| 摘要 |
A technique is provided which, in an exhaust gas recirculation apparatus for an internal combustion engine, can calculate a low-pressure EGR rate and a high-pressure EGR rate in an accurate manner, and control the flow rates of both a low pressure EGR passage and a high pressure EGR passage in a closed-loop control manner, thereby to make the temperature of intake air and a supercharging pressure stable and to suppress the deterioration of exhaust emissions as well as the deterioration of power performance. The low pressure EGR rate, representative of the proportion of an amount of low pressure EGR gas to an amount of intake air sucked into the internal combustion engine, and the high pressure EGR rate, representative of the proportion of an amount of high pressure EGR gas to the amount of intake air, are calculated by using a CO2 concentration in an intake passage at a location downstream of a connection portion of the low pressure EGR passage and upstream of a connection portion of the high pressure EGR passage, a CO2 concentration in the intake passage at a location downstream the connection portion of the high pressure EGR passage, and a CO2 concentration of an exhaust gas discharged from the internal combustion engine (S103). The low pressure EGR rate and the high pressure EGR rate to be calculated are controlled to individual target values, respectively (S104). |
