| 摘要 |
PURPOSE:To eliminate any faulty operation of the driller in the caption caused by disturbance such as mechanical vibration and the like so as to enhance the machining reliability of the driller by designing the driller in such a type as to perform cutting control only during a cutting feed mode. CONSTITUTION:The fast feed command of a cutting shaft motor 1 applied to a motor driving device is changed over to a cutting feed mode on the way. At the same time of the changeover, a reset signal 9 applied to an overload detector 7 is released so as to enable torque detection. In the case of a torque value at the time of drilling beyond a preset threshold value, an overload command is outputted from the detector 7 to a positioner 3. On the basis of the command, the reverse command of the motor 1 is outputted from the positioner 3 to a driving device 2, and simultaneously, the reset signal 9 is outputted to the overload detector 7 once more. In this way, a torque signal is taken in only at the time of the cutting feed, while it isn't taken in at the other time of fast feed and regression so that it is possible to previously prevent any faulty operation of a driller caused by disturbance such as mechanical vibration and the like. |
