Electric upsetting device with anvil electrode - includes electrode positioned in cavity within shaping die into which metallic member is inserted and second electrode is connected

摘要

The tubing P is inserted into a shaping die (3) to butt, at its one end face, an anvil electrode (1). An electrode (2) is contacted with the tubing P and electric current is caused to pass across the two electrodes. The portion P' of the tubing P between the electrodes becomes softened by generation of heat. In this state, when the tubing P is pushed in the arrowed direction, the portion P' swells to contact the inner surface of the die. As the inner surface of the die is covered with an insulating layer (5), the electric current always flows in the portion P' alone. Thus, the end part of the tubing P becomes sufficiently softened by the heat generation. It is readily deformed by pressure at the time of pushing to be upset until the end part is completely solid.