| 摘要 |
PURPOSE:To aim at reducing the inherent inductance of lead wires during high- speed electric discharge machining, by laying the lead wires in bundles from a machining power source to a machining gap, and as well by connecting one of the connecting branched terminals of lead wires in each bundle to an energizing bin and the other terminal to an energizing brush. CONSTITUTION:The discharge voltage of a charge capacitor 29 is changed into intermittent pulses by means of a switching element composed of a transistor 30 which is turned on and off by a control circuit 30, and is applied to a terminal 34 associated with an energizing bin 18 that is made in contact with a wire electrode 3 and to a terminal 35 associated with a workpiece 5 through lead wires 36, 37. Lead wires 38 each consisting of two lead wires 36, 37 in a bundle have several single lead wires which are laid in parallel with each other, so that the directions of currents passing through each adjacent lead wires 36a, 37a are in opposite to each other so that generated magnetic force lines are cancelled out with each other to reduce the inductance generated by the magnetic force lines. Further, since an arranging section 28 in which the switching element is provided is positioned in the vicinity of the machining gap, a machining current having a large discharge peak and a short discharge time may be fed. |
