| 摘要 |
<p>Variable valve lift in an engine is achieved by varying the location of the pivot (6) of the rocker arm or finger follower (2). The path of contact between the rocker arm or finger follower and the pivot may be circular or non-circular. The relationship between adjustment clearance and pivot shaft position yields controlled variation of phase and duration. At full lift, the clearance would be within usual limits, while at partial lift reduced contact velocities allow greater clearance without increasing idle noise, and thus opening of valves may be delayed, and closing advanced. Deactivation of valves (4) can occur with reduced lift and a suitably increased adjustment clearance, while maintaining adequately low contact velocities. With individual control of valves, one or more cylinders may be deactivated, or by varying lift independently on multi-valve engines, mixing of incoming gases may be enhanced.</p> |
