Engine residual gas amount estimation method and residual gas amount estimation device

摘要

PPROBLEM TO BE SOLVED: To provide an estimation method not deteriorating estimation accuracy of a combustion chamber residual gas amount even in operation of an exhaust valve open and close timing variable mechanism. PSOLUTION: A residual gas amount estimation device has the exhaust valve open and close timing variable mechanism capable of changing open and close timing of an exhaust valve between a first state and a second state and includes a processing means 59 for calculating a combustion chamber residual gas amount at intake valve open timing in the second state based on combustion chamber pressure at the intake valve open timing in the second state and on combustion chamber temperature at the intake valve open timing in the second state, a processing means 60 for calculating blow-back gas amounts during overlap in an intake valve open period and an exhaust valve open period in the second state based on exhaust valve close timing in the second state, and a processing means 61 for calculating a combustion chamber residual gas amount in the second state based on the combustion chamber residual gas amount at the intake valve open timing in the second state and on the blow-back gas amount during the overlap. PCOPYRIGHT: (C)2008,JPO&INPIT