| 摘要 |
PURPOSE:To make highly efficient machining attainable, by setting the charging voltage of a discharging condenser to a level of being below the supply voltage, while connecting a power source to a work and a wire electrode gap for the specified period long in time of discharging, in case of a working power unit for an electric discharge machining device. CONSTITUTION:A power reducing device, which checks the charging voltage of a discharging condenser 9 down to a level of being below the supply voltage, and a connecting device, which connects a power source to a work and a wire electrode gap for the specified period long in time of discharging, both are installed in an electric discharge machining device. That is to say, discharge voltage for the discharging condenser 9 is downed to some extent by partial resistors 16 and 17 so as to be charged with lower voltage than a DC power source 15 whereby discharge for an electrode gap is detected by a machining state detecting circuit 24. With this detection signal, a pulse control circuit 22 is set in motion, while switching elements 18 and 20 are made into the specified short time conducting state, and the DC power source 15 is connected to the work and the wire electrode. Therefore, such a large discharge pulse is securable without making the discharge voltage higher, so that highly efficient machining is performable. |
