INTERNAL COMBUSTION ENGINE AND INTERNAL COMBUSTION ENGINE CONTROL METHOD

摘要

An internal combustion engine includes a supercharger (66, 67) capable of compressing intake air and feeding the compressed intake air into a combustion chamber (22, 23), boost pressure detecting means (86) for detecting the boost pressure, air/fuel ratio changing means (83) for changing the air/fuel ratio, ignition timing changing means (83) for changing the ignition timing, and control means (83) for causing the ignition timing changing means to retard the ignition timing when the air/fuel ratio changing means changes the air/fuel ratio from a stoichiometric air/fuel ratio to a lean air/fuel ratio. When the control means (83) changes the air/fuel ratio from the stoichiometric air/fuel ratio to the lean air/fuel ratio while retarding the ignition timing, the control means (83) keeps the retard amount of the ignition timing at a constant value if the boost pressure becomes equal to or higher than a target boost pressure that is set in advance depending on operating conditions of the engine.