EXHAUST GAS RECIRCULATION SYSTEM FOR INTERNAL COMBUSTION ENGINE AND METHOD FOR CONTROLLING THE SAME

摘要

An exhaust gas recirculation system for an internal combustion engine includes: a turbocharger,- an exhaust gas catalyst (10); a low-pressure EGR unit; an EGR cooler(33); a bypass unit (35)that causes the exhaust gas flowing through the low-pressure EGR passage to bypass the EGR cooler; a catalyst activation-inactivation determination unit that determines whether the exhaust gas catalyst is in a predetermined active state; and a control unit that controls the bypass unit to cause the exhaust gas flowing through the low-pressure EGR passage (31) to bypass the EGR cooler, when it is determined that the exhaust gas catalyst is not in the predetermined active state.