摘要 |
<p>PURPOSE:To improve dimensional accuracy by detecting the difference between a rolling load in a state that a pipe is under rolling and a rolling load at a succeeding stand in a state that the pipe has run out of a preceding stand and controlling the number of revolutions of roll so as to make the detected value zero. CONSTITUTION:Immediately after the top of a blank pipe 2 is bitten by rolls 22 through rolls 21; the output value of a load cell 42 is read in a sampling device 5, and a rolling load burdened by the rolls 22 is sampled till the bottom of pipe 2 runs out of the rolls 21. Next, when the bottom of pipe 2 runs out of the rolls 21, the mean value of sampled values up to that time is calculated and outputted to an arithmetic device 6, on the other hand, the sampling of a rolling load outputted from the load cell 42 is started immediately after the bottom of pipe 2 runs out of the rolls 21 and is continued till the pipe 2 bottom runs out of the rolls 22. An arithmetic control device 6 calculates an interstand tension basing on the mean value outputted from the device 5 calculates the number of revolutions of roll 21 necessary for eliminating the tension to output it to a motor controlling device 7 thereby correcting the number of revolutions of roll 21.</p> |