INTERNAL COMBUSTION ENGINE AND CONTROL METHOD THEREFOR

An internal combustion engine includes an EGR system 10 having an EGR valve 12 and a reed valve 13 in an EGR passage Eg, and is provided with a control device 20 that expresses a relationship between an opening degree x egr of the EGR valve 12 and a mass flow rate m egr of an EGR gas by using a first volume flow rate V 1 of the EGR gas that can be expressed by using an isentropic flow equation of a nozzle of the EGR valve 12 and a second volume flow rate V 2 of the EGR gas pumped out by the reed valve 13 and thus, even if the reed valve (check valve) is provided in the EGR passage, the mass flow rate of the EGR gas can be calculated accurately.