摘要 |
A control apparatus includes a converter for converting an AC voltage to a DC voltage, a feed shaft motor inverter for converting the DC voltage to an AC voltage for a feed shaft motor, a main spindle motor inverter for converting the DC voltage to an AC voltage for a main spindle motor, a power outage detection unit for detecting a power outage of the AC power supply, a voltage detection unit for detecting the DC voltage, and a control unit which, upon power outage of the AC power supply side, outputs a feed shaft motor deceleration command to the feed shaft motor inverter and outputs, to the main spindle motor inverter, a main spindle motor acceleration command when a DC voltage is greater than an upper limit and a main spindle motor deceleration command when the DC voltage is less than a lower limit. |