ENGINE

PROBLEM TO BE SOLVED: To solve the following problem: even if the opening of an exhaust gas recirculation valve is constant, an exhaust gas recirculation rate is largely varied by intake air pressure or exhaust gas pressure of an engine, therefore it is not enough to efficiently reduce nitrogen oxides only by correcting the opening of the exhaust gas recirculation valve by atmospheric pressure and outside air temperature. SOLUTION: The engine includes: a rack position sensor 71 detecting an engine load LF; an engine speed sensor 72 detecting engine speed Ne; an intake pressure sensor 73 detecting engine intake pressure Pi; an exhaust gas pressure sensor 74 detecting engine exhaust gas pressure Pg; and an ECU 7 calculating differential pressure ΔP between the detected engine intake pressure Pi and the detected engine exhaust gas pressure Pg, storing an EGR valve opening Le according to the detected engine load LF and the detected engine speed Ne and an opening correction value Kα according to the calculated differential pressure ΔP, and correcting the EGR valve opening Le with the opening correction value Kα. COPYRIGHT: (C)2010,JPO&INPIT