JP2720192B2 - Fiber reinforced plastic molding die and method for producing fiber reinforced plastic molded body - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a mold for producing a fiber-reinforced plastic molded article having a portion substantially perpendicular to a main body, and a fiber reinforced using the mold. The present invention relates to a method for producing a plastic molded article.

[Conventional technology]

2. Description of the Related Art Conventionally, injection molding, sheet molding compound (SMC), and the like have been used to produce fiber-reinforced plastic molded articles. In general, the injection molding method is suitable for small molded products, and the SMC method is suitable for large molded products.

By the way, it has recently been proposed to form an outer plate of an automobile and other body parts with a fiber-reinforced plastic molded body. However, it has been found that it is difficult to form an automobile body from a fiber-reinforced plastic molded body by the conventional method because it is not only very large but also complicated in shape.

Therefore, the present applicant first applied for a patent on a method of preparing a preform by first adsorbing resin powder and reinforcing chop fibers on a preform mold, spraying a binder thereon, and then drying the binder. (JP-A-1-314146). This preform can be molded into a fiber-reinforced plastic molded article having a predetermined shape by stacking several pieces in a molding die and applying heat and pressure. Since a preform having a desired shape is formed in advance in this way, a fiber-reinforced plastic molded article having any shape can be manufactured.

[Problems to be solved by the invention]

However, in such a method for molding a fiber-reinforced plastic, when molding a flat or gently bent molded article, there is no particular problem, but a molded article having a portion substantially perpendicular to the main body portion. It has been found that when molding is to be performed, sufficient pressure is not applied to the vertical portion, and only a molded article having poor appearance and strength is obtained.

Accordingly, it is an object of the present invention to provide a molding die having a portion substantially perpendicular to a main body portion, which can be molded by applying sufficient pressure to the vertical portion to obtain a molded product having excellent appearance and strength. And a method for producing a molded article using the molding die.

[Means for solving the problem]

The present inventors have conducted various studies to achieve the above object, and as a result, by converting the pressing force of the upper die descending in the vertical direction into the pressing force in the horizontal direction through a wedge-shaped member, the vertical portion The present inventors have found that a pressing force can be applied equally to the present invention, and have reached the present invention.

That is, the fiber-reinforced plastic molding die of the present invention is particularly for producing a fiber-reinforced plastic molded body having a portion substantially perpendicular to the main body, and a lower mold having a substantially vertical molding surface, It is characterized by comprising a backup mold having an inclined pressing surface facing the molding surface, and an elastic mold having a wedge-shaped portion interposed therebetween.

Further, the method for producing a fiber-reinforced plastic molded article of the present invention is for producing a fiber-reinforced plastic molded article having a portion substantially perpendicular to the main body, and a lower mold having a substantially perpendicular molding surface, Using a mold comprising a backup mold having an inclined pressing surface corresponding to the molding surface, and an elastic mold having a wedge-shaped portion interposed therebetween,
After setting a fiber-reinforced plastic preform on the lower mold, and then applying an elastic mold on the preform, the backup mold is mounted and vertically pressed, and on the substantially vertical molding surface, The elastic body-type wedge-shaped portion applies a pressing force in a direction substantially perpendicular to the surface of the preform.

(Examples and actions)

 The present invention will be described below in detail with reference to the drawings.

FIG. 1 is a sectional view showing an example of a fiber-reinforced plastic molding die of the present invention. The molding die includes a lower die 1, a backup die 2, and an elastic die 3. Lower mold 1
Has a molding surface 12 substantially perpendicular to the molding surface 11 for molding the body portion, while the backup mold 2 is
And a pressing surface 22 facing the substantially vertical forming surface 12 of the lower mold 1 and slightly inclined from the forming surface 12. It is desirable that the pressure surface 22 has an angle θ with respect to a perpendicular line of 15 ° or more. More preferably, θ is between 15 ° and 60 °, even more preferably between 15 ° and 30 °.
If θ is smaller than 15 °, it is difficult to uniformly press the vertical surface.

The elastic mold 3 interposed between the lower mold 1 and the backup mold 2 includes a portion 31 existing between the molding surfaces 11 and 21;
It has a wedge-shaped portion 32 present in a wedge-shaped space formed between the substantially vertical forming surface 12 and the pressing surface 22.

It is desirable to interpose a spacer plate 4 between the outer surface of the elastic mold 3 and the pressing surface 22 to make the pressing uniform. A plurality of guide pins 5 and 5 ′ for positioning the elastic mold 3 are provided in the portion 31 of the elastic mold 3. ′.

The elastic mold 3 needs to have sufficient elasticity in order to convert a vertical pressing force into a uniform lateral pressing force at the wedge-shaped portion 32. At the same time, it is necessary that the molded body has sufficient heat resistance so that deformation and deterioration do not occur during heating and pressing of the molded body. Further, it is necessary that the material be a material that can easily release the fiber-reinforced plastic molded body after molding. From the above viewpoints, it is preferable to use silicon rubber or fluorine rubber. The thickness of the elastic mold 3 can be variously set, but is preferably about 50 to 80 mm in order to apply a uniform pressing force. Further, if the thickness of the rubber mold is made constant and the variation is constituted by the core, the thickness of the rubber mold is not limited.

Further, the spacer plate 4 has a role of making the pressing force constant as described above and improving the slidability between the backup mold 2 and the elastic mold 3. Further, by changing the thickness, shape, and the like of the spacer plate 4, it is possible to variously change the pressing force such as locally increasing the pressing force.

In order to form a fiber-reinforced plastic molded body using the above-mentioned mold, first, as shown in FIG. 2 (a), a preformed fiber-reinforced plastic preform 6 is placed in a lower mold 1 heated to a predetermined temperature. Then, as shown in FIG. 2 (b), the backup mold 2 is lowered, and the elastic mold 3 is attached on the preform 6. At this time, the preform 6 on the vertical molding surface 12
, The wedge-shaped portion 32 of the elastic mold 3 is in contact. Thereafter, as shown in FIG. 2 (c), the backup die 2 is completely lowered, and the pressing surface 22 is pressed against the elastic die 3. In this way, the vertical pressing force due to the lowering of the backup mold 2 is converted to the horizontal direction by the inclined pressing surface 4 of the backup mold 2 and is formed on the vertical molding surface 12 through the wedge-shaped elastic mold 3. The plastic component is melted, cooled and solidified while applying a sufficient pressure to the preform 6 to produce a molded body 7.

In this case, the elastic mold 3 has a shape corresponding to the shape of the preform 6 on the surface on the preform 6 side, and a portion facing the molding surface 12 in the vertical direction has an elastic mold 3 from above.
Is applied so that the elastic mold 3 is not strongly contacted with the preform 6 to prevent the preform 6 from being pulled in during the mold closing process. In order to accurately position the elastic mold 3, the elastic mold 3 is suspended from the backup mold 2 by guide pins 5, 5 '. Thereby, pressurization can be started in a state where the elastic body mold 3 is accurately in contact with the preform.

The molding surface of the lower mold 1 is desirably subjected to a fluororesin processing in order to improve the releasability of the molded body.

Also, instead of melting and cooling and solidifying the resin of the preform in the molding die as described above, the preform resin is melted in advance by sandwiching the preform between thin metal plates and heating. May be pressurized and solidified by cooling.

The preform of the molded article can be manufactured by the manufacturing method of Japanese Patent Application No. 63-143682. That is, first, carbon fiber or glass fiber chop fibers are uniformly adsorbed on a porous preform mold, and then resin powder is sprayed and adsorbed. Further, the preform is solidified by applying a binder and dried. Thereby, a preform in which the chop fibers and the resin powder are uniformly blended is obtained. Further, as the resin powder, either a thermoplastic resin or a thermosetting resin can be used depending on the application.

As described above, the backup mold 2 is lowered,
When pressure is applied in the vertical direction as shown by arrow A, the pressure is increased by the pressing surface 22 inclined by an angle θ from the vertical surface.
The pressure is converted into a horizontal pressure indicated by an arrow B. Therefore, the preform on the vertical molding surface 12 of the lower mold 1 can be pressure-molded by the vertical pressing of the backup die 2, and a molded article having a complicated shape including both the vertical surface and the horizontal surface can be formed. Can be manufactured.

Moreover, since the wedge-shaped space 32 formed by the molding surface 12 of the lower die 1 and the pressing surface 22 of the backup die 2 has the wedge-shaped portion 32 of the elastic die 3 interposed therebetween,
The pressure applied to the preform is made uniform, and a molded article having good appearance and strength can be obtained.

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited thereto.

Example 1 Carbon fiber as a chop fiber for reinforcement and nylon powder were adsorbed on a preform mold, and methanol 5 of alcohol-soluble nylon A-70 (manufactured by Toray Industries, Inc.) was placed thereon.
% Solution as a binder and dried to produce a preform with vertical faces.

After stacking three preforms, placing the preform on one molded iron plate and heating at 240 ° C for 20 minutes,
While being placed on the iron plate, it was set on the lower mold 1 shown in FIG. 1 and pressure-formed according to the procedure shown in FIG. The heating temperature of the mold was 190 to 200 ° C., the molding pressure of the backup mold 2 was 20 kg / cm ² , the angle θ between the pressing surface 4 of the backup mold 2 and the vertical surface was 15 °, and an elastic body made of silicone rubber was used. 3
(Hardness JISA50-70) was used.

The obtained molded body was uniformly press-molded on both the horizontal surface and the vertical surface, and was excellent in appearance and strength.

〔The invention's effect〕

According to the present invention, since the pressing force in the vertical direction can be converted to the horizontal direction, it is possible to press the surface in the vertical direction by pressing in the vertical direction. Therefore, it is possible to mold each surface of a molded article having a complicated shape in which a horizontal plane and a vertical plane are mixed, while sufficiently pressing each of them. It can be formed by a pressing operation.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one example of a fiber-reinforced plastic molding die of the present invention, and FIG. 2 is a cross-sectional view of a molding die in each step for explaining a method of manufacturing a fiber-reinforced plastic molded product of the present invention. It is. DESCRIPTION OF SYMBOLS 1 ... Lower mold 12 ... Molding surface 2 ... Backup mold 22 ... Pressing surface 3 ... Elastic type 32 ... Wedge-shaped part 4 ... Spacer plate 6 ... Fiber reinforced plastic preform 7 ... Fiber reinforced plastic Molded body

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location B29L 31:30 (72) Inventor Tomohiro Sakuraba 1-4-1 Chuo, Wako-shi, Saitama Stock Company (72) Inventor Kenji Hamanabe 1-4-1, Chuo, Wako-shi, Saitama

Claims (6)

(57) [Claims] 1. A mold for producing a fiber-reinforced plastic molded body having a portion substantially perpendicular to a main body, comprising: a lower mold having a substantially vertical molding surface; and an inclined pressing surface facing the molding surface. And a resilient mold having a wedge-shaped portion interposed therebetween. 2. The fiber-reinforced plastic molding die according to claim 1, wherein the pressure surface forms an angle of 15 ° or more with a perpendicular line. 3. The fiber reinforced plastic molding die according to claim 1, wherein a spacer plate is interposed between a pressing surface of the backup die and a wedge-shaped portion of the elastic die. Mold for molding fiber-reinforced plastic. 4. A method of manufacturing a fiber-reinforced plastic molded body having a portion substantially perpendicular to a main body, comprising: a lower mold having a substantially vertical molding surface; and an inclined pressing surface corresponding to the molding surface. Using a mold comprising a backup mold and an elastic mold having a wedge-shaped portion interposed therebetween, a fiber-reinforced plastic preform is set in the lower mold, and the elastic mold is first applied, and then the Attach the backup type and press vertically,
A method for producing a fiber-reinforced plastic molded product, characterized in that a pressing force is applied to the substantially vertical molding surface in a direction substantially perpendicular to the surface of the preform by the wedge-shaped portion of the elastic body. 5. The method for producing a fiber-reinforced plastic molded product according to claim 4, wherein an angle between the pressing surface and a perpendicular line is 15 ° or more. 6. The method for producing a fiber-reinforced plastic molded product according to claim 4, wherein a spacer plate is interposed between the elastic mold and the pressing surface.