Patent ID: 7584739

Claim:
An internal combustion engine comprising: a piston reciprocally displaced in response to rotation of a crankshaft; a main combustion chamber, the main combustion chamber being at least partially defined by the piston; an auxiliary combustion chamber; a partition disposed between the main combustion chamber and the auxiliary combustion chamber, the partition including at least one passage providing fluid communication between the main combustion chamber and the auxiliary combustion chamber; an exhaust valve reciprocally disposed with respect to the main combustion chamber; an intake valve reciprocally disposed with respect to the main combustion chamber; a variable valve timing device coupled to the intake valve, the variable valve timing device retarding movement of the intake valve relative to movements of the piston and the exhaust valve when a engine parameter representing combustion stability indicates a predetermined operation condition the retarding producing: a first pressure differential across the at least one passage between the main combustion chamber and the auxiliary combustion chamber, the first pressure differential including a lower pressure in the main combustion chamber relative to the auxiliary combustion chamber in response to an intake stroke of the piston; and a second pressure differential across the at least one passage between the main combustion chamber and the auxiliary combustion chamber, the second pressure differential including a higher pressure in the main combustion chamber relative to the auxiliary combustion chamber in response to an open configuration of the intake valve with respect to the main combustion chamber; and a fuel injection valve supplying fuel to be combusted in the main and auxiliary combustion chambers, such that the fuel injection valve injects the fuel while a pressure becomes the second pressure differential from the first pressure differential so that at least part of the fuel arrives at said at least one passage.