| 摘要 |
PURPOSE:To output a high power in the full open operation and accomplish a low rate of fuel consumption in a partial load operation by setting the pinching angle of the axis of the first one of two intake ports, whose intake amount is restricted in the partial load operation, and the axis of the first suction valve to a value smaller than the pinching angle which the second intake port forms. CONSTITUTION:The first and second intake valves 10, 11 are installed alongside the upper wall surface of a combustion chamber 1, and intake ports 20, 21 are extended in the radial direction of the combustion chamber 1 when viewed on the plan. The pinching angle theta1 of the axes of the first intake port 20 and first intake valve 10 is set smaller than the pinching angle theta2 formed alike by the second intake valve 11. The intake air flows in vigorously from the whole periphery of the first intake valve 10 in the full open operation when the two intake ports are fully opened, and a high intake efficiency is obtained - in a partial load operation, the intake amount from the first intake port 20 is limited, but the intake gas runs against the opposing intra-cylinder circumferential wall at a high speed because the angle theta2 is wide, and generation of tumble flow is promoted to lead to accomplishment of a low rate of fuel consumption.
|
