| 摘要 |
<p>PURPOSE: To securely detect a damage by emitting a minute tool damage alarm when the transient condition of the moving average of high frequency vibration signals of a cutting tool and low frequency signals related to a force acting on the tool is almost identical in time within a selected time interval. CONSTITUTION: The vibration of a cutting tool detected by a wide band accelerometer 50 passes a 30 to 70 kHz band filter 52, a double wave rectifier 53, a low band filter 54, and a sump hold circuit 55, the moving average of the vibration is calculated by a moving average calculation means 58 in a logic circuit 57, and the transient condition having a suspect of tool damage is detected by a judgment means 59. When its increase or decrease is over a specified value, a tool damage alarm is emitted. Also, the logic circuit 64 inputs signals related to a force acting on the tool detected by a low frequency accelerometer 51, and calculates the moving average by a moving average calculation means 65. When the logic circuit detects a suspect transient condition by a judgment means 66, it judges by a means 67 together with signals from the judgment means 59 whether it is within a time period or not. When the transient condition is present within the time period, it emits a tool damage alarm.</p> |
