JPH047111A - Manufacture of fiber reinforced plastic hollow body - Google Patents

Abstract

PURPOSE:To produce a fiber reinforced plastic hollow body, which has high strength and rigidity and desired wall thickness, without increasing production cost by a method wherein the hollow body is produced by joining two split semi-fabricated products, which are fabricated at the same time. CONSTITUTION:An upper panel 23 and a lower panel 24 are formed through the closing of an upper and a lower slide cores 9 and 14 and a core 18 by bringing an upper and a lower press platens 12 and 17 close to each other under the condition that resin-impregnated glass fiber base material cut in proper lengths is fed between an upper mold 8 and the core 18 and between the core 18 and a lower mold 13. In this case, only the main body parts of both the panels excluding their peripheral edge parts are hardened under the condition that heated fixed molds 10, 10, 15 and 15 are brought out of contact with both the panels 23 and 24. After that, by opening the molds 8 and 13 through the separation of the upper and the lower press platens 12 and 17 from each other, both the panels 23 and 24 are left respectively on the slide core 9 side and on the slide core 14 side. After the core 18 is removed and the slide cores 9 and 14 are retreated to proper positions, closing is performed again, resulting in pressing and thermally hardening the peripheral edge parts of both panels 23 and 24 with the fixed molds 10, 10, 15 and 15.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method for manufacturing a fiber-reinforced plastic hollow body.

(Prior Art) The following methods are known as conventional methods for manufacturing fiber-reinforced plastic hollow bodies: (a) As shown in Figure 7, two outer shells are molded in a divided form. A method of joining parts (upper panel 42 and lower panel 43) using adhesive 41.

(b) Same as (a) above, but without using adhesive.
A method of joining by welding.

(c) As shown in FIG. 8, a bag 48 that can be expanded and pressurized is placed as a core between the upper mold 45 and the lower mold 46, and the fiber base material 47 set in the mold is impregnated with resin. RTM (
A method of molding a hollow body 50 without a flange portion as shown in FIG. 9 by a resin transfer molding method or the like (see Japanese Patent Laid-Open No. 139433/1983).

(=l As shown in Figure 1O, the resin is placed inside the mold (fixed mold 52
and the movable mold 53), and then injecting gas into the mold to make it hollow
7-14968).

(N) As shown in FIG. 11, two cavities 57 and 58 are defined by the upper mold 54, the lower mold 55, and the core mold 56, and these cavities 57 and 58 are filled with resin.
After molding the two outer shell parts 59.60 having the engagement structure wI61.62 as shown in the figure, the core mold 56 is removed and the molds are clamped again, and the two outer shell parts 59.60 are engaged. A method of manufacturing a hollow body (see Japanese Patent Application Laid-Open No. 189431/1983).

(Problems to be Solved by the Invention) However, each of the above methods (A) to (N) has the following problems: Method (A)... requires an adhesion step after molding; This process requires additional materials, personnel, equipment, etc., which significantly increases manufacturing costs. Furthermore, since the material of the adhesive surface is discontinuous with respect to the general part, the strength of the product is likely to decrease due to stress concentration.

Method (b): Since a welding process is required, the method described above (
As with method b), manufacturing costs increase. In particular, the increase in energy costs is significant, and this method is not suitable for manufacturing hollow bodies having a thermosetting resin as a matrix.

Method (c): After molding, it is necessary to take out the bag that can be expanded and pressurized, and the bag is required to have durability. Furthermore, the bag, which can be easily expanded and pressurized, is deformed by the pressure during resin injection, making it difficult to control the wall thickness of the product.

(Method of gradation... [1, f) Compared to method (c), only short fibers can be used, and it cannot be applied to products that require strength and rigidity.

Method (ne)...The joint strength of the engaging part is insufficient,
In particular, it is substantially difficult to join fiber-reinforced plastic products whose matrix is a thermosetting resin.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a fiber-reinforced plastic hollow body with high strength and rigidity and a desired wall thickness without increasing manufacturing costs. The objective is to provide a manufacturing method.

(Means for Solving the Problems) The method for manufacturing a fiber-reinforced plastic hollow body of the present invention includes:
A mold is used in which cavities are defined by the core and the upper mold, and by the core and the lower mold, respectively, and the resin-impregnated fiber base material supplied to both cavities is simultaneously processed except for the peripheral edges of these base materials. After heating and hardening and molding the outer shell parts that form the hollow body separately, only the core is removed from the mold, and the upper mold and the lower mold are clamped together again, and the periphery of the above-mentioned split molded outer shell parts is removed. It is characterized by being cured under pressure and heat in the combined state.

That is, in the method of the present invention, two semi-finished products (the above-mentioned panels) are simultaneously produced in a divided form, and the hollow body is manufactured by joining them together. The process is carried out in two stages, first for the main body and then for the panel periphery. Therefore, in the mold, separate heating and cooling means are used for the part where the panel main body is molded and the part where the panel periphery is molded, or the metal mold is It is necessary to make each of the above-mentioned molding parts of the mold movable separately. In addition, it is necessary to make the mold release properties of the core relatively better than those of the upper and lower molds so that the core can be removed while leaving both panels in the upper and lower molds.

Resin-impregnated fiber base materials include cloths and mats of reinforcing fibers such as glass fibers, carbon fibers, and aramid fibers, raw materials (monomers) of thermosetting resins such as unsaturated polyester resins, epoxy resins, and phenolic resins, and as necessary. Examples include those impregnated with curing agents, catalysts, fillers, stabilizers, colorants, etc., depending on the needs. Note that this also includes prepregs in which the impregnated resin has been cured to the extent that it can be stored.

(Function) The above-mentioned mold in which cavities are defined by the core and the upper mold and by the core and the lower mold respectively makes it possible to separately mold the outer shell parts, Enables joining of outer shell parts (without removing the outer shell parts from the mold).

Partial molding of the shell allows the core to be removed from being trapped within the hollow body being molded. Even if the core is removed, the main body of the outer shell part is hardened and will not deform. By removing only the core and clamping the mold again, the unhardened peripheral edges can be pressurized and pressed together. When heated and cured, resin flows at the joint and subsequent reaction hardening of the resin occurs, and the separately molded outer shell parts are integrated to form a hollow body.

(Example) Hereinafter, an example of the method of the present invention will be described based on the drawings.

In this embodiment, a bumper reinforcement for a hollow air vehicle made of FRP 1 consists of an upper panel part 2, a lower panel part 3, and a flange part 4 as shown in FIGS. 4 and 5.
Manufacture.

To manufacture this hollow body 1, a molding apparatus as shown in FIG. 1 is used. The device includes an upper press plate 12 provided with an upper mold 8.
, a lower press plate 17 provided with a lower die 13, and a core 18 provided with a moving means that can be placed between them and removed. The core 18 is attached to a rail 21 that moves along a rail guide 22 via a support rod 20, and the surface of the core 18 is covered with a silicone rubber 19. The upper mold 8 has a central slide core 9
and fixed molds 10.10 on both sides thereof, and the lower mold 13 similarly consists of a slide core 14 and fixed molds 15.15. Each slide core 9 of the upper mold 8 and lower mold 13
．． 14 are movable in the vertical direction by push-out pins 11.16, respectively, and the panel portions 2.3 (
On the other hand, the fixed mold 10.1O1
15, 15 are responsible for forming the flange portion 4, and each slide core 9, 14 and each fixed mold 10, 10, 115, 15 are provided with temperature control piping 30, 30, . . . .

As shown in FIG. 3, the resin-impregnated glass fiber base material 25 molded into the hollow body 1 is a fiber base material 26 (a fiber bundle made from glass filaments with a diameter of 13 μm and a binder, which is made into a blind weave mat). ) into a resin impregnation mold 27, and into the mold 27, two-component type reactive resin raw materials A and B (here, vinyl ester is used as a monomer) are mixed with a mixing head 28, and sprue 2 is introduced.
9.

This resin-impregnated glass fiber base material 25 is cut into an appropriate length and is supplied between the upper mold 8 and the core 18 and between the core 18 and the lower mold 13, as shown in FIG. 2 (Al). , the upper and lower press plates 17 are moved closer together to form the upper and lower slide cores 9, the workpiece 4 and the core 1.
8, the upper panel 23 and lower panel 24 are formed.

At this time, the peripheral edges of both panels 23.24 (the portions that will become the flange portions 4 in FIG. 4) are Only the removed main body portion is cured to at least a state in which the resin does not flow (gel state).

Thereafter, when the mold 8.13 is opened by separating the upper and lower press plates 12.17, both panels 23.24 remain on each slide core 9.14 side. This is because the surface of the core 18 is covered with silicone rubber.
The fixed mold 1O1l is removed by lowering the pusher pin 11.16, retracting the slide core 9.14 to the appropriate position, and tightening it again as shown in FIG.
Pressure the peripheral edges of both panels 23 and 24 with O115, 15.
The resins on the peripheral edges of the two panels 23 and 24 to be heated and cured flow into each other at the initial stage of heating, and are finally cured as one piece. The body parts of both panels 23, 24 are then heated continuously in the sliding core 9, 14 and completely hardened. In this way, a hollow body l as shown in FIG. 4 is obtained.

As shown in FIG. 5, in the obtained FRP hollow body 1, the thickness t of the upper panel portion 2 and lower panel portion 3 is uniform throughout, and the error is within ±0.5 mm. As shown in an enlarged view in FIG. 6, in the flange portion 4, fiber bundles 5 made up of a large number of filaments 6 are uniformly dispersed in the matrix resin, and there is no evidence of joining of the two panels.

Since both panel parts 2.3 are integrally connected in this way, the hollow body 1 has high rigidity.

(Effects of the Invention) According to the method of the present invention, a hollow body made of fiber-reinforced plastic can be manufactured in a single line and through a process of heating and curing the molding material, resulting in improved productivity and reduced manufacturing costs.

Even if the matrix resin is a thermosetting resin, the resins mutually diffuse and react to harden at the joint, resulting in a completely integrated fiber-reinforced plastic hollow body. Since the hollow part is molded with a core without using a bag or gas that can expand and pressurize it, the thickness of the hollow part can be controlled as desired. That is, it is possible to prevent defects in strength and rigidity from occurring in the hollow body.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing a molding device used in one embodiment of the method of the present invention, Fig. 2 (A and (Bl) are consecutive explanatory views showing how to use the above molding device, and Fig. 3 is an explanatory diagram showing one embodiment of the method of the present invention. An explanatory diagram showing the manufacturing method of the resin-impregnated glass fiber base material used in the example, FIG. 4 is a perspective view showing the manufactured hollow body, FIG. 5 is a diagram showing a cross section of the central part of the hollow body, and FIG. 6 is an enlarged view of the part ■ in FIG. 5, and FIGS. 7, 8, 9, 10, 11, and 12 are explanatory diagrams showing different conventional manufacturing methods, respectively. In the figure, l...Hollow body (bumper reinforcement) 2...Upper panel part 3...Lower panel part 4...Flange part 8...Upper mold 9...Slide core lO...・Fixed mold 13...lower mold
14...Slide core 15...Fixed type
18... Core 23... Upper panel
24...Lower panel 25...Resin-impregnated glass fiber base Patent applicant Toyota Motor Corporation agent Patent attorney Yumi Kaede (2 others) Matrix Yuzuki's diagram Ro-no! N) Figure 10 M Pilgrimage ↓

Claims (1)

[Claims] A cavity is defined between the core and the upper mold, and a cavity is defined between the core and the lower mold, and the resin-impregnated fiber base material supplied to both cavities is heated and cured simultaneously except for the peripheral portion of these base materials, After separately molding the outer shell parts that form the hollow body, only the core is removed, the upper mold and the lower mold are clamped together again, and the peripheral edges of the separately molded outer shell parts are pressed and pressed together.
A method for producing a fiber-reinforced plastic hollow body characterized by heat curing.