CONTROL DEVICE FOR INTERNAL COMBUSTION ENGINE

摘要

Provided is a control device for an internal combustion engine, which can reliably prevent the external EGR gas quantity when external EGR is executed from becoming nonuniform among cylinders and suppress the deposition of deposits in an intake manifold. The control device for the internal combustion engine is provided with a fresh air backflow control means for performing fresh air backflow control for causing part of fresh air taken into cylinders to flow back into the intake manifold by operating an intake variable valve device such that the intake valve closing timing is later than that before the start of the external EGR when the external EGR is started. External EGR gas and the fresh air within the intake manifold are stirred by the backflow of the fresh air and the mixture ratio becomes uniform, thereby making it possible to make the external EGR gas quantities flowing into the respective cylinders uniform. In the fresh air backflow control, the fresh air instead of internal EGR gas (burned gas) flows back into the intake manifold. Consequently, deposits are prevented from adhering and being deposited.