Direct-fuel-injection-type spark-ignition internal combustion engine and method of controlling the internal combustion engine

摘要

A direct-fuel-injection-type spark-ignition internal combustion engine has a fuel injection valve (7) which directly injects fuel into a cylinder and switches its combustion mode in accordance with an operating state of the engine between stratified charge combustion in which fuel injection occurs during the latter half of a compression stroke and homogeneous combustion in which fuel injection occurs during an intake stroke. A nozzle hole of the fuel injection valve (7) directs fuel toward an impingement portion of the cylinder bore (10) located opposed to the nozzle hole in a lower section of the cylinder bore (10) so that fuel can be injected into a cavity (5a) formed in a top face of a piston (5) from an upper section of the cylinder bore (10) during the latter half of a compression stroke. A cooler (12A) located at least in the neighborhood of the impingement portion in the lower section of the cylinder bore has a lower cooling capacity than a cooler (11A) located in the neighborhood of the upper section of the cylinder bore (10). Because of this construction, even if fuel injected during the latter half of an intake stroke collides with the cylinder bore (10) and initially adheres thereto, the adherent fuel can be effectively gasified. <IMAGE>