| 摘要 |
PURPOSE:To prevent a punch-shaped member (member to be cut off) from slanting and falling even at the time of finishing the machining by a method wherein the punch-shaped member is helt by a holding means fitted rotatably to a work. CONSTITUTION:In advance to electric discharge machining, a pin 19 and a holding plate 20 are set at the substantially central portion of the predetermined position at which a punch-shaped member 7c is to be machined. Then, with a wire electrode inserted into an original hole 18 and with the machining started, an upper machining solution nozzle 9a comes into contact with the side surface of the holding plate 20, and the nozzle 9a continues pressing the holding plate 20 until the machining is completed. At the time of completion of the machining, therefore, the holding plate 20 suspends the punch-shaped member 7c in the state of being bridged at its both ends on die-shaped member 7d, thereby preventing the punch-shaped member 7c from falling. In addition, even immediately before the completion of machining, the holding plate 20 prevents the punch-shaped member 7c from slanting. |
