JPS5772704A - Rolling mill for metallic sheet - Google Patents

Abstract

PURPOSE:To eliminate the roll gap between a work roll and a backup roll under a no-load condition, and to reduce the deflection of the work roll to a minimum, by prescribing the relation between the crown of the work roll and the crown of the backup roll, at rolling a metallic sheet having a drum-shaped cross section. CONSTITUTION:In a four-high rolling mill, etc., for manufacturing a metallic sheet having nonuniform thickness, a work roll having a prescribed dimension is employed; that is, the difference CRW between the diameter DCW at the middle of the roll drum and the diameter Dew at the end of the roll drum is a negative value, and its abosolute value is >=1.0mm.. An initial curve is given to a backup roll so as to satisfy a relation CRB=-CRW, in which CRB is the difference between the diameter DCB at a part of the backup roll just corresponding to the middle of the work roll drum and the diameter DeB at a part of the backup roll corresponding to the work roll's drum end. Hereby, the gap between the work roll and the backup roll is eliminated under a no-load condition, the deflection of the work roll is reduced to a minimum, and the generation of a bending stress is reduced.