JPS59171617A - Preparation of frp molded object - Google Patents

Abstract

PURPOSE:To obtain the titled product free from gap, wrinkles, defects of the rubber bag, etc. by a method wherein the axial length of prepreg piece laminated on the inside of a truncated cone cylndrical laminated object is made longer than others and the end is fixed on the opening side of the larger diameter. CONSTITUTION:To take an example, on the inside of a molding box 10 a prepreg piece L wherein the axial length is larger to the side of the larger diameter than other prepreg pieces is fixed by heat resisting sticky tape to the dam rings 2 or the other mold 1 to obtain a laminated body 3. This laminated body 3 is sealed by a rubber bag 4 from inside the molding from 10 to exhaust the air in the rubber bag and hardened by the autoclave molding to obtain the desired product.

Description

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, an FRP product having a substantially frustoconical cylindrical shape is molded. This article relates to a forming force method for FRP molded bodies.

Conventionally, when molding a substantially truncated cylindrical FRP molded product, such as the nozzle part of a Rokento motor, as shown in FIG. A formwork 10 is used, which consists of a metal outer mold l having a shape, and two wooden dam rings 2 having a pentagonal cross-sectional shape and an annular cross section installed on the inner periphery of one section between both ends of the outer mold 1.

As a method of molding an FRP molded product using this formwork 10, prepreg pieces in a B stage state are laminated along the inner wall of the outer 51 between the self-dam rings 2 to form a laminate 3. . (See Figure 2) The shape of the prepreg piece varies depending on the thickness distribution of the laminate to be formed, etc., but it is a road type, and its axial dimension is the same as the generatrix between both dam links 2 of the formwork 10. Approximately the same as length - later is used. The prepreg pieces are stacked one after another in the circumferential direction, and the laminate 3 is formed by repeatedly stacking them up to a predetermined thickness. After the lamination is completed, it is cured, and this is done by an autoclave method using a so-called vacuum pander.

However, during this heating and pressing, the thickness t of the laminate 3 becomes the thickness T(
(shown in Figure 2). This occurs because the resin softened by heating penetrates into the woven fabric under pressure, expelling air and evaporating the solvent component of the resin.

This l]! The radius of the laminate 4 also increases as the thickness of the laminate 3 decreases, but this increase in radius is the same at any position in the axial direction of the rubber bag 4. Since the elongation rate of the rubber in each portion is substantially constant regardless of the radius, the elongation rate of the rubber in each portion is large in portions with a small radius dimension, and small in portions with a large radius dimension. For this reason, rubber bag 4
The tensile stress generated within the material differs depending on each part, and the rubber bag 4 is
(in the direction of the arrow in Fig. 3). As a result, the prepreg pieces on the inner surface of the laminate 3 and the prepreg pieces in the inner layer adjacent thereto are also shifted one after another.As shown in FIG. occurs and the small "1"
1 on the diameter side. There was a problem in that hc occurred and the shape of the product was defective. Also, the rubber bag 4 is large [1
There were also problems such as the rubber getting into the gap S on the radial side and causing the rubber to tear.

This invention was made in view of these problems, and its purpose is to prevent gaps S and C from occurring in the FRP layer, and to prevent the rubber/header 4 from entering gaps S and tearing. The object of the present invention is to provide a method for molding FRP that does not cause the occurrence of.

The gist of this invention is that the gap between the large-diameter opening and the small-diameter opening [''
On the inner wall of the formwork of a substantially truncated conical cylinder having a section and a section at both ends,
After forming prepreg pieces in which fiber woven fabric pieces are impregnated with a thermosetting resin by laminating them in a circumferential direction with a linear shift of 11 inches, the laminated body is cured by an autoclave method using a vacuum hanger and approximately cut out. In a method for manufacturing a conical-head cylindrical FRP molded body, prepreg pieces to be laminated on the inner surface layer of the laminate are laminated with an axial dimension longer than that of other prepreg pieces. At the same time, the ends of the prepreg pieces are fixed to the opening side of the first span of the formwork to form the laminate.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 4 shows a method of forming a prepreg piece according to an embodiment of the present invention. In this embodiment, the formwork 10 itself is the same as the conventional formwork 10 described above, and the prepreg pieces are laminated on the inner surface of the laminate 3 in both the =J method and the lamination method. It is the same as the conventional example except for.

The prepreg piece to be laminated on the inner surface has a length in the axial direction that is longer than the other prepreg pieces toward the I diameter side.When laminating this prepreg piece, the part longer than the other prepreg pieces is is fixed to the dam ring 2 on the large diameter side of the formwork or the outer mold 1 with heat-resistant adhesive tape or the like.

This laminate 3 is tightly packed with a rubber bag 4 from the inner side of the mold 10 in the same manner as in the past, the air inside the rubber hanger 4 is exhausted, and the laminate 3 is cured by the so-called autoclave method. At this time, even if the rubber bag 4 shifts and moves due to the difference in elongation rate of the rubber bag 4 mentioned above, the prepreg layer in contact with the rubber band 4 will not be able to maintain the shape of the outer mold 1 or the prepreg layer.

Since it is fixed to the tom ring 2, the prepreg does not shift, and the rubber bag does not break due to the formation of gaps or gaps due to the rubber bang getting into the gaps.

In this example, the prepreg piece on the innermost surface layer was fixed to the dam ring 2 or the outer mold 1 on the large diameter side, but the prepreg pieces were fixed on the large diameter side and small II + diameter side. It may be applied to both dam links 2 or outer mold l.

As explained above, in the method for producing an FRP molded body according to the present invention, since the prepreg pieces to be laminated on the inner surface layer are fixed to the mold, even if the rubber hanger moves, the FRP molded body will not be formed. To improve the molding accuracy and stability of products without creating gaps. In addition, it is possible to eliminate the possibility that the rubber pads and grooves will get stuck between the tom ring and the prepreg, resulting in rubber punctures or tears, which will cause air to enter the rubber hangs and cause molding failures.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway perspective view showing the molds used in the conventional and the present invention, Figs. 2 and 3 are explanatory diagrams showing the conventional FRP molding method, and Fig. 4 is the FRP molding according to the present invention. It is an explanatory diagram showing a method. 1... Outer mold 2... Tam ring 3...
Laminate 10... Formwork Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] The inner wall of the formwork (10), which is a substantially truncated conical cylinder having a large [1-span opening and a small-diameter opening at both ends], is coated with bobble legs 1, which are made by impregnating a piece of fibrous fabric with a thermosetting resin, around the circumference. A method of manufacturing an FRP molded body having a substantially frustoconical cylindrical shape by laminating and forming layers while sequentially shifting in the direction, and then curing the laminate (3) by an autoclave method using a vacuum/Hairgue. , [-] The prepreg pieces to be laminated on the inner surface layer of the laminate are laminated with the axial dimension longer than the other prepreg pieces, and the ends of the prepreg pieces are
- A method for manufacturing an FRP molded body, characterized in that the above-mentioned laminate is formed by fixing it to the large "J diameter opening 1" side of the formwork.