Apparatus for controlling air-fuel ratio in internal combustion engine

Patent · Tue Nov 25 04:00:00 EST 1986

OSTI ID:7226190

Saito, K; Iwamoto, K; Obayashi, H; Matuyama, T

This patent describes an apparatus for controlling the air-fuel ratio in an internal combustion engine having an exhaust pipe, comprising: air-fuel ratio sensor means, provided in the exhaust pipe, for sensing a concentration of a specific component of the exhaust gas of the engine and providing an output signal corresponding thereto; and control means for (a) determining whether or not the output signal of the air-fuel ratio sensor means is larger than a reference voltage, (b) calculating a differential waveform of the output signal with respect to time, (c) detecting a degree of functional deterioration of the air-fuel ratio sensor means by using successive measurements of the differential waveform of the output signal over a predetermined period of time, (d) controlling an air fuel ratio feedback control value in accordance with the detected degree of functional deterioration of the air-fuel ratio sensor means, (e) calculating an air-fuel ratio correction amount in accordance with the reference voltage determination of the output signal of the air-fuel ratio sensor means and the air-fuel ratio feedback control value, and (f) adjusting an amount of fuel to be supplied to the engine in accordance with the calculated air-fuel ratio correction amount so that the air-fuel ratio of the engine approaches a predetermined value.

• Assignee: Nippon Soken, Inc., Nishio
• Patent Number(s): US 4624232
• OSTI ID: 7226190
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330100* -- Internal Combustion Engines
COMPUTERIZED CONTROL SYSTEMS
CONTROL SYSTEMS
ELECTRIC POTENTIAL
ENGINES
EXHAUST SYSTEMS
FEEDBACK
FUEL-AIR RATIO
HEAT ENGINES
INTERNAL COMBUSTION ENGINES
MEASURING INSTRUMENTS
METERS
OXYGEN METERS
PIPES
SIGNALS
TIME DEPENDENCE
WAVE FORMS