| 摘要 |
In an internal combustion engine having a plurality of electromagnetically driven valves (16a, 16b) for each cylinder, when a required EGR amount Er is relatively small during an exhaust gas recirculation performed independently of the exhaust stroke, a first exhaust gas recirculation mode (S310 to S350) is entered by driving only a first exhaust valve of each cylinder. An open valve duration Td1 for achieving the required EGR amount Er in a one-valve drive manner is longer than a corresponding open valve duration in a two-valve drive manner. Therefore, even if the required EGR amount Er is small, a "one-valve drive in pattern 1" mode can be achieved provided that Td1 > a. That is, the incidence of performing the control in pattern 2, which allows only a narrow range of control, can be reduced. Hence, degradation of controllability can be prevented even if the required EGR amount Er is small. <IMAGE> |
