| 摘要 |
<p>PURPOSE:To accurately control the wall thickness of a material with a relatively simple method, by controlling the relative speed of the speed of a mandrel and the rolling speed of a pipe-shaped material, and changing the rolling speed, in rolling the material. CONSTITUTION:A mandrel bar 2 is inserted to the inside of a pipe-shaped material 1, which is rolled through plural rolling stands equipped with grooved rolls 3. In this case, the wall thickness of the material 1 is controlled while controlling the relative speed of the speed of a mandrel bar 2 and a rolling speed of the material 1 in rolling. The controlling of the relative speed of the material 1 and the mandrel bar 2, that is in other words, the controlling of rolling load is made possible by the number of revolutions of the roll and a moving speed of the bar 2. Accordingly the change of rolling load is related to the value of a mill rigidity, and then the wall thickness is controlled because the change of the wall thickness depends on the mill rigidity. Further, the speed of the material 1 is calculated from the relation between the peripheral speed of the roll and a forward slip, on the other hand, the speed of the material 2 is easily measured from a driving shaft because the bar 2 moves at a constant speed.</p> |
