| 摘要 |
PURPOSE:To weld steel pipes easily in a tunnel by putting two pieces of steel pipes on plural turning rollers, and welding the abutting end parts of both pipes from the inside while rotating the pipes. CONSTITUTION:Plural sets of turning rollers 2 each set consisting of a pair of right and left rollers are provided in a tunnel 1 in the longitudinal direction of the tunnel 1. Two pieces of steel pipes 7 carried in with a carrying-in carriage 4 are put on the rollers 2. Next, a backing strip 11 is mounted to the outside surfaces between the abutting end parts of both pipes 7, and both pipes 7 rotated. Thence, while a welding machine 12 located in the steel pipes 7 is moved to the side opposite from the pipes 7 in synchronization with the rotation of said pipes, the pipes 7 are welded from the inside surface. |
