JPS57165109A - Controlling method of plane form in thick plate rolling - Google Patents

Abstract

PURPOSE:To extremely and effectively eliminate a generation of malsquareness at plane corners of a plate product, by rolling a plate slanted by an angle derived from the specific equation based on the value of right angle deviation in the horizontal plane at the four corners of the plate plane on the way of rolling. CONSTITUTION:Corner angles at the four corners of a plate 1 plane are measured at the inlet side of a mill in the specific rolling pass, by an image processing unit 5 with a television camera, etc., and at the same time; the length and width of the plate 1 are measured. Next, a resistance absolute value¦DELTAthetaP¦of the malsquareness degree is obtained by an operator 6 to get its average value DELTAthetaP, and the values of plate thicknesses H0 and H1 before and after rolling, the values of which are preset basing on a rolling schedule, are derived from a process computor 7 then thetal is derived from the equationI. At the same time, width 2 of side guide B which is required when thetal is taken as the advancing angle is derived from the equation II. A controlling device 8 sends a command to driving mechanisms 9 and 10 from these values to control the opening degree of the guids 2 and the plate 1 is turned to the direction fitten with an obtuse angle corner by angle thetal against the normal rolling position by turning a turn table 11.