| 摘要 |
PURPOSE:To prevent reduction of the rate of operation in a machine due to its stop for a long time, by automatically decreasing a feed speed when vibration of the machine exceeds a preset value, releasing an abnormal load applied to a tool, and then gradually increasing the eed speed and resetting the feed speed to an initial speed. CONSTITUTION:A level of vibration is measured by a vibration measuring unit 17 mounted to a machine main unit, compared with a value preset to a vibration level setter 18 in a comparator 19 and indicated to a control circuit 21. If the level of vibration in a machine becomes at least the preset value, the control circuit 21 both starts a timer 16 and automatically changes an override value of a counter 22 to 50%. When the level of vibration is not decreased to not more than the preset value even after elapsed 1sec, an abnormal signal is fed to an NC device 10 to stop the machine, if the level of vibration becomes not more than the preset value, the override value of the counter 22 is increased every 10% at each 2.5sec in accordance with counting of the timer 16, and a feed speed is reset to an initial feed speed. |
