New NC Data Generating Method Including Tool Wear Compensation in ELID (Electrolytic In-Process Dressing) Grinding

Recent demands for ultraprecision machining has been for higher precision. The ELID grinding technique is widely known as a method which produces high precision ground surfaces in a short period of time.1) Aspherical optics, one typical example of super precision parts, require not only good mirror surface finish but also high form accuracy.2) But it involves considerable difficulty to achieve both good mirror surface finish and high form accuracy. The authors have proposed a new form control system for achieving high form accuracy regularly and efficiently in aspherical ELID grinding, and successful results could be obtained through some experiments3),4). But there had been some conditions, under which the profile errors could not converge because the radius of the grinding wheel decreased by the wear. This paper proposes a new form compensation method which can be applied to the condition under which the grinding wheel is much worn.