Dynamic Characteristics of a Four-bar Linkage-type Continuously Variable Valve Actuation Mechanism Based on ADAMS

摘要

This paper proposes a simple mechanical CVVA mechanism using a four-bar linkage, a rotating 1st cam and two oscillating 2nd cams in addition to the conventional overhead camshaft valve train system. The fundamental operating principle of the CVVA mechanism is described. A multi-body dynamic model of the CVVA mechanism of single cylinder in ADAMS is developed according to the kinematic design and topological structure of the mechanism. Valve motions and compressive loads of the mechanism are analyzed through the various lift phases and camshaft rotating speeds. The results of the dynamic simulation demonstrate that the CVVA mechanism sustains proper performance in the valve timing and event control through the whole speed range.