抄録
It is known that tool-work thermo-electromotive force (E.M.F.) includes the information on chip treatment or vibration frequency in turning. On the other hand, in case of interruptive cutting, reports on E.M.F. which aim to use the signal for monitoring tool failure are few. The present paper deals with a relation between tool wear of face mill and thermo-electric characteristics. Wave form of electric voltage and current in the workpiece which is caused by E.M.F.were observed and analyzed. The results obtained are as follows. In case of single tooth cutting, the rise time of E.M.F.is prolonged in accordance with the width of tool flank wear. In case of double tooth cutting, the wave form of composite E.M.F. at the time when the second tooth begins to cut is changed widely in accordance with the tool wear.Also electric current in the tool-workpiece closed circuit increases remarkably due to tool wear. This phenomenon is remarkable in light cutting. Theoretical analysis shows that main factor influenced is the change of junction electric resistance due to tool wear.
