JPS59226140A - Production of fiber-reinforced composite material - Google Patents

Abstract

PURPOSE:To obtain a fiber-reinforced composite material having an intricate shape by pressurizing intermixedly long fibers and short fibers and preforming the mixture to a desired member shape then impregnating the base phase of a molten metal therein. CONSTITUTION:Metallic or inorg. long fibers 3a are arranged in the housing parts 1a, 2a of primary forming molds 1, 2 and a prescribed amt. of short fibers 3b are successively inserted therein while the short fibers are bridged between the long fibers 3a and are superposed thereon generally like sponge. The long and short fiber groups 3a, 3b are molded under pressure by using pressing plates 4, 5. Such molding is housed in secondary forming molds having a desired shape and after the short fibers 3b are replenished in the required part, the molds are heated to cure the molding. A molten base phase material is impregnated with such molding to obtain a fiber-reinforced composite material. The fiber density in the composite material is made uniform by such method and the strength of the material is stabilized. Since adquate voids are formed among the fibres, the impregnation of the base phase is easy.

Description

[Detailed description of the invention] The present invention relates to a method for manufacturing fiber reinforced composite materials.

Obtained by combining two or more materials or forming two or more phases by physical or chemical methods,
A type of so-called composite material is a fiber-reinforced composite material manufactured by combining a long fiber reinforcing material and a matrix material.

When manufacturing fiber-reinforced composite materials, a method is often used in which reinforcing long fibers are preformed into a predetermined shape and the resulting molded body is impregnated with a molten matrix material. however,
If the molded shape is complicated, it is difficult to preform the long fibers to match the shape, and there are areas in the molded product where the fiber density is non-uniform, resulting in non-uniform material quality. In order to compensate for this inconvenience, a method has also been used in which a special jig is used to orient the long fibers according to a complex shape, and the matrix material is soaked in with the jig attached. , there was a problem that the jig had to be left behind in the finished product.

The present invention has been made in view of the above-mentioned points, and its purpose is to provide a manufacturing method that can easily manufacture a fiber-reinforced composite material having a complicated shape.

The method for producing a fiber-reinforced composite material according to the present invention is characterized in that long fibers and short fibers are mixed, the fibers are pressurized to form a member shape in advance, and the resulting molded body is impregnated with a molten matrix material. shall be.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a process for producing a preformed body of a valve used in a four-stroke automobile engine using the method for producing a fiber-reinforced composite material according to the present invention will be described with reference to the drawings.

First, a two-part primary mold l is molded into a symmetrical shape.
and 2 are superimposed on each other. Next, the long fibers 3a, such as metal fibers or inorganic fibers, are arranged in a direction that matches the mold, and the short fibers 3z are provided in the molds 1 and 2, respectively, in order to bridge between the long fibers 3α. Fiber storage section 1α
and 2a, into each other in a substantially spongy manner (((insert a predetermined amount while polymerizing).

Here, if the outer diameter and length of one ton of long fiber are d and t, then 4/cI1. 〉5oooO, on the other hand, short fibers with l/d≦5000 are referred to as short fibers. Examples of the material of the short fibers 3b include silicon carbide (SiC).
and grounder/@. Silicon carbide can be formed into both long fibers and short fibers by its tearing blades, and short fibers can also be obtained by cutting long fibers into predetermined dimensions.

In addition, during the composition process of Giron, it has already been made to satisfy the dimensional conditions as a short fiber as mentioned above.
, use this as is. Other materials for the short fibers 3b include
There is polyacrylonitrile carbon fiber (PAN), which is formed as long fibers and then cut to be used as short fibers, similar to the silicon carbide described above.

Fiber storage parts 1a and 2α for long fibers 3α and short fibers 3b
After the insertion into the fiber storage areas 1a and 2α is completed, the two symmetrical pressure plates 4 and 5 are placed one on top of the other.
the long fibers 3 by the force applied to the pressure plate.
A fiber group consisting of α and short fibers 3h is pressure-molded. The bottoms of the fiber storage sections 1α and 2α and the pressurizing ends of the pressurizing plates 4 and 5 are configured to form a cylindrical void as a whole, and the molded product obtained by pressure forming is circular. It becomes columnar. In addition, when the long fibers 3α and the short fibers 3b are mixed, molding becomes easier if a predetermined liquid is mixed with the short fibers 3h to make them semi-liquid. Furthermore, by mixing a suitable binder into the liquid, the molded product can be easily released from the mold and handled in the subsequent composite process.

The molded body 6 obtained as described above is placed in one of the two-part secondary molds 7 and 8. The secondary forming molds 7 and 8 have symmetrical shapes, and each of the secondary forming molds has storage portions 7α and 8α having an inner diameter corresponding to the axial diameter of the molded body 6, and a chime in the storage portions 7α and 8α.・9 parts 7b and 8
Continuous large diameter portions 7C and 8C are formed via h. As shown in FIG. 4(α), the molded body 6 is stored in the storage portion 7α (or 8α). Qi i4
Sections 7h and 8α are for forming pulp umbrellas. As shown in FIG. 4(A)K, for example, the end portion of the molded body 6 stored in the storage portion 7α on the tapered portion 7h side is loosened into a flower shape in line with the chi Δ portion. Next, short fibers 3b are replenished into the stripped portion.

When the replenishment of the short fibers 3h to the stripped portion is completed, the secondary molds 7 and 8 are overlapped, and the pressurizing piston 9 is inserted into the large diameter portions 7c and 8c as shown in FIG. 4(c). let Further, the ends of the storage portions 7α and 8α are closed by the bottom and the mold IO. The loosened portion of the molded body 6 is completely filled with the short fibers 3h that are later replenished by the pressure applied by the pressure piston 9 @The molded body 6 remains pressurized by the pressure piston 9 is heated by a heating means (not shown) to harden the molded body. From now on, 2
Next, by releasing the molds 7 and 8 and the bottom mold 10, the cured molded body 6 is taken out. - A preformed valve body is obtained by sintering.

As described in detail above, in the method for producing a fiber-reinforced composite material according to the present invention, long fibers and short fibers are mixed, and a molded article is formed by pressurizing the mixture. Therefore, due to the entanglement effect with the short fibers, the long fibers can be easily oriented in accordance with a complicated shape, making it possible to manufacture a fiber-reinforced composite material with a complicated shape. Also,
Since the short fibers play the role of a jig for setting the orientation of the long fibers, there is no need to manufacture a special jig for setting the orientation of the long fibers. If the jig is impregnated with the jig, the jig will not be left behind in the finished product.

In addition, in the method for producing a fiber-reinforced composite material according to the present invention, short fibers are replenished in areas where the fiber density of the long fibers is small, so that the fiber density becomes uniform as a whole, and the strength of the fiber-reinforced composite material is stabilized. be.

Furthermore, in the method for producing fiber-reinforced composite materials according to the present invention, long fibers and short fibers are oriented in a state of being entwined with each other, so even when producing products that have complex shapes and are subjected to complex loads, the and sufficient rigidity can be obtained.

In addition, in the method for producing a fiber reinforced composite material according to the present invention, appropriate voids are formed by the short fibers between the long fibers in the molded body, making it easy to impregnate the matrix agent into the molded body. be.

[Brief explanation of the drawing]

Figures 1, 2, 3, 4 (a), (b), and (C) show the preforming of valves of a four-cycle automobile engine using the method for manufacturing fiber-reinforced composite materials according to the present invention. It is a figure for explaining the process of manufacturing a body. Explanation of symbols of main parts 1.2...Primary mold 3a...Long fiber 3
h...Short fiber 4,5...Pressure plate 6...Molded body 7.8...Secondary mold 9...Pressure piston 10...Bottom mold agent Patent attorney Motohiko Fujimura

Claims (1)

[Claims] A method for producing a fiber-reinforced composite material, in which long fibers and short fibers are mixed and pressurized to form a member shape in advance, and the resulting molded product is impregnated with a molten matrix material.