| 摘要 |
<p>PURPOSE:To improve the accuracy of a tube length at the time of rolling the tube over a mandrel mill and a sizer in a tandem arrangement. CONSTITUTION:The cross sectional area of a tube stock after rolling with the mandrel mill 1 is obtd. with a control arithmetic unit 31 based on the rolling actual result value at the time of rolling the top part of the tube stock in the mandrel mill 1. Rolling reduction position and number of revolution of the roll of the mandrel mill 1 are controlled so that the cross sectional area at each part in the longitudinal direction of the tube stock equals the cross sectional area at the tip part of the tube stock. Further, the rolled length of the tube stock after rolling in the mandrel mill 1 is predicted based on the cross sectional area at the top part of the tube stock after rolling in the mandrel mill 1 and the premeasured tube stock wt. Number of revolution of the roll in the sizer 2 is obtd. based on a relation among the predicted rolled length of the tube stock, the aimed rolled length at the outlet side of the sizer 2, an elongation rate at the sizer 2 and a pattern of number of revolution of the roll to control the sizer 2.</p> |
