| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method and device for controlling an outside diameter capable of substantially bringing the outside diameter of a seamless steel pipe produced in the production process of the seamless steel pipe including the heat treatment in coincidence with approximately a target outside diameter. SOLUTION: The predicted fluctuations quantity of the pipe outside diameter through the heat treatment based on the conditions of the heat treatment by the device for controlling the outside diameter 4 is calculated. Further, the predicted fluctuations quantity is corrected based on the measuring values of outside diameter measuring sensors 2a, 2b and temperature sensors 23a, 23b. At the time of producing the seamless steel pipe, an adjustment quantity of the drafting position of rolls 2, 2,... is calculated using the predicted fluctuations quantity in the control portion and the control signal of the drafting position based on the adjustment quantity is output to a control device of the drafting position 7, which drives motors M, M,... and adjusts the drafting position of the rolls 2, 2,... based on the control signal of the drafting position.</p> |
