摘要 |
An EDM apparatus provided with an adaptive self-correcting system for achieving optimum maximum efficiency of machining operations. As the machining performance factor or index of an EDM apparatus continuously varies as a function of one of the machining parameters as, for example, the cut-off time interval between consecutive electrical discharges, such that the maximum performance index, achieved for a given optimum cut-off time interval, deteriorates rapidly when the cut-off time interval is shortened, thus resulting in poor and unstable machining conditions, the invention contemplates varying the cut-off time interval in successive steps, the steps being larger when operating along the negative slope portion of the representative curve of the performance index as a function of the cut-off time interval duration, and the steps being much smaller when operating within the portion of the representative curve having a positive slope. In addition, the invention contemplates reducing the steps to a much smaller value within a buffer or safety zone in the portion of the representative curve of negative slope proximate to the top of the curve.
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