JPS56114508A - Controlling method for rolling mill - Google Patents

Abstract

PURPOSE:To measure the actual value of interstand traveling speed of the rolled material to be rolled, and to control its tickness, by correcting the forward slip included in the set-up value set at starting the rolling work, depending on the measured interstand traveling speed and the speed signal produced on the run-out side of the rolling stand. CONSTITUTION:The interstand traveling speed of the material to be rolled 60, just undergoing the rolling work effected by the rolling stands 58 and 59, is measured by the looper roll 31 and the looper roll tachometer 32; the traveling speed on the run-out side of the rolling stand 59 is measured through the pinch roll in front of the coiler. The value of actual forward slip is computed from these two measured values; the time lag DELTAt between the moments, wherein a certain point of the rolled material 60 passes over each of outlets of rolling stands 58 and 59, is exactly computed by the computer 55. The converter 53 converts the rolling load variation DELTAP, detected through the rolling load detector 51 and the load variation detector 52, into the thickness variation DELTAh. The data delaying circuit 54 produces the thickness variation signal DELTAh after the time lag DELTAt, and the screw position adjustment computer 56 produces the correction signal DELTAS for the screw position of the rolling stand 59; hereby, the rolling stand 59 keeps constant the thickness of the material 60 on the run-out side of the stand 59.