PURPOSE: To prevent welding free from the change of gap at the root part of welding and the aberration of aimed position of arc without making tack welding by making fitting with the gap between a core and a frame member in 0 state or compressive stress is loaded on opposed contact face.
CONSTITUTION: A core 1 is fitted in the frame of a frame member 2 in the state where the gap of opposing parts is 0 or compressive force is loaded on the opposed contact face in the relation between the outer peripheral face of the core and the inner peripheral face of the frame member 2. Under such a state of fitting, welding is made making the contact face of opposed parts 3 as a welding root. Thereby, the occurrence of unstable penetration bead due to the change of gap and the occurrence of inadequate joint penetration that entails tack welding are prevented, and very satisfactory and uniform penetration bead can be obtained by automatic welding.
MURAI YASUO
KAYAMA KAZUO
TAKAYORI YOSHIAKI
