| 摘要 |
PURPOSE:To prevent the generation of erroneous operation due to the shape of cutting chips by detecting the breakage of a tool when the max. density of the probability-density function at each prescribed time for the data obtained by sampling the output signals of an AE sensor amplifying circuit exceeds a prescribed level. CONSTITUTION:An AE sensor 7 detects the AE signal having a broad band of 1kHz-1MHz and inputs an output into a preamplifier 8, which amplifies said output and transmits it into a band-pass filter 9. Said filter 9 allows the AE signal having a frequency of 100-300kHz out of the AE signal supplied from the AE sensor to pass, and removes the noise component accompanied with the mechanical vibration, etc., and transmits the output to a rectifying circuit 10. Then, an A/D converter 11 converts the output of the circuit 10 to the digital data in a prescribed minute sampling cycle and inputs the output into a microcomputer 12. The computer 12 signal-processes the AE signal, and compares the result with a prescribed threshold level, and transmits a tool-breakage detection signal into a breakage detector 13 and further outputs the signal outside. |
