Web conveyance controlling method, web slip amount measuring means, and web conveyance controlling device

Abstract

A method of controlling the conveyance of a web comprises a web measuring step of measuring the conveyance speed (V) and the tension force (T) of the web ( 2 ) during its conveyance, a slip amount calculation step of calculating the slip amount (W) of the web ( 2 ) relative to a guide roll ( 14 ) from the values of the conveying speed (V) and the tension force (T) of the web ( 2 ) measured in the web measuring step, and a web control step of controlling the tension force of the web ( 2 ) during its conveyance so that the slip amount (W) of the web ( 2 ) relative to the guide roll ( 14 ) calculated in the slip amount calculation step is equal to a preset target slip amount (W 1 ). Consequently, the slip of the web is accurately controlled, whereby the lateral displacement of the web can be reduced.

1 . A web conveying control method of controlling a slip of the web with respect to a roll arranged in a conveying line for conveying the web continuously, comprising:
 a step of measuring a conveying speed and tension of the web during conveying;   a step of calculating a slip amount of the web with respect to a guide roll using the measured conveying speed and tension of the web; and   a step of controlling the conveying speed and/or the tension of the web such that the slip amount becomes a target slip amount set in advance.   
   
   
       2 . The method according to  claim 1 ,
 wherein the step of controlling comprises:   deciding whether a difference between the calculated slip amount and the target slip amount is within a preset threshold range;   calculating, when deciding that the difference goes beyond the threshold range, an ideal conveying speed or an ideal tension of the web with regard to the target slip amount in case that the conveying speed or tension is constant; and   controlling the conveying speed and/or the tension of the web so as to be the calculated ideal conveying speed or ideal tension.   
   
   
       3 . A web conveying control method of controlling a slip of the web with respect to a roll arranged in a conveying line for conveying the web continuously, comprising:
 a step of measuring a conveying speed and tension of the web during conveying;   a step of measuring a rotational speed of a guide roll;   a step of measuring the slip amount of the web with respect to the guide roll on the basis of a difference between the measured conveying speed of the web and the measured rotational speed of the guide roll; and   a step of controlling the conveying speed and/or the tension of the web such that the slip amount becomes a target slip amount set in advance.   
   
   
       4 . A web conveying control method of controlling a slip of the web with respect to a roll arranged in a conveying line for conveying the web continuously, comprising:
 a step of measuring a conveying speed and tension of the web during conveying;   a step of measuring a rotational speed of a drive roll which conveys the web;   a step of measuring a rotational speed of a guide roll;   a step of measuring the slip amount of the web with respect to the guide roll on the basis of a difference between the measured rotational speed of the drive roll and the measured rotational speed of the guide roll; and   a step of controlling the conveying speed and/or the tension of the web such that the slip amount becomes a target slip amount set in advance.   
   
   
       5 . A web conveying control method of controlling a slip of the web with respect to a roll arranged in a conveying line for conveying the web continuously, comprising:
 a step of measuring a conveying speed and tension of the web during conveying;   a step of detecting a shifting amount of the web from a surface of the roll;   a step of measuring the slip amount of the web with respect to the roll on the basis of the shifting amount; and   a step of controlling the conveying speed and/or the tension of the web such that the slip amount becomes a target slip amount set in advance.   
   
   
       6 . A web conveying control device for controlling a slip of the web with respect to a roll arranged in a conveying line for conveying the web continuously, comprising:
 means of measuring a conveying speed and tension of the web during conveying;   means of calculating a slip amount of the web with respect to a guide roll using the measured conveying speed and tension of the web; and   means of controlling the conveying speed and/or the tension of the web such that the slip amount becomes a target slip amount set in advance.   
   
   
       7 . The device according to  claim 1 ,
 wherein the means of controlling comprises:   means of deciding whether a difference between the calculated slip amount and the target slip amount is within a preset threshold range; and   means of calculating, when deciding that the difference goes beyond the threshold range, an ideal conveying speed or an ideal tension of the web with regard to the target slip amount in case that the conveying speed or tension is constant,   wherein the conveying speed and/or the tension of the web is controlled so as to be the calculated ideal conveying speed or ideal tension.   
   
   
       8 . A web conveying control device for controlling a slip of the web with respect to a roll arranged in a conveying line for conveying the web continuously, comprising:
 means of measuring a conveying speed and tension of the web during conveying;   means of measuring a rotational speed of a guide roll;   means of measuring the slip amount of the web with respect to the guide roll on the basis of a difference between the measured conveying speed of the web and the measured rotational speed of the guide roll; and   means of controlling the conveying speed and/or the tension of the web such that the slip amount becomes a target slip amount set in advance.   
   
   
       9 . A web conveying control device for controlling a slip of the web with respect to a roll arranged in a conveying line for conveying the web continuously, comprising:
 means of measuring a conveying speed and tension of the web during conveying;   means of measuring a rotational speed of a drive roll which conveys the web;   means of measuring a rotational speed of a guide roll;   means of measuring the slip amount of the web with respect to the guide roll on the basis of a difference between the measured rotational speed of the drive roll and the measured rotational speed of the guide roll; and   means of controlling the conveying speed and/or the tension of the web such that the slip amount becomes a target slip amount set in advance.   
   
   
       10 . A web conveying control device for controlling a slip of the web with respect to a roll arranged in a conveying line for conveying the web continuously, comprising:
 means of measuring a conveying speed and tension of the web during conveying;   means of detecting a shifting amount of the web from a surface of the roll;   means of measuring the slip amount of the web with respect to the roll on the basis of the shifting amount; and   means of controlling the conveying speed and/or the tension of the web such that the slip amount becomes a target slip amount set in advance.