| 摘要 |
PURPOSE:To improve the sureness in the detection of chipping without being restricted by conditions of cutting tools and work pieces by detecting tool chipping from the shapes of the frequency spectra of the vibration of a tool rest. CONSTITUTION:The output of an acceleration pickup 12 is amplified by a charge amplifier 13, and is applied to an AD converter 18 via a 1/3 octave band pass filter, a logarithmic compressor 15, a rectifier circuit 16 and a smoothing circuit 17. The output of the AD converter 18 and the signal from an interface part 19 are applied to the input of a comparator 21, by which the steady cutting state by full band vibration levels is judged. When the state is judged to be a steady cutting state, the output is fed to a vibration frequency spectrum calculating circuit 22. In the circuit 22, vibration frequency spectra are determined and are outputted to a buffer circuit 23, by which frequency spectra are accumulated. In the comparator 24 connected to a buffer circuit 23, a reference data memory device 27 and a set value table memory device 28, the presence or absence of chipping by the comparison with the reference data is decided. |
