Air-fuel ratio feedback control method for internal combustion engines

Patent · Tue Oct 21 04:00:00 EDT 1986

OSTI ID:7069050

Otobe, Y; Yamato, A

A method is described of controlling the air-fuel ratio of an air-fuel mixture being supplied to an internal combustion engine. The engine is equipped with an exhaust system in a feedback manner responsive to output from ingredient concentration detecting means. The detecting means is arranged in the exhaust system for detecting the concentration of an ingredient contained in exhaust gases from the engine to produce as the output a normally fluctuating output signal indicative of the exhaust gas ingredient concentration. The method includes: comparing the value of the output signal from the ingredient concentration detecting means with a predetermined reference value, detecting from the result of the comparison a first change in the air-fuel ratio of the mixture supplied to the engine from a value richer than a predetermined value to a value leaner than the predetermined value. A second change is also detected in the air-fuel ratio of the mixture from a value leaner than the predetermined value to a value richer than the predetermined value, correcting the value of an air-fuel ratio control signal by varying the air-fuel ratio control signal value by a first predetermined correction value in response to a detected one of the first and second changes, and controlling the air-fuel ratio of the mixture in response to the value of the air-fuel ratio control signal thus corrected, to thereby effect the feedback control of the air-fuel ratio.

• Assignee: Honda Giken Kogyo K.K., Tokyo
• Patent Number(s): US 4617901
• OSTI ID: 7069050
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330100* -- Internal Combustion Engines
COMPUTERIZED CONTROL SYSTEMS
CONTROL SYSTEMS
CORRECTIONS
DISPERSIONS
ENGINES
EXHAUST GASES
EXHAUST SYSTEMS
FEEDBACK
FLUCTUATIONS
FLUIDS
FUEL-AIR RATIO
GASEOUS WASTES
GASES
HEAT ENGINES
INTERNAL COMBUSTION ENGINES
MIXTURES
SIGNALS
VARIATIONS
WASTES