FUEL FLOW PASSAGE MEMBER AND FUEL INJECTION VALVE INCLUDING THE SAME

A first tubular portion forms a part of a fuel flow passage therein. A first joint surface is formed in one end surface of the first tubular portion. A first inner diameter enlarged portion is formed on a side opposite to the first joint surface. A second tubular portion forms a part of the fuel flow passage therein. A second joint surface is formed in one end surface of the second tubular portion and joined to the first joint surface. A second inner diameter enlarged portion is formed on a side opposite to the second joint surface. A welded portion is formed in an annular shape to extend radially inward from the radially outside of the first joint surface and the second joint surface by welding the first tubular portion and the second tubular portion.