| 摘要 |
PURPOSE:To effectively use a power supply die and reduce a running cost, by forming an external shape of the power supply die in a polygonal shape and changing a contact position of the power supply die with an electrode wire at each rotary movement of the power supply die. CONSTITUTION:The external shape of a power supply die 2a is a polygonal shape, and the internal shape of a holder 3a is also formed in a polygonal shape. In the position of a contact point 16, as an electrode wire 1 passes a point contact condition disappears by gradually wearing the die 2a and the electrode wire 1. Accordingly, a contact condition with the wire 1 is corrected to the initial point contact condition by rotating the die 2a in the direction of an arrow head (a) in the drawing so as to move a vertex B to the position of a vertex A. In this way, the position can be surely changed in accordance with the polygonal shape by further rotating the die 2a to be moved in the direction (a) in each fixed angle, and a contact position of the die 2a with the wire 1 is also surely changed. |
