| 摘要 |
PROBLEM TO BE SOLVED: To allow an EGR valve to be reliably retained in a fully-closed state when the EGR valve of an engine mounting a supercharger is controlled to be fully-closed.SOLUTION: When an operation state of an engine 11 is in a predetermined operation state where an EGR valve 31 is controlled to be fully-closed (in a low-speed and high-load operation state where an engine speed is lower than a predetermined value and a target intake pressure is higher than a predetermined value), a control duty of the EGR valve 31 is corrected according to target amounts of valve overlapping of an intake valve and an exhaust valve and a retaining force for retaining the EGR valve 31 in a fully-closed position is corrected. As a result, in response to a change in a required retaining force (appropriate retaining force) for retaining the EGR valve 31 in the fully-closed position when a difference pressure between an intake pressure and an exhaust pressure (a difference pressure between the front and rear of the EGR valve 31) is changed according to an actual amount of the valve overlapping which is changed according to the target amount of the valve overlapping, the retaining force of the EGR valve 31 is corrected and the retaining force of the EGR valve 31 is set to the appropriate retaining force. |
