Warpage correction apparatus for metal strip and continuous plating facility for metal strip

Abstract

A warpage correction apparatus for a metal strip to be used in a continuous plating facility for the metal strip includes a sink roll disposed downstream of a fixed roll, configured to change the conveying direction of the metal strip, with respect to a conveying direction of the metal strip and inside a molten metal pot for plating, and a correction roll disposed between the fixed roll and the sink roll and configured to correct warpage of the metal strip. A ratio D 3 /D 1 of a diameter D 3 of the sink roll to a diameter D 1 of the fixed roll is not less than 1.5.

1 . A warpage correction apparatus for a metal strip to be used in a continuous plating facility for the metal strip, the warpage correction apparatus comprising:
 a sink roll disposed downstream of a fixed roll with respect to a conveying direction of the metal strip and inside a molten metal pot for plating, the fixed roll being configured to change the conveying direction of the metal strip; and   a correction roll disposed between the fixed roll and the sink roll and configured to correct warpage of the metal strip,   wherein a ratio D 3 /D 1  of a diameter D 3  of the sink roll to a diameter D 1  of the fixed roll is not less than 1.5.   
     
     
         2 . The warpage correction apparatus according to  claim 1 ,
 wherein the correction roll is capable of adjusting a pressing amount of the correction roll toward the metal strip.   
     
     
         3 . The warpage correction apparatus according to  claim 1 ,
 wherein D 1 <D 2 <D 3  is satisfied, where D 2  is an apparent diameter of the correction roll corresponding to a pressing amount of the correction roll toward the metal strip.   
     
     
         4 . The warpage correction apparatus according to  claim 1 ,
 wherein the diameter D 3  of the sink roll is not less than 1200 mm.   
     
     
         5 . The warpage correction apparatus according to  claim 1 ,
 wherein the fixed roll is disposed inside a furnace for heat treatment of the metal strip.   
     
     
         6 . The warpage correction apparatus according to  claim 5 ,
 wherein the fixed roll is disposed at an outlet portion of the furnace.   
     
     
         7 . The warpage correction apparatus according to  claim 1 ,
 wherein the fixed roll is a bridle roll for adjusting a tension applied to the metal strip.   
     
     
         8 . The warpage correction apparatus according to  claim 1 ,
 wherein the correction roll is disposed inside a snout disposed between the molten metal pot and an outlet portion of a furnace for heat treatment of the metal strip.   
     
     
         9 . The warpage correction apparatus according to  claim 1 , further comprising:
 a warpage measuring device disposed downstream of the sink roll with respect to the conveying direction; and   a controller configured to adjust a pressing amount of the correction roll toward the metal strip based on a measurement result of the warpage measuring device.   
     
     
         10 . A continuous plating facility for a metal strip, comprising:
 the warpage correction apparatus according to  claim 1 .