| 摘要 |
PURPOSE:To prevent the pipe end from a deformation caused by diametral contraction, by controlling roll gaps so as to close the gaps after passing through the tip of a steel pipe and to open the gaps before passing through the tail end of the pipe, in straightening the steel pipe by 3 rolls at the inlet, center, and exit. CONSTITUTION:Before biting the tip of a steel pipe by upper and lower rolls (r11) and (r12) of an inlet straightening roll device R1, a roll gap of the device R1 is set to the zero clashing position and roll gaps at the center and the exit of respective straightenig roll devices R2 and R3 are opened; after passing through the tip of the pipe, the roll gaps are closed successively. Then the roll gap at the roll device R1 is set to a set crashing quantity position, and the roll gaps at the devices R2 and R3 are closed to set-crashing-quantity positions after being given the time-delays by setting once the devices R2 and R3 to the zero clashing position. After that, respective gaps between upper and lower rolls are released successively, from the gap of the inlet rolls, just before the tail end of the pipe reaches the respective devices R1, R2, and R3. |
