Kazuyuki Nagatomi

To examine the possibility of monitoring the tool wear of spur machine-bits by the cutting sounds, the relationships between the amounts of tool wear and the sound pressure levels of cutting sounds were investigated in the machine boring of six work materials: particleboard, MDF (medium density fiberboard), hinoki (Chamaecyparis obtusa Endl.), kuri (Castanea crenata S. et Z.), lauan (Shorea sp. (Sabah)), and western hemlock (Tsuga heterophylla Sarg.). In this work, sound pressure levels decreased remarkably with increases of the amounts of tool wear in the frequency ranges of 10 kHz-12 kHz or 8 kHz-10 kHz for each work material. The absolute values of regression coefficients and coefficient correlations in the regression line showing the relationships between sound pressure levels and the amounts of tool wear in these frequency ranges are extremly large compared with those in the frequency ranges of 10 Hz-20 kHz and 10 kHz-20 kHz and the other frequency ranges dividing 20 kHz into 2 kHz widths. From these experimental results, measuring sound pressure levels of cutting sounds in the specific frequency range above-mentioned is considered to be a promising way for monitoring tool wear of spur machine-bits.