| 摘要 |
<p>PURPOSE:To accurately control the outer diameter by reconsidering the succeeding control pitch at the stand one less than the final stand and deciding a control pitch at the final stand based on operating situations of a rolling driver performing draft control. CONSTITUTION:When a passing through length calculator 36 detects passing of a tube stock (p) for a preset control pitch distance through a stand 6, a rolling controller 11 gives a signal indicating a draft position to a motor 6a and the stock (p) is rolled by the stand 6. In that time, an arithmetic unit 20 decides that the present operation of the motor 6a finishes or not by the time at which the control in the succeeding control pitch is started based on an operation completing period of time of the motor 6a. In the case of completion, the unit 20 calculates a draft amount of the stand 6 in the succeeding control pitch; in the case incompletion, the unit 20 corrects a control range and checks completion of the operation of the motor 6a in that duration time. If capability of the completion is confirmed, the unit 20 calculates a draft amount in the control pitch at that time and gives a motor 7a a timing signal based on a corrected controlled variable. A stand 7 rolls the stock (p) synchronously with the control pitch of the stand 6.</p> |
