Patent ID: 7194996

Claim:
An internal combustion engine, comprising: at least one cylinder, comprising: a combustion chamber; a piston whose compression action causes a mixture of air and fuel within said combustion chamber to be ignited; at least one inlet valve for admitting gas which includes fresh air into said cylinder; at least one exhaust valve for exhausting combusted gases from said cylinder; a fuel injection system comprising at least one fuel injector, through which fuel is injected into said combustion chamber of said cylinder; at least one sensor for measuring an engine operation parameter; and a controller for controlling said fuel injection system and said spark ignition system to achieve a desired combustion phasing, such that during compression ignition mode, while using a first fuel injection strategy, said exhaust valve is arranged to be closed before top dead center during an exhaust stroke of said piston and said intake valve is arranged to be opened after top dead center during an induction stroke of said piston therefore achieving a negative valve overlap to retain residual exhaust gas, said controller further controlling said fuel injection system so as to perform a first fuel injection in the interval after the closing of said exhaust valve and before top dead centre of a subsequent piston exhaust stroke and to perform a first combustion during the negative valve overlap before top dead centre of the piston exhaust stroke, and performing a second fuel injection before top dead centre of the piston compression stroke and a subsequent, second combustion prior to a third combustion comprising a compression ignition.