JPH01258918A - Fiber reinforced composite material formed item and manufacture thereof - Google Patents

Abstract

PURPOSE:To easily form a complicated shape with good workability without distributing the orientation of long fibers in FRP by a method wherein a thermal fusion process and a compression process are done at separate positions, when one end of an FRP rod is formed. CONSTITUTION:One end 2a of a round FRP rod 2 is inserted in the insertion hole 4a of a heating pot 4 in order to soften the end 2a of the round rod 2 by heating. Next, a mold 3 is connected to one end 4b of the heating pot 4 so as to loosely insert the round rod 2 in the insertion hole 3b of the thread mold 3. By pulling the rod 2 leftwards (in the direction indication with the arrow) out of the pot 4 so as to pull the softened portion 2a of the round rod 2 in the thread part 3a of the thread mold 3 and simultaneously compressive force is applied to the one end 2a of the round rod 2 with a punch 5 in order to form a male threaded part 8. Since the one end 2a of the round rod 2 is compression-molded with the punch 5 simultaneously with the pulling of the round rod 2 out of the pot 4, the long fiber material within the round rod 2 is shifted without any axial disturbance, resulting in obtaining threaded parts 8 and 9 having no fluctuation of strength therein.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a fiber-reinforced composite molded product and a method for manufacturing the same. It relates to resin molded products or intermediate molded products made in the process of manufacturing these molded products.

(Prior art) In recent years, fiber-reinforced composite materials 1 have been used for machine parts or machine elements that require light weight and high strength, such as glass fiber and resin or silicon carbide fiber and metal for the fiber material and base material, respectively. Various methods are known that use .

These fiber-reinforced composite material products are manufactured by various manufacturing methods depending on the shape and characteristics of the product. For example, in the fiber-reinforced composite molded product disclosed in Japanese Patent Application No. 62-49488, a base material and a fiber material are placed in a heated mold, and a compressive force is applied in the direction in which the long fibers are arranged. This makes it possible to obtain a molded product with a predetermined shape that corresponds to the shape of the mold.

(Problem to be Solved by the Invention) However, according to the conventional manufacturing method of fiber-reinforced composite molded products, the process of heating and melting the composite material and the process of compression molding the composite material are performed at the same time. It has been difficult to accurately mold molded products into complex specific shapes such as screws.

The present invention was made to solve these problems, and by separating the heat-melting process and the compression process of composite materials, lightweight and high-strength fibers with complex shapes such as screw shapes can be produced. The purpose is to manufacture reinforced composite molded products with high precision and workability.

(Means for Solving the Problems) To achieve this, the fiber-reinforced composite molded product of the present invention is a rod-shaped composite molded product made of a thermoplastic resin and reinforcing long fibers, and the ends of the rod-shaped composite molded product are The cross-sectional area of the body is set to be larger than or equal to the cross-sectional area of the body.

The end portion is characterized in that it has a male thread.

The method for producing a fiber-reinforced composite molded article of the present invention involves forming a rod from a thermoplastic resin and reinforcing long fibers arranged in the axial direction, and heating at least one end of the rod with a heating device to soften it. Thereafter, the one end is compressed in the axial direction while the rod is being drawn into a mold, and the rod is cooled and solidified.

The reason why the cross-sectional area of the end of the rod-shaped composite molded product is set to be larger than or equal to the cross-sectional area of the body is that the composite molded product This is to bulge out the edges and mold it into a specific shape with high precision.

The rod only needs to have a large number of long fibers oriented in the axial direction in the base material, and may be one formed by compression molding with a large number of single fibers oriented in the base material, or a braid made of the above-mentioned composite material. A material made by knitting several strands and compression molding can be used.

(Example) Embodiments of the present invention will be described based on the drawings.

1 Arashi ■U A molding device 1 as shown in FIG. 1 was used to mold a screw. The screw standard was MIOXl, 25, a metric fine screw specified in J'1S-80207.

In Fig. 1, 2 is a round bar made of fiber-reinforced composite material;
3 is a screw mold, 4 is a heating pot for heating the end of the round bar 2, and 5 is a punch.

The round bar 2 is made of 6-nylon 50v as the base material.
o 1%, glass fiber yarn 50v as fiber material
It is composed of a fiber reinforced composite material consisting of 1% o. The diameter of the round bar 2 is 8 mm.

One end 2a of this round rod 2 is connected to a heating pot 4 as shown in FIG.
For example, one end 2a of the round bar 2 is inserted into the insertion hole 4a of the round bar 2.
Heat to 0-320°C to soften.

Next, the mold 3 is connected to one end 4b of the heating bot 4, and the round bar 2 is loosely inserted into the insertion hole 3b of the screw mold 3.

Then, the round bar 2 is pulled out to the left in FIG. 1, and the softened end 2a of the round bar 2 is pulled into the threaded part 3a of the screw mold 3. At the same time, a compressive force is applied to the one end 2a of the round bar 2 with a punch 5, and the rod is cooled and compressed. The end of the round bar 2 is bulged in a radial outward direction, and a male thread is formed in this bulge.

The obtained composite material molded product is a composite material molded product 7 having a round bar body as shown in FIG. 2, and a male screw portion 8 is formed at the end of the round bar. A male threaded portion 9 was similarly formed at the other end of the round bar.

According to this embodiment, the round bar 2 is connected to the screw mold 3 shown in FIG.
When the round bar 2 is pulled out from the insertion hole 3b in the direction of arrow 7 in the figure, 1. At the same time, since one end 2a of the round bar 2 is compression-molded by the punch 5, the fiber material inside the round bar 2 is moved without being disturbed in the axial direction, so that the male threaded part of the resulting composite molded product 7 is As is clear from the data described below, the 8.9 screw strength is high and has less variation in strength.

Comparative Example 2 In Comparative Example 2, a predetermined amount of a round bar similar to the round bar used in Example 1 was cut out, and after heating and melting this round bar in a heating pot,
Push the round bar into a screw mold with a punch, and compress both ends of the round bar in this mold.1. Ta.

In this example, the round bar was pushed into the mold, and the round bar was not pulled out.

Composite molded products obtained by the methods of Example 1 and Comparative Example 2 described above were subjected to a screw tensile test,
The screw tensile strength was measured. In the screw tensile test, a nut with a standard diameter of 14 mm was fitted into the male screw part of the composite molded product obtained by each of the above-mentioned manufacturing methods, and the tensile test was conducted.

The results are shown in Table 1. The values in Table 1 indicate the average values of 30 test specimens.

(Hereinafter, blank space) Table 1 As is clear from Table 1, the screw tensile strength of the composite molded product obtained by the manufacturing method of Example 1 is stable and high with a tensile strength value of 25 kgf/mm” or more. In contrast, in the composite molded product obtained by the manufacturing method of Comparative Example 2, the screw tensile strength was as low as 24 kgf/mm" or less, and it varied in the range of 10 to 24 kgf/mm". occurred.

The reason why the thread tensile strength of the composite material molded product obtained by the manufacturing method of Comparative Example 2 was lower than that of the composite material molded product manufactured by Example 1 is that in Comparative Example 2, a round rod was placed in the mold. It is presumed that this is because a part of the fibrous material buckles when it is pushed in with a punch, and the high strength of the threaded fibrous material is not exhibited.

In Example 3, in place of the male threaded portion of Example 1, a tapered portion whose cross-sectional area gradually increases toward the end of the round bar is formed.

The mold device 8 used in Example 3 is as shown in FIG.
A mold is used in which a tapered inner circumferential surface 10a whose inner diameter gradually increases from the insertion hole job of the mold 10 to the right side in the figure is used. Taber inner peripheral surface 1 of the mold 10 in this case
0a has an inclination angle of approximately 5° with respect to the axial direction.

The steps of the manufacturing method are the same as those in Example 1, so the explanation thereof will be omitted.

The shape of the obtained composite molded product is as shown in FIG. That is, the axial end portions formed at both ends of the body of the round bar-shaped composite material molded product 11 are formed into tapered portions 12.13 whose outer circumferential diameters gradually increase toward both ends. The composite material molded article II obtained in this example is used as a joining part for joining to a fastening part such as a bolter.

In each of the embodiments described above, a round bar was used as the rod, but the rod of the present invention is not limited to this.

A square rod-vibrator or the like may also be used. Furthermore.

It is also possible to cut the male threaded portions 8, 9 of the composite material molded product 7 obtained in the above embodiment and use the cut male threaded portions 8, 9 as a star/nod port.

Although 6-nylon was used as the base material of the composite molded product in the above example, other thermoplastic resins such as 6.6-nylon were used.
Nylon, 12-nylon, polycarbonate, polybutylene terephthalate, polyethylene terephthalate,
Polyphenylsulfate or the like can be used.

As the long fiber material, glass fiber, carbon fiber, aramid fiber, etc. can be used.

Further, the present invention can be applied to not only composite molded products such as screw parts and bolt joint parts, but also fastening parts such as steel frame pars and transformer cores.

(Effects of the Invention) As explained above, according to the present invention, the ends of a rod-shaped composite molded product made of a thermoplastic resin and reinforcing long fibers are heated and melted, and then the long fibers softened by this heating are arranged. The end part is compression molded without disturbing the body part, so it is possible to mold fiber-reinforced composite molded products with complex shapes such as screws in a simple process. It has the advantage that it can be manufactured with

According to the manufacturing method of the present invention, when manufacturing a fiber-reinforced composite molded product using thermoplastic resin, the heating softening process and the compression molding process are manufactured as a series of continuous processes, so that the molded product can have a complex specific shape. This has the effect that fiber-reinforced composite molded articles can be manufactured with good workability.

[Brief explanation of the drawing]

Fig. 1 is a schematic sectional view showing an embodiment of the present invention, and is a schematic cross-sectional view for explaining the method of IJQing a composite molded product having a male threaded part, and Fig. 2 is a composite material obtained by the method shown in Fig. 1. Fig. 3 is a schematic cross-sectional view for explaining the method for manufacturing a composite molded product with a tapered part, and Fig. 4 shows a composite material obtained by the method shown in Fig. 3. It is a front view showing a molded product. 1...Mold device, 2...Round bar, 3...Screw mold, 3a...Threaded part, 4...Heating pot,
5...Punch, 7...Composite molded product, 8.9...Male thread part.

Claims (3)

[Claims] (1) A rod-shaped composite molded product made of thermoplastic resin and reinforcing long fibers, where the cross-sectional area of the end of the rod-shaped composite molded product is set to be larger than or equal to the cross-sectional area of the body. A fiber-reinforced composite molded product characterized by: (2) The fiber-reinforced composite molded article according to claim 1, wherein the end portion has a male screw portion. (3) A rod is formed from thermoplastic resin and reinforcing long fibers arranged in the axial direction, at least one end of this rod is heated with a heating device to soften it, and then the rod is drawn into a mold. A method for manufacturing a fiber-reinforced composite molded article, characterized in that the one end is compression-molded in the axial direction, and then cooled and solidified.