TRANSITION FROM HOMOGENEOUS CHARGE COMPRESSION IGNITION COMBUSTION MODE TO SPARK IGNITED COMBUSTION

摘要

A method of controlling an engine includes initiating a transition from homogenous charge compression ignition (HCCI) to spark ignited (SI) combustion mode of the engine under low load. The method includes commanding an exhaust valve actuator to increase lift of the exhaust valve to maximize expulsion of combustion chamber contents. The method also includes injecting into the combustion chamber sufficient amount of fuel after the lift of the exhaust valve was increased to generate substantially stoichiometric air-fuel ratio of the gas mixture contained in the chamber. The method also includes igniting the gas mixture after the fuel was injected into the combustion chamber to maximize combustion of the gas mixture. The method additionally includes commanding an intake camshaft phaser to change the position of the intake camshaft to a position configured for predetermined throttled SI combustion mode after the gas mixture was ignited to maximize operating efficiency of the engine.

主权项

1. A method of controlling, via an electronic controller, an internal combustion engine capable of transitioning from a homogenous charge compression ignition (HCCI) combustion mode to a spark ignited (SI) combustion mode, the method comprising:
initiating a transition from the HCCI to the SI combustion mode of the engine under low load, wherein the engine includes a combustion chamber provided with an intake valve actuated by an intake camshaft, an intake camshaft phaser configured to change a position of the intake camshaft, an exhaust valve actuated by an exhaust camshaft, an exhaust valve actuator configured to vary lift of the exhaust valve, a throttle configured to regulate entry of fresh air into the combustion chamber, a fuel injector configured to supply fuel into the combustion chamber, and a spark plug configured to generate a spark to ignite the fuel and air; commanding the exhaust valve actuator to increase the lift of the exhaust valve such that expulsion of contents of the combustion chamber is maximized; injecting, via the fuel injector, into the combustion chamber, a sufficient amount of fuel after said commanding the exhaust valve actuator to increase the lift of the exhaust valve such that a substantially stoichiometric air-fuel ratio of the gas mixture contained in the combustion chamber is generated; igniting the gas mixture via the spark plug after said injecting a sufficient amount of fuel into the combustion chamber such that combustion of the gas mixture is maximized; and commanding the intake camshaft phaser to change the position of the intake camshaft to a position configured for a predetermined throttled SI combustion mode after said igniting the gas mixture, such that operating efficiency of the engine is maximized.