Carburetor for internal combustion engines

摘要

A carburetor for internal combustion engines includes an inner vent passage through which the space on the free surface of liquid fuel in a float chamber is communicated with the intake passage of the carburetor and an outer vent passage through which the space in the float chamber is communicated with a charcoal canister adapted to store the fuel vapor coming from the space of the float chamber. A valve is movable between a first position in which the inner vent passage is closed and the outer vent passage is opened and a second position in which the inner vent passage is opened and the outer vent passage is closed. A pressure responsive valve actuator normally holds the valve in the first position and moves the valve to the second position as a vacuum is generated in the intake passage. A further valve actuator holds the valve in the second position regardless of the action of the pressure-responsive valve actuator on the valve when the throttle valve has been opened to and beyond a predetermined opening.