Measurement of Wire Deflection in Wire-cut EDM Machining

摘要

It is well understood that the wire electrode is flexible and leads to a big lag in cutting, especially in the middle part of the wire. Measurements of the deflection of wire when it passes through the workpiece are studied in this paper. It is found that there is discharge spark first at the upper and lower parts of the wire when it cuts to the edge of the workpiece. The discharge spark appears at the middle part of the wire a few seconds later. Based on this result, a method coined Camera Picture Analysis (CPA) is proposed to estimate the wire lag. A digital camera is used to capture the time difference of the sparks between the upper part and the middle part of the workpiece. Another method of cross section measurement by the CCD is proposed to make a cross reference with the CPA method. Applying these two methods, the wire deflection models can be established, and used for the corner cut control of wire-cut EDM to improve accuracy of the machined part.