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U.S. Department of Energy
Office of Scientific and Technical Information

Air-fuel ratio control system

Patent ·
OSTI ID:5582175

A system for controlling the air-fuel ratio for a carburetor for an internal combustion engine has an intake passage, an exhaust passage, a throttle valve, a detector for detecting the concentration of a constituent of the exhaust gases, an on-off type electromagnetic valve for correcting the air-fuel ratio of the air-fuel mixture supplied by an air-fuel mixture supplier and an electronic controller. The electronic controller comprises a judging circuit for comparing the output signal of the detector with a stoichiometric reference signal, for driving the on-off electromagnetic valve for controlling the air-fuel ratio to a value approximating the stoichiometric air-fuel ratio. A load sensor and an engine temperature sensor are provided respectively. A correcting circuit renders the electronic controller non-responsive to the detector, when the engine temperature sensor actuates in the cold engine operation and responsive to the output of the load sensor, whereby the on-off electromagnetic valve operates in accordance with the output of the sensor.

Assignee:
Fuji Jukogyo K K (Japan); Nissan Motor Co. Ltd (Japan)
Patent Number(s):
US 4388905
OSTI ID:
5582175
Country of Publication:
United States
Language:
English