| 摘要 |
PURPOSE:To perform spinning work while controlling the NC driving part of a working tool, by converting a signal given by an AE sensor provided on the working tool into effective value voltage and detecting failure of a blank material by comparing the effective value voltage and the range of failure limit AE effective value voltage of the blank material. CONSTITUTION:When spinning work is in progress normally, an AE sensor detects AE oscillation waveform for a material 2 caused by a working tool 4 of low level as shown in a figure, and sends it to a processing circuit 6. However, at the moment of failure of the material 2, the sensor detects much higher AE oscillation waveform (b) compared with the level when failure does not take place, and sends it to the circuit 6. This signal is passed through an amplifier circuit 8, an AE measuring circuit 9, a frequency separation circuit 10, an effective value voltage converting circuit 11, a peak holding circuit 12 etc., and compared with predetermined range of AE effective value voltage in the failure limit by a comparing device using a comparator, etc. When the AE signal is within the range of the failure limit AE effective value voltage, it is judged as failure, and the work is emergently stopped or the working tool 4 is detached by operating the NC driving section 7 of the working tool 4. |
