JPH1163355A - Electrofusion type plate shaped cap - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify structure for facilitation of handling so as to reduce production costs by embedding an electric heating body in the part, with which an opening end face of a resin tube is brought into contact, on a plate type object face whose dimension is large enough to cover the opening part of the resin tube completely. SOLUTION: The subject cap is constructed of a disc type resin plate 1 whose dimension is large enough to cover an opening part of a resin tube 3 completely, and the resin plate 1 is made of the same kind of resin as that for the resin tube 3 to be closed. A band type electric heating body 2 is embedded in the resin plate 1 in the position, with which the opening end face of the resin tube 3 is brought into contact when the opening part of the resin tube 3 is covered with the resin plate 1, and both end parts of the electric heating body 2 are exposed from the side wall of the resin plate 1 for application of electric current. When the opening part of the resin tube 3 is covered with the resin plate 1 and electric current is applied to the electric heating body 2, the part, in which the electric heating body 2 is arranged, in the resin plate 1 and the opening end face, which touches this part, of the resin tube 3 are fused together, so that the resin tube 3 is closed airtightly. In this way, an electrofusion cap, whose structure is simplified to the extent to which workability is not inhibited, can be produced at low costs.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrofusion cap for hermetically closing a resin tube made of polyethylene, polybutene or the like.

[0002]

2. Description of the Related Art In recent years, resin pipes, such as polyethylene pipes for gas and polybutene pipes for hot water supply, which are lightweight, have excellent corrosion resistance, and are flexible and resistant to earthquakes, have rapidly become widespread. Correspondingly, the demand for an electro-fusion cap for hermetically closing such a resin tube has been increasing.

[0003] Generally, as seen in Registered Design No. 841163 and Registered Design No. 938875, the electrofusion cap is formed of the same kind of resin as the resin tube to be closed, and has a cylindrical shape with one end closed. A heating wire is embedded in the inner surface or the outer surface of the cylindrical wall to melt the resin and fuse it with the resin tube. The production is often performed in a complicated process such as producing an inner by injection molding, wrapping a heating wire around the inner surface, and injection-molding an outer around the inner wrapped with the heating wire.

[0004]

Recently, with the spread of electrofusion caps, the use of electrofusion caps has increased in narrow places such as indoor ceilings and under floors, and the work of manually covering or inserting cylindrical caps has been performed. Is not easy to do. Further, there is a need for a device that is as inexpensive as possible in terms of cost.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an object of the present invention is to provide an electrofusion cap having a structure simple enough to be easily handled and which can be manufactured at low cost.

[0006]

The object of the present invention is to provide a plate-like object formed of the same kind of resin as a resin tube to be closed and having a size capable of completely covering an opening of the resin tube. The problem is solved by an electrofusion-type plate-like cap in which an electric heating element is embedded in a portion on the plate-like material surface where the opening end surface of the resin tube comes into contact when the opening of the resin tube is covered with the plate-like material.

[0007] The shape of the electrofusion cap formed of the same resin as the resin tube to be closed is formed into a plate having a size capable of completely covering the opening to be closed of the resin tube. If the electric heating element is embedded in a portion on the plate-like object surface where the opening end face of the resin pipe comes into contact when covering the opening of the resin pipe with the above, the plate-like object covers the opening of the resin pipe and becomes an electric heating element. When the electric current flows, the portion of the plate-shaped object where the electric heating element is provided is fused to the opening end surface of the resin tube in contact with the portion, so that the resin tube is airtightly closed. Since it is a plate-like object, its structure is simple, and it can be easily handled even in a small space.

Further, an electric heater is applied to the surface of the resin plate, and a current is applied to the electric heater to melt the plate surface and embed the electric heater, or is heated in a spot by another means to partially adhere to the plate surface. The production cost can be significantly reduced as compared with the case of the conventional cylindrical electrofusion cap.

If the plate is formed into a disk and its outer diameter is made substantially equal to the outer diameter of the opening of the resin pipe to be closed, the shape can be minimized, so that the handling properties are further improved and the cost can be reduced. become. Further, since the outer diameter is substantially equal to the outer diameter of the opening end of the resin tube, it is possible to easily cover the opening of the resin tube by groping.

[0010]

FIG. 1 shows an embodiment of an electrofusion type plate cap according to the present invention. A strip-shaped electric heating element 2 is embedded in a disk-shaped resin plate 1, and both ends of the electric heating element 2 are exposed from a side wall of the resin plate 1 for energization.

FIG. 2 shows another embodiment of the electrofused plate cap of the present invention. Although the basic structure is the same as that of FIG. 1, the center of the resin plate 1 is raised with an outer diameter substantially equal to the inner diameter of the opening of the resin tube so as to easily match the opening end of the resin tube. In addition, a linear electric heating element 2 is provided at a portion around the raised portion, that is, at a portion in contact with the opening end surface of the resin tube.
Is provided.

FIG. 3 schematically shows a state in which the resin tube is closed using the electro-fused plate cap of FIG.

The raised portion at the center of the resin plate 1 is inserted into the opening of the resin tube 3 so that the surface in which the electric heating element 2 is embedded is brought into contact with the opening end surface of the resin tube. Then, the resin at the portion where the electric heating element 2 is embedded and the resin at the opening end face of the resin tube 3 are fused, and the resin tube 3 is closed with good airtightness. In this case, if an electric heater is also provided on the side surface of the raised portion,
The fusion of the cap and the resin tube can be performed more reliably.

As the electric heating element, a nichrome wire, a carbon fiber sheet or the like can be used. Further, the electric heating element may be heated by a dielectric heating method without energization.

The electrofusion-type plate cap of the present invention can be manufactured by preparing a resin in which a heating wire is embedded in the same kind of resin as the resin tube in advance, and attaching this to the surface of the resin plate.

[0016]

Since the present invention is constructed as described above, it is possible to provide an electrofusion cap which has a simple structure so as not to impair workability and can be manufactured at low cost.

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of the present invention.

FIG. 2 is a diagram showing another embodiment of the present invention.

FIG. 3 is a schematic diagram when a resin tube is closed using the electrofusion-type plate-like cap of FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Resin plate 2 Electric heating body 3 Resin tube

Claims (2)

[Claims] 1. A plate-like object made of the same kind of resin as a resin tube to be closed and having a size capable of completely covering an opening of the resin tube. An electrofusion-type plate-like cap in which an electric heating element is embedded in a portion on the surface of the plate-like material, which is in contact with an opening end surface of the resin tube when the opening is covered. 2. The electrofusion-type plate-like cap according to claim 1, wherein said plate-like object is a disk, and an outer diameter thereof is substantially equal to an outer diameter of an opening of said resin tube.