| 摘要 |
PURPOSE:To reduce a tension detecting pitch and to improve the controlling precision by detecting an electric current valve, a number of rotation, a rolling load of a roll driving motor at each stand and requiring a tension between stands to be given to a tube stock in a specified condition. CONSTITUTION:A mandrel bar 2 is inserted into the tube stock 1 and rolled. An arithmetic and control unit 3 fetches a rolled load P, a number of rotation (n), a current value Ia of a roll at the same timing from a load detector 4, a speed meter 8, an ammeter 9 of each stank S1-Sn and an acting force between stands given to the tube stock 1 is operated by the formula. In the formula, Fi-Fi-1: acting force given to tube stock i, Gi: rolling torque of roll driving motor at stand i, alphai: coefficient of torque arm at stand i, mui: coefficient of friction between tube stock at stand i and mandrel bar, Ri: radius of equivalent roll at stand i, Pi: rolling load at stand i. |
