Angles of an upper-side pair of an upper work roll 110A and an upper backup roll 120A, and a lower-side pair of a lower work roll 110B and a lower backup roll 120B are adjusted in a state where the upper-side pair is kept parallel and in a state where the lower-side pair is kept parallel. Thereafter, work-roll pressing apparatuses 130A and 130B, work-roll position control apparatuses 140A and 140B, backup-roll pressing apparatuses 150A and 150B, and backup-roll position control apparatuses 160A and 160B are controlled such that the angles of the upper work roll 110A and the lower work roll 110B are adjusted in a state where the angles of the upper backup roll 120A and the lower backup roll 120B are maintained.

A roller guide (1) for guiding stock in a longitudinal feeding direction (A) toward a pair of rolls for shaping the stock. The roller guide comprises a frame arrangement (2), a pair of guide rollers (3, 4) configured to, in a closed position, engage opposite surface portions of the stock,and positioning means for adjusting a lateral distance between the guide rollers. The roller guide further comprises detection means (13) configured to detect a longitudinal position of a piece of stock (20) with respect to the guide rollers. The positioning means is configured to adjust the lateral distance between the guide rollers in response to said detection.

[Object] To provide a rolling apparatus capable of accurately detecting a rolling direction force applied to a work roll chock. [Solution] A rolling apparatus for flat-rolled metal materials including a pair of upper and lower work rolls 1 and 2 includes a pair of work roll chocks 5 and 6 configured to hold the respective work rolls 1 and 2, housings 10 configured to hold the work roll chocks, and rolling direction force measurement devices 21, 22, 23, and 24 configured to measure rolling direction forces. The rolling direction force measurement devices include a plurality of load detection devices on an entry side or an exit side of the work roll chocks in a rolling direction, and the plurality of load detection devices are provided to one of the housings, and the plurality of load detection devices are disposed in a manner that, during rolling of the flat-rolled metal materials, at least two of the load detection devices are arranged adjacent to each other in a draft direction facing a side surface of a corresponding one of the work roll chocks. In this case, the at least two load detection devices are disposed in a manner that a line extending in the rolling direction and including a roll axis, which is a point of effort of a rolling direction force, is interposed between the at least two load detection devices in the draft direction.

[Object] To provide a rolling apparatus capable of accurately detecting a rolling direction force applied to a work roll chock. [Solution] A rolling apparatus for flat-rolled metal materials including a pair of upper and lower work rolls 1 and 2 includes a pair of work roll chocks 5 and 6 configured to hold the respective work rolls 1 and 2, housings 10 configured to hold the work roll chocks, and rolling direction force measurement devices 21, 22, 23, and 24 configured to measure rolling direction forces. The rolling direction force measurement devices include a plurality of load detection devices on an entry side or an exit side of the work roll chocks in a rolling direction, and the plurality of load detection devices are provided to one of the housings, and the plurality of load detection devices are disposed in a manner that, during rolling of the flat-rolled metal materials, at least two of the load detection devices are arranged adjacent to each other in a draft direction facing a side surface of a corresponding one of the work roll chocks. In this case, the at least two load detection devices are disposed in a manner that a line extending in the rolling direction and including a roll axis, which is a point of effort of a rolling direction force, is interposed between the at least two load detection devices in the draft direction.

[Object] To provide a rolling apparatus capable of accurately detecting a rolling direction force applied to a work roll chock. [Solution] A rolling apparatus for flat-rolled metal materials includes a pair of upper and lower work rolls 1 and 2, and a pair of upper and lower backup rolls 3 and 4. The rolling apparatus includes a pair of work roll chocks 5 and 6 configured to hold the respective work rolls, housings 10 configured to hold the work roll chocks, and load detection devices 21 to 24 provided in the work roll chocks, the load detection devices each detecting a load acting on one of the housings from one of the work roll chocks on an entry side in a rolling direction or on an exit side in the rolling direction. The load detection devices are each disposed so as to face one of the housings using a point of effort of a rolling direction force of one of the work rolls as a reference, such that a rotation moment generated on each of the work roll chocks caused by the rolling direction force is equal to a counter rotation moment generated by counterforce against the rotation moment.

[Object] To provide a rolling apparatus capable of accurately detecting a rolling direction force applied to a work roll chock. [Solution] A rolling apparatus for flat-rolled metal materials includes a pair of upper and lower work rolls 1 and 2, and a pair of upper and lower backup rolls 3 and 4. The rolling apparatus includes a pair of work roll chocks 5 and 6 configured to hold the respective work rolls, housings 10 configured to hold the work roll chocks, and load detection devices 21 to 24 provided in the work roll chocks, the load detection devices each detecting a load acting on one of the housings from one of the work roll chocks on an entry side in a rolling direction or on an exit side in the rolling direction. The load detection devices are each disposed so as to face one of the housings using a point of effort of a rolling direction force of one of the work rolls as a reference, such that a rotation moment generated on each of the work roll chocks caused by the rolling direction force is equal to a counter rotation moment generated by counterforce against the rotation moment.

There is provided a method for identifying thrust counterforce working point positions of backup rolls of a rolling mill, the method including: changing at least either friction coefficients and inter-roll cross angles between the rolls with an unchanged kiss roll load to cause thrust forces at a plurality of levels to act between the rolls, and measuring thrust counterforces in a roll-axis direction acting on rolls forming at least one of roll pairs other than a roll pair of the backup rolls and measuring backup roll counterforces acting in a vertical direction on the backup rolls at reduction support positions in a kiss roll state; and identifying, based on the measured thrust counterforces, thrust counterforce working point positions of thrust counterforces acting on the backup rolls, using first equilibrium conditional expressions relating to forces acting on the rolls and second equilibrium conditional expressions relating to moments acting on the rolls.

There is provided a method for identifying thrust counterforce working point positions of backup rolls of a rolling mill, the method including: changing at least either friction coefficients and inter-roll cross angles between the rolls with an unchanged kiss roll load to cause thrust forces at a plurality of levels to act between the rolls, and measuring thrust counterforces in a roll-axis direction acting on rolls forming at least one of roll pairs other than a roll pair of the backup rolls and measuring backup roll counterforces acting in a vertical direction on the backup rolls at reduction support positions in a kiss roll state; and identifying, based on the measured thrust counterforces, thrust counterforce working point positions of thrust counterforces acting on the backup rolls, using first equilibrium conditional expressions relating to forces acting on the rolls and second equilibrium conditional expressions relating to moments acting on the rolls.

The present invention provides a method for identifying an inter-roll cross angle in a rolling mill of four-high or more including at least a pair of work rolls and a pair of backup rolls by, when rolling is not performed, applying a roll bending force to apply a load between rolls of an upper roll assembly including the work roll on the upper side and between rolls of a lower roll assembly including the work roll on the lower side, in a state where a roll gap between the work rolls is put into an open state, detecting vertical roll loads that act in the vertical direction on the rolling support positions on the working side and the driving side of at least one of the backup roll on the upper side or the backup roll on the lower side, and calculating a load difference between the vertical roll loads on the working side and the driving side.

There is provided a zigzagging control method for a workpiece including: an estimation step of, before rolling of a tail portion of the workpiece, acquiring at least any one of an inter-roll thrust force estimated based on an inter-roll cross angle and an inter-roll friction coefficient and a material-roll thrust force estimated based on a material-roll cross angle and a material-roll friction coefficient; and a tail control step of, during the rolling of the tail portion of the workpiece, measuring work-side and drive-side rolling loads, correcting a rolling load difference or a rolling load difference ratio based on any two of acquired parameters including a roll-axis-direction thrust counterforce at the measurement of the rolling loads, the inter-roll thrust force, and the material-roll thrust force, and performing reduction leveling control on a rolling mill based on the corrected rolling load difference or rolling load difference ratio.