| 摘要 |
<p>PURPOSE:To drastically improve the accuracy of a product such as a seamless steel tube. CONSTITUTION:When a mandrel bar 3 is inserted into the internal part of a tube stock 2 to be rolled and the material 2 to be rolled is rolled as the rear end part of the mandrel bar 3 is held by an electric motor 13 on a running device 11 driven in the rolling direction, a torque controller 18 is equipped to control the output torque of the electric motor 13 so that the reference of output torque of the electric motor 13 corresponding to the tension or compression actuated to the mandrel bar 3 agrees to the measured value of the output torque of the electric motor 13. Preferably, a detecting device is equipped to detect the tension or compression actuated by the running device on the mandrel bar, the torque controller calculates the measured value of the output torque based on the detected tension or compression and simultaneously, the output torque of the electric motor 13 is controlled so that the measured value of this output torque and the reference of the output torque agree to each other.</p> |
