| 摘要 |
PURPOSE:To make an overrarefeed air-fuel ratio compensable in a proper manner, by closing a bypass passage when the opening of a throttle valve is small enough, and enlarging a pressure differential between a float chamber and a Venturi part whereby making the air-fuel ratio rich in mixture content. CONSTITUTION:With a throttle valve 19 choked to some extent, when a pressure differential inside an actuator 28 goes beyond the specified value, a switch 28 is turned to ON, while a solenoid valve 22 is closed whereby both passages 21 and 23 are cut off from their interconnection. Therefore, when an overrarefied A/F range or the pressure differential inside the actuator 24 goes beyond the specified value, the whole quantity of air passes a Venturi 18 so that dynamic pressure at the Venturi 18 grows large, causing the pressure differential between a float chamber 17 and the Venturi 18 to become large enough, therefore the outflow of fuel also grows large, thus the increment of fuel at a compensation range or the overrarefeed A/F range is promoted. With this constitution, rationalization in the air-fuel ratio at all driving ranges is well advanced and durability can be kept in goodness. |
