin and the hardener and supply them into the mold 50. In this embodiment, the control unit 80 starts timing with a timer from the timing when the resin supply unit 40 starts supplying the resin material. The control unit 80 supplies a predetermined amount of resin material into the mold 50 over a predetermined time, such as 20 seconds. As a result, the resin material is filled into each part of the mold 50, such as the resin storage unit 526, the flow path 528, and the periphery of the base 20 in the base accommodating unit 54. At this time, for example, in order to give the base 20 strength that can withstand the impregnation step of the resin material, the inside of the liner 10 of the base 20 may be filled with, for example, nitrogen, to apply internal pressure to the liner 10.

[0034] In step S40, the control unit 80 controls the pressurizing mechanism 60 to impregnate the base 20 with the resin material. In step S50, the resin material is hardened. In this embodiment, the resin material is hardened by allowing a predetermined time to elapse while the mold 50 is clamped. The control unit 80 determines that the hardening of the resin material is completed when a predetermined time has elapsed since the start of supplying the resin material into the mold 50. The predetermined time is set to a time required for the two-component epoxy resin to sufficiently harden, such as 600 seconds. In step S60, the control unit 80 drives the drive device of the mold 50 to open the upper mold 51. The base 20 in a state in which the resin material has been impregnated and hardened is removed from the mold 50 that has been opened by being pushed out by, for example, an ejector. As a result, a gas tank 100 having a reinforcing layer made of fiber-reinforced plastic is obtained.

[0035] 7 is a process diagram showing details of the impregnation step in the manufacturing method for fiber-reinforced plastic of the present embodiment. In the impregnation step of the present embodiment, the control unit 80 performs an impregnation determination to determine whether the fiber layer of the base 20 is sufficiently impregnated with the resin material.

[0036] In step S402, the control unit 80 starts driving the pressurizing mechanism 60, and starts acquiring the output torque of the motor 64 by the torque sensor 36. In step S404, the control unit 80 starts acquiring position information of the pin 62 by the displacement sensor 34. In step S406, the control unit 80 starts acquiring the internal pressure of the substrate accommodating portion 54 by the pressure sensor 32. In the impregnation step shown in FIG. 7, data acquisition by the sensors 32, 34, 36 in steps S402 to S406 can be repeatedly and continuously executed at any timing, such as every second. In addition, the data acquired by the sensors 32, 34, 36 is stored in a storage device of the control unit 80.

[0037] In step S408, the control unit 80 drives the motor 64 of the pressurizing mechanism 60 to move the pin 62 toward the upper die 51 along the direction DP1 shown in Fig. 5. In this embodiment, the control unit 80 uses the detection result of the torque sensor 36 to control the motor 64 so that the output torque is constant, and controls the pin 62 to extrude the resin material at a constant pressure. The control unit 80 may control the output torque of the motor 64 so that the detection result of the pressure sensor 32, instead of the torque sensor 36, or the detection result of the pressure with which the pin 62 pressurizes the resin material becomes a constant pressure.

[0038] In step S409, the control unit 80 detects that a predetermined impregnation completion timing has arrived. The impregnation completion timing means the timing at which impregnation of the resin material into the base 20 is predicted to be completed under normal circumstances. The impregnation completion timing can be set, for example, using the timing at which the position of the pin 62 reaches a predetermined position, or the timing at which a predetermined time has elapsed since the driving of the pressurizing mechanism 60 has started. The position of the pin 62 as the impregnation completion timing can be set, for example, using the movement amount of the pin 62 required to feed the amount of resin material required to impregnate the fiber layer of the base 20. The predetermined time can be set, for example, using the shortest driving time of the pin 62 required to feed the amount of resin material required to impregnate the fiber layer of the base 20. By providing step S409, for example, it is possible to avoid a defect in which impregnation insufficiency is determined at a timing before the impregnation completion timing is reached. When the detection accuracy of the impregnation determination is high, step S409 may be omitted.

[0039] In step S410, the control unit 80 waits for detection of the maximum value of the internal pressure of the base body accommodating section 54. Specifically, the control unit 80 detects the point at which the amount of change in the internal pressure changes from a positive value to a negative value as the maximum value, using the internal pressure detected by the pressure sensor 32. When the maximum value is detected (S410: YES), the control unit 80 checks whether the internal pressure of the base body accommodating section 54 continues to decrease for a predetermined time from the timing at which the maximum value is detected. For example, if the internal pressure does not continue to decrease, such as the internal pressure increasing again after passing through a minimum value (S412: NO), the process returns to step S410. If the internal pressure continues to decrease for a predetermined time (S412: YES), the process proceeds to step S414, and it is determined that the determination timing for performing the impregnation determination has arrived. The timing at which the maximum value is finally detected is also referred to as the "maximum value detection timing." In this embodiment, the control unit 80 specifies the maximum value detection timing as the curing and shrinkage start timing at which the resin material starts to cure and shrink. In this embodiment, the cure shrinkage start timing is used as the timing for checking the displacement of the pin 62 because it is considered that at the cure shrinkage start timing, the curing of the resin material has progressed sufficiently and it becomes difficult to impregnate the fiber material with the resin material after this timing. The internal pressure of the base body accommodating section 54 does not necessarily need to continue decreasing until a predetermined time has elapsed from the maximum value detection timing, and it may be determined that the determination timing has arrived when it is detected that the internal pressure of the base body accommodating section 54 at the time when a predetermined time has elapsed from the maximum value detection timing is lower than the internal pressure of the base body accommodating section 54 at the maximum value detection timing.

[0040] In step S420, the control unit 80 uses the position information of the pin 62 acquired from the displacement sensor 34 to determine whether or not the pin 62 is displaced at the maximum value detection timing, which is the start timing of the curing shrinkage. In this embodiment, the control unit 80 uses the position information of the pin 62 stored in the storage device at the determination timing to determine whether or not the pin 62 is displaced, going back to the maximum value detection timing. If the control unit 80 determines that the pin 62 is displaced at the maximum value detection timing (S420: YES), it proceeds to step S422 and determines that there is insufficient impregnation. If there is no displacement of the pin 62 at the maximum value detection timing (S420: NO), it proceeds to step S424 and determines that there is no insufficient impregnation. With the above, the impregnation process ends. The drive of the pressure mechanism 60 by the control unit 80 may end when the impregnation process ends, or may be continued in the curing process after the impregnation process ends. The method of checking the displacement of the pin 62 at the maximum value detection timing is not limited, and the control unit 80 may determine that there is insufficient impregnation when continuous displacement of the pin 62 is detected from the impregnation completion timing to the maximum value detection timing.

[0041] The details of the impregnation judgment by the control unit 80 in the impregnation process will be described with reference to Figs. 8 and 9. Fig. 8 is a graph showing the change in the internal pressure of the base body accommodating unit 54 and the position of the pin 62 when the control unit 80 judges that there is no insufficient impregnation. Fig. 9 is a graph showing the change in the internal pressure of the base body accommodating unit 54 and the position of the pin 62 when the control unit 80 judges that there is insufficient impregnation. The horizontal axis of Figs. 8 and 9 is the time axis. Two vertical axes are shown in Figs. 8 and 9, the left vertical axis shows the magnitude of the internal pressure of the base body accommodating unit 54, and the right vertical axis shows the position of the pin 62. The right vertical axis corresponds to the length of the distance L1 shown in Fig. 5. The zero point of the time axis of Figs. 8 and 9 is the time when the resin supply unit 40 completes the supply of the resin material into the mold 50, and corresponds to the timing when the control unit 80 starts driving the pressurizing mechanism 60. The graphs shown in Figs. 8 and 9 are stored in the storage device of the control unit 80 using the data acquired by each of the sensors 32, 34, and 36.

[0042] A graph GP1 shown in FIG. 8 indicates a change in the internal pressure of the base body accommodating portion 54. The internal pressure of the base body accommodating portion 54 can be acquired from each of the six pressure sensors 32. In the examples of FIG. 8 and FIG. 9, an average value of the detection results by the six pressure sensors 32 is shown. A graph GL1 shown in FIG. 8 indicates a change in the position of the pin 62, specifically, the position of the upper surface 62T of the pin 62. The position of the pin 62 can be acquired from each of the six displacement sensors 34. In the examples of FIG. 8 and FIG. 9, an average value of the detection results by the six displacement sensors 34 is shown.

[0043] When the control unit 80 starts driving the pressurizing mechanism 60, the output torque of the motor 64 rises to a predetermined value, and the upper surface 62T of the pin 62 starts to move toward the upper mold 51 along the direction DP1 shown in FIG. 5. Accordingly, the internal pressure of the base body accommodating portion 54 starts to rise. When the output torque of the motor 64 reaches a predetermined value, the internal pressure of the base body accommodating portion 54 stabilizes, for example, near a predetermined pressure PS1 shown in FIG. 8. The output torque of the motor 64 and the target value of the internal pressure of the base body accommodating portion 54 are preferably adjusted according to the size of the base body 20, that is, the size of the gas tank 100, etc. For example, the output torque of the motor 64 and the target value of the internal pressure of the base body accommodating portion 54 are preferably set in consideration of the strength of the base body 20, the void removal of the fiber layer, the impregnation speed of the resin material, etc. In this embodiment, the pressure PS1 is set to be about several MPa.

[0044] When the resin material starts to be impregnated into the fiber layer of the base 20, the resin material encounters resistance from the fiber layer as it is fed into the fiber layer. Therefore, for example, as shown by the arrow PT1 in Fig. 8, the pin 62 moves while changing the moving speed, and the position of the pin 62 starts to gradually converge toward the position PL1 where the fiber layer can be sufficiently impregnated with the resin material. At this time, the internal pressure of the base accommodating portion 54 increases or decreases near the pressure PS1 due to the influence of the change in the moving speed of the pin 62, as shown by the arrow PT2 in Fig. 8.

[0045] Time T1 is an example of the timing of impregnation completion. When time T1 is reached, the position of the pin 62 is such that the internal pressure of the base accommodating portion 54 exceeds the pressure with which the pin 62 presses the resin material, because the fiber layer of the base 20 has been sufficiently impregnated with the resin material. As a result, the position of the pin 62 becomes constant, for example, near position PL1 shown in FIG.

[0046] When the time T1 is reached, the internal pressure of the base body accommodating section 54 becomes stable. In the example of FIG. 8, the internal pressure of the base body accommodating section 54 increases slightly after the time T1 and reaches the maximum value IP1 at the time T2. As shown by the arrow PT4, the internal pressure of the base body accommodating section 54 continues to decrease after reaching the maximum value IP1 at the time T2. This is presumably due to the progress of hardening of the resin material in the base body accommodating section 54, causing the resin material to shrink. The control section 80 detects that the internal pressure of the base body accommodating section 54 continues to decrease until the time T3, which is a predetermined time TD after the detection of the maximum value IP1. The predetermined time TD is preferably a sufficient time to determine that the last maximum value is reached, and can be set to any time, such as 10 seconds, 20 seconds, or 30 seconds. In this embodiment, the time TD is set to 20 seconds. Therefore, the control section 80 determines that the determination timing has arrived at the time T3. The time T3, which is the time TD after the maximum value detection timing, is also called the "first timing". In the example of Fig. 8, time T2 corresponds to the maximum value detection timing when the last maximum value was detected. Note that, in the example of Fig. 8, as shown by arrow PT2, multiple maximum values ​​may be detected from when the resin supply unit 40 starts supplying the resin material until time T1 is reached, but the control unit 80 does not determine that the determination timing has arrived because the detection is before the impregnation completion timing and the next maximum value is detected before the lapse of the predetermined time TD after the detection of the maximum value.

[0047] When the control unit 80 determines that the determination timing has arrived, it uses the data stored in the storage device to determine whether or not there has been any displacement of the pin 62 going back to time T2, which is the maximum value detection timing. Specifically, the control unit 80 determines that there has been no displacement of the pin 62 if the amount of change in the position of the pin 62 per unit time at time T2 is zero or is smaller than a predetermined threshold. In the example of Fig. 8, the displacement of the pin 62 after time T1 is zero. The control unit 80 determines that there has been no displacement of the pin 62 at time T2, and determines that there is no insufficient impregnation.

[0048] 9 indicates the average value of the internal pressure of the base body accommodating portion 54 obtained from the pressure sensor 32, and graph GL2 indicates the average value of the position of the pin 62 obtained from the displacement sensor 34. When the control portion 80 starts driving the pressurizing mechanism 60, the internal pressure of the base body accommodating portion 54 rises and then stabilizes near a predetermined pressure PS1 in accordance with the constant torque control by the control portion 80, similar to the example of FIG.

[0049] The pin 62 starts to move as a result of the pressure mechanism 60 being driven. As shown by the arrow PT5 in Fig. 9, the position of the pin 62 continues to rise even after time T1, unlike the example in Fig. 8. It is presumed that such a result occurs, for example, when the resistance of the fiber layer of the base 20 is high, making it difficult for the resin material to impregnate the fiber material as compared to normal, and therefore the impregnation speed of the resin material is not sufficient, or when the fiber layer of the base 20 can be impregnated with a larger amount of resin material than normal, and the resin material cannot be completely impregnated by the time when curing shrinkage begins.

[0050] As shown by the arrow PT6 in FIG. 9, the internal pressure of the base body accommodating section 54 is not stable, and a maximum value is detected even after time T1, which is the impregnation completion timing. This is considered to be because the pin 62 continues to move even after time T1, so that the impregnation of the resin material continues. When time T4 is reached, the internal pressure of the base body accommodating section 54 indicates a maximum value IP2 and continues to decrease thereafter. The control section 80 detects that the internal pressure of the base body accommodating section 54 continues to decrease until time T5, which is a predetermined time TD after the last maximum value IP2 is detected. Therefore, the control section 80 determines that the judgment timing has arrived at time T5. In the example of FIG. 9, time T4 corresponds to the maximum value detection timing at which the last maximum value was detected, and time T5 corresponds to the first timing.

[0051] The control unit 80 uses the data stored in the storage device to determine whether or not there has been any displacement of the pin 62 going back to time T4, which is the maximum value detection timing. In the example of Fig. 9, since the displacement of the pin 62 increases after time T1, the control unit 80 determines that there has been displacement of the pin 62, and therefore determines that there is insufficient impregnation.

[0052] As described above, the manufacturing method of fiber reinforced plastic of this embodiment includes a mold clamping step of arranging the base 20 using a fiber material in the base housing part 54 inside the mold 50 and closing the mold 50, a supply step of supplying a resin material to the inside of the closed mold 50, and an impregnation step of feeding the resin material supplied to the inside of the mold 50 by moving the pin 62 capable of pressurizing the resin material into the base housing part 54 to impregnate the base 20. In the impregnation step, if the displacement of the pin 62 is detected from the impregnation completion timing when the impregnation of the base 20 with the resin material is predicted to be completed to the curing shrinkage start timing when the resin material starts to shrink, it is determined that the impregnation of the base 20 with the resin material is insufficient. Therefore, in the manufacturing process of fiber reinforced plastic, insufficient impregnation of the fiber material of the base 20 with the resin material can be detected. In addition, since insufficient impregnation of the resin material is detected in the manufacturing process of fiber reinforced plastic, productivity can be improved compared to the case where insufficient impregnation of the resin material is detected by an inspection such as an X-ray inspection after the manufacturing of fiber reinforced plastic.

[0053] According to the manufacturing method of fiber reinforced plastic of this embodiment, if displacement of pin 62 is detected at the timing when cure shrinkage starts, it is determined that there is insufficient impregnation of the resin material into base 20. Therefore, by checking the displacement of pin 62 at the critical timing when it becomes difficult for the resin material to impregnate the fiber material, it is possible to determine the insufficient impregnation of the resin material at the appropriate timing.

[0054] According to the manufacturing method for fiber reinforced plastic of this embodiment, the impregnation step further includes acquiring the internal pressure of the base accommodating portion 54, and detecting a maximum value IP1 at which the amount of change in the internal pressure changes from a positive value to a negative value using the acquired internal pressure. If the internal pressure at a first timing, which is a predetermined time after the maximum value detection timing at which the last maximum value IP1 was detected, is lower than the internal pressure at the maximum value detection timing, the maximum value detection timing is identified as the cure shrinkage start timing. According to the manufacturing method for fiber reinforced plastic of this embodiment, the detection result of the internal pressure of the base accommodating portion 54 can be used to identify the cure shrinkage start timing.

[0055] According to the manufacturing method of fiber reinforced plastic of this embodiment, in the impregnation step, the pin 62 is moved so as to pressurize the resin material with a predetermined pressure. Therefore, the detection accuracy of the displacement of the pin 62 can be improved compared to the case where the pin 62 is not pressed with a constant pressure.

[0056] According to the manufacturing method of fiber reinforced plastic of this embodiment, the base body 20 is formed by winding a fiber material on the outer surface of the liner 10. Therefore, during the manufacturing process of the gas tank 100, it is possible to determine whether or not the resin material has sufficiently impregnated the fiber material.

[0057] According to the manufacturing method of the fiber reinforced plastic of the present embodiment, the resin material is a two-component epoxy resin. For example, by mixing the epoxy resin and the curing agent at the timing of starting to supply the resin material, the timing of starting the curing can be set at any timing, and it becomes easy to estimate the timing when the curing of the resin material has progressed sufficiently.

[0058] The fiber-reinforced plastic manufacturing apparatus 200 of this embodiment includes a mold 50 having a base accommodating section 54 for accommodating a base 20 using a fiber material, a resin supplying section 40 for supplying a resin material to the inside of the mold 50, a pin 62 for impregnating and piercing the base 20 while pressurizing the resin material by moving inside the mold 50, a displacement sensor 34 for detecting the displacement of the pin 62, and a control section 80 for controlling the pin 62. The control section 80 acquires position information of the pin 62 from the displacement sensor 34, and when the displacement of the pin 62 is detected from the acquired position information at the start timing of the curing and shrinkage of the resin material, the control section 80 judges that the impregnation of the resin material into the base 20 is insufficient. Therefore, the fiber-reinforced plastic manufacturing apparatus 200 of this embodiment can detect the insufficient impregnation of the resin material into the fiber material of the base 20 in the manufacturing process of the fiber-reinforced plastic.

[0059] B. Other embodiments: (B1) In the above embodiment, the insufficient impregnation is judged at the first timing when a predetermined time has elapsed from the maximum value detection timing when the maximum value was last detected. In contrast, the second timing when a predetermined time has elapsed from the start of the movement of the pin 62 in the impregnation process may be specified as the cure shrinkage start timing. The second timing is set to a timing later than the impregnation completion timing when the impregnation of the resin material into the base 20 is predicted to be completed. In this case, the control unit 80 checks the displacement of the pin 62 at the second timing, and judges that the impregnation of the resin material into the base 20 is insufficient when the displacement of the pin 62 is detected at the second timing. According to this embodiment of the manufacturing method for fiber reinforced plastic, the impregnation judgment can be performed without using the detection result of the internal pressure of the base accommodating portion 54.

[0060] The second timing may be set as the timing at which impregnation is normally completed, for example, at a timing included in the timing after time T1 and before time T2 shown in Fig. 8. The second timing may be determined experimentally in advance, for example, as the timing at which the resin material becomes difficult to impregnate into the fiber material, or may be set using actual manufacturing values, etc. Alternatively, the second timing may be set using a correspondence relationship between elapsed time and the viscosity of the resin material, such as the time when the viscosity exceeds a predetermined value.

[0061] (B2) In the above embodiment, insufficient impregnation is judged at a first timing when a predetermined time has elapsed from the maximum value detection timing when the maximum value was last detected. In contrast, in the impregnation process, a third timing when the viscosity of the resin material becomes equal to or greater than a predetermined threshold value may be specified as the cure shrinkage start timing. In this case, the control unit 80 checks the displacement of the pin 62 at the third timing, and judges that the impregnation of the resin material into the base 20 is insufficient when the displacement of the pin 62 is detected at the third timing. According to this embodiment of the manufacturing method for fiber reinforced plastic, it is possible to judge the impregnation without using the detection result of the internal pressure of the base accommodating portion 54.

[0062] The viscosity of the resin material increases gradually as it is supplied into the mold 50 and begins to harden, and then increases rapidly near the timing when hardening shrinkage begins. The threshold value can be set, for example, by obtaining the relationship between the viscosity of the resin material and the elapsed time from the start of hardening in advance through an experiment or the like, and using the viscosity at the timing when hardening shrinkage begins. The viscosity of the resin material may be a value obtained by a viscosity sensor or the like during the impregnation process.

[0063] (B3) In the above embodiment, an example was shown in which the pin 62 functions as a pressure applying unit. However, the pressure applying unit is not limited to the pin 62. When the manufacturing apparatus 200 is, for example, an apparatus in which the upper mold 51 applies pressure in a direction toward the lower mold 52 to impregnate the base 20 with the resin material, the upper mold 51 functions as a pressure applying unit. When the upper mold 51 functions as a pressure applying unit, the pressure applied to the resin material by the upper mold 51 is controlled to be a constant pressure in the impregnation step, and the displacement of the upper mold 51 is acquired. When the displacement of the upper mold 51 is detected, it is determined that the impregnation of the resin material into the base 20 is insufficient.

[0064] (B4) In the above embodiment, the example of Fig. 8 and Fig. 9 shows an example in which the average value of the detection results by the six pressure sensors 32 is used, and the example of Fig. 8 and Fig. 9 shows an example in which the average value of the detection results by the six displacement sensors 34 is used. In contrast, the present invention is not limited to the case where the average value of the detection results by the multiple pressure sensors 32 and the average value of the detection results by the multiple displacement sensors 34 are used, and multiple detection results by the multiple pressure sensors 32 may be used. In this case, for example, the timing at which a maximum value is detected in the detection results of all pressure sensors 32 or the majority of the pressure sensors 32 can be set as the maximum value detection timing. Also, when it is determined that there is no displacement from the detection results of all displacement sensors 34 or the majority of the displacement sensors 34, it can be determined that there is no insufficient impregnation.

[0065] (B5) In the above embodiment, the control unit 80 checks whether or not the pin 62 is displaced at the time T2 and the time T4, which are the timings for detecting the maximum value, and determines whether or not there is insufficient impregnation. In contrast, the control unit 80 may check the displacement of the pin 62 at any timing from the impregnation completion timing before the time T2 and the time T4.

[0066] (B6) In the above embodiment, the base 20 is formed by winding the fiber bundle 18 around the liner 10 for the gas tank 100, and the fiber reinforced plastic is manufactured as a reinforcing layer of the gas tank 100. In contrast, the base 20 is not limited to the case where the liner 10 is used. The base 20 may be formed only from a fiber material without using the liner 10, and may be formed into any shape by weaving the fiber material. In addition, the base 20 may use an insert material such as urethane foam or a bolt together with the fiber material. The fiber reinforced plastic is not limited to the use of the reinforcing layer of the gas tank 100, and may be used for various purposes such as vehicle parts used in the interior and exterior of automobiles and railroad cars, the hull of ships such as boats and yachts, helmets, bathtubs, septic tanks, pipes, and other housing equipment parts.

[0067] The control unit and the method described in the present disclosure may be realized by a special-purpose computer provided by configuring a processor and memory programmed to execute one or more functions embodied in a computer program. Alternatively, the control unit and the method described in the present disclosure may be realized by a special-purpose computer provided by configuring a processor with one or more dedicated hardware logic circuits. Alternatively, the control unit and the method described in the present disclosure may be realized by one or more special-purpose computers configured by a combination of one or more hardware-programmed processors and memories and a processor configured with one or more hardware logic circuits. In addition, the computer program may be stored in a computer-readable non-transitory tangible recording medium as instructions executed by a computer.

[0068] The present disclosure is not limited to the above-mentioned embodiment, and can be realized in various configurations without departing from the spirit of the present disclosure. For example, the technical features in the embodiments corresponding to the technical features in each aspect described in the Summary of the Invention column can be appropriately replaced or combined to solve some or all of the above-mentioned problems or to achieve some or all of the above-mentioned effects. Furthermore, if the technical feature is not described as essential in this specification, it can be appropriately deleted. [Explanation of symbols]

[0069] 10...liner, 12...body, 14...dome, 16, 17...mouthpiece, 18...fiber bundle, 19...fiber reinforced resin layer, 20...base, 32...pressure sensor, 34...displacement sensor, 36...torque sensor, 40...resin supply section, 50...mold, 51...upper mold, 52...lower mold, 54...base housing section, 60...pressurizing mechanism, 62...pin, 62T...upper surface, 64...motor, 66...shaft section, 80...control section, 100...gas tank, 200...fiber reinforced plastic manufacturing apparatus, 512...supply path, 514...upper base housing section, 524...lower base housing section, 526...resin storage section, 528...flow path, AX...central axis

Claims

1. A method for producing fiber reinforced plastic, comprising: a mold clamping step of placing the substrate using the fiber material inside a mold and closing the mold; a supplying step of supplying a resin material into the closed mold; an impregnation step of impregnating the base with the resin material while applying pressure to the resin material using a pressure unit capable of applying pressure to the resin material supplied into the interior of the mold by moving the pressure unit; In the impregnation step, when a displacement of the pressurizing unit is detected from an impregnation completion timing, which is predicted to be when the impregnation of the base body with the resin material is completed, to a curing shrinkage start timing, which is when the resin material starts to cure and shrink, the impregnation of the base body with the resin material is determined to be insufficient. A method for producing fiber-reinforced plastics.

2. A method for producing a fiber-reinforced plastic according to claim 1, In the impregnation step, when a displacement of the pressurizing unit is detected at a timing when the cure shrinkage starts, it is determined that the base body is insufficiently impregnated with the resin material. A method for producing fiber-reinforced plastics.

3. A method for producing a fiber-reinforced plastic according to claim 2, In the impregnation step, further acquiring an internal pressure of the mold, Using the acquired internal pressure, a maximum value at which an amount of change in the internal pressure changes from a positive value to a negative value is detected; When the internal pressure at a first timing, which is a predetermined time after the maximum value detection timing at which the maximum value was last detected, is lower than the internal pressure at the maximum value detection timing, the maximum value detection timing is identified as the cure shrinkage start timing. A method for producing fiber-reinforced plastics.

4. A method for producing a fiber-reinforced plastic according to claim 2, In the impregnation step, a second timing at which a predetermined time has elapsed since the start of the movement of the pressurizing unit is specified as the cure shrinkage start timing. A method for producing fiber-reinforced plastics.

5. A method for producing a fiber-reinforced plastic according to claim 2, In the impregnation step, a third timing at which the viscosity of the resin material becomes equal to or higher than a predetermined threshold is specified as the cure shrinkage start timing. A method for producing fiber-reinforced plastics.

6. The method for producing a fiber-reinforced plastic according to claim 1 , wherein in the impregnation step, the pressurizing unit is moved so as to pressurize the resin material with a predetermined pressure.

7. The method for producing a fiber-reinforced plastic according to any one of claims 1 to 6, wherein the substrate is formed by winding the fiber material on an outer surface of a liner.

8. The method for producing a fiber-reinforced plastic according to any one of claims 1 to 7, wherein the resin material is a two-component epoxy resin.

9. A fiber reinforced plastic manufacturing apparatus, comprising: A mold capable of accommodating a substrate using a fibrous material; A resin supply unit for supplying a resin material to the inside of the mold; a pressurizing unit that moves within the mold to pressurize the resin material while impregnating the base; a pressure unit displacement detection unit for detecting a displacement of the pressure unit; A control unit for controlling the pressurizing unit, The control unit is when the pressure unit is controlled to impregnate the base with the resin material, if displacement of the pressure unit is detected from an impregnation completion timing at which the impregnation of the base with the resin material is predicted to be completed to a curing shrinkage start timing at which the resin material starts to cure and shrink, it is determined that the base is insufficiently impregnated with the resin material. Fiber reinforced plastic manufacturing equipment.

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