Application of a Valve Lift and Timing Control System to an Automotive Engine

This paper describes a new variable valve lift and timing control system, which varies the lift and timing by changing the fulcrum of the rocker arm. The fulcrum is varied according to the inclination of a lever that engages with a control cam. The control cam is driven by an actuator mechanism so as to provide multistage control over valve lift and timing. As a result, this new system reduces valve train noise and delivers stable valve operation through the high-speed range. The compact actuator mechanism provides excellent response for controlling valve lift and timing. When applied to a 1.8-liter 4-cylinder gasoline engine, the system contributed to higher power output, lower fuel consumption and reduced noise.