WELDING TORCH FOR GAS SHIELD WELDING AND GAS SHIELD WELDING METHOD

摘要

PROBLEM TO BE SOLVED: To obtain a welding torch including a gas nozzle with a simple circular cross section, capable of carrying out gas shield welding of a material with a deep groove or a material where a groove is not formed in an optimum condition without being restricted by a groove width relative to the structure of the welding torch used in the gas shield welding.;SOLUTION: The welding torch includes a gas nozzle which is relatively movable in a torch axis direction to a torch body. A nozzle port is forwardly/backwardly movable by allowing the gas nozzle to be slidably fitted into a guide cylinder in the torch axis direction and by a bellows structure extendable and contractable in the axial direction or the like. The gas nozzle is coupled with a forward/backward drive device such as a servo cylinder which is stroke controllable by NC control and the nozzle port is moved and positioned. When a part of a bottom of a narrow deep groove is welded, welding is carried out while the gas nozzle is retreated and a welding wire is protruded long from the nozzle port.;COPYRIGHT: (C)2012,JPO&INPIT