| 摘要 |
<p>PROBLEM TO BE SOLVED: To perform fusion of an electro-fusion joint of a large diameter by the use of normal generator and connector without requiring a large amount of energy, supply sufficient electric energy by the use of a large-sized power generator, and prevent melting of the joint and a synthetic resin pipe. SOLUTION: A reception port of an electro-fusion joint 1 into which a synthetic resin pipe 2 is inserted is divided into plural fusion areas A to D. Heating wires are independently embedded in the fusion areas A to D in the form of coils. The terminals of all the wires are arranged in plugs 4. When a connector 6 is inserted into the plug 4 and current is carried, the current reaches first to the wire in the area A, and an inner peripheral surface of the area A is heated and melted. After a specified time of current carrying, the current reaches sequentially the areas C, B, D. Power and current carrying time to be controlled by a controller 5 is decreased step by step.</p> |
