Research On The Model Of Flying Gauge Change Control In 5-stand Tandem Cold Mills

As the exclusive process of fully continuous tandem cold mills, flying gauge changeis the key technique to realize fully continuous rolling. Therefore, research on flyinggauge change in tandem cold mills has an important significance in keeping the normalproduction, the increase of its yield and improvement of its quality.This paper took the conventional 5-stand tandem cold mills as the research object. Onthe basis of the characteristics of flying gauge change, by combining the theoreticalanalysis with computer simulation, the control of the process of flying gauge change wasstudied.The exact position of the head of wedge-shaped strip and its primary parameters weredetermined before the weld entered the mills. The control strategy of flying gauge changeand justification method for thickness, velocity and tension were established.Control and setting mathematical models, i.e. nonlinear full amount model andlinearization incremental model were established. The control model in variable tensionconditions was also established. According to the theory of cold rolling and thecharacteristics of tension during flying gauge change, the static and dynamic discretetension formulas were deduced so as to calculate the tension during flying change process.Flying gauge change simulation system of 5-stand tandem cold rolling mills wasestablished. Hydraulic pressure system and model was analyzed and simplified. Two setsof rolling schedule were chosen and calculated. Three schemes of flying gauge changewere simulated. In the comparison of the curves of the three schemes, off-gauge andtensile stress were analyzed.