Petrol injection engine and method for controlling the gasoline injection engine

摘要

A gasoline fuel injection engine having a self-ignition combustion operating range that allows autoignition of fuel injected into a cylinder through an injector and containing at least gasoline, the engine having a geometric compression ratio in the range of 18 to 40, including both limits, the engine comprising: an injection control section configured to control fuel injection of the injector; andan ignition assisting section configured to apply energy to the fuel injected into the cylinder through the injector to assist the autoignition combustion of the fuel when the engine is within the autoignition combustion operating range, wherein when the engine is within the autoignition combustion operating range, the injection control section sets a start time of the fuel injection within a period from an end stage of a compression stroke to an upper compression dead center, and the ignition assisting section applies the energy to the fuel injected into the cylinder in a period from the start of fuel injection to an initial stage of an expansion stroke, characterized that is, a time of a specific crank angle which is in a range of 4 ° CA to 15 ° CA after the upper compression dead center, and at wherein a cylinder internal pressure increase rate, which is a ratio of a change in the cylinder internal pressure to a change in crank angle in operation of the engine, reaches a negative maximum value overlaps with a main combustion period in which a combustion mass percentage of the fuel is in the range of 10% up to 90%, both limits included, with the ignition assist section applying the energy to the fuel injected into the cylinder through plasma ignition.