| 摘要 |
<p>PURPOSE:To restrain the thickness at both ends from increasing and to improve the yield by estimating and operating unstable tensions and learning-controlling the following controlled variable at tube ends rolled in accordance with a deviation from a target set tension. CONSTITUTION:Initial and final unstable tensions are estimated and operated by a tension arithmetic unit 12 in accordance with the driving current of a motor driving a stretch reducer and the number of rotation of a roll of the stretch reducer. The set value of the number of rotation of the stretch reducer is corrected in accordance with the deviation between the tension and the target tension by estimated operation. When a next tube is rolled, the number of rotation of the stretch reducer is controlled in accordance with the corrected set value. As a result, the tube end parts are rolled appropriately, the length of a crop end is reduced and the yield is improved.</p> |
