| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide the manufacturing method of an electric heating coil body and an electric fusion joint which does not move an electric heating wire at the time of injection molding, has excellent safety at low cost and gives an electric fusion joint uniform in heating, and provide an electric fusion joint. SOLUTION: This heating coil body is composed of a thin wall resin cylindrical body 10 and an electric heating wire 20, a spiral recessed groove 11 and a linear recessed groove 12 crossing the recessed groove 11 are formed on an outer surface of the resin cylindrical body 10, the electric heating wire 20 is inserted from one end side of the resin cylindrical body 10 to the other end side along the spiral recessed groove 11, the electric heating wire 20 which reaches the other end side is folded, and is inserted from the other end side to one end side along the linear recessed groove 12. In the electric heating wire 20, a heating wire 21 is formed in a spiral shape, and an heating wire 22 is folded linearly. The heating coil body is disposed in a mold, fused resin is injection-molded in a cavity through a gate so as to provide an electric fusion joint.</p> |
