Patent ID: 6964256

Claim:
A combustion control apparatus for an engine, comprising: a fuel injector extending into a combustion chamber of a cylinder of the engine, exhaust gas recirculation regulator means for adjusting the amount of the exhaust gas recirculated to the combustion chamber; main-injection control means for controlling the injector to inject fuel at a timing during an intake stroke or a compression stroke to achieve a combustion in which a ratio of a premixed combustion is larger than that of a diffusion combustion when the engine is in a predetermined operational condition; exhaust gas recirculation control means for controlling said exhaust gas recirculation regulator means, so that an exhaust gas recirculation value associated with the recirculation amount of the exhaust gas is a first predetermined value or more when the engine is in the predetermined operational condition; and auxiliary-injection control means for controlling the injector to perform auxiliary-injection at a predetermined timing at a late stage of the compression stroke, wherein said predetermined timing is a timing where fuel by the auxiliary-injection delay a transition from a cool flame reaction to a hot flame reaction caused by the compression stroke of the cylinder at increasing temperature by a premixture of the fuel occurring during the main-injection, wherein said auxiliary-injection control means further adjusts the auxiliary-injection amount according to an engine operational condition so that the transition form the cool flame reaction to the hot flame reaction occurs within a predetermined period near the top-dead-center of the compression stroke of the cylinder.