| 摘要 |
<p>A method for manufacturing a rocker arm capable of increasing the durability of the rocker arm and providing excellent productivity. According to the method, firstly, an intermediate product (13) having both side-walls (20) disposed parallel with each other extendedly in a predetermined direction and an one end side connection wall (30) connecting the lower ends of the both side-walls (20) to each other at the longitudinal one end side is obtained. Secondly, the both side-walls (20) of the intermediate product (13) at one end side are bent so as to be tilted inward. Thereafter, the outer surface parts of the both side-walls (20) are molded by pressing a die (60) for molding by ironing against the outer surfaces of the tilted both side-walls (20) from the upper side to the lower side to plastically fluidize the components of the both side-walls (20) downward. As a result, valve stem guide walls (35) projected downward can be formed at both sides of the one end side connection wall (30).</p> |
