Patent ID: 8156925

Claim:
An exhaust gas recirculation system for an internal combustion engine, comprising: a turbocharger that includes a compressor and a turbine; a throttle valve, provided in an intake passage upstream of the compressor; an exhaust gas recirculation passage through which a portion of exhaust gas flowing in an exhaust passage is recirculated to a intake passage between the throttle valve and the compressor; an exhaust gas recirculation valve that regulates a flow rate of exhaust gas flowing in the exhaust gas recirculation passage; a valve control unit that controls an opening degree of the throttle valve and an opening degree of the exhaust gas recirculation valve so that pressure in the intake passage between the throttle valve and the compressor is maintained at or above a predetermined pressure; and a first minimum opening degree setting unit that sets a minimum opening degree of the exhaust gas recirculation valve based on an intake air amount of the internal combustion engine, wherein the valve control unit closes the throttle valve after the exhaust gas recirculation valve is opened, and wherein, when the exhaust gas is recirculated, the valve control unit opens the exhaust gas recirculation valve, and then closes the throttle valve after the exhaust gas recirculation valve has been opened to at least the minimum opening degree when an exhaust gas recirculation execution condition is satisfied.