Method for pattern controlled electrode movement for E.D.M.

Claim 1

An electro-discharge machining method for progressively conducting precise machining through relative approach movements between an electro-discharge machining electrode and a workpiece in the horizontal direction substantially perpendicular to a direction in which said electrode is opposed to said workpiece, which method is characterized by generating basic movement patterns for said relative approach movements, dividing a movement region of said relative approach movements within the horizontal plane into respective sections, designating desired patterns in said basic movement patterns to the respective sections, designating step amounts for actual relative approach movements in the respective sections, computing actual trajectories for said actual relative approach movements based on designated patterns and designated step amounts and storing data of said actual trajectories, and carrying out relative approach movements in accordance with stored data, wherein said carrying out comprises generating a voltage-controlled pulse signal having a frequency corresponding to a voltage across a machining gap, and controlling a reading-out speed of stored data according to said voltage across said machining gap.