JPH06106632A - Method for molding composite material product - Google Patents

Abstract

PURPOSE:To provide a method for molding a composite material product which is light in weight and high in strength at low cost, with which even a product having complicated closed sectional shape can be manufactured easily by using composite material. CONSTITUTION:A male mold 1 of desired shape is made of low-melting alloy, on which a reinforced fiber prepreg composite material 2 with thermosetting resin as a matrix is layered. The layer of the prepreg composite material 2 is set with heat by autoclave method. Thereafter the male mold 1 is fused with heat and removed, so that a flex hollow pipe A as a composite material product can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly uses a composite material (fiber reinforced plastic) to form a composite material product having a desired complicated closed cross-sectional shape such as a square pipe, a hollow panel or a hollow block. The present invention relates to a method of molding a product.

[0002]

2. Description of the Related Art In recent years, for the purpose of weight reduction and high strength, development of a reinforced fiber prepreg composite material in which a plastic such as epoxy resin or polyester is used as a matrix and a reinforcing material such as carbon fiber, boron fiber or glass fiber is added. Remarkably, the needs for various products using these composite materials have increased significantly.

In particular, since this kind of composite material is a material having excellent characteristics capable of producing a light-weight and high-strength structural product, it is a composite material product as various members used under the extreme conditions such as the aerospace field. Can be considered to exert great power. Among them, from the viewpoint of structural mechanics, it is important to form a composite material into a thin closed cross-sectional shape such as a pipe or a hollow body in order to obtain a lightweight and high-strength product.

[0004]

However, a composite material product having various closed cross-sectional shapes has a drawback in that it is difficult in terms of molding technology, and if it has a simple shape such as a simple right cylinder, it may be formed by a method such as filament winding. Although it can be manufactured, in the case of pipes and hollow bodies with other complicated closed cross-sectional shapes, a troublesome method such as independently molding the main body part and the lid and then adhering them to each other is taken. . Therefore, the production of the composite material product is troublesome and costly, and
There were problems such as many restrictions in shape.

The present invention has been made in view of the above circumstances, and it is an object of the present invention that even a product having a complicated closed cross-sectional shape can be easily manufactured by using the composite material, and the composite material is excellent in light weight and high strength. It is to provide a molding method that allows a product to be obtained at low cost.

[0006]

Means and Actions for Solving the Problems In order to achieve the above-mentioned object, a method for molding a composite material according to the first aspect of the present invention comprises forming a male mold of a required shape with a low melting point alloy, and thermosetting the male mold. A composite product is obtained by laminating a reinforced fiber prepreg composite material using a resin matrix, thermally curing this prepreg composite material layer with an autoclave, etc., and then thermally melting and removing the male mold. To do.

As described above, since a male mold is formed by using the low melting point alloy, the composite material is laminated on the male mold, and after hardening, the male mold made of the low melting point alloy is thermally melted and removed. The degree of freedom can be greatly improved, and it becomes possible to easily, reliably, and cheaply manufacture a composite material product that is thin, has a complicated closed cross-sectional shape, and is excellent in lightweight and high strength.

In order to achieve the above-mentioned object, the method for molding a composite material of the second invention comprises laminating a reinforced fiber prepreg composite material having a thermosetting resin as a matrix on a metal jig having a required shape, It is characterized in that a composite material product is obtained by thermally curing the prepreg composite material layer by an autoclave or the like, and then dissolving and removing the metal jig with a solvent.

Even when the metal jig is used as described above,
Since the metal jig is removed by dissolving it with a solvent after the composite material is laminated and cured, the degree of freedom in design can be greatly improved, and the thin, complex closed cross-sectional shape with light weight and high strength can be achieved. Superior composite products can be manufactured easily, reliably and cheaply.

In order to achieve the above-mentioned object, the molding method of the composite material according to the third aspect of the present invention forms a core having a required shape with wax, a low melting point alloy, aluminum or the like, and cures at room temperature on the peripheral surface of the core. The resin and the reinforcing fiber are laminated by a wet method and cured, and in this state, the core is melted by heat or removed by a solvent to form an inner surface layer, and a thermosetting resin is formed on the peripheral surface of the inner surface layer as a matrix. It is characterized in that a composite material product is obtained by laminating the reinforced fiber prepreg composite material and heat-curing it in an autoclave or the like.

As described above, after the room temperature curable resin and the reinforcing fiber are wet-laminated using the core and cured, the core is heat-melted or dissolved in a solvent to remove the inner surface layer,
Since the reinforcing fiber prepreg composite material is laminated on the peripheral surface of this inner surface layer and heat-cured, the degree of freedom in design can be greatly improved in the same manner as described above, and a composite material product having a complicated closed cross-sectional shape can be easily and surely obtained. In addition, it can be manufactured at low cost, and the precision of the inner surface dimensions and shape of the composite material product can be improved.

[0012]

EXAMPLES The first example of the method for molding a composite material product of the present invention will be described below.
The embodiment will be described with reference to FIG. The composite material product in this embodiment is intended to be a bent hollow pipe A used for hydraulic pipes of aircrafts, which are strongly required to be lightweight and have high strength and oil resistance.

First, as shown in FIG. 1 (a), a low melting point alloy is poured into a mold (not shown) such as gypsum to form a bent rod-shaped male mold 1 having a diameter slightly smaller than the desired bent hollow pipe A. . As shown in FIG. 1 (b), a reinforcing fiber prepreg composite material 2 having a thermosetting resin as a matrix is laminated on the outer peripheral surface of the male mold 1 to have a uniform thickness as much as possible. Heat cure with crepe.
After that, the male mold 1 is heat-melted and removed to obtain a bent hollow pipe A which is a composite material product as shown in FIG. 1 (c). The bent hollow pipe A is finished by trimming and painting.

As the low melting point alloy forming the male die 1, solder (tin-lead alloy) whose melting point can be arbitrarily set by changing the composition is used as a material. For example, low temperature solder 143 (melting point 143 ° C., manufactured by Senju Metal Co., Ltd.) is used. In this case, as the reinforcing fiber prepreg composite material 2, a carbon fiber prepreg (made by Toray Industries, Inc., resin NO.
Carbon fiber prepreg F6151 using 2500) is used.

When high-temperature solder 220 (melting point 220 ° C., manufactured by Senju Metal Co., Ltd.) is used, as the reinforcing fiber prepreg composite material 2, a carbon fiber prepreg having a 180 ° C. thermosetting epoxy resin matrix (Toray Co., Ltd.) is used. Made of resin N
O. Carbon fiber prepreg F6142 using 3601 or MXG-6001 / 7581 manufactured by Mitsubishi Kasei Fiberlight Co., Ltd.) is used.

As a means for laminating the reinforcing fiber prepreg composite material 2 on the outer peripheral surface of the male die 1, a sheet winding method (a prepreg having a width of several centimeters to several tens of centimeters is wound around the male die 1) or a filament is used. There are a winding method (wrapping around the male mold 1 while passing the reinforcing fiber through the molten resin) and a hand layup method. The sheet winding method is preferable when manufacturing efficiency is important, and the filament winding method is preferable when strength is important.

As described above, since the male die 1 is made of the low melting point alloy, the composite material 2 is laminated on the male die 1 and cured, and then the male die 1 is thermally melted and removed, so that only the composite material 2 is formed. The bent hollow pipe A having a closed cross-section, which is excellent in light weight, high strength, and oil resistance, can be manufactured easily, reliably and inexpensively.

Next, a second embodiment of the present invention will be described with reference to FIG. Here, as the composite material product, for example, the square pipe B used for structural members of high-performance automobiles, motorcycles, aircrafts, etc., which are strongly required to be lighter and stronger and have oil resistance as described above, is targeted. .

First, as shown in FIG. 2 (a), a disposable metal jig 11 in the shape of a square pipe having a diameter slightly smaller than the desired square pipe B is used as a male mold. A reinforcing fiber prepreg composite material 12 using a thermosetting resin as a matrix is laminated on the outer periphery of the metal jig 11 as shown in FIG. 2 (b), and the prepreg composite material layer 12 is autoclaved. Heat cure. After that, the metal jig 11 is dissolved and removed with a solvent to obtain a square pipe B made of only the composite material 12 as shown in FIG. This square pipe B is finished by trimming and painting.

As the disposable metal jig 11, for example, an aluminum alloy (pure aluminum may be used) is used. In this case, if the diameter is up to about 50 mm, sufficient mold strength can be obtained with a wall thickness of 1 mm. As a solvent that dissolves the aluminum jig 11 after the thermosetting of the reinforcing fiber prepreg composite material 12, an alkaline aqueous solution such as sodium hydroxide is used. The reinforced fiber prepreg composite material 12 can be used in addition to the carbon fiber prepreg in which a thermosetting epoxy resin is used as a matrix, as well as a fiber prepreg in which a thermosetting polyester resin is used as a matrix, because it has excellent alkali resistance.

It is also possible to use, for example, iron or carbon steel as the disposable metal jig 11. In this case, if the diameter is up to about 50 mm and the wall thickness is 0.3 mm or more, sufficient mold strength can be obtained. An aqueous solution of hydrochloric acid or the like is used as a solvent for dissolving the iron jig 11 after the thermosetting of the reinforcing fiber prepreg composite material 12. Since most of the thermosetting resins for the reinforced fiber prepreg composite material 12 have excellent acid resistance,
Various resins can be used.

Even when the metal jig 11 is used as described above, it is dissolved and removed with a solvent after the composite material 12 is laminated and cured.
The rectangular pipe B having a closed cross-section excellent in high strength and oil resistance can be manufactured easily, reliably and inexpensively.

Next, a third embodiment of the present invention will be described with reference to FIG. Here, as the composite material product, for example, the hollow box C used as a tank member of a piping system, which is strongly required to be lightweight and high-strength and oil resistance as described above, is targeted.

First, as shown in FIG. 3 (a), wax (paraffin) is poured into a mold (not shown) such as gypsum or clay to form a core 21 which is one size smaller than the desired hollow box C. As shown in FIG. 3B, an epoxy resin as a room temperature curable resin and a glass cloth as a reinforcing fiber are wet laminated on the outer peripheral surface of the core 21. At this time, the glass cloth is 4 to 7
Wrap about a layer. Since the strength required for the mold varies depending on the size and shape of the product, the number of laminated glass cloths should be changed accordingly. In this state, the epoxy resin and the glass cloth layer 22 are cured at room temperature. After this the whole 65
The core 21 is heated to about ℃ (melting point of paraffin is 45-65
C.) is melted, melted, and removed to form an inner surface layer (mold) 23 composed only of the epoxy resin and the glass cloth layer 22.

In this state, a carbon fiber prepreg composite material 24 having a thermosetting resin such as a 120 ° C. curing type epoxy resin as a matrix as described above is laminated on the outer peripheral surface of the inner surface layer 23, and this is laminated by an autoclave or the like. By thermosetting, a hollow box C that is a composite material product is obtained. After the prepreg is cured, trimming, painting and other finishing are performed as described above to obtain a finished product.

As described above, after the room temperature curable resin and the reinforcing fiber 22 are wet-laminated and cured by using the core 21, the core 21 is thermally melted and removed to form the inner surface layer 23,
The reinforcing fiber prepreg composite material 2 is provided on the outer peripheral surface of the inner surface layer 23.
Since 4 is laminated and heat-cured, it becomes possible to manufacture a hollow box C with a closed cross-section that is lightweight, high strength, and excellent in oil resistance easily, reliably, and cheaply, and the inner surface dimension and shape of the hollow box C. The accuracy of can be improved.

In the case of the third embodiment, the core 21
However, the core 21 is made of a low melting point alloy as in the first embodiment, and is removed by heat melting after molding and hardening the inner layer surface 23, or by using a metal such as aluminum. The core 21 may be configured so that after the inner layer surface 23 is molded and cured, it is dissolved and removed by a solvent.

[0028]

EFFECTS OF THE INVENTION With the above-described method for molding a composite agent product of the present invention, the degree of freedom in design can be greatly improved, and a product having a complicated closed cross-sectional shape can be easily and surely manufactured using a composite material. As a result, thin-walled, lightweight, high-strength composite material products can be provided at a low price.

[Brief description of drawings]

FIG. 1 is a process diagram showing a first embodiment of a method for molding a composite material product of the present invention.

FIG. 2 is a process drawing showing a second embodiment of the method for molding a composite material product of the present invention.

FIG. 3 is a process drawing showing a third embodiment of the method for molding a composite material product of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Male type, 2, 12, 24 ... Reinforcing fiber prepreg composite material using a thermosetting resin as a matrix, 11 ... Metal jig, 21 ... Core, 22 ... Room temperature curable resin and reinforcing fibers, 2
3 ... Inner surface layer, A ... Composite agent product (A ... Hollow bent pipe, B
… Square pipe, C… Hollow box).

Claims (3)

[Claims] 1. A low-melting-point alloy is used to form a male mold of the required shape,
This male mold is laminated with a reinforced fiber prepreg composite material having a thermosetting resin as a matrix, and the prepreg composite material layer is heat-cured by an autoclave or the like, and then the male mold is thermally melted to remove the composite material. A method for molding a composite material product, which comprises obtaining the product. 2. A reinforced fiber prepreg composite material having a thermosetting resin as a matrix is laminated on a metal jig having a required shape, and the prepreg composite material layer is heat-cured by an autoclave or the like, and then the metal treatment is performed. A method for molding a composite material product, which comprises obtaining a composite material product by dissolving and removing a tool with a solvent. 3. A core having a required shape is made of wax, a low melting point alloy, aluminum or the like, and a room temperature curable resin and reinforcing fibers are wet laminated on the peripheral surface of the core to cure the core. To make an inner layer by melting the child by heat melting or dissolving with a solvent, stacking a reinforcing fiber prepreg composite material with a thermosetting resin as a matrix on the peripheral surface of this inner layer, and heat curing with an autoclave etc. A method of molding a composite material product, comprising: