| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent meandering by setting a control holding time after a material to be rolled is passed through the (i-1)th stand till reducing and leveling control at the i-th stand is started and executing the reducing and leveling control. SOLUTION: A timing when the tail end part of a rolled steel 7 is passed through is detected at the (i-1)th stand. This timing is determined from the variation of the detected value of load of with a load detector 13b because rolling load at the (i-1)th stand becomes zero. Right and left rolling loads are detected with the load detector 13c of the i-th stand, load difference or load difference rate is calculated in an arithmetic processor 22 based on these rolling loads, the manipulated variable of a screw-down and leveling controller 12 of the i-th stand is calculated and the reducing and leveling controller 12c is operated. Like this, by repeatedly executing this control based on the load difference or load difference rate till the tail end part of a rolled stock 7 is passed through the i-th stand, meandering and breakage are prevented.</p> |
