Air-to-fuel ratio control means for carbureter

Claim 1

An air-to-fuel ratio controlling system for an internal combustion engine comprising; a carbureter connected to an intake manifold of an internal combustion engine and including a main passage and a bypass passage for supplying air-fuel mixture to said engine; said main passage being provided with a main valve for controlling an amount of the air-fuel mixture, and said bypass passage being also provided with a bypass valve for compensating the air-to-fuel ratio of said air-fuel mixture by controlling an amount of air-flow flowing therethrough; an air-to-fuel ratio sensing means mounted in an exhaust manifold of said engine for detecting the air-to-fuel ratio of the air-fuel mixture supplied to said engine; an electric control circuit connected to said air-to-fuel ratio sensing means for producing an output signal in accordance with the output of said air-to-fuel sensing means; a driving means coupled to and driving said bypass valve in response to said output signal from said electric control circuit, whereby the amount of the air-flow flowing through said bypass passage is decreased when the air-to-fuel ratio of the air-fuel mixture detected at said air-to-fuel ratio sensing means is higher than a predetermined value, and the amount of the air-flow flowing through said bypass passage is increased when the air-to-fuel ratio of the air-fuel mixture detected at said air-to-fuel ratio sensing means is lower than said predetermined value, thus to compensate the air-to-fuel ratio of the air-fuel mixture to be supplied to said engine; an engine condition detecting means for detecting the condition of said engine and for producing an actuating signal when said engine condition of said engine is sufficient for said air-to-fuel ratio sensing means to effectively operate; and an electric clutch means connected between said bypass valve and said driving means;