| 摘要 |
<p>PURPOSE:To equalize a wall thickness of the axial direction of a blank pipe which has been rolled, by averaging an estimated calculation of a tension or a compressive force working on the axial direction of the blank pipe, and adjusting a moving speed of a mandrel bar so that the representative value is included in a correct range of said tension or compressive force. CONSTITUTION:Plural pieces of roll interval regulators 1 and roll revolving speed regulators 2 are installed by one piece each to each of plural pieces of stands A1-An of a mandrel mill. Also, plural pieces of load cells 3 for measuring a rolling load are installed by one piece each to the stands A1-An. A mandrel bar speed regulator 2' adjusts a revolving speed of a truck driving motor 5, based on a result of calculation of an arithmetic control device 7. Next, a voltage and a current of each roll driving motor 6 of the stands A1-An, and a roll revolving speed are measured, respectively, and sent to the device 7 by the same timing. Also, the device 7 outputs an adjusting command to each regulator 1 and each regulator 2 before rolling a blank pipe 8, so that a wall thickness of the blank pipe which has been rolled becomes a prescribed wall thickness, by which the wall thickness of the axial direction of the blank pipe 8 which has been rolled is equalized.</p> |
