| 摘要 |
PURPOSE:To fix a shape of a pipe material to be rolled at the exit side of a reeling mill, by correctingly computing a set-controlling-quantity of a rolling-condition-controlling device based on outputs from a desired wall-thickness-computing device and a wall-thickness reducing-quantity-computing device. CONSTITUTION:The length and outer dia. of a pipe are measured by a length gauge 3 and an outer dia. guage 4 respectively at the exit side of a plug mill 1, and the wall thickness of it is computed by an operator 6. A desired wall thickness is computed based on a desired outer dia., an outer dia. obtained from a memory unit 5, and the wall thickness from the operator 6 by a desired wall-thickness computing device 8. An actual reduced quantity of the wall thickness is computed based on a roll driving force of a reeling mill derived from a motor controlling device 16 by a wall-thickness reducing-quantity computing device 9. A prescribed wall-thickness reducing-quantity, obtained from the difference of wall thickness between a desired wall thickness of the device 8 and the wall-thickness at the exit side of the plug mill, is compared with the actual wall-thickness reduced-quantity of the device 9 to obtain a correcting quantity of wall thickness reducing of a reeling mill 11. The result is fed back to a leading-control device 14 to control automatically the rolling condition of the mill 11 from the actual rolling results, and then a steel pipe having fixed outer dia. and wall thickness is obtained in highly finishing accuracy. |
