Web conveying apparatus with brake

Abstract

A conveying apparatus includes: a conveyor configured to convey a web while unwinding the web from a web roll; a brake configured to apply brakes to rotation of the web roll; and a controller configured to perform control to unwind the web from the web roll and convey the web with the conveyor while giving tension to the web by applying brakes to the rotation of the web roll using torque of the brake. The controller is configured to determine the torque of the brake during deceleration of the web to be a value depending on an inertial load of the web roll.

What is claimed is: 
     
         1 . A conveying apparatus comprising:
 a conveyor configured to convey a web while unwinding the web from a web roll;   a brake configured to apply brakes to rotation of the web roll; and   a controller configured to perform control to unwind the web from the web roll and convey the web with the conveyor while giving tension to the web by applying brakes to the rotation of the web roll using torque of the brake,   wherein the controller is configured to determine the torque of the brake during deceleration of the web to be a value depending on an inertial load of the web roll.   
     
     
         2 . The conveying apparatus according to  claim 1 , wherein the controller is configured to:
 upon stopping conveyance of the web by the conveyor, control a stop operation of the conveyance of the web based on one of different stop modes each having different deceleration time of the web; and   in the stop operation of the conveyance of the web in each stop mode, determine the torque of the brake during the deceleration of the web to be a value depending on the inertial load of the web roll in accordance with the deceleration time of the stop mode.   
     
     
         3 . The conveying apparatus according to  claim 1 , wherein upon changing the torque of the brake to set the torque of the brake at the deceleration of the web to the value depending on the inertial load of the web roll, the controller is configured to gradually change the torque of the brake. 
     
     
         4 . The conveying apparatus according to  claim 3 , wherein the controller is configured to adjust a torque change rate for gradually changing the torque of the brake in accordance with a diameter of the web roll at the deceleration of the web. 
     
     
         5 . The conveying apparatus according to  claim 1 , further comprising a web roll holder including a web-roll supporting shaft rotatably supporting the web roll,
 wherein the brake is configured to apply brakes to rotation of the web-roll supporting shaft.   
     
     
         6 . The conveying apparatus according to  claim 1 , wherein the controller is configured to calculate the inertial load of the web roll used for calculation of the torque of the brake during the deceleration of the web, using a diameter of the web roll at a start timing of the deceleration of the web. 
     
     
         7 . The conveying apparatus according to  claim 1 , wherein the inertial load of the web roll during the deceleration of the web is a product of a moment of inertia of the web roll and an angular acceleration of the web roll from a print conveyance speed of the web to stoppage of the web.