This experimental work was concerned with comparison of inlet valve actuation strategies in a thermodynamic single cylinder spark ignition research engine equipped with a mechanical fully variable valvetrain on both the inlet and exhaust. The research involved study of the effects of the valvetrain on combustion, fuel economy and emissions when used to achieve variable valve timing alone and wh...

INTRODUCTION VEHICLE engines have made remarkable progress since they first appeared and the operating range of engines in terms of rpm (revolutions per minute) and torque have expanded significantly. However, optimum engine design becomes difficult if the operation timing of the engine valves is fixed. For this reason, variable valve actuation has been used to optimize the valve timing in resp...

In an electro-mechanical valve actuated engine, solenoid actuators drive the valves that control airflow into the cylinders, allowing elimination of the camshaft and flexible control of the valve timing. Individual control of the valves provides flexibility in valve timing over all engine operating conditions and fully enables the benefits of variable valve timing. This paper describes a closed...

As one of variable valve timing (VVT) approaches, the electromechanical valve actuator (EMVA) uses solenoid to actuate valve movement independently for the application of internal combustion engine. This paper proposed an EMVA structure by incorporating the hybrid magneto-motive force (MMF) implementation in which the magnetic flux is combined by the coil excitation and permanent magnets. Makin...

A considerable amount of research is currently being done on electromechanical valve (EMV) actuators as a potential replacement for the camshaft in order to achieve variable valve timing. Unfortunately, EMV actuators suffer from large impact velocities between the valve, valve seat, and the actuator itself resulting in excessive wear on the system and producing unacceptable levels of noise. Add...