ElectroMagnetic Intake Valve Actuation Using a Subwoofer

Abstract

For this project I proposed that a linear voice coil found in a subwoofer speaker could be used to actuate the intake valve of a small 4-stroke engine in order to operate it at least idle speeds. I then prototyped the direct actuation of the intake valve and valve spring on a real engine base using such an actuator under non-engine running conditions. I was able to show through my results that high speed intake valve actuation is possible using a linear voice coil to achieve the correct amount of lift and the correct timing to achieve idle for a small 4-stroke engine. Continuous variable valve timing is even possible through input signal manipulation. I was also able to show that a simple method used to estimate the maximum instantaneous power necessary to actuate the intake valve accurately reflected the actual maximum instantaneous power measured by the system. Though I did not achieve this myself, my results warrant the further investigation of voice coil actuators in engine running conditions as a potential replacement for the typical cam-actuated valve timing system.