Method and system for monitoring the gap in rolling mills

A method for monitoring wear to cylinders of mill stands of a rolling mill for bars or rods, comprising the steps of:

• providing a database comprising:
• a first plurality of data relating to initial conditions of one or more monitored rolling cylinders of a corresponding rolling mill stand, the first plurality of data relating to initial conditions of one or more monitored rolling cylinders being selected from a group comprising at least:
• channel in use, in case of multichannel cylinders, cylinder hardness, cylinder diameter;
• maximum permitted wear for each channel of the cylinder, wear thresholds to activate operations like generation of alarms or adjustment of the distance between cylinders, and geometric features of the calibration;
• and
• a second plurality of data relating to preset process data, the second plurality of data relating to preset process data being selected from a group comprising at least:
• mechanical features in rolling conditions, in particular a temperature of the processed material, distance between cylinders if not measured in the plant, dimensional and shape parameters of a workpiece, and area of a section of a bar entering;
• and
• providing a plurality of sensors in corresponding rolling mill stands gathering a third plurality of data relating to parameters of running of the process, the third plurality of data relating to parameter of running of the process being selected from a group comprising at least:
• start time of rolling of workpiece, rotation speed of the cylinders, rolling forces and torque, temperature of the entering workpiece, temperature measured along the rolling mill, distance between the cylinders, and length of the workpiece that has passed through the cage;
• reading, by a neural network, the first plurality of data, the second plurality of data, and the third plurality of data relating to the parameters of running of the process;
• generating, by the neural network, signals relating to a state of wear of the rolling cylinders, the state of wear being evaluated as a linear value of a variation in depth of a runner in a preset point and a variation value of an area of a section of an exiting bar;
• and
• performing tasks on a corresponding mill stand according to the generated signals relating to a state of wear of the rolling cylinders.