Meta - CVD System An Electro-Mechanical Cylinder and Valve Deactivation System 2001-01-0240
A variable valve actuation mechanism suitable to activate and deactivate the intake and exhaust valves of reciprocating engines will be presented within this paper. This system called the “CVD System” (Cylinder and Valve Deactivation) allows a reliable activation and deactivation of the valves of conventional cam-controlled valve trains within one engine cycle, independent of the oil feeding system. The system can be used for both the deactivation of single valves of multi-valve engines - e.g. to increase the in-cylinder charge motion - or the deactivation of complete cylinders of multi-cylinder engines.
Different to the well known hydraulic valve shifting or switching devices the CVD system represents an electromechanical device with an unlocked (deactivated) position being mechanically offered to a solenoid operated coupling lever once per cam revolution. If valve deactivation is required the solenoid is switched on to cut the force line between cam and valve. This system can principally be applied to both types of rocker-arms valve trains, the overhead valve train and the push rod valve train.
This paper describes the principle function of the CVD mechanism, showing examples for different applications. Results of simulations and experimental investigations will be presented to evaluate the kinematic and dynamic behavior of the system. The potentials of cylinder deactivation with the CVD system will be discussed on the base of thermodynamic test bench experiences and vehicle results.