WELDING ROBOT AND CIRCUMFERENTIAL WELDING METHOD USING THIS ROBOT

PROBLEM TO BE SOLVED: To provide a circumferential welding method using a welding robot which forms shift data on an exact and same circular orbit by correcting the shifted teaching data when the teaching data on the circular orbit is shifted and this shifted teaching data does not exist on the same circular orbit. SOLUTION: This circumferential welding method using the welding robot comprises teaching the first pass for performing welding in a circumferential direction, then shifting the teaching data on the resultant three-dimensional coordinate axes, automatically forming the welding position data of the second and subsequent passes, setting one coordinate axis of the fresh three-dimensional coordinate axes on a segment connecting the central point of the circumference determined from the teaching data of the first pass and one teaching point of the first pass when welding is performed in the circumferential direction of the second and subsequent passes in accordance with the welding position data obtained in the manner described above, previously determining the angle θ formed by the set fresh coordinate axis and the original coordinate axis, forming the welding position data of the second and subsequent passes and forming the welding position data of the second and subsequent passes exactly on the circular orbit using the data obtained by rotating the resultant welding position data to a reverse direction at the same angle as the rotated angle θ described above as the welding position data of the second and subsequent passes.