JPS55156616A - Detector for metal-off of rolling mill - Google Patents

Abstract

PURPOSE:To prevent the shock due to the change in the feed rate of the pressure oil at the point of metal-off of the rolled material, by actuating the timer for a period of time to travel a distance corresponding to the rolling speed during the rolling work, by producing the timing signal for the metal-off of the rolled material, by intercepting the output of the automatic control, and by widening the roll gap depending on the signal for some period of time. CONSTITUTION:The arithmetic circuit 13 operates the distance-timer value (t) from the distance given by the reference value circuit 10 and the rolled material's speed (v) given by the line speed signal generator 11. To this result the correction value of the timer value correction circuit 14 is added, in order to correct the detecting error of detectors 20, 21, respectively for the front end face and the tail end face of the rolled material 1. The time-up detecting circuit 16 detects the time-up, and the metal-off signal generating circuit 17 generates the metal-off signal, and these signals are given to the control system. If the timing detecting circuit 12 detects that the detecting output of the detector 20 becomes OFF, the timer is started at this timing, and the metal-off signal is produced depending on that time-up, and hereby, the metalff of the rolled material 1 is detected independently of the reaction force against the rolling load.