Patent ID: 7232974

Claim:
An all position welding head for tube butt welding, comprising: a welding torch; an arch-shaped torch base that supports the torch; a horseshoe-shaped torch rotating ring that rotates on the outer circumferences of the to-be-welded tubes and supports one end of the torch base at a front end of the torch base, wherein the torch rotating ring matches the torch with the central axis of the to-be-welded tubes; a horseshoe-shaped torch vertical moving ring provided inside the torch rotating ring, the torch vertical moving ring supporting the other end of the torch base at the front end of the torch base, wherein the torch vertical moving ring is disposed on a circle concentric with the torch rotating ring; a first drive mechanism including a first gear group that is configured to rotate the torch rotating ring around the to-be-welded tubes, a second gear group disposed in parallel to the first gear group and configured to rotate the torch vertical moving ring around the to-be-welded tubes together with a part of the first gear group, a drive shaft configured to drive the first gear group and the second gear group, and a torch rotating motor that drives the drive shaft; a second drive mechanism including a third gear group that drives and rotates the torch vertical moving ring around the to-be-welded tubes together with the second gear group except for a first gear of the second gear group, the second drive mechanism driving the ring at a speed higher or lower than the speed of the first gear group in the same direction as or in reverse to the rotating direction of the ring torch rotating ring during driving the first gear group, and a torch vertical moving motor configured to drive the third gear group; a control that controls the driving of the first drive mechanism and the second drive mechanism, respectively; a filler wire feed mechanism that feeds a filler wire to the vicinity of the torch; and a clamp mechanism that clamps the to-be-welded tubes at a position different from the positions of the torch rotating ring and the torch vertical moving ring.