When an opposite direction shift for obtaining a required equivalent roll crown and a same direction shift for wear dispersion are used in combination, a difference occurs in the roll gap at both edge portions in the width direction of a rolling target material. Therefore, the difference between a work-side screw down position and a drive-side screw down position is changed so that the roll gap difference between both the edge portions in the width direction of the rolling target material is made close to zero. As a result, the distance between the work roll shafts on a work side and a drive side is changed, so that the roll gap difference at both ends in the width direction of the rolling target material approaches zero. Therefore, the wear of the work rolls can be dispersed while maintaining the equivalent roll crown.

When an opposite direction shift for obtaining a required equivalent roll crown and a same direction shift for wear dispersion are used in combination, a difference occurs in the roll gap at both edge portions in the width direction of a rolling target material. Therefore, the difference between a work-side screw down position and a drive-side screw down position is changed so that the roll gap difference between both the edge portions in the width direction of the rolling target material is made close to zero. As a result, the distance between the work roll shafts on a work side and a drive side is changed, so that the roll gap difference at both ends in the width direction of the rolling target material approaches zero. Therefore, the wear of the work rolls can be dispersed while maintaining the equivalent roll crown.

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.

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.

Method for monitoring wear to cylinders of the cages of a rolling mill, in particular for bars or rods, including the following steps: reading by a neural network of a plurality of data relating to the initial conditions of one or more rolling cylinders, in particular one or more pairs of cylinders each belonging to a rolling cage, to the settings, and to the running of the process; and generation by the neural network of signals relating to the state of wear of the cylinders.

A roll stand of a rolling mill is supplied with a metal strip by an upstream supply device at an in-feed speed (v), with said metal strip being rolled in the roll stand. A measuring device between the supply device and the roll stand detects a respective thickness value (d) of the metal strip for consecutive sections of the metal strip and supplies said value to a control device of the rolling mill. The control device determines final thickness deviations based on the preliminary thickness deviations. The control device determines a respective control value (A2, A3) for the roll stand and/or the supply device for the sections of the metal strip based on the final thickness deviation of the respective section of the metal strip and the final thickness deviations of multiple preceding and/or subsequent sections of the metal strip.

A roll stand of a rolling mill is supplied with a metal strip by an upstream supply device at an in-feed speed (v), with said metal strip being rolled in the roll stand. A measuring device between the supply device and the roll stand detects a respective thickness value (d) of the metal strip for consecutive sections of the metal strip and supplies said value to a control device of the rolling mill. The control device determines final thickness deviations based on the preliminary thickness deviations. The control device determines a respective control value (A2, A3) for the roll stand and/or the supply device for the sections of the metal strip based on the final thickness deviation of the respective section of the metal strip and the final thickness deviations of multiple preceding and/or subsequent sections of the metal strip.

A first exemplary aspect is a press roll apparatus including: a first roll and a second roll configured to hold a workpiece therebetween to press the workpiece; a mobile unit configured to move the second roll; a detection unit configured to be able to detect a load that acts between the first and the second rolls; and a control unit configured to control the mobile unit. The control unit moves the second roll in a direction in which the second roll approaches the first roll in a state in which the workpiece is not held between the first and the second rolls, and sets a position of the second roll where the load detected by the detection unit has become equal to or greater than a predetermined value as an origin position.

A first exemplary aspect is a press roll apparatus including: a first roll and a second roll configured to hold a workpiece therebetween to press the workpiece; a mobile unit configured to move the second roll; a detection unit configured to be able to detect a load that acts between the first and the second rolls; and a control unit configured to control the mobile unit. The control unit moves the second roll in a direction in which the second roll approaches the first roll in a state in which the workpiece is not held between the first and the second rolls, and sets a position of the second roll where the load detected by the detection unit has become equal to or greater than a predetermined value as an origin position.

A method and a corresponding computer program product calculate a pass schedule for a stable rolling process when rolling metal strip in a rolling mill. The offset here is varied until the calculated target horizontal force satisfies a predefined limit criterion. The satisfaction of the limit criterion means that the set of rolls and the rolling process are stable. For cases in which a sole iteration of the offset of the working roll does not result in the limit criterion being satisfied, the present invention provides that the draws on the material to be rolled are then changed on the feed side and/or on the outlet side of the rolling stand with constant offset until the calculated target horizontal force satisfies the limit criterion.