DIRECT INJECTION GASOLINE ENGINE AND CONTROL METHOD FOR DIRECT INJECTION GASOLINE ENGINE

摘要

A direct injection engine equipped with an ignition assistance means which imparts energy to the fuel injected into the cylinders by an injector and assists the self-ignition combustion of the fuel when the engine is in the self-ignition combustion operating region. The time for initiating fuel injection is set within the period from the termination of the compression stroke to the compression top dead center, and energy is imparted to the fuel injected into the cylinders during the period from the initiation of fuel injection until the beginning of the expansion stroke, such that the crank angle time point for which the maximum negative value is achieved for the rate of rise of the in-cylinder pressure, which is the change in the in-cylinder pressure with respect to the change in the crank angle during engine motoring, overlaps the combustion period wherein the mass fraction burned of the fuel is 10%-90%.