Internal combustion engine and control device for internal combustion engine

A control device for an internal combustion engine,

• the internal combustion engine comprising;
• an engine body;
• a fuel injector injecting fuel for combustion inside a combustion chamber of the engine body;
• and
• a vibration sensor detecting vibration acceleration of the engine body, wherein
• the control device comprises a combustion control part configured to control an injection amount and injection timing of fuel injected from the fuel injector to a target injection amount and target injection timing set based on an engine operating state to cause the fuel to burn by self ignition so as to cause generation of heat in the combustion chamber two times in stages so a pressure waveform showing a change along with time of a rate of rise of cylinder pressure becomes a two-peak shape and so that a peak interval from a first peak value of a first peak of the pressure waveform formed by the first heat generation to a second peak value of a second peak of the pressure waveform formed by the second heat generation becomes a reference peak interval suppressing vibration acceleration of a specific frequency band in vibration acceleration of the engine body, and
• the combustion control part is configured to:
• calculate a first vibration level of the engine body in a first judgment frequency band of a second overtone of the specific frequency based on vibration acceleration detected by the vibration sensor;
• and,
• when the first vibration level is less than a predetermined first reference vibration level set in advance according to the engine operating state, correct one or both of the target injection amount and the target injection timing so that the first vibration level becomes the first reference vibration level or more.