| 摘要 |
PURPOSE:To enable to work J-shaped groove efficiently and at low cost by only gas cutting by gas cutting a groove working part vertically, and cutting a part of the cut face at an angle, and further fusion cutting to a curved face. CONSTITUTION:The first cutting torch 7 is operated in conformance to the groove working part, and at the same time, a gas automatic cutter 3 is moved along a guide rail 2, and cutting is made perpendicular to the surface 1a of a plate 1 to be welded, that is I-shaped cutting is made. Then, cutting is made obliquely (V-shaped cutting) from the cut face 1b by the second cutting torch 8 having a nozzle 8a inclining at about 45 deg. to the cut face 1b made by the first cutting torch 7 and a slanted cut face 1C is obtained. The slanted cut face 1C is fusion-cut to a curved face and a J-shaped groove 1d is obtained. Flames from the nozzle 9a of the third cutting torch 9 become parabolic by collision with the plate 1 to be welded and as the nozzle 9a is fixed to a specified position. Thus, a curved face is formed by cutting. |
