Development of Stainless Steel Fuel Filler Pipe

Thin austenitic stainless steel pipes have been applied to automobile fuel filler pipe. Problems exist in the forming and welding process. The factors that have influenced the forming and welding will be discussed. The solution will be described and illustrated in detail. The methods used in a mass production have been developed by an experimental study. The problems that we encounter in the expanding and bending thin stainless steel pipes were solved by punch design and bender machine. In a welding process with plasma welding between retainer pipe and filler pipe, the clearance at press fitting area is one of the most effective factors. A new brazing method using divided high frequency heating coil has been developed and a filler pipe was designed to maintain the strength at the brazing area.