Method and device for controlling the thickness of a rolled product

A device for controlling a final thickness of a rolled product in a tandem rolling mill including at least two roll stands spaced apart from one another, and each roll stand determining a portion of a reduction in thickness, each roll stand including at least two working rolls delineating a gap for letting through the rolled product, means for applying an adjustable clamping load between said working rolls and motorised means for driving said working rolls into rotation at an adjustable speed, the rolling mill being associated with a speed control system of the at least two roll stands determining a gradual increase in a rotational speed of the working rolls in relation to a gradual variation in thickness of a roll stand (i) at a next roll stand (i+1), and to a control device for controlling a reduction in thickness and in tension of the rolled product in each space between two successive roll stands, wherein the control device includes a closed-loop circuit for dynamic balancing, between different roll stands, of the torques applied by the motorised means of each roll stand to obtain the final thickness desired and to maintain the latter at a substantially constant value.

A rolling mill including at least two roll stands operating in tandem, fitted with means for adjustable clamping of working rolls and with electric means for driving said working rolls into rotation and including means for controlling a thickness of a rolled product at an outlet of the rolling mill and tractions between the roll stands, a pre-adjustment system for adjusting a rate of reduction in thickness of each roll stand and a speed control system for all the roll stands, wherein the rolling mill also includes a device for dynamically balancing currents of the driving motors of the roll stands operating as a closed-loop.