Ignited internal combustion engine operated with charge stratification

Claim 1

In a spark ignited internal combustion engine operated with charge stratification and including a cylinder head having a main combustion chamber, an auxiliary combustion chamber connected to the main combustion chamber through a connecting passage, fuel delivery means for supplying fuel to the auxiliary combustion chamber, ignition means for igniting a fuel-air mixture in the auxiliary combustion chamber, and an intake and an exhaust conduit communicating with the main combustion chamber; the improvement wherein: the auxiliary combustion chamber has at least one wall portion in heat exchange relationship with hot exhaust gases flowing through the exhaust conduit from the main combustion chamber of the internal combustion engine, the auxiliary combustion chamber being positioned in the immediate vicinity of the exhaust conduit in such a manner that the wall portion of the auxiliary combustion chamber in heat exchange relationship with hot exhaust gases flowing through the exhaust conduit from the main combustion chamber projects into the exhaust conduit, whereby hot exhaust gases flowing through the exhaust conduit flow externally around the wall portion of the auxiliary combustion chamber to heat the auxiliary combustion chamber and maintain the auxiliary combustion chamber at an elevated temperature so that fuel components of a fuel-air mixture in the auxiliary combustion chamber are rapidly evaporated.