Air-fuel ratio control system
An air-fuel ratio control system is disclosed for an internal combustion engine having an intake passage, an exhaust passage, an air-fuel mixture supply device, an on-off type electromagnetic valve for correcting the air-fuel ratio of the air-fuel mixture supplied by the air-fuel mixture supply device, a dither signal generating circuit for producing a periodical dither signal, a shift control circuit for shifting the level of the center of the dither signal, a driving circuit for producing a driving output for the on-off type electromagnetic valve, and an O/sub 2/ sensor for detecting the concentration of oxygen in exhaust gases passing through the exhaust passage. A timing circuit is provided for detecting the period of the time when the output of the O/sub 2/ sensor is higher than a predetermined level and the period of the time when the output is lower than the predetermined level for producing an output signal in dependency on the difference between the periods. A shift signal generating circuit is provided for generating a shift signal in dependency on the output of the timing circuit. The shift control circuit is so arranged to control the air-fuel ratio of the mixture in such a direction that the difference is decreased.
- Assignee:
- Fuji Jukogyo Kabushiki Kaisha (Japan); Nissan Motor Co., Ltd. (Japan)
- Patent Number(s):
- US 4402292
- OSTI ID:
- 5363513
- Country of Publication:
- United States
- Language:
- English
Similar Records
Air-fuel ratio control system
Air-fuel ratio control system
Related Subjects
330100* -- Internal Combustion Engines
CONTROL EQUIPMENT
CONTROL SYSTEMS
DETECTION
ELEMENTS
ENGINES
EQUIPMENT
EXHAUST GASES
FLOW REGULATORS
FLUIDS
FUEL FEEDING SYSTEMS
FUEL SYSTEMS
FUEL-AIR RATIO
GASEOUS WASTES
GASES
HEAT ENGINES
INTERNAL COMBUSTION ENGINES
NONMETALS
OXYGEN
SIGNALS
VALVES
WASTES