Method and lubrication application device for regulating the flatness and/or roughness of a metal strip

Abstract

A method and a lubricant application device for regulating flatness and/or roughness of a metal strip in the outlet of a cold rolling stand by suitable metering of the amount of a lubricant per unit time applied to the metal strip in the inlet of the cold rolling stand. The invention that the applied amount of lubricant is metered in the form of a quantitative distribution over the width of the metal strip per unit time according to a detected control deviation between an actual and a desired flatness distribution over the width of the metal strip in the outlet of the cold rolling stand or a control deviation between an actual and a desired roughness distribution over the width of the metal strip in the outlet of the cold rolling stand or a combination of the two control deviations.

We claim: 
     
         1 . A method for regulating the flatness of a metal strip in the outlet of a cold rolling stand by suitable metering of the amount of at least one lubricant applied to the metal strip in the form of a quantitative distribution over the width of the metal strip per unit time in the inlet of the cold rolling stand, wherein the metering is effected according to a detected control deviation (e −RHV ) between an actual and a desired roughness distribution over the width of the metal strip in the outlet of the cold rolling stand. 
     
     
         2 . The method according to  claim 1 , wherein the quantity of applied lubricant is varied in a range of 1-20 ml/minute/100 mm width of the metal strip. 
     
     
         3 . The method according to  claim 1 , wherein the metal strip is only cooled on the outlet side but not on the inlet side of the cold rolling stand. 
     
     
         4 . The method according to  claim 1 , wherein a plurality of lubricants each having a different friction-coefficient lowering effect in the rolling gap of the cold rolling stand are available and the metering of the quantitative distribution of the lubricant applied to the metal strip per unit time and over the width of the metal strip is effected by a suitable mixture of the available lubricants amongst one another and with air with regard to a desired friction coefficient in the rolling gap. 
     
     
         5 . The method according to  claim 1 , wherein the metal strip, for example, comprises a steel or a nonferrous metal strip, e.g. an aluminium strip. 
     
     
         6 . The method according to  claim 1 , wherein the magnitude of the rolling gap of the cold rolling stand is kept constant during the total processing time of the metal strip. 
     
     
         7 . The method according to  claim 1 , wherein in the inlet of the cold rolling stand, the lubricant is applied to the upper and/or lower side of the metal strip and/or to at least one working roller of the cold rolling stand. 
     
     
         8 . A computer program with a program code for a control device of a lubricant application device wherein the program code is configured for carrying out the method according to  claim 1 . 
     
     
         9 . A data carrier with a computer program according to  claim 8 . 
     
     
         10 . A lubricant application device comprising:
 a container for at least one lubricant; at least one nozzle beam with a plurality of nozzles, wherein the nozzle beam is arranged at the inlet side of a cold rolling stand transverse to the direction of transport of a metal strip for metering the lubricant on the metal strip per unit time; and   a control device for suitable controlling of the nozzles of the nozzle beam with regard to a desired flatness of the metal strip; wherein a roughness sensor device is provided on the outlet side for detecting the actual roughness distribution there over the width of the metal strip; and   the control device is configured in cooperation with the nozzle beam to meter the at least one lubricant distributed quantitatively over the width of the metal strip and per unit time according to a control deviation (e −RH ) between the actual and the desired roughness distribution over the width of the metal strip in the outlet of the cold rolling stand.   
     
     
         11 . The lubricant application device according to  claim 10 , including a container for at least one lubricant; at least one nozzle beam with a plurality of nozzles, wherein the nozzle beam is arranged at the inlet side of a cold rolling stand transverse to the direction of transport of a metal strip for metering the lubricant on the metal strip per unit time; and
 a control device for suitable controlling of the nozzles of the nozzle beam with regard to a desired flatness of the metal strip; wherein a roughness sensor device is provided on the outlet side for detecting the actual roughness distribution there over the width of the metal strip; and   the control device is configured in cooperation with the nozzle beam to meter the at least one lubricant distributed quantitatively over the width of the metal strip and per unit time according to a control deviation (e-RH) between the actual and the desired roughness distribution over the width of the metal strip in the outlet of the cold rolling stand, wherein the lubricant application device is configured to carry out the method according to  claim 1 .