| 摘要 |
PURPOSE:To carry out unmanned operation at a high machining rate for a long time, by coating a power feeding element which is made into contact with a workpiece by a spring in a conductor attaching board, onto a permanent magnet with the use of arc-resistant alloy. CONSTITUTION:A conductor element 13 which is made into contact with, by means of a spring 14, the inside of a conductor element attaching board 12 attached to a nozzle 4 held in a holder 3, is coated onto a permanent magnet 13a with the use of wear-resistant alloy 13b such as, for example, Cu-W, Cu-G, Ag-W or Cu, and a power source circuit 19 is connected at its one end with the conductor element 13 and the other end with the feed terminal of a conductor pin 16 so that an electrical discharge circuit is established. A conductor ring 13 is surely abutted against a workpiece 17 under the attracting force of the permanent magnet 13a and the resilient force of the spring 14, and therefore, power supply for the above-mentioned workpiece 17 is surely made. |
