Apparatus for cutting a plate into a predetermined size

An apparatus for cutting a plate into a predetermined size comprising:

• knife cylinders for cutting said plate at a selected cut length, said knife cylinders being rotatably driven through a series of rotational angles by a plurality of motors, said motors driving said knife cylinders at a rotational speed;
• a reduction gear mechanism for reducing the rotational speed of said motors and for outputting a comprehensive torque from said motors to said knife cylinders;
• means for moving the plate toward said knife cylinders at a moving speed;
• set means for setting the cut length for the plate and for outputting a cut length command signal;
• plate moving speed detection means for detecting the moving speed of said plate and for generating a plate moving speed signal;
• knife cylinder rotational angle detection means for detecting the rotational angle of said knife cylinders and for outputting a rotational angle signal;
• motor speed command signal generation means for generating a rotational speed command signal in response to the cut length command signal, the plate moving speed signal and the rotational angle signal;
• motor speed detection means for detecting the speed of said motors and for outputting a rotational speed detection signal;
• and
• speed control means for controlling speed of said motors in response to the rotational speed command signal and said rotational speed detection signal, said speed control means comprising,
• a speed compensator for receiving the rotational speed command signal from said motor speed command signal generation means and for receiving the rotational speed detection signal from said motor speed detection means, and for outputting a torque command signal,
• motor torque detectors associated with each of the plurality of motors, said motor torque detectors detecting torque of the associated motor and outputting a torque detection signal in response thereto for its associated motor,
• torque compensators associated with each of the plurality of motors, said torque compensators receiving said torque command signal from said speed compensator and receiving the torque detection signal for its associated motor and outputting a motor armature voltage command signal in response thereto for its associated motor, and
• power amplifiers for each of the torque compensators, said power amplifiers receiving said motor armature voltage command signal from its associated torque compensator and for driving the motor associated with its torque compensator in response to the associated motor armature voltage command signal.