| 摘要 |
PURPOSE:To obtain a metallic pipe having high quality by detecting the seam of a metallic tape formed into a pipe shape by means of a sensor and rising and descending the forming roll in accordance with the detection signal thereby correcting automatically the circumferential deviation of the seam and stabilizing welding of the seam. CONSTITUTION:A metallic tape 1' is formed to a pipe shape by using forming rolls 7A, 7B, 8, 4A, 4B. The position of the seam 2 of the tape 1' is detected with a photoelectric sensor 9 just before forming rolls 4A, 4B and the signal thereof is fed to a controller 11. The signal from the controller 11 is applied to a motor 17 of a roll lifting mechanism 13 to run forward or backward the motor 17 thereby rising or descending at least one roll, for example, 4A and correcting automatically the deviation of a seam 2. The seam 2 is thus always positioned opposite to the electrode of a welding machine 3 and stable seam welding is accomplished. Generation of a defective welded point with the metallic pipe 1 is prevented. |
