WELD LINE DETECTING DEVICE

PURPOSE:To provide the weld line detecting device that the weld line can surely be detected and being made by composing so as to locate a welding torch at the very low temp. position to be caused on the junction part between base metals which is calculated based on the temp. detection data at the peripheral part of the molten pool of base metals in welding. CONSTITUTION:The temp. of the peripheral part of a molten pool 2 is detected in welding and the very low temp. position 4 to be caused on the junction part 5 of the above of base metal 1, 1' is found based on the detected data thereof. In this case, the pool 2 side is at the highest temp. and said part 4 is caused as shown in the figure at the highest temp. position thereof. And by locating the welding torch 12 to this position 4 the weld line of the position 4 can be detected simply and surely and the torch 12 can surely be located to this weld line.