Mazda Motor Corporation

Takeshi Inazumi

Naotoshi Shirahashi

Takeshi Matsubara

Tsunehiro Mori

Tetsuya Fujioka

Keisuke Kawahara

Takahiro Yamamoto

A diesel engine system is provided, which includes a piston having a cavity dented downwardly in a crown surface thereof and having a bottom part, a peripheral part dented so as to be convex radially outward, and a lip part formed above the peripheral part and protruding so as to be convex radially inward in a cross-sectional view. An injection controller causes an injector to perform, during operation in a given operating range, a main injection in which injected fuel is directed to the lip part, and an after-injection in which a smaller amount of the fuel than the main injection is injected at a given timing later than the main injection in an expansion stroke. An injection interval period from an end of the main injection to a start of the after-injection is shorter as a temperature parameter related to a progress of a warmup of engine increases.

Diesel engine system

A method of controlling a fuel injection of a diesel engine for performing a plurality of fuel injections to cause a plurality of combustions inside a cylinder in one combustion cycle, is provided, which includes acquiring an oxygen concentration inside the cylinder, performing, on compression stroke, the plurality of fuel injections at substantially even injection intervals while increasing the injection intervals as the oxygen concentration decreases, and performing, after the plurality of fuel injections, another fuel injection including a larger injection amount than in the plurality of fuel injections, near a top dead center of the compression stroke.

Method and device for controlling fuel injection of diesel engine

A method of controlling a fuel injection of a diesel engine for performing a plurality of fuel injections to cause a plurality of combustions inside a cylinder in one combustion cycle, is provided, which includes performing, on compression stroke, the plurality of fuel injections at substantially constant injection intervals while increasing an injection amount as an in-cylinder oxygen concentration decreases, and performing, after the plurality of fuel injections, another fuel injection including a larger injection amount than in the plurality of fuel injections near a top dead center of the compression stroke.

The compression self-ignition engine fuel injection control device is configured to, during one combustion stroke, perform multiple fuel injections to induce multiple combustions in a cylinder. The fuel injection control device comprises a PCM () configured to set an interval between a pre-injection and a main injection in the multiple fuel injections, so as to allow valley regions of a curve indicative of a frequency characteristic of a combustion pressure wave generated by the multiple combustions to fall within respective ranges of a plurality of resonant frequency bands of a structure of an engine body of the engine, wherein the PCM is operable to increase a fuel injection amount of the pre-injection more largely as an engine load becomes lower at the same engine speed.

Growing community of inventors

Hiroshima, Japan

Takeshi Inazumi