| 摘要 |
PURPOSE:To prevent the generation of a clearance in a welded part in the stage of welding by forming a penetration bead on the rear of a pipe structure and preventing the drooping of a molten metal therefrom. CONSTITUTION:A forming device of penetration bead for one-side welding consists of a body 1 provided with two support rolls 2 and a freely vertically movable backup rolls 3 and a fixing shaft 11 for fixing non-rotatably the body 1. The body 1 is inserted into the butt part of the pipe construction and thereafter the roll 3 is moved upward to press the three rolls 2, 3 respectively into the pipe construction; at the same time the body 1 is fixed non-rotatably via the shaft 11 and while the pipe construction is rotated, the butt part is welded from the rear thereof at the contact point with the roll 3. |
