Full-automatic welding method for compressor shell and pipe fitting

The invention discloses a full-automatic welding method for a compressor shell and a pipe fitting. A positioning backup plate is mounted on a positioning mechanism base through an up-down sliding mechanism. An end face hole opening of the compressor shell is positioned by a positioning flange arranged on the positioning backup plate. The end face of the compressor shell is positioned by the plane of the positioning backup plate. A positioning backup plate jacking block driven by a jacking block cylinder is arranged on the positioning mechanism base. The up-and-down sliding of the positioning backup plate is controlled by an inclined surface on the positioning backup plate jacking block. According to the technical scheme, the pre-positioning mode is adopted, positioning error compensation is achieved, and the positioning precision is high; the production efficiency and the automation degree are high, the labor intensity of workers is greatly reduced, and the safety and the reliability are good; the structure i