Method and device for adjusting heights of slitter blade

1. A method for adjusting a height of a circular slitter blade which slits a corrugated board web traveling continuously along a traveling direction of the corrugated board web while the corrugated board web being interposed between a receiving roll and the circular slitter blade, comprising the steps of:

rotating the slitter blade and the receiving roll such that an outer circumferential surface of the slitter blade and the receiving roll move in the same direction as the traveling direction of the corrugated board web, the slitter blade having a center that is located on a downstream side of a center of the receiving roll in the traveling direction of the corrugated board web;

emitting a light beam in a width direction of the corrugated board web to pass through a contact point of the outer circumferential surface of the receiving roll with the corrugated board web;

determining a height of the slitter blade at which the circular outer edge of the slitter blade intercepts the light beam while moving the slitter blade toward the receiving roll; and

setting the height of the slitter blade to the determined height as a slitting position.

2. The method for adjusting the height of a circular slitter blade according to claim 1 , wherein the light beam includes a laser beam.

3. The method for adjusting the height of a circular slitter blade according to claim 1 , wherein

the light beam is a diffusive light, and

The step of determining the height of the slitter blade includes: measuring an interception position where the circular outer edge of the slitter blade intercepts the outer edge of the diffusive light; and adding an correction value determined from a diffusion angle of the diffusive light to the measured interception position so as to determine the height of the slitter blade.

4. The method for adjusting the height of a circular slitter blade according to claim 1 , wherein

the light beam is a diffusive light,

the step of determining the height of the slitter blade includes: measuring an interception position where the circular outer edge of the slitter blade intercepts the outer edge of the diffusive light, the interception position being measured at a predetermined distance from a light source of the diffusive light in the width direction of the corrugated board web; calculating a diffusion angle of the diffusive light from the distance and the interception position; and adding an correction value determined from the calculated diffusion angle to the measured interception position so as to determine the height of the slitter blade.

5. A device for adjusting the height of a circular slitter blade which slits a corrugated board web traveling continuously along a traveling direction of the corrugated board web while the corrugated board web being interposed between a receiving roll and a circular slitter blade, the receiving roll and the circular slitter blade having outer circumferential surfaces that move in the same direction as the traveling direction of the corrugated board web, the circular slitter having a center that is located on a downstream side of a center of the receiving roll in the traveling direction of the corrugated board, the device comprising:

an emitting device which emits a light beam in a width direction of the corrugated board web to pass through a contact position of the outer circumferential surface of the receiving roll with the corrugated board web;

a light receiver which receives the light beam;

an actuator which moves the slitter blade close toward or away from the receiving roll;

a memory device which memorizes a height of the slitter blade where the circular outer edge of the slitter blade intercepts the light beam; and

a controller which controls the actuator so as to move the slitter blade toward the receiving roll to the height where the circular outer edge of the slitter blade intercepts the light beam.