METHOD FOR CONTROLLING ROLL FORCE DURING THREADING IN COLD ROLLING MILL

摘要

PURPOSE: A method for controlling roll force during threading in cold rolling mill is provided to prevent fracture, breakage or twisting of strip that can be generated during the initial threading operation by slowly increasing roll force from initial threading operation of the cold rolling mill to normal rolling operation of the cold rolling mill. CONSTITUTION: The method comprises a roll force initial value setting step of setting an initial roll force value in which a preset roll force value during normal rolling operation is reduced to a certain ratio according to thickness of strip manufactured by pressing of rolls; a threading time setting step of setting a threading time required from the initial threading operation to the normal operation; and a roll force control step of threading the strip as constantly increasing roll force from the initial roll force value to the set roll force value during the set threading time, wherein the certain ratio in the initial value setting step is 50 to 60%, and wherein the initial roll force value is a predetermined roll force lower limit value or more.