Internal Combustion Engine Having Dedicated EGR and Increased Rich Limit for Dedicated EGR Cylinder

摘要

A method of providing internal EGR to an engine having at least one dedicated EGR cylinder. The main (non dedicated) cylinders are operated with internal EGR, in addition to external EGR from the dedicated EGR cylinder. The dedicated EGR cylinder has separate valve control so that it need not be operated with internal EGR, thereby allowing it to be operated at a richer air-to-fuel ratio.