Preventing worn edges when rolling flat rolled products

Abstract

A roll stand (1) having at least one pair of rollers (4, 5) between which a flat rolled product (2) is located. The rollers (4, 5) can be moved axially in opposite directions. The roll stand (1) has a bending system (6) for the rollers (4, 5). A controller (8) of the roll stand (1) uses the bending and the axial movement of the rollers (4, 5) in order to regulate the roll gap contour as an adjustment mechanism. Prior to rolling a respective rolled product (2), the controller determines a respective axial position (x) as the resulting axial position (x) and sets the axial position as the axial position (x) of the rollers (4, 5) for the roll stand (1) in order to roll the next flat rolled product (2). For this purpose, the controller (8) ascertains how far a specified target roll gap contour can be approximated for a plurality of axial positions (x) of the rollers (4, 5) by actuating the adjustment mechanism (6, 7) while taking into consideration technological boundary conditions and classifies the axial positions (x) at which a deviation of the resulting roll gap contour from the target roll gap contour lies below a specified limit as being permissible. The controller then removes the axial positions (x) excluded from the plurality of axial positions (x) classified as being permissible as long as at least one axial position (x) classified as being permissible still remains after the excluded axial positions (x) are removed. The controller (8) determines one of the remaining axial positions (x) as the resulting axial position (x).

1 . A method for rolling a flat rolled product in a rolling stand, wherein the rolling stand has at least one pair of rollers, wherein the rollers are axially displaceable in opposite directions, the rolling stand has a bending system for the rollers;
 the method comprising:   situating the flat rolled product between the two rollers;   operating a control device of the rolling stand for controlling the rolling gap contour using as adjusting mechanisms the bending and the axial displacement of the rollers;   prior to the rolling of a respective rolled product, operating the control device to determine a respective axial position (x) as the resulting axial position (x) and prescribing the resulting axial position for the rolling stand as axial position (x) of the rollers for rolling the next flat rolled product;   prior to the rolling of the respective rolled product, operating the control device to determine for a plurality of axial positions (x) of the rollers how far a predetermined target rolling gap contour can be approximated by actuating the adjusting mechanisms while taking account of technological boundary conditions,   the control device classifies as permissible those axial positions (x) in which a deviation of the resulting rolling gap contour from the target rolling gap contour lies below a predetermined limit;   the control device removes blocked axial positions (x) from the set of the axial positions (x) classified as permissible insofar as at least one axial position (x) classified as permissible still remains even after the removal of the blocked axial positions (x); and   the control device determining one of the remaining axial positions (x) as the resulting axial position (x).   
     
     
         2 . The method as claimed in  claim 1 , further comprising
 the rolling stand has backup rollers in addition to the rollers, and arranging the rollers in each case between the backup rollers and the rolled product.   
     
     
         3 . The method as claimed in  claim 1 , wherein at least some of the rollers are each provided with a contour which is curved in the manner of a bottleneck. 
     
     
         4 . The method as claimed in  claim 1 , further comprising the control device determining the resulting axial position (x) on a stochastic basis. 
     
     
         5 . The method as claimed in  claim 1 , further comprising operating the control device to assign an evaluation to at least the remaining axial positions (x) on the basis of an evaluation criterion, and operating the control device to determine the resulting axial position (x) on the basis of the evaluation. 
     
     
         6 . The method as claimed in  claim 5 , further comprising the control device to determine the evaluation on the basis of technological criteria. 
     
     
         7 . The method as claimed in  claim 1 , further comprising the control device receives a blocking command from an operator, and the control device blocks axial positions (x) specified in the blocking command. 
     
     
         8 . The method as claimed in  claim 1 , further comprising the control device determining a resulting edge of one of the rollers while taking into consideration a camber, a thermal crown and/or a wear of the rollers, and; and
 the control device blocking those axial positions (x) in which the resulting edge of one of the rollers would be positioned on a rolled product edge of the flat rolled product.   
     
     
         9 . The method as claimed in  claim 1 , further comprising the control device blocking those axial positions (x) which are situated in a predetermined region around that axial position (x) in which the flat rolled product that was rolled immediately beforehand is rolled. 
     
     
         10 . The method as claimed in  claim 9 , further comprising the control device blocking those axial positions (x) having spacing (a) which is situated below the minimum spacing (amin) from that axial position (x) in which the flat rolled product that was rolled immediately beforehand is rolled, for a predetermined number of flat rolled product and then cancelling the block again. 
     
     
         11 . A control program for a control device for controlling a rolling stand, wherein the control program comprises machine code which can be processed by the control device, wherein the processing of the machine code by the control device has the effect that the control device carries out a method as claimed in  claim 1 . 
     
     
         12 . A control device for a rolling stand, wherein the control device is programmed with a non-transitory control program operable to carry out a method as claimed in  claim 1 . 
     
     
         13 . A rolling stand for rolling a flat rolled product,
 wherein the rolling stand has a pair of rollers;   and the flat rolled product is situated between the two rollers;   the rollers are axially displaceable in opposite directions;   the rolling stand has a bending system for the rollers;   the rolling stand for controlling by a control device as claimed in  claim 12 .