Cold rolling mill and method for cold roll forming a metallic strip

Abstract

The invention relates to a method for cold roll forming a metallic strip ( 8 ), a steel strip in particular, comprising a single fame ( 1 ), having means for adjusting a roll gap, a winding device ( 9 ) which is arranged upstream of the cold roll single frame for unwinding the strip ( 8 ), and a winding device ( 10 ) which is arranged downstream of the cold roll single frame ( 1 ) for winding the strip ( 8 ). The aim of the invention is to eliminate all problems connected to strip tension when the thickness of the strip varies and to increase the speed of the strip. To achieve this, a strip accumulator ( 2 ) is arranged between the upstream winding device ( 9 ) and the single frame ( 1 ) for controlling the mass flow and/or tension of the rolling process, particularly when flexible rollers are used.

1 . A cold rolling mill for the cold rolling metallic strip ( 8 ), especially steel, with a single-frame mill ( 1 ) with means for adjusting a rolling gap as well as a coiler device ( 9 ) upstream of the single-frame cold rolling mill for unwinding the strip ( 8 ) of the single-frame cold rolling mill for unwinding the strip ( 8 ) and a coiling device ( 10 ) downstream of the single-frame cold rolling mill ( 1 ) for winding up the strip ( 8 ), characterized in that between the upstream coiling device ( 9 ) and the single frame rolling mill ( 1 ) a strip storage ( 2 ) is arranged for a mass flow control and/or strip tension control of the rolling process, especially in the case of flexible rolling.  
     
     
         2 . A cold rolling mill according to  claim 1 , characterized in that in addition to the first strip storage ( 2 ) arranged between the upstream coiler device ( 9 ) and the single frame mill ( 1 ), a second strip storage ( 3 ) is arranged between the single frame mill ( 1 ) and the downstream coiler device ( 10 ).  
     
     
         3 . A method of cold rolling a metal strip ( 8 ) especially of steel, in a cold rolling mill with a single frame ( 1 ) with means for adjusting a rolling gap for the cold rolling of the strip as well as a coiler device ( 9 ) arranged upstream of the single frame ( 1 ) for unwinding the strip ( 8 ) and a coiler device ( 10 ) downstream of the single frame ( 1 ) for winding up the strip ( 2 ), characterized in that by means of the single frame ( 1 ) a rolling, especially a flexible rolling is carried out in which the strip thickness during the rolling is continuously changed in accordance with a predetermined pattern and that by means of a strip storage ( 2 ) which is arranged between the upstream coiler device ( 9 ) and the single frame mill ( 1 ) a mass flow control and/or a strip tension control of the rolling process is effected.  
     
     
         4 . The method according to  claim 3 , characterized in that the coiler devices ( 9 ,  10 ) are speed-controlled coiler devices.  
     
     
         5 . The method according to claims  3  or  4 , characterized in that in a control circuit for the control of the position of the strip storage ( 2 ,  3 ), especially of a dancer roller ( 6 ,  7 ), a force correction value is calculated by means of a force controller from an actual force value and a setpoint force value obtained from the positioning unit ( 18 ) whereby the setpoint force value is calculated from an actual angle value derived from the dancer roller and a predetermined setpoint tension value.  
     
     
         6 . The method according to one of  claims 3  to  5 , characterized in that the strip storage ( 2 ,  3 ) is controlled as a function of a known variation in the strip thickness pattern.