Low speed fuel supply system for a carburetor

Abstract

A low speed fuel supply system for a carburetor of an engine, with the system including an ascending fuel passage communicating with a fuel supply. A fuel-air passage is provided with an air bleed at an upper end, with the fuel-air passage opening, at the upper end thereof, into an induction passage of the carburetor upstream of a throttle valve mounted across the induction passage. A lower end of the fuel-air passage communicates with the induction passage in a vicinity of the throttle valve. A horizontally disposed fluid passage is provided for connecting both the upper ends of the fuel-air passage and the ascending fuel passage. The horizontally disposed fluid passage forms a valve seat, with a guide member being provided forming a valve body disposed in alignment with the valve seat. An air bleed introduces air into the upper portion of the ascending fuel passage directly toward the valve body. By operation of the low pressure induced in the induction passage, fuel is sucked from the fuel supply, guided by the valve body, and directed to the valve seat, while air introduced from the air bleed is directed to the valve body. The air and fuel are divided into two layers and flow into the valve seat. The flows of two layers into the fuel-air passage, with fuel flowing while adhering on a wall of the fuel-air passage and the air flows along a central portion of the flowing fuel, while the fuel adheres to the wall of the induction passage so that an annular flow is formed and a stable and continuous flow can be effected.