| 摘要 |
<p>A valve operating system in an overhead cam type multicylinder internal combustion engine having three intake-side rocker arms (36,37,38) disposed to operate a pair of intake-valves (Vl1,Vl2) and two exhaust-side rocker arms (41,42) disposed to operate a pair of exhaust valves (VE1,VE2). The intake-side rocker arms are provided with a connection switchover mechanism (60) capable of switching-over the connection and disconnection of the adjacent intake-side rocker arms. Exhaust-side cams (34,35) are provided on a cam shaft (25) on opposite sides of intake-side cams which are provided adjacent one another. Two of the intake-side rocker arms and both of the exhaust-side rocker arms are in rolling contact with the corresponding cams through rollers (42,43,44,45) mounted on the rocker arms. The exhaust-side rocker arms are provided with notches (47,48) in the area near the cam shaft for accommodating portions of the intake-side rocker arms, respectively. Thus, it is possible to reduce valve operational frictions loss to the utmost, to position the rocker arms in an axially compact arrangement and to position the intake valves and exhaust valves such that their axes lie at a small angle. <IMAGE></p> |
