| 摘要 |
An electronic control unit of an internal combustion engine computes a remaining combusted gas amount M egr1 , which exists in a cylinder immediately before an intake valve is opened, based on an intake pipe pressure Pm, an engine speed NE, and an intake valve opening timing T open . At the same time, the control unit computes a backflow combusted gas amount M egr2 , which is the amount of combusted gas that flows back into the cylinder from an exhaust pipe after the intake valve is opened, based on the intake pipe pressure Pm, the engine speed NE and a valve overlap amount OL. The control unit computes the sum of the remaining combusted gas amount M egr1 and the backflow combusted gas amount M egr2 , and sets the sum as an estimated internal EGR amount M egrALL . As a result, the internal EGR amount is readily and accurately estimated. |
