Patent ID: 11872613
Assignee: NIPPON STEEL CORPORATION
Field: Machine tools (Mechanical engineering)
Classification: CPC B | IPC B

Claim 0:
1. A rolling mill of four-high or more that includes a plurality of rolls including at least a pair of work rolls and a pair of backup rolls supporting the work rolls, wherein any one roll among respective rolls arranged in a vertical direction is adopted as a reference roll, the rolling mill comprising: two hydraulic cylinders, which face each other in a rolling direction on either side of roll chocks of the rolls other than the reference roll, is provided on either one of an entrance side and an exit side in the rolling direction, the hydraulic cylinders pressing at least the roll chocks of the rolls other than the reference roll in the rolling direction, the hydraulic cylinders moving at least the roll chocks of the rolls other than the reference roll in the rolling direction; and a position controller configured to fix a rolling direction position of roll chocks of the reference roll as a reference position, and based on a rolling direction force difference, which is the difference between rolling direction forces in a rolling direction which act on roll chocks on a work side and roll chocks on a drive side of each of at least the rolls other than the backup rolls, drive the hydraulic cylinders to control positions in the rolling direction of the roll chocks of the rolls other than the reference roll so that the rolling direction force difference of each of the rolls becomes a value within an allowable range.