| 摘要 |
PURPOSE:To prevent both ends of a pipe material from producing deformation by installing the detectors of the position and speed of material and controlling the tensions at both ends of material by the change of rolling speed, in a conventional pipe rolling mill consisting of plural rolling stands. CONSTITUTION:In case of rolling a pipe material 2 by plural stands No.1- No.22, the rolling speed of rolling stand capable of providing a tension to the end part of material 2 is detected by a speed detector 6 at the times when the front end of material 2 is bitten by the 1st stand and the rear end runs out of the 1st stand. At the same time, the end positions are detected by position detectors 15-17 and 7, and these detecting signals are inputted to a speed-reference changing-timing arithmetic circuit 18 to calculate the timing of biting the end part by the next stand or that of the running out of the next stand. The calculated results are inputted to a speed-reference arithmetic device 14, to control a motor 3 for driving each rolling roll 1 by a speed control device 5 of each stand. Thus the tensions provided to both ends of material 2 are properly controlled to prevent both ends from producing deformations such as blistering. |
