JP4269923B2 - FRP manufacturing method and manufacturing apparatus thereof - Google Patents

Description

  The present invention relates to an FRP manufacturing method and manufacturing apparatus capable of shortening a molding cycle in an RTM (Resin Transfer Molding) molding method used when manufacturing FRP (fiber reinforced plastic).

  Conventionally, as a method of molding an FRP molded body, a reinforcing fiber base material is placed in a sealed cavity formed by combining upper and lower molds, and a resin is forcedly injected into the cavity. A so-called RTM molding method is known in which a resin is impregnated into a reinforcing fiber base by filling the cavity, and then cured by heating or the like (see, for example, Patent Document 1).

  The resin injection and discharge methods in this conventional RTM molding method are generally performed through a through-hole that leads from the outer surface to the cavity of the die as disclosed in Patent Document 1 above. At the same time, in order to withstand the resin pressure applied at the time of resin injection by the resin injection member, the fastening with the mold is complicated, for example, like a screwing structure.

  In addition, in the above RTM molding method, there is a method in which the inside of the cavity is in a reduced pressure atmosphere in order to obtain a product free of voids and pinholes. A closed loop is built with an O-ring in the cavity, and the air in the cavity is degassed or resin is directly injected into the molding cavity through a through-hole drilled in the closed loop built with the O-ring. ing.

  However, this conventional molding method has the following problems.

  In the conventional molding method, as a method of injecting resin through a through hole drilled in a mold, a resin injection sleeve can be directly injected from the through hole or can be attached to and detached from the through hole drilled in the mold. (Injection plug) is inserted, and the sleeve is screwed directly to the mold, or the resin is injected through the sleeve in a state where the sleeve is fixed to the mold with a bolt or the like. The deaeration in the cavity is also performed by the same sleeve (bleeding plug). In these cases, the resin remaining in the through hole for resin injection and in the sleeve is cured as it is, and after molding, the next molding is performed after cleaning the through hole and replacing the sleeve. Further, the sleeve may be reused after a process of burning the resin clogged therein at a high temperature. Moreover, since the through hole for injection and the runner in the cavity are orthogonal, there is a problem that it takes a lot of time to eliminate the resin after curing.

  As in the above-described conventional molding method, resin injection and resin discharge are performed through a through-hole directly drilled in the mold, or through a resin injection sleeve fixed to the mold. In addition, it takes a lot of time to set the resin discharging member and to clean the cured resin fixed to the through hole after molding, and the molding cycle becomes long. In addition, even when a separate part from a mold such as a sleeve having a fastening screw portion at the tip is used, there is a problem that it takes a lot of time to attach and detach the resin injection sleeve and to clean it before and after.

That is, in the conventional method, a long molding cycle time is a big problem.
Japanese Patent No. 2778407

  Therefore, the object of the present invention is to solve the problem of a long molding cycle time as in the conventional RTM molding method described above, and to keep the vacuum in the molding cavity with a reliable seal of the mold mating surfaces and prevent resin leakage. However, the FRP manufacturing method and FRP manufacturing that can shorten the time required for the setting operation of the resin injection portion and the resin discharge portion and the cleaning operation of the cured resin before and after the molding, thereby shortening the molding cycle. To provide an apparatus.

  In order to solve the above problems, the manufacturing method of the present invention employs the following configuration. That is, in the FRP manufacturing method in which a reinforcing fiber base material is disposed in a cavity of a molding die divided into a plurality of surfaces, and then a resin is injected and cured, the mold is provided on the mating surface of the cavity. A resin injection tube that injects resin into the mold and / or a resin discharge tube that discharges excess resin in the mold is provided and pressed between the mold mating surfaces, and then the resin is injected and discharged into the cavity. It is characterized by doing.

  According to this manufacturing method, by using a tube for the resin injecting part and / or for the resin discharging part, and using a tube in which a metal pipe is inserted in a portion sandwiched between the molds of the tube, Resin leakage and vacuum leakage due to crushing can be solved. At the same time, by applying a sealing tape to the sealing portion between the resin injection tube and / or the excess resin discharge tube and the mold surface, leakage of the resin in the cavity can be prevented.

  Also, the manufacturing apparatus of the present invention has a resin injection cavity inside, and a mold is divided into a plurality of surfaces, and a resin is injected into a reinforcing fiber base disposed in the cavity and a surplus In an FRP manufacturing apparatus provided with a resin injection / discharge means for discharging resin, a tube sandwiched between mold fitting surfaces is provided for injection of resin and / or for resin discharge. It is characterized in that a sealing elastic body is interposed at the contact site.

  According to such a manufacturing apparatus, a die cut in the shape of a resin injection tube and / or a resin discharge tube is used at a portion where the resin injection tube and / or the resin discharge tube are disposed, and the closed loop is cut. Further, by holding the sealing elastic body in the O-ring portion and simultaneously incorporating the O-ring end portion in the sealing elastic body, it is possible to achieve vacuum retention and prevention of resin leakage.

  The present invention uses a resin injection through hole or a sleeve drilled in a mold by fixing a resin injection and / or resin discharge tube to a mold-matching portion in a mold having multiple surfaces. In addition, the resin injection member and the resin discharge member can be easily set and cleaned. As a result, the molding cycle can be shortened, and more efficient molding can be achieved.

  Further, by using an inexpensive resin tube for the tube and discarding the tube as it is after the molding, the cleaning work can be greatly reduced, and the cost can be reduced by reducing the work amount.

  Also, by using a sealing elastic body and / or sealing tape, it is possible to ensure vacuum in the cavity and hold the vacuum during molding at the same time, and at the same time prevent resin leakage. You can get a product.

Hereinafter, an example of an embodiment of a manufacturing method of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view of upper and lower molds 1 and 2 used in the manufacturing apparatus of the present invention, FIG. 2 is an enlarged sectional view of the lower mold, and FIG. 3 is a resin injection member 30 mounted between the upper and lower molds of FIG. It is.
(Embodiment 1)
As shown in FIG. 1, the reinforcing fiber base material 12 shaped in advance into a product shape is used for the lower mold 2 in which an O-ring 11 is disposed on the outer periphery of a molding cavity 3 formed on the upper surface of the lower mold 2. Place in the molding cavity 3. Next, a semi-cross-sectional groove 10 of the resin injection tube 6 and the resin discharge tube 7 communicating with the resin injection liner 4 and the resin discharge runner 5, and an NBR sealing elastic body 8 provided in the middle of the groove 10. , 9 and a groove provided in the seal elastic body 8 communicating with the groove 10, and a metal tube 32 is inserted into the distal end portion of the tube 31 contacting the groove as shown in FIG. The resin injection member 30 around which the sealing tape 33 is wound is disposed. Then, the upper mold 1 is closed and the upper mold is pressurized to the lower mold, and the resin injection member 30 is narrowed. In this state, the temperature of the entire mold is raised by flowing warm water through a pipe (not shown) provided in the mold.

Thereafter, the inside of the molding cavity 3 is evacuated through a resin discharge tube 7 connected to a vacuum trap (not shown) connected to a vacuum pump, and then the resin is injected into the molding cavity 3 through a resin injection tube 6. Resin is injected under pressure. After the resin injection is completed, the resin injection tube 6 and the resin discharge tube 7 are closed. After that, the resin is heated by the mold for a predetermined time and the resin is cured. Get the product.
(Embodiment 2)
As shown in FIG. 2, a reinforcing fiber preform body 13 having a sandwich structure in which a core material 14 made of a foam processed into a product shape is coated on the outer periphery of a reinforcing fiber base 15 is formed on the outer periphery of a molding cavity 23. A resin injection runner 28 and a resin injection runner 28 are disposed in a molding cavity 23 composed of an upper die 21 and a lower die 22 provided with sealing elastic bodies 26 and 27 communicating with an O-ring (not shown) provided. In order to seal the resin injection tube 24 communicating with the resin discharge runner 29 and the resin discharge tube 25 by contacting the elastic bodies 26 and 27, the upper and lower molds are clamped.

  The resin injection tube 24 and the resin discharge tube 25 are made of metal. In this state, the mold is heated by flowing warm water into a pipe (not shown) provided in the mold. After that, after the inside of the molding cavity 23 is evacuated through the resin discharge tube 25 connected to the vacuum trap communicating with the vacuum pump as in the first embodiment, the resin is injected into the molding cavity through the resin injection tube 24. Is injected under pressure. After the pressurized resin fills the resin injection runner 28, the resin flows through the injection film gate 16 into the molding cavity 23 in which the reinforcing fiber preform body 13 is disposed, and the reinforcement The reinforcing fiber of the fiber preform body 13 is impregnated. Meanwhile, the surplus resin passes through the discharge film gate 17 and fills the resin discharge runner 29 and then flows out through the discharge tube 25 to the vacuum trap. Then, after the resin injection is completed, the resin injection tube 24 and the resin discharge tube 25 are closed, and in this state, the resin is cured by heating for a predetermined time, and then the mold is opened to form a hat shape. A highly rigid CFRP sandwich structure is obtained.

  Carbon fibers, glass fibers, aramid fibers, metal fibers, boron fibers, alumina fibers, silicon carbide high-strength synthetic fibers, etc. can be used as reinforcing fibers, and epoxy resins, unsaturated polyester resins, vinyls can be used as molding resins. Thermosetting resins such as ester resins and phenol resins, and thermoplastic resins such as nylon, polypropylene, polyester, polyimide, and PEEK can be used.

  FIG. 3 is a structural diagram of the resin injection tube 6 and the resin discharge tube 7 used in the first embodiment. In this structure, a metal pipe 32 is inserted into the tip of a resin injection tube or resin discharge tube made of resin, and a seal tape 33 is applied to the outer surface.

  When the upper mold 1 and the lower mold 2 are closed and the resin injection tube (denoted by reference numeral 31) or the resin discharge tube is clamped between the upper mold and the lower mold, the metal pipe 32 is formed by the upper mold and the lower mold. Also, the resin injection tube 6 and the resin discharge tube 7 are not crushed by the semi-circular grooves (R smaller than the radius of curvature of each tube) 10 and 10 ′ formed in the sealing elastic bodies 8 and 9. There is an effect of maintaining the cross-sectional shape and smoothing the vacuum suction in the molding cavity and the smooth flow of the resin.

  The seal tape 33 is sealed by bringing the seal tape 33 into contact with the sealing elastic body when the upper mold and the lower mold are closed and the resin injection tube and the resin discharge tube are sandwiched between the upper mold and the lower mold. Therefore, the sealing effect of the elastic body can be enhanced, and the vacuum retention in the cavity can be stably increased. If the sealing elastic body is disposed on both the upper mold and the lower mold, it can be omitted.

  Plastic tubes such as nylon, polyethylene, polypropylene, and “Teflon” (registered trademark) are used for the resin injection tube and resin discharge tube, but iron, aluminum, brass, copper, stainless steel, etc. The metal tube can also be used.

  Moreover, iron, aluminum, brass, copper, and stainless steel are used for the metal pipe | tube 32 inserted in the inside of the front-end | tip of the resin injection tube or the resin discharge tube. Furthermore, it is possible to use a plastic tube such as ABS, polyethylene, polypropylene, nylon, vinyl chloride, or acrylic. It is preferable that any pipe has a thickness of 0.5 mm or more.

  Furthermore, a tape made of fluororesin such as “Teflon” (registered trademark), nylon, polyester, polypropylene resin, etc. can be applied to the sealing tape 33 applied to the outer surface of the tip of the resin injection tube or the resin discharge tube. is there. When the sealing elastic body is used on both the upper and lower molds, it can be omitted.

  FIG. 4 is a cross-sectional view showing several examples of the relationship between the resin injection tube and resin discharge tube used in the present invention and the sealing elastic body. The O-ring 44 and the sealing elastic body 43 can be made of fluororesin such as silicon, NBR, “Teflon” (registered trademark), and are solid or hollow. Moreover, the foam comprised with the said resin can also be used.

  The sealing elastic body 43 disposed on one or both of the upper mold 41 and the lower mold 42 protrudes slightly from the disposed mold surface, and the upper mold 41 is closed to close the mold surface of the upper mold 41. When the sealing elastic body 43 is pressed and compressed, the sealing elastic body 43, the upper mold 41, and the resin injection tube 40 (or the resin discharging tube) generate a reaction force against each other to ensure sealing performance. ing.

  Furthermore, by incorporating the O-ring 44 in the sealing elastic body 43, the sealing elastic body 43 is compressed by the reaction force generated in the sealing elastic body 43 and the O-ring 44 compressed when the upper die 41 is closed. And the O-ring 44 are pressed against each other, and the vacuum in the molding cavity is secured while maintaining the continuity of the seal (O-ring).

  Hereinafter, the sealing method for the resin injection tube and the resin discharge tube according to the present invention will be described with reference to FIG.

  4A shows a sealing elastic body 43 in which a groove having a curved surface with the same curvature as the resin injection tube 40 (or resin discharge tube) or a smaller curvature than the resin injection tube 40 is formed. The elastic body 43 for sealing on the O-ring 44 is disposed in the upper mold 41 and / or the lower mold 42 engraved in the shape of the elastic body for sealing, and the resin injection tube 40 or the resin discharge tube 40 is provided. The disposing portion is cut at the center of the O-ring 44, and the upper mold 41 is disposed in the upper mold 41 and / or the lower mold 42 in which the sealing elastic body 43 is engraved in the shape of the sealing elastic body. And the lower mold 42 sandwich the resin injection tube or the resin discharge tube 40. At this time, the end of the O-ring 44 is built in the sealing elastic body 43 to secure the vacuum retention in the cavity and prevent resin leakage.

  FIG. 4B shows the sealing elastic body 43 and the upper die 41 in which grooves having the same curvature as the tube 40 or a smaller curvature than the tube 40 are sealed, and the sealing elastic body 43 on the O-ring 44 is sealed. The O-ring closed loop is cut on the O-ring 44 on the resin injection tube or the resin discharge tube 40 in the lower die 42 engraved in the shape of the elastic body 43 for use. The resin injection tube and the resin discharge tube 40 are sandwiched between the upper mold 41 and the lower mold 42 in a state where the sealing elastic body 43 is disposed in the lower mold 42 engraved in the shape of the sealing elastic body. At this time, by incorporating the end of the O-ring 44 in the sealing elastic body 43, the vacuum in the cavity is maintained and resin leakage is prevented.

  FIG. 4C shows that the resin injection tube and the resin discharge tube 40 are also provided in the upper die 41 or the lower die 42 in which grooves having the same curvature as the tube 40 or a smaller curvature than the tube are formed. By cutting a closed loop of the O-ring on the O-ring 44 and bringing the cut portion of the O-ring 44 into contact with the tube used, vacuum retention in the cavity is ensured and resin leakage is prevented.

  FIG. 4D shows an upper mold 41 and an O-ring 44 formed with a groove having the same curvature as the tube 40 or a smaller curvature than the tube, and a continuous sealing elastic body 43 and resin injection. The tube 40 and / or the resin discharge tube 40 are clamped by the upper die 41 and the lower die 42 to ensure the vacuum retention in the molding cavity and prevent resin leakage.

  FIG. 4E shows a resin injection tube or a resin discharge tube 40 processed into an upper mold 41 and a lower mold 42 in which grooves having the same curvature as the tube 40 or a smaller curvature than the tube 40 are formed. The continuous O-ring 44 is disposed along the same curvature as the resin injection tube or the resin discharge tube 40, or along a smaller curvature than the resin injection tube or the resin discharge tube 40 across the groove, A resin injection tube or resin discharge tube 40 is disposed on the O-ring 44 and is sandwiched between the upper die 41 and the lower die 42 to ensure vacuum retention in the cavity and prevent resin leakage.

  FIG. 4 (F) is a state in which there is no upper mold of FIG. 4 (A) or FIG. It is.

  FIG. 5 shows a conventional mold structure. The tip of an injection plug 54 that functions as a resin injection sleeve and a bleed plug 55 that functions as a resin discharge sleeve are fixed to the mold 51. For this purpose, a fastening screw portion 60 is provided, and the sleeve is attached and detached by turning the screw portion before and after molding.

Example 1
As shown in FIG. 1, “Torayca” (registered trademark) T300 woven fabric (weight: 200 g / m ² ) manufactured by Toray Industries, Inc. is laminated in 5 ply in advance, and a reinforcing fiber substrate 12 shaped into a product shape is molded. A resin injection tube 6 and a resin discharge tube are disposed in the molding cavity 3 of the lower mold 2 in which a silicon O-ring 11 is disposed on the outer periphery of the cavity 3 and communicated with the resin injection liner 4 and the resin discharge runner 5. As shown in FIG. 3, a groove 10 having a semi-cross-sectional shape of the tube 7, an NBR sealing elastic body 8, 9 provided in the middle of the groove 10, and a groove provided in the sealing elastic body 8 communicating with the groove 10 An aluminum tube 32 is inserted into the tip of the tube 31 that contacts the groove, and a nylon resin injection member 30 having an outer diameter of 12 mm and an inner diameter of 9 mm is disposed around the outer periphery of the tip. The upper mold 1 was closed and the upper mold was pressurized with a pressing force of 50 tons. In this state, the mold was heated to 95 ° C. by flowing warm water through a pipe (not shown) provided in the mold.

Thereafter, the inside of the molding cavity 3 is evacuated through a resin discharge tube 7 connected to a vacuum trap (not shown) connected to a vacuum pump, and then the resin is injected into the molding cavity 3 through a resin injection tube 6. Epoxy resin was injected under pressure at 0.5 MPa. After the resin injection was completed, the resin injection tube 6 and the resin discharge tube 7 were closed. Then, after the epoxy resin was cured by heating with a mold for a predetermined time (30 minutes), the mold was opened and removed to obtain a high-quality CFRP product.
(Example 2)
As shown in FIG. 2, “Torayca” (registered trademark) T700 woven fabric (weight: 300 g / m ² ) manufactured by Toray Industries, Inc. is coated on the outer periphery of each 4 ply 15 with a core material 14 made of a foamed urethane body processed into a product shape. The upper mold 21 provided with the sealing elastic bodies 26 and 27 communicating with the silicon O-ring (not shown) provided on the outer periphery of the molding cavity 23. The resin injection tube 24 and the resin discharge tube 25, which are disposed in the molding cavity 23 constituted by the lower mold 22 and communicate with the resin injection runner 28 and the resin discharge runner 29, are provided with the silicon sealing elasticity. In order to seal by contacting the bodies 26 and 27, the upper and lower molds were clamped with a clamping force of about 100 tons.

  The resin injection tube 24 and the resin discharge tube 25 were aluminum tubes having an outer diameter of 14 mm and an inner diameter of 12 mm. In this state, the mold is heated to 85 ° C. by flowing warm water through a pipe (not shown) provided in the mold. After that, after the inside of the molding cavity 23 is evacuated through the resin discharge tube 25 connected to the vacuum trap connected to the vacuum pump as in the first embodiment, the epoxy is injected into the molding cavity through the resin injection tube 24. The resin was pressure injected at 0.7 MPa. After the pressurized resin fills the resin injection runner 28, the resin passes through the injection film gate 16 having a gap of about 1 mm into the molding cavity 23 in which the reinforcing fiber preform body 13 is disposed. It flows and is impregnated into the reinforcing fibers of the reinforcing fiber preform body 13. Meanwhile, the surplus resin passes through the discharge film gate 17 and fills the resin discharge runner 29 and then flows out through the discharge tube 25 to the vacuum trap. After the resin injection was completed, the resin injection tube 24 and the resin discharge tube 25 were closed with a tube wrench (not shown). In this state, the epoxy resin was cured by heating for a predetermined time (25 minutes), and then the mold was opened to obtain a hat-like high-rigidity CFRP sandwich structure.

  The FRP manufacturing method and mold of FRP (fiber reinforced plastic) according to the present invention can be applied to molding of automobile parts that require high quality, short molding cycle, high efficiency and low cost production. The application range is not limited to these.

It is a schematic perspective view of the metal mold | die used for the manufacturing method of FRP of this invention. It is a longitudinal cross-sectional view of the metal mold | die of FIG. FIG. 2 is a perspective view of a resin injection / discharge tube used for a mating surface of the mold of FIG. 1. It is a structure conceptual diagram which shows the various seal | sticker form of the tube part for resin injection | pouring / discharge | discharging arrange | positioned at the die matching surface. It is a longitudinal cross-sectional view of the conventional metal mold | die.

Explanation of symbols

1, 21, 41: Upper mold 2, 22, 42: Lower mold 3, 23: Molding cavity 4, 28: Runner for resin injection 5, 29: Runner for resin discharge 6, 24: Tube for resin injection 7, 25: Tubes for discharging resin 8, 9, 26, 27, 43: Sealing elastic bodies 11, 44: O-ring 12: Reinforcing fiber base material 13: Reinforcing fiber preform body 14: Core material 15: Reinforcing fiber base material 16, 17: Gate 54: Injection plug 55: Extraction plug

Claims (6)

In the FRP manufacturing method in which a reinforcing fiber base material is disposed in a cavity of a molding die divided into a plurality of surfaces, and then injected and cured, the resin enters the cavity on the mating surface of the die. A resin injection tube for injecting resin and / or a resin discharge tube for discharging excess resin in the mold are provided and pressed between the mold mating surfaces, and then the resin is injected and discharged into the cavity. The manufacturing method of FRP characterized by these. The method for producing FRP according to claim 1, wherein an elastic body is used as the resin injection tube and / or the resin discharge tube. 3. The FRP according to claim 1, wherein a metal pipe is inserted into at least a portion of the resin injection tube and / or resin discharge tube sandwiched between molds. Production method. The FRP according to any one of claims 1 to 3, wherein a seal tape is applied to at least a seal part of the outer periphery of the resin injection tube and / or the resin discharge tube with a mold. Manufacturing method. Resin injection / discharge means that has a resin injection cavity inside and is divided into a plurality of surfaces, and a resin injection / discharge means for injecting resin into the reinforcing fiber base disposed in the cavity and discharging excess resin In the FRP manufacturing apparatus provided with the above, for the injection of the resin and / or for the discharge of the resin, a tube clamped by the mating surface is provided on the mold mating surface, and a seal is provided at a contact portion with the mold An apparatus for producing FRP, wherein an elastic body is interposed. 6. The FRP manufacturing apparatus according to claim 5, wherein the sealing elastic body incorporates an end portion of an O-ring that seals the molding cavity surface.

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