Fuel injection apparatus for internal combustion engine.

摘要

A fuel feeding apparatus for an internal combustion engine in which a thermal type flow sensor (32) is disposed in a bypass air path (30) supplying bypass air from a point upstream of a Venturi portion (28) formed in a main air-intake path (12) to the Venturi portion, and the quantity (q) of air flowing through the bypass air path is controlled by a solenoid unit (42) so that the output signal (SA) of the thermal type flow sensor (32) attains coincidence with a pre-set level (SR). A fuel-metering valve (50) actuated by the solenoid unit (42) meters the quantity (Qf) of fuel meeting a variation of the quantity (Q ) of intake air being supplied to the engine so as to inject the metered quantity of fuel in a continuous flow into the main air-intake path. An oxygen sensor (80) senses the concentration of oxygen in engine exhaust gases, and, on the basis of the output signal of the oxygen sensor, the valve of the pre-set level (SR) is modified so that the rate (λ) of excess air in engine exhaust can be maintained to be λ = 1.