JPH02162021A - Manufacture of screw made of synthetic resin - Google Patents

Abstract

PURPOSE:To produce a screw made of the synthetic resin reinforced with long fibers and having the sufficient strength of screw thread by a method in which a rodlike reinforced stock is pushed into a stock on the axis of longitudinal direction, thereby exnpanding radially the stock, and thus, the screw thread is molded on the outer peripheral surface of the stock. CONSTITUTION:A member of long fibers 2 with high strength are contained in thermoplastic synthetic resin 1, and it is extrusion-molded of drawing molded, whereby a circular rodlike stock 3 is molded. Then, the long fibers 2 are arranged along the longitudinal direction of the stock 3. As the long fiber 2, for example carbon fiber is used. The stock 3 is cut into a prescribed length, and it is inserted into a mold 4, and then is softened under heating. A circular rodlike reinforced stock 8 is inserted under pressure into the stock 3 on the longitudinal axis. The stock 3 is expanded in radial direction, and the molded object 9 in which the stock 3 and the reinforced stock 8 are integrally made, and screw threads 9a, are formed, is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial Application Field" The present invention relates to a method for manufacturing a synthetic resin screw reinforced with long fibers.

``Prior art'' Screws made of synthetic resin have been widely used in cases where light weight and corrosion resistance are required, but screws made only of synthetic resin do not necessarily have sufficient strength as they are. Conventionally, reinforcement with long fibers such as carbon fibers has been carried out.

In order to manufacture screws reinforced with such long fibers, a cylindrical material is made from uncured resin containing long fibers, and after the resin is cured, the screw threads are cut. Methods are conventionally and commonly employed.

``Problem to be Solved by the Invention'' However, in such a method, the long fibers are also cut when cutting the screw threads, so the reinforcing effect of the long fibers is not fully exerted, and the screw threads are easily cut. The problem was that it was destroyed.

The present invention has been made in view of the above-mentioned conventional problems, and it is an object of the present invention to manufacture a synthetic resin screw reinforced with long fibers, which fully exhibits the reinforcing effect of long fibers and has sufficient thread strength. The purpose is to provide a method.

"Means for Solving the Problems" The method for manufacturing a synthetic resin screw of the present invention is a circular rod-shaped material made of a thermoplastic synthetic resin containing long fibers such as carbon fibers arranged in the longitudinal direction. is inserted into a mold, heated and softened, and then a rod-shaped reinforcing material is press-fitted onto the longitudinal axis of the material, which spreads the material in the radial direction and tightens the screw onto the outer circumferential surface of the material. It is characterized by the fact that the inside is formed.

"Function" In the method for manufacturing a synthetic resin screw of the present invention, the rod-shaped reinforcing material is press-fitted onto the longitudinal axis of the material, thereby spreading the material in the radial direction and enveloping the inside of the screw onto the outer peripheral surface of the material. Let it form.

At this time, the long fibers of the material remain within the screw over the entire length and are not cut. The long fibers on the outer periphery of the material are distributed so as to meander along the shape of the screw and enter the thread of the screw.

``Example'' An example of the present invention will be described below with reference to FIGS. 1 to 3.

First, a thermoplastic synthetic resin 1 contains a large number of high-strength long fibers 2, and is extruded or pultruded to form a circular rod-shaped material 3 as shown in FIG. 3. At that time, the long fibers 2 are arranged along the length direction of the material 3.

Here, as the thermoplastic synthetic resin 1, for example, PEEK (polyetheretherketone) resin which is lightweight and has sufficient strength can be used, and as the long fibers 2, for example, carbon fiber can be used.

Next, the material 3 is cut into a predetermined length, inserted into a mold 4 as shown in FIG. 1, and heated and softened.

Here, the mold 4 is used when manufacturing a headless screw, and is composed of a screw part molding mold 5, a head end face molding mold 6, and a guide 7, and includes a screw internal molding part 4! and a reinforcing material guide portion 4b.

Thereafter, as shown in FIG. 2, the round bar-shaped reinforcing material 8 is
The material 3 is press-fitted onto the longitudinal axis using a press-fitting device (not shown). As a result, the material 3 is expanded in the radial direction, and a threaded interior is formed on the outer peripheral surface. In this way, a molded product 9 in which the material 3 and the reinforcing material 8 are integrated and a threaded interior 9a is formed is obtained.

At this time, the long fibers 2 of the raw material 3 remain within the molded product 9 over the entire length and are not cut. Further, the long fibers 2 on the outer periphery of the material 3 meander along the shape inside the screw,
It is distributed so that it goes inside the screw mountain.

Here, as the reinforcing material 8, a high-strength material such as a wire or bar such as steel can be used, and the same material as the material 3 can also be used. The outer dimensions of the reinforcing material 8 are determined according to the size of the screw to be manufactured, etc. When the reinforcing material 8 is press-fitted, the material 3 is sufficiently expanded, and the molded part 4 inside the screw of the mold 4! Select so that it is sufficiently distributed throughout the country. Further, it is preferable that the tip of this reinforcing material 8 is made into an acute angle as shown in the figure.

Furthermore, after cooling and hardening the molded product 9, the reinforcing material 8 is cut along the end face A-A of the screw, and a slot etc. is formed on the end face by cutting or the like, thereby completing a headless screw.

According to the method for manufacturing a synthetic resin screw of this embodiment, as shown in FIG. 2, the long fibers 2 of the screw remain within the molded product 9 over the entire length and are not cut. In addition, the long fibers 2 on the outer periphery of the material 3 are distributed so as to meander along the shape inside the screw and enter into the screw threads, so that the long fibers reinforced with long fibers that have sufficient strength inside the screw can be used. Resin screws can be manufactured.

In addition, if a high-strength material is used as the reinforcing material 8, the high-strength material will be placed on the axis of the manufactured screw. A screw with higher strength against tension in the axial direction can be obtained compared to other screws.

In the above example, the reinforcing material 8 is longer than the length of the screw to be manufactured, and is cut after being press-fitted and integrated with the material 3. However, the length of the reinforcing material 8 is different from the length of the screw to be manufactured. They may be made equal and no cutting operation is performed.

In addition, two types of reinforcing material 8 are prepared: one for forming threads made of steel, for example, and one for forming threads made of the same material as material 3, and once the reinforcing material 8 is used for forming threads. After forming the inside of the screw by press-fitting, it may be pulled out, and the material for the material may be press-fitted and integrated.

Furthermore, a reinforcing material 10 and a mold 11 having a shape as shown in FIG. A headed screw 13 having an inner screw 13a and a head 13b may be formed by using the press ram 12 and performing the same operation as in the embodiment shown in FIGS. 1 and 2.

"Effects of the Invention" According to the method for manufacturing a synthetic resin screw of the present invention, the long fibers of the screw remain within the screw over the entire length and are not cut. In addition, the long fibers on the outer periphery of the screw meander along the shape inside the screw and are distributed so as to enter the thread threads, so synthetic resin reinforced with long fibers with sufficient strength inside the screw can be used. screws can be manufactured.

[Brief explanation of the drawing]

1 to 3 are views showing embodiments of the present invention, in which FIG. 1 shows a state in which the material is placed in a mold, FIG. 2 shows a state in which the material is molded, FIG. 3 is a perspective view of the material. Further, FIG. 4 shows a second embodiment of the present invention, and is a diagram showing a state in which the material is molded. 1...Thermoplastic synthetic resin, 2...Long fiber, 3...Material, 4.11...Mold,
8, 1O... Reinforced material, 9a, 13a...
...Inside the screw.

Claims (1)

[Claims] A circular rod-shaped material made of thermoplastic synthetic resin containing long fibers such as carbon fibers arranged in the longitudinal direction is inserted into a mold, heated and softened, and then A method for manufacturing synthetic resin screws in which a rod-shaped reinforcing material is press-fitted on the directional axis to spread the material in the radial direction and form thread threads on the outer circumferential surface of the material.