| 摘要 |
<p>PURPOSE:To shorten the length of a flare generated at the rear end part of a tube material and to improve the yield by adjusting the opening of rolling rolls so that the reduction of thickness of the rear end part of the tube material is prevented in rolling the rear end part of the tube material in the inclined stretch rolling of the tube material. CONSTITUTION:Since a rolling load is reduced quickly at the rear end part of a hollow part H, the rear end part of the hollow shell H is detected by detecting this time of reduction of load. Since the reduction of such rolling load is shown as the change of the driving electric powers for the main rolls 1, 2, the rear end part of the hollow shell H can be detected by detecting the change between them both. Simultaneously, since the increase of the opening between the rolls is controlled in accordance with the variation of the rolling load or the motor driving electric power. The length in the direction of the tube axis of a flare generated at the rear end part of the tube material can be reduced drastically and the yield is improved.</p> |
