| 摘要 |
PROBLEM TO BE SOLVED: To allow a torque desired by a main drive motor to approach a load torque by applying a control current to a regenerative brake motor while the control current is changed to a value in accordance with the load torque. SOLUTION: When a load torque competes with a spindle 1, that is, its value is sufficiently large, an output is delivered from a speed control part 14, having a sign with which a motor side torque is generated from a main drive motor 4, that is a positive sign. In this phase, no action is taken for a second current control part 12 for a regenerative brake motor 5 due to the operation of a proportional control element 14 (an output value of current on a side where a speed deviation is positive is zero), and the torque of the regenerative brake motor 5 is generated only by a current instruction set in a first current setting unit 18 in which a lower limit value of current is set for always applying a pressure higher than a predetermined value to a second decelerating device 3. |
