Method and apparatus for controlling the tension in the rolling stock between rolling stands

摘要

The invention relates to a method and apparatus for controlling the tension in the rolling stock between rolling stands of a hot-strip rolling mill. Use is made here of the principle of minimum tension control, in which a quotient of the rolling torque and the rolling force determined and divided by the rolling force at the stand housings. The torque is formed in a known manner by measuring the armature current, the armature voltage and the speed of rotation of the driving motor, this being followed for correction purposes by the subtraction of the acceleration torque and the friction torque. The considerable distance between the driving motor and the rolling stand leads to a considerable delay within the control loop, this being eliminated essentially, according to the invention, by the fact that the rolling torque is recorded on the driving spindle in the vicinity of the deformation zone. This is accomplished, in particular, by providing the driving spindles or universally-jointed shafts of the rolling mill with a torsion-measuring device.