Patent ID: 8037601

Claim:
A method for manufacturing a rocker arm, the method comprising: a step of obtaining an intermediate product having both side walls extended in a predetermined direction and arranged in parallel with each other and a one end side connection wall connecting lower ends of both the side walls at a longitudinal one end side of the intermediate product; a cutout forming step of forming cutout portions extended in a longitudinal direction of the intermediate product on outer surface portions of both the side walls by pressing cutout forming punches against both side walls located at one end side of the intermediate product from the outside thereof; a first pressing step of forming raising walls in a downwardly protruded manner at both sides of the one end side connection wall by pressing a first pressing punch against the outer surface portions of both the side walls from the outside thereof to cause downward plastic flows of regions of the outer surface portions of both the side walls positioned below the cutout portions; and a second pressing step of forming valve stem guide walls by pressing second pressing punches against both the raising walls of the one end side connection wall.