Control unit for a coreless stator for use with SI engine stepping valve

Abstract

Engine efficiency could be increased if valve timing could change with engine revolutions per minute. Poppet valves are fitted with strong springs which return them to their rest positions after being pushed down by cam lobes. Overcoming the spring loaded camshaft drive train requires a lot of engine power. Valve lift, lift duration and phase cannot be adapted with cam lobes on the camshaft but electromagnetic actuators or hydraulic/pneumatic phasing mechanisms could achieve change of lift duration and phase change. Stepping valves with flexible valve event software control, move perpendicular to the piston, thus avoiding piston valve collision problem. Engine cranking requiring fuel, spark and valve event can be done electronically without engine turning. The design of a control unit for an axial coreless stator to control the motion of the stepping valve through the Otto cycle positions intake, exhaust and power / compression is presented with successful simulation of the control algorithm. A 3phase, 12V coil prototype stator with 4 coils per phase, connected in series and consuming 3A from a 12V car battery has been prototypically realized. The project aims at essential processes to run the engine as fuel, air, spark all being software controlled, leading to a more efficient, environmentally friendly, reliable and powerful engine.