| 摘要 |
PURPOSE:To make a welding device simpler than heretofore and to stabilize welding by forming a rotating magnetic field that rotates an arc column only on the anode side of pipes to be welded, and forming the strongest magnetic field only near the end face of the anode. CONSTITUTION:An electromagnetic coil 14 is provided only on the anode side of pipes 1, 2 to be welded where the anode point is difficult to transfer and said pipes are welded by the magnetically rotating arc. The strongest magnetic field is only near the anode point and an arc column 16 does not extend longer than an arc column 6 of the prior art as shown right in the figure. At the same time, the arc column 16 is bent at a sharp angle near the anode end face and is easier to be radiated of heat, resulting in small and regular transfer intervals of the anode point. Since there are no rotating magnetic fields on the cathode side, the magnetic blow of the cathode is small and the rate to be blown to the axial center side of the pipes is reduced. Therefore, the above-described ratio can be adjusted by adjusting the position between the end faces of the pipe and the coil 14. This method permits welding of thick-walled pipes as well which are heretofore difficult to weld. |
