JPS59129119A - Forming method of composite material product - Google Patents

Abstract

PURPOSE:To remove an accurate finish process for a formed piece and a secondary process in fastener connection after forming, etc. by a method wherein two kinds of prepreg different in hardening temperature are laminated and temporary formed objects preformed at a low temperature are assembled and then formed in a regular way at a high temperature. CONSTITUTION:Low temperature hardening prepreg (such as prepreg of glass fiber etc.) 2 is set on a forming jig 1, further, high temperature hardening prepreg (such as prepreg of carbon fiber etc.) 3 is set on the above-said prepreg. They are heated and pressed to harden the low temperature hardening prepreg 2 and the high temperature hardening prepreg 3 is preformed into a semi-hardening state. Said temporary formed object 7 and another temporary formed object 8 are set on a sole plate 9, assembled with an upper jig 11, heated and pressed. Said formed object 13 and another formed object 14 are connected with fasteners 15. EFFECT:Spot facing process under a flange in fastener connection time, application of a special form space around a fastener hole, a backup plate are not necessary.

Description

[Detailed description of the invention] The present invention relates to a method for forming composite material products.

Molded products of composite materials such as carbon fiber/epoxy resin, etc.
When manufacturing a reinforced skin/skeleton structure, each component such as the girder and skin may be molded separately and then assembled using bolts or other fasteners, or each component may be preformed by heating and reduced pressure. , methods such as combining them into a predetermined shape, integrating them in an autoclave, and simultaneously molding them are employed.

However, these methods have the following drawbacks.

(1) For example, a corrugated web girder 1 as shown in Fig.
In the case of molding, since the density of the fibers of the carbon fiber composite material is concentrated in the flange portion 1', the thickness of the seven flange 1 becomes uneven after molding.

Therefore, for example, when connecting the separately molded outer plate 2 with a fastener using bolts 3, etc. as shown in FIG.
In order to eliminate unevenness, it is necessary to counterbore the surface of the flange 1' or use a specially shaped washer, and if counterbore is performed, it is also necessary to consider the reduction in strength due to fiber cutting.

(2) In addition, in the case of integral molding and simultaneous molding, the end portion of the molded product 1 is In the case where the shape of the na part is irregular, the above (1
For the same reasons as in case 2), a counterbore or a specially shaped washer is required, and the part b, which is usually oversized by about 30 mm, needs to be finished to the exact size after molding. In Figure 2 (A) and (B), the same symbols as in Figure 1 (A) and (B) are in Figure 1 (A) and (B).
shows the same parts, 4 is the lower outer panel, 5 is the backing material, 6 is the same part.
II′i upper mold, 7Fi buffer plate, 8 is a coal plate.

(3) In fastener hole processing, a backup plate 9 as shown in FIG. 6 is required to avoid defects such as cracking of the molded product and delamination between layers. 10 in FIG. 3 is a drill.

Conventional molding methods have the drawbacks shown above.
The more complicated the process becomes, the more practical it becomes. Not only does it become an important problem and increase the cost, but it is well predicted that there will be cases where it is impossible to implement depending on the molded product.

The present invention was designed to eliminate the above-mentioned drawbacks in view of the tendency for composite material products such as carbon fiber/epoxy resin to become larger and more complex in the future.

That is, the present invention relates to a method for forming a composite material product, which is characterized in that two types of prepregs having different curing temperatures are laminated and pre-formed at a low temperature, and then the pre-formed bodies are combined and main-formed at a high temperature. It is.

The new idea of the present invention is that two types of prepregs (fiber/resin composite materials, hereinafter the same) with different curing temperatures are used in the molding of composite material products, and the parts to be processed with fastener holes and finished dimensions after molding are A prepreg (hereinafter referred to as low-temperature curing prepreg) that cures the end portion of the molded product during the preforming stage by heating and reducing pressure of each component under the temperature conditions of preforming. , and other prepregs (hereinafter referred to as temperature-cured prepregs)
The objective is to apply a low-temperature curing prepreg with excellent compatibility with a high-temperature curing prepreg in an 8F layer. In this way, since the low-temperature curing prepreg is cured during preforming, a smooth surface can be maintained in that part even during the final curing molding using an autoclave, so there is no need for the above-mentioned secondary processing after molding. There is an advantage that it can be done. Furthermore, one of the new ideas of the present invention is that the type of low-temperature curing prepreg can be selected according to all uses.

Does the method of the present invention connect fasteners after molding? It can be applied to all composite material molded products that require molding to the finished dimensions from the time of molding.

The method of the present invention will be explained below using specific examples.

Specific example 1 Among the components of the frame-reinforced skin structure, girders and ribs are
As shown in FIG. (High temperature curing prepreg) Lay up the entire filter. Next, as shown in FIG. 4(B), the silica cloth 4, the vacuum film 5, and the vacuum sealant 6 are all used, and a vacuum pressure of 15 psi is applied to prepare the carbon fiber prepreg 3 to a semi-cured state at a temperature of 120°C. Shape.

In this preformed state, the carbon fiber prepreg 6 is in a semi-hardened state, but the glass fiber prepreg 2 is in a hardened state, as shown in FIG.

Next, as shown in FIG. 5(A), the lower skin plate 8, which was preformed in FIG. 7' flange 7'
Assemble the buffer plate 10 and the upper mold jig 11 on the surface, back it with the backing material 12, and heat it in an autoclave at 50~1
Curing and molding is performed under pressure of 00 psi and heating at 180°C.

From this f'LvC, a molded product as shown in FIG. 5(B) K is obtained.

In addition, the number of laminated layers of Karasu* and fiber prepreg 2 used here depends on the shape of the part to be molded, and the number of layers of Karasu 5 fiber prepreg 2.
It varies depending on the thickness ζ, etc., but usually 2 to 6 IrJ sheets are suitable.

Next, as shown in Fig. 6, in Fig. 5, the upper outer plate 14, which was formed separately from the molded awn: n, girder/rib/lower outer shell 1 and f', was processed with fastener holes. Then, connect them with fasteners 15 using bolts or the like.

Specific example 2 In FIG. 4(A), 1 is used as the high temperature curing prepreg 3.
When using a 20°C curing type, e.g. carbon fiber prepreg, use a type curing at 70 to 80°C, e.g. glass #2 fiber prepreg, as the low temperature curing prepreg 2, and otherwise follow the same method as in Example 1. All you have to do is implement it.

In the method of the present invention, the type of low-temperature curing prepreg that is cured during preforming is preferably selected depending on the intended use as shown in Table 1. The high-temperature curing prepreg to be used as a sheath layer with the low-temperature curing prepreg thus selected may be of a type that cures at a higher temperature than the low-temperature curing prepreg.

Table 1 The effects of the method of the present invention detailed above are as follows.

(1) There is no need to counterbore the bottom surface of the flange or apply special shaped spacers.

In other words, low-temperature curing prepreg such as glass fiber grippreg applied to the lower surface of the flange during the preforming stage of girders and ribs hardens and retains the shape of that part, resulting in deformation of the flange thickness at the time of forming in an autoclave. does not occur. Therefore, it is not necessary to counterbore the lower surface of the flange when joining the fastener or to apply a specially shaped smoother that matches the shape VC of the molded product around the fastener hole.

(2) The backup plate for fastener hole processing is disrespectful.

1' That is, the low-temperature curing prepreg such as glass fiber grippreg applied to the lower surface of the flange also serves as a bank-up plate during fastener hole machining, so a special dedicated backup plate is not required.

(3) Exact size finishing processing of the molded product end IIj) is no longer necessary.

That is, for the same reason as in (1) above, the shape of the 0 end of the flange lower surface is bent into a retaining awn, so there is no need to process the end after molding. Therefore, the finished product can be molded to exact dimensions from the time of molding.

(4) Carbanic corrosion protection is not required.

That is, by appropriately combining the fiber types of the two types of prepregs that are laminated together, it is possible to provide a single item body with a protection bed against galvanic corrosion caused by contact with different metals, and the protection bed can be provided separately. There is no need to use it.

[Brief explanation of the drawing]

Figure 1 (Shu), (B) shows an example of a molded product (wavy web girder) made of carbon grain 11 bid material. a is 1lyi plane view, Fig. 2 (Δ) is the 1st
Fig. 1 (A) and (B) are diagrams showing an example of the conventional leg-shaping method for molded products, and Fig. 2 (B) is a diagram illustrating the disadvantages of forming the molded product into a Dv shape using the method shown in Fig. 2 (A). Figure 6 is an explanatory diagram of the case where one fastener hole hole is applied to the molded product shown in Figures 1 (A) and (B). Figure 4 (C) is a diagram showing an embodiment of the preliminary forming process of the inventive force method in the order of steps, Figure 4 (C) is a diagram showing the beautiful molded product obtained in the process of Figures 4 (A) and (B), Figure 5 (A) is a diagram showing an embodiment of the main forming step of the method of the present invention, and FIG.
P+ b A diagram showing the main molded product obtained in the process of Figure (A),
FIG. 6 is a diagram showing a state in which molded products obtained by the method of the present invention are joined together with a fastener. Sub-agent 1) Meifuku agent Ryo Hagiwara −

Claims (1)

[Claims] A method for forming a composite material product, which is characterized in that two types of prepregs with different curing temperatures are laminated and temporarily formed at a low temperature, and then the temporary formed bodies are combined and main formed at a high temperature.