Vertical down welding process by gravity arc welding and welding machine therefor

摘要

PCT No. PCT/JP81/00123 Sec. 371 Date Jan. 29, 1982 Sec. 102(e) Date Jan. 29, 1982 PCT Filed Jun. 2, 1981 PCT Pub. No. WO81/03453 PCT Pub. Date Dec. 10, 1981.A vertical down welding process by gravity arc welding, in which a guide rail 5a is disposed aslant upwardly at an inclination angle theta 1 of 40 DEG to 60 DEG to a vertical weld line 3 and, while a holder 6 of a welding rod 4 is brought down along the guide rail 5a, the welding rod 4 is moved down along the vertical weld line 3 for welding. A welding machine for use with this vertical down welding process is constructed so that the upwardly inclined guide rail 5a is provided at the inclination angle theta 1 of 40 DEG to 60 DEG ;, the guide rail 5a is comprised of a main rail 5c and a sub-rail 5b; and the holder 6 of the welding rod 4 is lowered from the sub-rail 5b to the mail rail 5c.