JPS5570408A - Roll draft controller - Google Patents

Abstract

PURPOSE:To properly, quickly correct the roll draft, and to exclude the deviation in the outer diameter of the rolled seamless steel pipe, by arranging the roll draft position detector, the measuring device for outer diameter of steel pipe, the computer for operating the difference between the measured outer diameter and the aim outer diameter of the steel pipe, and for producing the correction signal, etc. CONSTITUTION:The steel pipe blank 1 is rolled with the mill 3 possessing the screw driver 2 and the caliber roll for manufacturing the seamless steel pipe, under the control of the draft controller; in this draft controller on the exit side of the mill 3, the outer diameter measuring device 5 is installed, and its signal B is inputted to the arithmetic controller 7. The mill draft position A is detected by the encoder 4 whose signal is inputted to above arithmetic controller 7. The controller 7 operates the exact amount of wear of the roll from above input signal and the reference data for outer diameter to be inputted from the setter; then, the controller 7 produces the command signal C for reducing above difference and inputs to the roll draft controller 6 in order to control the mill draft driver 2 for correcting the draft of the mill 3. According to this method, the troublesome resetting due to the wear of caliber of the conventional roll or the deviation of outer diameter of the rolled pipe, can be excluded.