Patent ID: 7597089
Filing Date: 2009-10-06
Classification: F02B,F02D,F02M,Y02T

Abstract:
1. An engine with an EGR (exhaust gas recirculation) system comprising: a particulate filter; an EGR conduit for introducing a fraction of exhaust gas flowing through an exhaust gas passage to an inlet air passage of the engine; an EGR valve for controlling opening and closing of the EGR conduit; a means for detecting an exhaust gas pressure difference in the particulate filter; and a controller, in which reference values of pressure difference in the particulate filter commensurate with reference values of EGR rate of internal EGR are established, for calculating an EGR amount-to-be-corrected based on a pressure difference deviation between the detected exhaust gas pressure difference and the reference values of pressure difference in the particulate filter, and controlling valve opening of the EGR valve in accordance with the calculated EGR amount-to-be-corrected, wherein the controller performs exhaust valve sub-lift type internal EGR by allowing an exhaust valve or exhaust valves to lift by a small lift in an intake stroke to allow a fraction of exhaust gas in an intake passage in a cylinder of the engine to flow back into the cylinder.