JPS597029A - Preparation of synthetic resin rod reinforced by metal tube - Google Patents

Abstract

PURPOSE:To obtain the titled rod-like product which is light, rigid, excellent in corrosion resistibity and useful for construction, etc., by such an arrangement wherein a plug stopper is provided in the internal wall of two adjoining metal tubes respectively, and a plug-like body is inserted into the metal tubes and the outer circumference of the metal tubes and the plug-like body are continuously extrusion covered with synthetic resin, and then the plug is cut off at its middle point. CONSTITUTION:A plug stopper 2 is protrudingly provided on the internal wall of two adjoining metal tubes 1 respectively, and a plug-like body made of synthetic resin 3 having such an outer diameter suitable to be inserted into the metal tube 1 is inserted between the ends of the two adjoining metal tubes 1 until it is held by the plug stoppers 2 and the outer circumference of the metal tubes 1 and the plug-like body 3 are continuously extruded with synthetic resin and by this, a synthetic resin covered layer 4 is formed, and the titled synthetic resin rod-like product is obtained by cutting the plug-like body 3 at its middle point. It is also possible to use such a method that a hole 5 is drilled in the metal tube 1 and a small rod is inserted a hole 5 is drilled in the metal tube 1 and a small rod is inserted into the hole 5 and fixed and the rod is used as a plug stopper 2.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a synthetic resin rod reinforced with metal tubes.

Synthetic resin rods, which are made of a metal tube as a core material, sealed at both ends, and coated with synthetic resin on the outer periphery, are relatively lightweight, strong, and have excellent corrosion resistance, and are widely used as structural materials for construction, agriculture, fisheries, and fisheries. The manufacturing method for this rod-shaped object is to insert a synthetic resin plug between the ends of adjacent metal tubes in series, and to cover the metal tube and the plug with molten synthetic resin by extrusion, cooling and assimilating the ends. After that, a method is used in which the plug is cut in the middle to obtain a rod-shaped object with a sealed end.When using this method, the plug is inserted into a metal pipe and the position is fixed. Generally, the body of the stopper has a diameter V1, which is approximately equal to the outer diameter of the metal tube, and has a step and a flange at the end that is fitted into the tube so as to come into contact with the end surface of the metal tube.

However, when covering with molten synthetic resin using the above-mentioned plug, the fusion between the molten synthetic resin and the plug may be incomplete, and moisture may enter through this gap, causing corrosion of the metal pipe. This also causes damage when the end of a stick is struck and driven into the ground.

The inventor of the present application believes that the cause of the defective fusion described above is due to the presence of air remaining between the molten coating synthetic resin and the plug, and the relative relationship between the heat capacity of the plug and the amount of heat held by the molten synthetic resin. They discovered something and completed the present invention.

The object of the present invention is that the plugs at both ends of the synthetic resin rod are integrally fused with the coating synthetic resin without any gaps, and there is no risk of corrosion etc. The purpose is to provide a method.

The gist of misfire 1 river is to fit a synthetic resin stopper between the ends of both adjacent metal pipes, cover the outer periphery of the metal pipe and the stopper with synthetic resin by extrusion, and then cut the middle part of the stopper. In the method of manufacturing a synthetic resin rod-shaped article, a stopper is provided on the inner wall of a metal tube (the stopper is protruding from the inner wall of the metal tube), and a stopper having an outer circumferential diameter that can be obtained by fitting into the metal tube is inserted into the metal tube, and the stopper is engaged with the stopper. In other words, a synthetic resin stopper with both ends having a cross-sectional shape that is almost the same as the internal cross-sectional shape of the metal tube is inserted into the metal tube, and the stopper is inserted into the stopper that protrudes from the inner wall of the metal tube. The end surfaces of the plug are brought into contact and brought into contact.

By making the diameter of the plug body approximately equal to the inner diameter of the metal tube or narrower, the heat capacity of the plug body, which is proportional to the volume of the plug, is increased compared to the conventional case where the diameter of the plug body is equal to the outside diameter of the metal tube. greatly reduced. In addition, as the coating with the molten resin progresses, the air between the molten coating resin and the body is continuously expelled through the inner and outer surfaces of the metal tube that follows, and there is no intervening air layer. The FIIi between the plug bodies (-) is dramatically increased.

Note that at least one annular groove or a spiral groove can be provided in the body of the plug body, and the molten synthetic resin can be introduced into the groove to further strengthen the fusion bond.

In addition, the stopper may be made equal to the inner diameter of the metal pipe as described above, or may be made thinner over the entire outer circumference of the stopper or a part of the outer circumference, such as by narrowing the center part as shown in Fig. 6. . Next, in the present invention, a stopper inserted into a metal tube is locked with a stopper provided protruding from the inner wall of the pipe.

As a first example, Fig. 1 is a front view from the end between the metal pipes, and Fig. 2 shows a longitudinal cross-sectional view of the plug body covered with molten synthetic resin after the plug body has been inserted. A metal protrusion is removed by welding or the like on the inner wall of the pipe 1 to form a stopper 1-flange 2, and the end surface of the stopper 3 abuts and locks on this protrusion.4. indicates a synthetic resin coating layer.As a plug stopper, as shown in Fig. 3, the plug stopper 2 may be formed by strongly pressing the pipe wall in spots from the outer circumference of the metal pipe and protruding the corresponding portion from the inner wall. In this figure 3, there are four places, but any number may be used, and the stopper may be formed by pressing and squeezing it into an annular shape and forming an annular protrusion on the inner wall to form a stopper. As shown in FIG. 5, a long thin tube wall piece made by making a vertical cut at the end of the metal tube is bent inward to form a plug stopper 2, and a through hole 5 is drilled through the metal tube as shown in FIG. Then, you can fix a rod through this through hole and use it as a plug stopper, and the rod can be passed through to the opposite wall of the pipe as shown in the figure. It is possible to use a thermosetting resin material having sufficient strength to hold the material.

Although the plug stopper has been illustrated above, the plug stopper is not limited to these, but in short, it can be anything that protrudes from the inner wall of the metal pipe, comes into contact with the end surface of the plug, and locks the stopper. good.

Since the present invention has the above-mentioned configuration, the heat capacity of the plug is smaller than that of the conventional one, and there is no remaining air layer between the covering synthetic resin and the plug, so the fusion strength between the plug and the covering synthetic resin is dramatically increased. It is possible to prevent poor fusion.

Also, the plug body and coating are synthesized! Since it is integrally fused with the oil, the mechanical strength of the end of the rod increases, which is convenient when driving it into the ground.

[Brief explanation of drawings]

Fig. 1 is a front view from the open end of a metal tube provided with a collar on the stopper S1 used in the present invention, Fig. 2 is a longitudinal cross-sectional view of the stopper after being coated with synthetic resin, and Fig. 3 5 to 5 are partially cutaway perspective views of a metal tube provided with another stopper, and FIG. 6 is a longitudinal sectional view of the stopper when a stopper of another shape is used. 1...Metal pipe, 2...Bung stopper. 3...Plug body, 4...Synthetic resin coating layer, 5...
・Through hole. Patent applicant Zeon Kasei Co., Ltd. Patent attorney Keiji Matsunaga

Claims (1)

[Claims] 1. A synthetic resin rod is made by inserting a synthetic resin stopper between the ends of two adjacent metal tubes, continuously extruding the outer circumference of the metal tube and the stopper with synthetic resin, and then cutting the middle part of the stopper. A method of manufacturing a metal product, characterized in that a stopper is provided protruding from the inner wall of a metal tube, and the stopper has an outer circumferential diameter that can be fitted into the metal tube, and the stopper is inserted into the metal tube and locked with the stopper. A method for producing synthetic resin rods reinforced with tubes.