| 摘要 |
PROBLEM TO BE SOLVED: To provide a rocker arm formed by plastic working of a plate allowing further weight reduction and high rigidity while preventing crack initiation and degradation of machining accuracy. SOLUTION: The rocker arm 100 formed of a plate-like material has a pair of sidewall parts 1; a valve stem receiving part connection part 2 and a pivot receiving part connection part 3 connecting the sidewall parts 1; and a roller arrangement opening 4 between them. The spacing of the outer side faces of the pair of sidewall parts 1 in the valve stem receiving part connection part 2 is decreased stepwise with step difference of two steps or more toward the lower edge from the upper edge to form a first outer side face 21 and a second outer side face 22. The spacing of the inner side faces of the pair of sidewall parts 1 in the valve stem receiving part connection part 2 is increased stepwise with step difference of one step or more toward the lower edge. Further, the offset quantity which is the step difference of the outer side faces of the sidewall parts 1 is 0.2-2.0 times as large as the plate thickness of the material. COPYRIGHT: (C)2007,JPO&INPIT |
