| 摘要 |
PURPOSE:To secure safety and improve reliability in machine tools by preparing an automatic means which can detect tool damages, etc. in driving machine tools. CONSTITUTION:A moving coil type oscillation pickup 2, for example, is mounted on a drill 1 and the mechanical vibration due to the motion of a drill edge 3 is detected by the pickup 2. With the pickup 2 is connected a band pass filter 5 constituting a filtration mechanism through an amplifier 4 and therefore after the oscillating signals detected by the pickup 2 has been amplified in a suitable gain through the amplifier 4, the signals only having the predetermined frequency component, that is, the frequency of teeth number times rotation number of a drill is detected. When the drill teeth 3 are hurted the input signals to a comparison mechanism are sent nearly three times as many as in the normal occasion and accordingly the signals in abnormal states of a drill cutter 3 are securely detected and an alarm device, etc. is driven. |
