| 摘要 |
A vector control processor performs speed loop processing to obtain a torque command (Tc). It is also adapted to carry out (S4, S7) a vector control operation in accordance with a magnetic flux command (phic), which is set to a predetermined constant level (CF), when it judges that the main shaft motor is driven in a contour mode. Irregularity in speed of the motor and vibration which are ascribed to a delay of the actual magnetic flux in the main shaft with respect to the magnetic flux command are prevented to enable contour machining to be carried out. In a normal speed control mode or a tool change orientation mode, a vector control operation is carried out (S4-S6, S8) in accordance with a torque command (Tc) and its maximum value (Tcmax) a maximum mnetic flux command (phicmax) determined according to the rotational speed of the motor. A magnetic flux command (phic) is determined on the basis of a minimum magnetic flux command (NRphicmin, ORphimin). |
