Abstract: A fuel injection control system for a diesel engine is configured to, during one combustion cycle, perform multiple fuel injections to induce multiple combustions in a cylinder. The fuel injection control system comprises a PCM for controlling a fuel injection of the diesel engine. The PCM is configured to execute control for: at a first timing during compression stroke, injecting fuel in a first amount; at a second timing after the first timing and during the compression stroke, injecting fuel in a second amount greater than the first amount; and, at a third timing after the second timing and approximately a top dead center of the compression stroke, injecting fuel in a maximum amount greater than the first and second amounts.

Abstract: A fuel injection control system for a diesel engine configured to perform multiple fuel injections to induce multiple combustions. A PCM is configured to, during compression stroke, perform a main injection and multiple pre-stage injections prior to the main injection, and to cause a ratio of a maximum injection amount of the multiple pre-stage injections to an injection amount of the main injection to become smaller when the load of the diesel engine is less than a given load than when the load of the diesel engine is greater than the given load, and cause an injection interval between the main injection and one of the multiple pre-stage injections immediately preceding the main injection to become smaller when the load of the diesel engine is less than the given load than when the load of the diesel engine is greater than the given load.

Abstract: A second dynamic vibration absorber is higher in resonance frequency than a first dynamic vibration absorber. At least one of the resonance frequency of the first dynamic vibration absorber or the resonance frequency of the second dynamic vibration absorber is shifted from associated at least one of the first resonance frequency or the second resonance frequency such that a peak frequency of antiresonance occurring in a higher frequency region of the first dynamic vibration absorber than the resonance frequency of the first dynamic vibration absorber is substantially different from that of antiresonance occurring in a lower frequency region of the second dynamic vibration absorber than the resonance frequency of the second dynamic vibration absorber.

Abstract: A second dynamic vibration absorber is higher in resonance frequency than a first dynamic vibration absorber. At least one of a ratio of a mass of a body of the first dynamic vibration absorber to a reciprocating inertial mass of the reciprocative rotation mechanism or a ratio of a mass of a body of the second dynamic vibration absorber to the reciprocating inertial mass of the reciprocative rotation mechanism is set such that a peak frequency of antiresonance occurring in a higher frequency region of the first dynamic vibration absorber than the resonance frequency of the first dynamic vibration absorber is substantially different from that of antiresonance occurring in a lower frequency region of the second dynamic vibration absorber than the resonance frequency of the second dynamic vibration absorber.

Abstract: A fuel injection control system for a diesel engine is configured to, during one combustion cycle, perform multiple fuel injections to induce multiple combustions in a cylinder. A PCM controls fuel injection of the diesel engine. The PCM is configured to execute control for: at a first timing during compression stroke, starting a first fuel injection; a second timing during the compression stroke at which a time period corresponding to a first crank angle period has elapsed after a completion of the first fuel injection, starting a second fuel injection; and, at a third timing approximately a top dead center of the compression stroke at which a time period corresponding to a second crank angle period has elapsed after a completion of the second fuel injection, starting a third fuel injection. The second crank angle period is less than the first crank angle period.

Abstract: 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.

Abstract: 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.

Abstract: A second dynamic vibration absorber is higher in resonance frequency than a first dynamic vibration absorber. At least one of the resonance frequency of the first dynamic vibration absorber or the resonance frequency of the second dynamic vibration absorber is shifted from associated at least one of the first resonance frequency or the second resonance frequency such that a peak frequency of antiresonance occurring in a higher frequency region of the first dynamic vibration absorber than the resonance frequency of the first dynamic vibration absorber is substantially different from that of antiresonance occurring in a lower frequency region of the second dynamic vibration absorber than the resonance frequency of the second dynamic vibration absorber.

Abstract: A second dynamic vibration absorber is higher in resonance frequency than a first dynamic vibration absorber. At least one of a ratio of a mass of a body of the first dynamic vibration absorber to a reciprocating inertial mass of the reciprocative rotation mechanism or a ratio of a mass of a body of the second dynamic vibration absorber to the reciprocating inertial mass of the reciprocative rotation mechanism is set such that a peak frequency of antiresonance occurring in a higher frequency region of the first dynamic vibration absorber than the resonance frequency of the first dynamic vibration absorber is substantially different from that of antiresonance occurring in a lower frequency region of the second dynamic vibration absorber than the resonance frequency of the second dynamic vibration absorber.

Abstract: 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 (70) configured to set an interval between temporally-adjacent two of 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 the interval between the temporally-adjacent multiple fuel injections to 1.7±0.1 msec.

Abstract: 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.

Abstract: 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 atmospheric pressure decreases, and performing, after the plurality of fuel injections, another fuel injection including a larger injection amount than in the plurality of fuel injections.

Abstract: 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.

Abstract: 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 intake air temperature 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.

Abstract: 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 (70) 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.

Abstract: A fuel injection control apparatus for an engine in which fuel is injected into a cylinder a plurality of times to cause a plurality of combustions is provided, which includes a controller for controlling a time interval of performing the plurality of fuel injections so that a waveform indicating a frequency characteristic of a combustion pressure wave that is produced by each of the plurality of combustions has valley points at frequencies within a plurality of resonant frequency bands of a structural system of the engine, respectively.

Abstract: 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 (70) 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 the interval between the pre-injection and the main injection more largely as an engine load becomes lower at a same engine speed.

Abstract: In order to reduce bending vibration of a connecting rod, a dynamic absorber (50) configured to reduce the bending vibration of the connecting rod (10) is provided on a piston (1).

Abstract: An engine piston structure includes: a piston (1); a connecting rod (10) having a small end part (10a) coupled to the piston (1), and having a large end part (10b) coupled to a crankshaft; a piston pin (2) through which the piston (1) and the small end part (10a) of the connecting rod (10) are coupled together and which has a hollow cross section; and at least one dynamic vibration absorber (20) provided inside the piston pin (2) to reduce resonance of the piston (1), the piston pin (2), and the small end part (10a) of the connecting rod (10) in combination with respect to the large end part (10b) of the connecting rod (10) during a combustion stroke.

Abstract: 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 (70) 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 the interval between the pre-injection and the main injection more largely as an engine load becomes lower at a same engine speed.