JPS645729A - Electric discharge processing machine - Google Patents

Abstract

PURPOSE:To suppress the distortion of a column minimum by controlling the difference of the current value from a movement command value to an electrode rise/fall speed control device, i.e. droop amount, sensing the distortion of column, and by controlling the rise/fall speed. CONSTITUTION:An electrode rise/fall command is given by a memory 7 through a memory 2 at every unit time to move a table 12 or an electrode 16 with a motor 8, and the actual moving amount is measured by an encoder 9 to be stored in a memory 1. A device 3 makes cumulative calculation of the deviation of the memories 1, 2, and a comparator 5 compares it with the allowable value of a memory 4, and if below the allowable value, a device 6 adds the stored data in the device 3 to the data in memory 2, and the result is forwarded to the memory 7. When the allowable value is exceeded, on the other hand, the stored data in the device 3 is forwarded to the memory 7, and next data input to the memory 2 is stopped, and moving command speed for electrode 16 is decreased. Thus the distortion of column 14 is suppressed minimum, and interpolar discharge products are exhausted quickly to lead to stabilization of the processing condition.