Slitter and slitter control program

A slitter comprising:

• a plurality of slitter heads arranged along and positionally adjustably in a width direction perpendicular to a conveyance direction of a corrugated paperboard, each of the plurality of slitter heads including a circular slitter blade and a drive motor for rotating the slitter blade;
• a blade radius acquisition unit operable to acquire respective radii of the plurality of slitter blades;
• and
• a control unit operable, based on the radii of the plurality of slitter blades acquired by the blade radius acquisition unit, to control respective rotational speeds of the plurality of drive motors so as to allow respective blade edges of the plurality of slitter blades to have a same circumferential speed,
• wherein the control unit includes:
• a reference circumferential speed acquisition section operable to acquire a reference circumferential speed of the blade edge of each of the slitter blades;
• a command speed calculation section operable, based on the radii of the plurality of slitter blades acquired by the blade radius acquisition unit, and the reference circumferential speed, to calculate respective command speeds for the plurality of drive motors;
• and
• a speed control section operable, according to the calculated command speeds, to control the respective rotational speeds of the plurality of drive motors, and
• wherein the reference circumferential speed acquisition section determines the reference circumferential speed in such a manner that the reference circumferential speed is a speed calculated from the conveyance speed of the corrugated paperboard, while the conveyance speed of the corrugated paperboard is equal to or greater than a predetermined conveyance speed, and the reference circumferential speed is a fixed predetermined circumferential speed while the conveyance speed of the corrugated paperboard is less than the predetermined conveyance speed.