| 摘要 |
PURPOSE:To increase a braking torque instruction by a quantity corresponding to the internal loss of an armature, when the result of addition of a set torque and a negative inertia compensation torque in acceleration is positive, by judging the polarity of the result of the addition. CONSTITUTION:An unwinding core 1, center rollers 2 and a winding core are provided. The acceleration and deceleration compensation torque of a motor 4 for driving the unwinding core 1 is zero. The tension of an unwound and wound material is controlled on the basis of a set torque 1/2.TD determined from a tension T set by a tension setting unit 13 and a core diameter D computed by an unwinding core diameter calculator 14, so that a braking torque is sent out. When the motor 4 is shifted from a constant-speed stationary state to acceleration or deceleration due to some cause, an inertial force is caused due to the moment of inertia of the unwinding core 1 and the motor 4 so that a phenomenon equivalent to the superposition upon the preceding set torque takes place. An actual torque instruction is thus increased or decreased by the inertial force. |
