JPS56144807A - Multistage rolling mill having shape controllability - Google Patents

Abstract

PURPOSE:To control the thickness shape in the direction of breadth with high accuracy over a wide range, by making the diameter of one of two work rolls smaller than another roll, by placing this smaller work roll on the downstream side from the reducing line, by driving these work rolls so as to rotate at different circumferential speed, and by controlling the shape of steel sheet from horizontal and vertical directions. CONSTITUTION:The multistage rolling roll comprises upper and lower backup rolls 1, 2 and upper and lower work rolls 3, 4 wherein the lower work roll 4 is made into a small diameter and is placed on the downstream side from the reducing line. A push roll 7 having a length of drum almost equal to that of the lower work roll 4 is arranged so as to push the lower work roll 4, and a backup roll 8 suitably segmented breadthways into plural sections is arranged for backing up the push roll 7. Besides, each section of the backup roll 8 is provided with a shafter 11 through a holder 9. The work rolls 3, 4 are driven to rotate at different circumferential speed. The shifter 11 works in adjusting the pushing force of each segment of the backup roll 8 against the push roll 7 separately; hereby, the displacement of the pushing force is made a vertical displacement, and the deflection of the lower work roll 4 is adjusted freely in respect of each part along the direction of length. By the present arrangement, the shape of rolled material 6 is arbitrarily controlled.