CONTROL DEVICE FOR SPARK IGNITION TYPE DIRECT-INJECTION ENGINE AND FUEL INJECTION TIME SETTING METHOD

摘要

PURPOSE: To properly execute stratified charge combustion from the low-speed side through the high-speed side of a stratified region to enhance a fuel economy improving effect, in a spark ignition type direct-injection engine for realizing stratification by using tumble flow. CONSTITUTION: The spark ignition type direct-injection engine is so structured that a combustible air-fuel mixture is produced in the vicinity of a spark plug at an ignition time by making tumble flow collide with fuel spray in a combustion chamber in stratified charge combustion. The engine is provided with a fuel pressure control means 55 for controlling fuel pressure so as to intensify the penetration force of spray from a fuel injection valve in a stratified charge combustion region as the engine rotation speed is increased, and a fuel injection time control means comprising an injection time setting means 49 and the like. The fuel injection time control means controls the interval between a fuel injection ending time and an ignition time so as to temporally shorten it as the engine rotation speed is increased in the same load condition in the stratified charge combustion region.