Variable venturi carburetor

摘要

A variable venturi carburetor is disclosed which includes a mixture conduit having therein a throttle plate, a fixed venturi, and a vacuum sustaining plate for variably opening and closing the throat of the fixed venturi. A first fuel nozzle opens into the mixture conduit at a point on the downstream side of the vacuum sustaining plate. An electromagnetic valve is provided for controlling the amount of fuel drawn from the auxiliary fuel nozzle so that it can vary in accordance with the degree of opening of the vacuum sustaining plate but is held at a level when the degree of opening of the vacuum sustaining plate is over a predetermined level. A second fuel nozzle is provided which opens into the mixture conduit at a point on the upstream of the vacuum sustaining plate for allowing discharge of fuel in amounts proportional to vacuums appearing in the mixture conduit upstream of the vacuum sustaining plate.