A method and system for controlling a transition from a homogeneous compression ignition combustion mode to a spark ignited combustion

摘要

A method of controlling an internal combustion engine (12) that is capable of transitioning from a homogeneous compression ignition (HCCI) combustion mode to a spark ignited combustion (SI) combustion mode by electronic controller (56), the method comprising in that under low load a transition is initiated from the HCCI to the SI combustion mode of the engine (12), the engine (12) including a combustion chamber (24) provided with an inlet valve (26, 28) passing through a combustion chamber Inlet camshaft (40) is actuated, an intake camshaft phaser (44) adapted to change a position of the intake camshaft (40), an exhaust valve (30, 32) actuated by an exhaust camshaft (42), an exhaust valve actuator (50 ) configured to vary a lift of the exhaust valve (30, 32), a throttle (23) adapted to allow entry of fresh air into the combustion comb a fuel injector (34) configured to supply fuel to the combustion chamber (24) and a spark plug (36) configured to provide a spark to ignite the fuel and the air instructing the exhaust valve actuator (50) to increase the lift of the exhaust valve (30, 32) to maximize exhaust of contents of the combustion chamber (24); a sufficient amount of fuel into the combustion chamber via the fuel injector (34) (24) is injected after the exhaust valve actuator (50) has been commanded to increase the lift of the exhaust valve (30, 32) to produce a substantially stoichiometric air-fuel ratio of the mixed gas contained in the combustion chamber (24) The gas mixture is ignited by means of the spark plug (36) after a sufficient amount of fuel has been injected into the combustion chamber (24) e, so that the combustion of the gas mixture is maximized; and instructing the intake camshaft phaser (44) to change the position of the intake camshaft (40) to a position adapted for a predetermined throttled SI combustion mode after the gas mixture has been ignited so that the operating efficiency of the engine (12) is increased. is maximized; characterized in that it directs a predetermined position of the throttle (23) adapted to minimize entry of fresh air into the combustion chamber (24); a combusted gas mixture for a combustion cycle is retained in the combustion chamber (24) which is generating is followed by the substantially stoichiometric air-fuel ratio of the gas mixture, so that an amount of fresh air entering the combustion chamber (24) is minimized, a timing and duration of injection of the fuel and ignition of the gas mixture are controlled so that the Combustion efficiency is maximized; and commanding a position of the throttle (23) such that a sufficient amount of air enters the combustion chamber (24) for a stable SI combustion mode at the substantially stoichiometric air-fuel ratio.