JP2010064392A - Manufacturing method of fiber reinforced plastic and manufacturing equipment thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a homogeneous FRP product having a hollow shape by using an RTM (Resin Transfer Molding) method and to provide equipment for manufacturing the FRP product. <P>SOLUTION: The method of manufacturing the FRP product having a hollow shape by using the RTM method comprises following processes: a hollow core 3 having a hollow shape is disposed in a molding tool, reinforcing fibers 14 are disposed on a cavity part 4 between the hollow core 3 and the molding tool and resin is injected into the cavity part 4; in a cavity part reduced pressure process, an internal pressure in the hollow core 3 is controlled such that the hollow core 3 pushes the reinforcing fibers 14 in such an extent as not to deform the reinforcing fibers 14; in a resin injection process, the internal pressure in the hollow core 3 is controlled such that a force in such a direction as to push the reinforcing fiber 14 against the molding tool is not exerted; and, in a resin curing completion process, the internal pressure of the hollow core 3 is controlled such that the force in such a direction as to push the reinforcing fiber 14 against the molding tool is exerted, whereby an excessive increase of flow resistance of the resin is suppressed and the homogeneous FRP product having a hollow shape can be manufactured. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method apparatus for producing a fiber reinforced plastic by an RTM (Resin Transfer Molding) method.

  Fiber Reinforced Plastics (FRP) is made by impregnating a reinforced fiber with a resin having fluidity and curing the resin in that state. In a wide range of fields, from the aerospace industry to the automobile industry, etc. It's being used. Since FRP products are desired to be light and at the same time have as high strength and rigidity as possible, there are cases in which a core material such as urethane foam is included inside or in a hollow shape.

  In order to mold a hollow FRP product, a method is known in which a core is placed inside a mold, and a flowable resin is injected into a space (cavity portion) between the mold and the core and cured. Yes. A hollow shape can be created by using a core.

  A hollow core may be used for the core. Patent Document 1 discloses a method of forming a hollow FRP product using an elastic bag as a core. In this method, reinforcing fibers are installed along the inner surface of the mold, and when the mold is closed, an elastic bag is installed at a position surrounded by the reinforcing fibers, the mold is closed, and the elastic bag is added to the inside of the elastic bag. The elastic bag is inflated by sending pressurized gas, the reinforcing fiber is pressed against the mold by the inflated bag, and the resin is injected between the mold and the inflated bag in this state to impregnate the reinforcing fiber with the resin. A hollow FRP product is formed by curing the resin impregnated in the reinforcing fiber.

  The RTM (Resin Transfer Molding) method is a molding method in which reinforcing fibers are installed in the cavity inside the mold, the cavity is decompressed, resin is injected into the decompressed cavity, and the resin injected into the cavity is cured. is there. Since the resin is injected in a decompressed state, the reinforcing fiber is easily impregnated with the resin, and an FRP product excellent in strength and dimensional accuracy can be manufactured. The RTM method has attracted attention as an FRP molding method with excellent quality stability and low waste.

  Even when an FRP product is molded using the RTM method, a hollow FRP product can be manufactured by using a hollow core such as an elastic bag, as in Patent Document 1.

In the technique of Patent Document 2, an elastic tube is used for the hollow core. Also, a mold that allows one mold to slide on the other mold is used. In the technique of Patent Document 2, the cavity is decompressed prior to injecting resin into the cavity formed between the hollow core and the mold. In Patent Document 2, in order to use a slidable mold, when the cavity portion is decompressed, the slidable mold slides toward a non-slidable mold and crushes the tube. Therefore, the cavity is depressurized after the inside of the tube is pressurized to the extent that it can counter the pressing force generated by the depressurization of the cavity.
JP-A-4-246510 JP 2001-150465 A

  In the technique of Patent Document 2, the hollow space of the hollow core is pressurized when the cavity portion is decompressed in order to perform the RTM method using the hollow core using a slidable mold. By pressurizing the hollow space of the hollow core, the reinforcing fiber is sufficiently pressed against the mold by the hollow core.

  When using a mold that does not move during molding, there is no need to pressurize the hollow space of the hollow core. Even if the hollow space of the hollow core is not pressurized, that is, even if the pressure of the hollow space of the hollow core is maintained at atmospheric pressure, the hollow core expands by reducing the pressure of the cavity portion, and the mold is formed. This is because the reinforcing fiber is pressed.

  However, even if the hollow space of the hollow core is not pressurized, that is, even if the pressure of the hollow space of the hollow core is maintained at the atmospheric pressure, the internal pressure of the cavity portion is smaller than the internal pressure of the hollow space of the hollow core. It becomes too low, the hollow core expands excessively, and the volume of the cavity part may be excessively reduced, or the expanded hollow core may excessively compress the reinforcing fiber. When the injection of the resin is started in such a state, the flow resistance of the resin increases, and a phenomenon that the reinforcing fiber is not impregnated with the resin occurs. The target FRP product cannot be obtained.

  In the conventional technology, when the RTM method is performed using a hollow core, the hollow core expands excessively when the cavity is decompressed, the reinforcing fibers are compressed excessively, and the volume of the cavity is excessively small. It is not recognized that the phenomenon occurs, which reduces the molding quality.

  In carrying out the RTM method using a hollow core, the present invention deals with various problems caused by excessive expansion of the hollow core.

The present invention relates to a method for forming a hollow FRP product into an RTM method using a hollow core. In the method of the present invention, the cavity portion and the hollow space of the hollow core are formed in a state where the reinforcing fiber is installed in the cavity portion surrounded by the molding die and the hollow core installed in the molding die. A step of depressurizing, a step of injecting a resin into the cavity portion being depressurized, and a step of curing the resin injected into the cavity portion. In the method of the present invention, in a vacuum process, to achieve a state which satisfies the relationship P _a> P _2> P ₁ pressure P ₁ and the pressure P ₂ of the hollow core of the cavity is the atmospheric pressure P _a, that The injection process is started with the relationship being satisfied.

  According to the present invention, when the cavity for injecting the resin is decompressed, the hollow space of the hollow core is also decompressed, so that the hollow core is prevented from being excessively expanded and the reinforcing fiber is excessively compressed. And the volume of the cavity portion can be prevented from being excessively reduced. Since the resin is injected in that state, the cavity portion is too narrow to allow the resin to pass through, or the reinforcing fiber is compressed too densely to be impregnated with the resin, or the shape of the cavity portion is intended (hollow shape of FRP product) A series of problems such as deviation from Good hollow shaped FRP products can be produced by the RTM method.

  In the method of the present invention, it is preferable to inject the resin while controlling the injected resin flow rate. When the resin is injected while controlling the flow rate of the injected resin, the flow rate of the resin does not increase excessively even if the RTM method in which the cavity is decompressed and the resin is injected is used, and the reinforcing fiber is used. Such a problem can be prevented.

This method also realized a new molding apparatus. The molding apparatus includes a molding die, a hollow core installed inside the molding die, a resin injection device connected via a resin injection path to a cavity portion surrounded by the molding die and the hollow core, and a cavity portion. to a vacuum device connected via a vacuum passage, a first pressure sensor for detecting a pressure regulating device connected via a communication path to the hollow space of Kinakazora core, the internal pressure P ₁ of the cavity, medium a second pressure sensor for detecting the internal pressure P ₂ of Kuchuko, and a control device.

Controller, a state which satisfies the relationship P _a> P _2> P ₁ and the first pressure sensor a pressure reducing unit and a pressurization device controlled on the basis of the second pressure sensor detection results with respect to the atmospheric pressure P _a After that, the operation of the resin injection device is started.

  According to this apparatus, when the cavity part is decompressed, the hollow space of the hollow core is also decompressed, the hollow core is prevented from excessively expanding, the reinforcing fibers are prevented from being excessively compressed, and the volume of the cavity part is reduced. The RTM method can be carried out while avoiding excessive reduction.

  The above technique can cope with the problem of the resin injection start stage when the RTM method is performed using the hollow core.

  When the RTM method is performed using a hollow core, it is preferable to cope with problems during the resin injection process and the curing process.

For this reason, in the resin injection process, the internal pressure P _{1 of the} cavity and the internal pressure P _{2 of the} hollow core are controlled so as to satisfy the relationship of P ₁ ≧ P _{2. In} the resin curing process, the internal pressure of the cavity is controlled. P ₁ and pressure _{P 2} of the hollow core _is preferably controlled to satisfy the relation P 2> _{P 1.}

If control is performed so as to satisfy the relationship of P ₁ ≧ P ₂ during the resin injection process, the hollow core will not expand, and therefore a gap in the cavity portion can be secured. Resin injection resistance is low, and the resin easily impregnates the reinforcing fibers. Even if a pressing force acts in the direction in which the hollow core is contracted during the resin injection process, if the control is performed so as to satisfy the relationship of P ₂ > P _{1 in} the subsequent curing process, the resin is caused to expand by the expanding hollow core. Since it is pressed against the mold, it is possible to take measures against the phenomenon that the hollow shape of the FRP product becomes smaller than planned. Further, by controlling so as to satisfy the relationship of P _2> P ₁ in the curing process, it is possible to sink the FRP product (depression caused by molding shrinkage of the resin) can be prevented.

The above method of production, the duration of operation of the resin injection device controls the decompressor and pressurization apparatus such that P ₁ ≧ P _2, after stopping the operation of resin injection device becomes P _2> P ₁ As described above, the apparatus is executed by a fiber-reinforced plastic manufacturing apparatus including a decompression device and a control device that controls the pressure-reduction device.

  According to the present invention, when a hollow-shaped FRP product is molded by the RTM method using a hollow core, the hollow core is prevented from excessively expanding and the reinforcing fiber is not excessively compressed. The volume of the cavity portion can be prevented from being excessively reduced. Therefore, the resin can be injected with a low resin injection pressure, and the occurrence of the problem that the resin does not impregnate the reinforcing fiber can be suppressed.

  Further, in the resin injection step, the hollow core contracts to facilitate the injection of the resin, and in the curing step, the resin can be cured while being pressed against the mold by the expanding hollow core. A high-quality hollow FRP product without sink marks can be obtained at a low injection pressure.

The main features of the embodiments described below are listed below.
The depressurizing step of (feature 1) cavity, the difference between the internal pressure P ₁ and the pressure P ₂ of the hollow core of the cavity is controlled within a range of pressure differences reinforcing fibers is not deformed.
(Feature 2) In the resin injection step, the flow rate of the resin is controlled by adjusting the injection pressure.
In the step of injecting a resin into (Feature 3) cavity, to follow to the internal pressure P ₁ of the cavity is increased, the condition of which is not higher than the internal pressure P _1, to increase the internal pressure P ₂ of the hollow core .
(Feature 4) The resin injection pressure is controlled so as not to exceed a preset threshold value. When the resin injection pressure reaches the threshold value, the flow rate of the injected resin is reduced.
(Feature 5) In the curing process of the resin, the internal pressure P ₂ of the hollow core is maintained higher than the internal pressure P ₁ of the cavity.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a system configuration diagram of the FRP manufacturing apparatus of this embodiment. The FRP manufacturing apparatus includes a first mold 1, a second mold 2, a hollow core 3, a cavity portion 4, a resin injection device 5, a pressure reducing device 6, a pressure increasing / decreasing device 7, and a control device 8. The hollow core 3 is made of a material whose internal volume changes due to deformation due to the difference between the internal pressure and the external pressure. For example, an elastic body or a plastic body can be used. The hollow core 3 is installed in the internal space of the mold formed by closing the first mold 1 and the second mold 2 together. A space between the first mold 1 and the second mold 2 and the hollow core 3 is a cavity portion 4. Reinforcing fibers 14 are installed in the cavity portion 4. The reinforcing fiber 14 is preliminarily molded according to the shape of the cavity portion 4. The foamed urethane core 15 is installed in a part of the cavity portion 4 as shown in FIG. When the FRP manufacturing apparatus shown in FIG. 1 is used, an FRP product having a hollow bent tubular shape as shown in FIG. 2 and having one end closed is manufactured.

  The hollow space of the hollow core 3 and the pressure-intensifying device 7 are connected by a communication path 11 of the hollow core. The cavity portion 4 and the resin injection device 5 are connected by a resin injection path 12. In addition to the resin injection path 12, a resin discharge path 16 that opens to the cavity portion 4 is provided. The resin discharge path 16 connects the cavity portion 4 and the resin discharge valve 32. Further, the resin discharge path 16 branches off from the cavity portion 4 to before reaching the resin discharge valve 32, and is connected to the pressure reducing path valve 31. The decompression path valve 31 and the decompression device 6 are connected by a decompression path 13.

The first pressure sensor 21 that detects the internal pressure P ₁ of the cavity portion 4 is installed inside the cavity portion 4. The second pressure sensor 22 that detects the internal pressure P ₂ of the hollow core 3 is installed inside the hollow space of the hollow core 3. A third pressure sensor 23 for detecting the resin injection pressure P ₃ is installed in the resin injection path 12. Based on the detection results of the first pressure sensor 21, the second pressure sensor 22, and the third pressure sensor 23, the control device 8 is a resin injection device 5, a pressure reduction device 6, a pressure increase / decrease device 7, a pressure reduction path valve 31, and a resin discharge valve. 32 is controlled.

In the present embodiment, the first pressure sensor 21 is installed in the cavity portion 4, but the first pressure sensor 21 is installed between the cavity portion 4 and the resin discharge valve 32 in the resin discharge path 16 to provide the cavity portion. pressure P ₁ of 4 can also recognize. Similarly, the second pressure sensor 22 can be installed in the hollow core flow passage 11 to recognize the internal pressure P ₂ of the hollow core 3.

A control method of the FRP manufacturing apparatus according to the present embodiment will be described with reference to the flowchart shown in FIG. First, the reinforcing fibers 14, the core 15, and the hollow core 3 are installed inside the first mold 1 and the second mold 2, and the mold is closed. Detection values _P 1, _{P 2} of the first and second pressure sensors 21 and 22 is equal to the atmospheric pressure _{P a} both in this state.

After the mold is closed, the operation of the FRP manufacturing apparatus is started. In step S1, the decompression device 6 is activated and decompression of the cavity 4 is started. In step S1, the resin discharge valve 32 is closed and the pressure reducing passage valve 31 is opened. Next, in step S2, it is determined whether or not P ₂ −P ₁ = A for the pressure difference between the internal pressure P ₁ and the internal pressure P ₂ . Here, the pressure difference A is a positive constant, and is set in advance by experiments and calculations so as to have a pressing force that does not deform the reinforcing fiber. If not P ₂ −P ₁ = A, the process proceeds to step S 3, and the internal space of the hollow core is depressurized by the pressure increasing / decreasing device 7 so that the pressure P ₂ of the hollow core 3 becomes P ₂ = P ₁ + A. Then, the process proceeds to step S4. Thus, by controlling the pressure difference A as a positive constant to be P ₂ −P ₁ = A, and reducing the internal pressure P ₂ of the hollow core 3 by following the internal pressure P ₁ by reducing the internal pressure P ₁ , The relationship P _a > P ₂ > P ₁ can be realized during the decompression step.

In step S4, it is determined whether or not the internal pressure P ₁ of the cavity portion 4 is P ₁ ≦ B relative pressure value B. The pressure value B is a target value of P _{1 in} the decompression process, and the inside of the cavity portion 4 is decompressed by the decompression device 6 until P ₁ reaches B. When P ₁ ≦ B, the process proceeds to step S5, the pressure reducing passage valve 31 is closed, the pressure reducing device 6 is stopped, the pressure reducing process is ended, and the resin injection process is started. That is, the resin injection is started when the relationship P _a > P ₂ > P ₁ is satisfied and the internal pressure P ₁ is sufficiently reduced. In addition, after the internal pressure P ₁ becomes P ₁ ≦ B, the resin injection process may be started after a predetermined time. Pressure P ₁ can start the resin injection in a stable state.

When the step of depressurizing the cavity portion is completed in step S5, the process proceeds to step S6. In step S6, the resin injection device 5 is activated to start resin injection. Since the flow resistance of the resin is low at the start of resin injection, when the injection is started by controlling the resin injection pressure P ₃ , the resin is suddenly injected into the cavity portion 4 due to the pressure difference from the reduced cavity portion 4, and in the vicinity of the injection port These reinforcing fibers are twisted and cause defects in the FRP product. Since in this embodiment for starting the resin injection at a constant flow rate Q = Q _0, be employed RTM method cavity keep in vacuo to inject resin, without flow rate of the resin is excessively increased The occurrence of problems such as twisting of the reinforced resin can be prevented.

Resin injection start transition, the internal pressure P ₁ of the cavity 4 increases. In step S7, it is determined whether the _P 1 _-P 2 = C relative pressure difference C set in _advance, when a P 1 _-P 2 = C proceeds to step S9. If P ₁ −P ₂ = C is not satisfied, the pressure increasing / decreasing device 7 is controlled so that P ₂ = P ₁ −C in step S 8, and then the process proceeds to step S 9. Here, the pressure difference C is a constant that satisfies C ≧ 0. By thus pressurizing the internal pressure P ₂ of the hollow core 3 so as to follow to the internal pressure P ₁ is increased, it can be controlled so as to satisfy the relation P ₁ ≧ P ₂ during injection of the resin step.

In step S9, it is determined whether or not P ₁ ≧ P ₃ with respect to the internal pressure P ₁ and the resin injection pressure P ₃ of the cavity portion 4, and if P ₁ ≧ P ₃ is not satisfied, the process proceeds to step S13. If P ₁ ≧ P ₃ , the resin discharge valve 32 is opened in step S10. By opening the resin discharge valve 32, the gas in the cavity portion 4 is extracted, excess resin is allowed to flow out, and the reinforcing fiber is uniformly impregnated with the reinforcing fiber. Pressure P ₁ when opening the resin discharge valve 32 is reduced. If it is determined in step S11 that P ₁ <P ₃ , the resin discharge valve 32 is closed in step S12, and the process proceeds to step S13.

  Next, in step S13, it is determined whether or not the specified amount of resin has been injected. If completed, the process proceeds to step S16. In step S16, the resin injection device 5 is stopped and the resin injection process is terminated. The cavity 4 is in a sealed state. If not completed, the process proceeds to step S14, and the flow rate control for resin injection is performed.

If the resin is continuously injected at a constant flow rate, the resin injection pressure P ₃ and the internal pressure P ₁ of the cavity portion 4 increase as the total injection amount of the resin increases. In step S14 are pre-threshold D is set for the pressure P ₁ of the cavity portion 4 determines whether or not the P ₁ ≧ D. Here, the threshold value D can be set according to the device characteristics of the resin injection device 5 (for example, the upper limit value of the injection pressure). Further, in the case of manufacturing an FRP product partially including a foamed urethane core as in this embodiment, if the resin pressure in the cavity 4 is too high, the foamed urethane is impregnated with the resin. If the threshold value D is set smaller than the impregnation pressure at which the core 15 is impregnated with the resin, the core 15 can be prevented from being impregnated with the resin. Incidentally, a threshold value is set D with respect to the resin injection pressure P ₃ in place of the internal pressure P ₁ in step S14, it may be determined whether P ₃ ≧ D.

When P ₁ ≧ D, the process proceeds to step S15 to reduce the flow rate of resin injection, and then proceeds to step S7. If P ₁ ≧ D is not satisfied, the process directly proceeds to step S7. Since the internal pressure _{P 1} is lower by reducing the flow rate and vacuum the internal pressure _{P 2} of the hollow core 3 so as to follow the internal pressure _{P 1} in step _S7, the _{P 2 -P 1 = C (C} ≧ 0) To control.

In step S17, the control device 8 determines whether or not P ₂ −P ₁ = E with respect to the preset pressure difference E. If P ₂ −P ₁ = E is not satisfied, the process proceeds to step S18 and P _2. After controlling the pressure increasing / decreasing device 7 so that = P ₁ + E, the process proceeds to step S19. If P ₂ −P ₁ = E, the process directly proceeds to step S19. Here, the pressure difference E is set to a positive constant so that a force in a direction of pressing the reinforcing fiber against the mold acts. By thus the internal pressure P ₂ is pressurized, it can be controlled so as to satisfy the relationship of P _2> P ₁ during the injection of the resin step.

  In step S19, the curing of the resin is completed and the FRP manufacturing apparatus is stopped. When the manufactured FRP product is taken out, the shape is as shown in FIG. The hollow core 3 may be taken out from the FRP product or may be left inside the FRP product.

(Experimental example)
One experimental example using the FRP manufacturing apparatus of this example is shown in FIG. FIG. 4 shows the internal pressure P ₁ of the cavity 4, the internal pressure P ₂ of the hollow core 3, and the resin injection flow rate Q. Internal pressure _{P 1} and pressure _{P 2} is shown by the pressure difference between the atmospheric pressure _{P a,} e.g. -50kPa is, 50 kPa indicates a pressure lower than the atmospheric pressure _{P a.} Hereinafter, for the pressure values, described by the differential pressure between the atmospheric pressure P _a. In this experimental example, a nylon bag was used as the hollow core 3 and an epoxy resin was used as the resin, and the resin was cured with a curing agent. The pressure difference in step S2 was set to A = 50 kPa, and the pressure value B in step S4 was set to B = −100 kPa. As a result, as shown in FIG. 4, in the cavity portion decompression step, control is performed so that P _a > P ₂ > P _1, and the internal pressure P ₁ is −100 kPa and the internal pressure P ₂ is −50 kPa. Infusion started.

In the resin injection step, the initial injection flow rate of the resin was 500 ml / min. The initial injection pressure was 100kPa above atmospheric pressure _{P a.} In step S7, the pressure difference C was set to 50 kPa. Pressure P ₁ As you injecting resin as shown in FIG. 4 becomes high, substantially linear, the internal pressure P ₂ is increased following the internal pressure P _1, is controlled so that P _1> P _2.

In this experimental example, a urethane foam core was used, and the impregnation pressure of the urethane foam core was 500 kPa higher than the atmospheric pressure Pa with respect to the epoxy resin. In step S14, the pressure value D is set to 500 kPa. In step S15, ΔQ = Q / 2, and the current flow rate is set to be halved. When the internal pressure P ₁ of the cavity portion 4 becomes high and P ₁ ≧ D, the control device 8 reduces the resin injection flow rate by half from 500 ml / min to 250 ml / min, thereby reducing the internal pressure P ₁ stepwise. . Since the internal pressure _{P 1} is lower, the internal pressure _{P 2} of the hollow core 3 is reduced by the pressurization device 7 such that _P 1 _-P 2 = _C, is controlled so that P 1> _{P 2.} When the specified amount of resin was injected, the resin injection device 7 was stopped and the cavity 4 was sealed.

In step S19, the pressure difference E was set to 50 kPa. After stopping the resin injection device, the internal pressure P ₂ was pressurized so that P ₂ = P ₁ + E (E = 50 kPa). Thus, control was performed so that P ₂ > P ₁ .

As described above, according to this embodiment, when the cavity portion for injecting the resin is decompressed, the hollow space of the hollow core is also decompressed, so that the hollow core is prevented from being excessively expanded and strengthened. The fiber can be prevented from being excessively compressed, and the volume of the cavity portion can be prevented from being excessively reduced. Since the resin is injected in a state where P _a > P ₂ > P ₁ is satisfied, the cavity portion is too narrow to allow the resin to pass through, or the reinforcing fibers are compressed too tightly so that the resin is not impregnated, or the cavity portion is A series of problems such as deviation from the intended shape (hollow shape of the FRP product) does not occur. Good hollow shaped FRP products can be produced by the RTM method.

Further, in this embodiment, control is performed so as to satisfy the relationship of P ₁ ≧ P ₂ during the resin injection process, and the hollow core does not expand, so that a cavity gap can be secured. Resin injection resistance is low, and the resin easily impregnates the reinforcing fibers. Even when a pressing force is applied in the direction in which the hollow core is contracted from the internal pressure of the cavity during the injection of the resin, control is performed so as to satisfy the relationship of P ₂ > P _{1 in} the subsequent curing process. It is possible to take measures against the phenomenon that the hollow shape of the product becomes smaller than planned. Further, by controlling so as to satisfy the relationship of P _2> P ₁ in the curing process, it is possible to sink the FRP product (depression caused by molding shrinkage of the resin) can be prevented.

In the present embodiment, since the internal pressure P ₂ of the hollow core at the time of starting the FRP manufacturing equipment was state equal to the atmospheric pressure P _a, followed by vacuum in the hollow core at the front resin injection depressurizing step However, when the internal space of the hollow core is preliminarily depressurized with a vacuum pump or the like and then installed in the FRP manufacturing apparatus, control is performed so as to satisfy P _a > P ₂ > P ₁ by pressurizing with the pressure increasing / decreasing apparatus. You can also.

The FRP manufacturing apparatus of a present Example. FRP product manufactured using the FRP manufacturing apparatus of the present embodiment. The flowchart of the FRP manufacturing apparatus of a present Example. An experimental example using the FRP manufacturing apparatus of this example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st shaping | molding die 2 2nd shaping | molding die 3 Hollow core 4 Cavity part 5 Resin injection apparatus 6 Depressurization apparatus 7 Pressurization / decompression apparatus 8 Control apparatus 11 Communication path 12 of hollow core Resin injection path 13 Decompression path 14 Reinforcement fiber 15 Core 16 Resin discharge passage 21 First pressure sensor 22 Second pressure sensor 23 Third pressure sensor 31 Pressure reduction passage valve 32 Resin discharge valve

Claims (5)

Depressurization step of depressurizing the cavity part and the hollow space of the hollow core in a state where the reinforcing fiber is installed in the cavity part surrounded by the molding die and the hollow core installed in the molding die When,
An injection step of injecting resin into the cavity portion;
A method for producing a fiber reinforced plastic including a curing step of curing the resin injected into the cavity part,
Wherein a reduced pressure step, the internal pressure P ₂ in said Kuchuko the internal pressure P ₁ of the cavity portion can be regarded as the state satisfies the relationship P _a> P _2> P ₁ with respect to atmospheric pressure P _a, the relationship is less than A method for producing a fiber-reinforced plastic, characterized in that the injection step is started in a state where the fiber is reinforced.   2. The method for producing a fiber reinforced plastic according to claim 1, wherein in the injection step, the resin is injected while controlling a flow rate of the injected resin. A mold,
A hollow core installed inside the mold,
A resin injection device connected via a resin injection path to a cavity surrounded by the mold and the hollow core;
A decompression device connected to the cavity portion via a decompression path;
A pressurizing and depressurizing device connected to a hollow space of the hollow core via a communication path;
A first pressure sensor for detecting the internal pressure P ₁ of the cavity portion,
A second pressure sensor for detecting the internal pressure P ₂ in said Kuchuko,
Equipped with a control device,
The control device controls the pressure reducing device and the pressure increasing / decreasing device based on detection results of the first pressure sensor and the second pressure sensor so that P _a > P ₂ > P ₁ with respect to the atmospheric pressure P _a . An apparatus for producing a fiber-reinforced plastic, characterized in that a state satisfying the relationship is realized, and thereafter the operation of the resin injection device is started. A depressurizing step of depressurizing the cavity part in a state where the reinforcing fiber is installed in the cavity part surrounded by the hollow mold installed inside the mold and the mold;
An injection step of injecting resin into the cavity portion;
A method for producing a fiber reinforced plastic including a curing step of curing the resin injected into the cavity part,
Wherein in the injection step, the internal pressure P ₂ in said Kuchuko the internal pressure P ₁ of the cavity portion is controlled so as to satisfy the relation P ₁ ≧ P _2,
Wherein in the curing step, the internal pressure P ₁ and the pressure P ₂ in said Kuchuko of the cavity portion, P _2> method for producing a fiber-reinforced plastic, characterized by controlling so as to satisfy a relation of P _1. A mold,
A hollow core installed inside the mold,
A resin injection device connected via a resin injection path to a cavity surrounded by the mold and the hollow core;
A decompression device connected to the cavity portion via a decompression path;
A pressurizing and depressurizing device connected to a hollow space of the hollow core via a communication path;
A first pressure sensor for detecting the internal pressure P ₁ of the cavity portion,
A second pressure sensor for detecting the internal pressure P ₂ in said Kuchuko,
Equipped with a control device,
The controller controls the pressure reducing device and the pressure increasing / decreasing device so that P ₁ ≧ P ₂ while the operation of the resin injection device is continued, and P ₂ > P after the operation of the resin injection device is stopped. _The apparatus for producing fiber-reinforced plastic, wherein the pressure reducing device and the pressure increasing / decreasing device are controlled to be 1.

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