Research On The Axial Distribution Of Vertical Displacement Response Of Rollers For Four-high Mill

Shape and thickness are two important parameters for measuring the quality of cold rolledstrip. At present there are many researches, which are most about one-dimensional response ofequivalent mass on the dynamic control of plate thickness; through the some research progresseson the modeling for the dynamics of a rolling mill system have been found. The shape controlactually is the expanding of thickness control along the strip width direction. The factors whichaffect the plate shape are complex and many problems such as basic theory, control technologyand simulation technology still remain to be solved. In view of the present situations, the paperfocuses on the establishment of dynamic modeling along the transverse direction for rollers in arolling mill system in the concept of an integrated control of shape and thickness, the works asfollows:(1) By taking the hydraulic roll gap control system of 2030mm four-high mill as theresearch object, the working principle of control of roll gap and the working principle ofhydraulic control loop of HAGC system are expatiated. With the analysis about electro-hydraulicposition servo control system and three-ways valve controlled cylinder, the dynamic equilibriumequation is established which has laid a foundation for solving dynamics boundary conditionsabout roll system transverse dynamic equations.(2) By use of the theory of dynamics and take the rollers as the elastic continuum, thedynamic model with the dynamic effects of continuously distributed mass is obtained. Byanalyzing the transverse dynamic response of the model shows that: the vibration of the center ofroller was more violent than the edge, the roll deflection is changing constantly with time, andthe changes in deflection lead to the real-time changes in roll gap. This means that deformationof roller is not only the static beam deformation in the transverse but also with the time-variationdynamic properties in the rolling direction.(3) By the application of bending force with hydraulic roll bending system, the modeobtained is used to discuses the transverse dynamic response of rollers, especially the responsecharacteristics with differences of bending force on both sides. This work presents a referencefor selecting the best bending force.