| 摘要 |
PURPOSE:To make a mean thickness value of a pipe constant, by commanding a roll screw-down position so that a pipe mean thickness value at the delivery side becomes a target value at every pass by sectional area information, by a method which uses no rolling load of a mill stand of a high regidity value. CONSTITUTION:After a material or a pipe has been taken out from a furance 1, each one piece is measured as to its unit weight value W and it is stored in a device 2. An actual value SO in case of rolling by a previous process device 3 of the pipe, and an actual value LO after rolling are stored in the device 2. Accordingly, sectional area information of the device 3 is shown by unit weight of W/LO. When the pipe reaches in front of a device 4, a roll screw-down position S1 where unit weight of the tube at the delivery side of 1 pass becomes a target value is calculated by the stored information, target unit weight of the pipe at the delivery side of 1 pass, and a unit weight actual value of the pipe rolled by the plug used by its pipe. As for 2 passes, a roll screw-down position S2 is calculated by an actual value W/L1 at the delivery side of 1 pass, a target value W/L2 at the delivery side of 2 passes, and a unit weight actual value of the pipe rolled by the plug used by its pipe. |
