AIRRFUEL RATIO CONTROLLER

摘要

PURPOSE:To accurately control an air-fuel rario, by providing nozzles for injecting fuel upstream to a throttle valve, a fuel injection control valve for supplying a prescribed quantity of the fuel to the nozzles and a control circuit for regulating the action of the control valve depending on an engine condition signal. CONSTITUTION:A fuel injector 22 is provided upstream to a throttle valve 14 in a throttle chamber 12. A main passage 36 for fuel injection is provided in the fuel chamber 24 of the fuel injector. The main passage 36 is equipped with an orifice 38 and a fuel injection control valve 40 in the proximity of the fuel chamber 24 and with nozzles 44 projected on the face of the chamber 12. The nozzles are made of a pluratity of injection holes 46. A bypass 50 is provided beside the nozzles 44 to conduct air around them. An air flow rate sensor 52 is installed in the bypass. A selenoid 42 or the like is regulated by a control circuit 100 on the basis of the outputs of the sensor 52 and an engine condition sensor 200 to control an air-fuel ratio.