| 摘要 |
PROBLEM TO BE SOLVED: To provide an intake system of an internal combustion engine that can change stratified distribution of a first gas and a second gas in response to changes of a generating region of emission in a cylinder.SOLUTION: A passage 22 in which an EGR lean gas (a first gas) having a lean exhaust concentration flows is connected to a swirl generation port 12 of an engine 10, and a passage 25 in which an EGR rich gas (a second gas) having a rich exhaust concentration flows is connected to a tumble generation port 13 of the engine 10. The EGR lean gas continues to be sucked from the swirl generation port 12 during an intake stroke. An ECU 50 delays valve opening of an intake valve 142 of the tumble generation port 13 further than valve opening of an intake valve 141 of the swirl generation port 12, and thereby causes the EGR rich gas to be sucked in the middle of the intake stroke. The ECU 50 changes a period of starting valve opening or a lift amount in the intake valve 142 so that a suction amount of the EGR rich gas in the first half of intake increases and a suction amount in the second half reduces as a load becomes higher. |
