Carburetor/mixing chamber and dual throttle control and cold starting apparatus for gasoline engine

摘要

Apparatus including a mixing chamber is installed between a standard carburetor base and the intake manifold of a gasoline engine. The mixing chamber includes an air inlet port for admitting a controlled amount of outside air into the mixing chamber and a gasoline vapor port for admitting gasoline vaporized externally of the carburetor into the mixing chamber, a carburetor inlet port for receiving a mixture of air and partially vaporized gasoline from the carburetor throat, and an outlet port through which a mixture of all the gases exhausts into the intake manifold. The carburetor includes a first throttle valve for controlling the air amount and partially vaporized gasoline passing into the mixing chamber. A second throttle valve controls the amount of mixed gas drawn through the mixing chamber outlet port into the intake manifold. A linkage connected to the automobile accelerator cable opens the second throttle in response to initial accelerator displacement. As the engine load increases and the accelerator is depressed further, the second throttle valve opens further and the linkage causes the first throttle valve to partially open, admitting a normal air charge and partially vaporized gasoline into the mixing chamber along with the air and gasoline vapor admitted through the two ports thereof. During cold start, while an automatic choke is closed, the first throttle valve opens. The linkage forces the second throttle valve open, and a rich mixture suitable for cold engine conditions passes through the mixing chamber into the intake manifold.