MULTI-LAYER WELDING METHOD

PURPOSE:To automate the multi-layer welding of a mutually pierced joint of a pipe and besides, to improve the weld quality by deducing profiling data of a welding torch, a lamination layer pattern and a welding condition using a computer and a visual sensor. CONSTITUTION:At the time of the multi-layer welding of the mutually pierced joint 3 of the pipe, a weld line and a cross-section shape of a groove are calculated from the dimensional data of the joint 3 and the visual sensor is moved along the deduced weld line to obtain the profiling data of the welding torch. Furthermore, the cross-sectional shape data of the groove are composed by the picture processing and arithmetic operation of the groove by the visual sensor and the lamination layer pattern is formed based on the data to decide the welding condition for every pass of the lamination layer pattern. Then, the welding torch is controlled by the profiling data and moreover, the groove is welded according to the welding condition. As a result, even the complicated shape of the mutually pierced joint 3 of the pipe can be automated and besides, the weld quality is improved.