Abstract: The welding apparatus has a positioner (1) provided with workpiece supporting means (11) which is rotatable about a first central axis (Ca) and is pivotable up and down about a second central axis (Cb) crossing the first central axis (Ca). A welding robot (2) includes a robot body (20) mounted on the workpiece supporting means (11). Therefore, even when the workpiece supporting means (11) operates, it is possible to prevent a torch (3) carried by the robot body (20) from positionally deviating relative to a workpiece (W) supported on the work supporting means (11).

Abstract: An automatic welding apparatus for forming a circular bead along a circumference of a first workpiece at its junction with a second workpiece in order to weld the former to the latter, comprising a turntable, clamp members for clamping the second workpiece to the turntable, a torch holder for holding a welding torch in an adjusted position, a torch positioner which is engageable with the first workpiece, for maintaining a constant relative positional relationship between the welding torch and the first workpiece, a positioner guide mechanism for supporting and guiding the torch positioner to a desired position in a plane extending in parallel relationship with respect to a surface plane of the turntable, and the torch holder being restricted from rotating.