Internal egr control system for internal combustion engine

Abstract

An internal EGR control system for an internal combustion engine, which is capable of controlling the internal EGR amount with accuracy, when controlling the internal EGR by changing both the exhaust cam phase and the exhaust valve lift. An internal EGR control system for an internal combustion engine controls internal EGR in which combustion gases are caused to remain in a cylinder. An ECU sets a target cam phase serving as a target of the exhaust cam phase, and controls a variable exhaust cam phase mechanism such that the exhaust cam phase becomes equal to the target cam phase. ECUsets a target lift of an exhaust valve according to a detected actual cam phase and calculated valve-closing timing, and controls a variable exhaust valve lift mechanism such that the lift of the exhaust valve becomes equal to the target lift.