| 摘要 |
PURPOSE:To perform surely a tack welding in an offsetless and gapless state by tack welding the abutting part of an O-pipe by a welder which moves along a boom arranged horizontally in the inside of the O-pipe in an O-press. CONSTITUTION:A boom 13, a welding dolly 18, and each welder 21 are previously made on standby. Then a U-pipe P' is carried into the inside of an O-press through a closing stand 8. Next, an O-forming is started, and a tack welding is successivly started when an O-pipe before finishing is fitted with upper and lower dies 6, 7, to actuate a horizontally moving motor, and then each welder 21 is moved by the amount of its given pitch to tack weld the whole length. After finishing the tack welding and the O-pressing, an O-pipe is carried out by opening the dies 6, 7 and is sent directly to a regular welding stage of omitting a tack welding stage. |
