HCCI and SI combustion control methods for a direct injection internal combustion engine

摘要

A method of operating a direct-injection, four-stroke internal combustion engine (10) including a combustion chamber (20), an intake valve (24) having an intake valve profile defining a lift, a time and a duration, and an exhaust valve (28) an exhaust valve profile defining a stroke, a time and a duration, the method comprising: Operating the internal combustion engine (10) in a homogeneous charge compression ignition mode when the engine load is at or below a first predetermined value; Operating the internal combustion engine (10) in a throttled spark ignition mode when the engine load is at or above the second predetermined value; and Providing a spark in the combustion chamber (20) for at least a portion of the homogeneous charge compression ignition mode to complete an auto-ignition process, characterized in that the method further comprises: Operating the internal combustion engine (10) in an unthrottled load-controlled spark-ignition mode when the engine load is above the first predetermined value and below a second predetermined value; and Injecting fuel into the combustion chamber (20) at least twice during each cycle of the internal combustion engine (10) when the internal combustion engine (10) is operating in the unthrottled spark-ignition mode with load control and / or the spark-ignition throttled mode, wherein a total fuel charge for an engine cycle is split into two injection events and in the intake stroke 10 to 30% of the total fuel charge is injected into the combustion chamber (20) and the remainder of the total fuel charge is injected in the compression stroke.