Patent ID: 8682568

Claim:
A diesel engine, comprising: an engine body to be supplied with fuel containing diesel fuel as its main component, a geometric compression ratio being set to 15:1 or below; a fuel injection valve arranged in the engine body so as to be oriented toward a cylinder of the engine body and for directly injecting the fuel into the cylinder; and a control module for controlling a mode of injecting the fuel into the cylinder through the fuel injection valve; wherein the control module performs a main injection where the fuel is injected to cause a main combustion mainly including a diffusion combustion and performs a plurality of pre-stage injections where the fuel is injected prior to the main injection to cause a pre-stage combustion prior to the main combustion, where the plurality of pre-stage injections are injected at a timing near top dead center of a compression stroke, and where each of the pre-stage injections is performed at a timing in which injected fuel reaches within a cavity formed in a top surface of a piston fitted in the cylinder, and fuel injected later collides with fuel previously injected, and a gas mixture with a high equivalence ratio is locally generated; and wherein the control module controls the injection mode of the pre-stage injections and the injection mode of the main injection so that a heat release rate of the main combustion starts to increase after a heat release rate of the pre-combustion starts to decrease at the same time when the heat release rate of the pre-combustion reaches a peak.