| 摘要 |
PURPOSE:To devise solving the problem of responce characteristic's becoming worse due to fuel supply lag at transient operation of an engine without impairing the effect of the air assist by suppressing the expance of fuel spray angle and thus decreasing the sticking quantity of fuel to the suction port wall and the like. CONSTITUTION:A fuel injection valve 23 is installed almost at the center of a suction port 4 at the upstream of a suction control valve 21. A hollow adaptor is connected to an assist air delivery pipe 25 through an assist air lead-in tube 28. At medium and low load operation the suction control valve 21 closes the inlet portion of a No.2 suction port, so that most of the air-fuel mixture flows into a combustion chamber 8 through a No.1 suction valve 19a. On the other hand, at a heavy load operation, the suction control valve 21 is fully opened, so that the air-fuel mixture flows into the combustion chamber 8 through the No.1 and the No.2 suction valve 19a, 19b and thus a high charging efficiency can be obtained. |
