| 摘要 |
PROBLEM TO BE SOLVED: To prevent an air/fuel ratio, in the case of opening an intake air control valve, from making over rich by means of eliminating any possibility of fuel stagnation in an intake air port part between the intake air control valve and an intake air valve when the intake air control valve is closed, by providing an air flow through hole below a port central line positioned above the axial center of a valve rotary shaft, in the intake air control valve. SOLUTION: The intake air port 6 in an internal combustion engine 2 used for lean combustion is separated into a normally opened side intake air port part 20 and a closed side intake air port part 22 by means of a bulkhead 18 and the closed side intake air port part 22 is provided with an intake air control valve 36. And, in the bulkhead 18, the first and second injection passages 26, 28 opened to the intake air port parts 20, 22 located downstream from the intake air control valve 36 are formed and a fuel injection valve 34 is provided so as to inject fuel to respective injection passages 26, 28. And in this case, an air flow through hole 42 of a small diameter is formed below a port central line in the intake air control valve 36. Thereby, no fuel can stagnate at the closed side intake air port part 22 located downstream from the intake air control valve 36 during closing action of the intake air control valve 36. |
