MOTOR TORQUE CONTROL METHOD FOR PRESS MACHINE AND PRESS MACHINE

摘要

A torque command Tc is limited to a torque limit value Tm' by a torque limiting means (2) and supplied to the current limiting means (3) of a motor. The torque limit value Tm' is the sum of a torque limit value Tm corresponding to a target press force (F) and a torque limit correction value DELTA Tm which is calculated by a torque limit correction value calculating means (7). The torque limit value DELTA Tm is given in accordance with the acceleration when a motor is accelerated or decelerated. The acceleration is calculated from a feedback velocity Vf from a speed sensor (6) and a command speed Vc. Alternatively, the acceleration is calculated from the output of an observer to which a torque command Tc' given to the current control means (3) of the motor and the feedback speed Vf are inputted.