Rolling mill and rolling method

A rolling mill comprising:

• a pair of upper and lower work rolls having curved contours with diameters that increase and decrease repetitively from one end to another end in an axial direction, the pair of upper and lower work rolls being arranged to be point symmetric with each other;
• a pair of upper and lower backup rolls that support the work rolls, respectively;
• work roll horizontal direction actuators that move the work rolls in a horizontal direction;
• work roll axial direction actuators that move the work rolls in the axial direction;
• and
• a control device that controls angle adjustment performed by the work roll horizontal direction actuators, and axial position adjustment performed by the work roll axial direction actuators, wherein
• the control device
• has a first angle instruction section that issues an instruction to adjust an angle between an upper side pair of the upper work roll and the upper backup roll and a lower side pair of the lower work roll and the lower backup roll in a state in which the upper side pair has a parallel state and besides in a state in which the lower side pair has a parallel state,
• a second angle instruction section that issues an instruction to tilt the work rolls in a state in which an angle between the backup rolls is maintained, and
• an axial position instruction section that issues an instruction to move the work rolls in a direction in which total thrust force received, by the work rolls tilted by the instruction issued by the second angle instruction section, from the backup rolls and a rolled material acts, and
• controls the work roll horizontal direction actuators and the work roll axial direction actuators on a basis of the instructions issued by the first angle instruction section, the second angle instruction section, and the axial position instruction section.