Air/fuel ratio sensor apparatus for use with internal combustion engine
Patent
·
OSTI ID:6948635
An air/fuel ratio sensor apparatus is described for use with an internal combustion engine, comprising: two sensing elements, each comprising an oxygen-ion-conductive solid electrolyte having a porous electrode formed on both sides thereof; a closed compartment that limits inflow of exhaust, the two sensing elements defining at least portions of the compartment; pump current control means, using one of the sensing elements as an oxygen concentration electrochemical cell and the other sensing element as an oxygen pump, for controlling pump current flowing through the oxygen pump such that an electromotive force generated by the oxygen concentration electrochemical cell is maintained as a preset reference voltage; air/fuel ratio signal detecting means for detecting the controlled pump current and producing an associated air/fuel ratio signal, the sensor further including: reference voltage changing means for, when the internal combustion engine is running without fuel supply, changing the reference voltage for the pump current control means to a value smaller than that when the engine is running with fuel supply; deterioration detecting means for, when the engine is running without fuel supply, detecting deterioration of the two sensing elements by comparing the air/fuel ratio signal produced by the air/fuel ratio signal detecting means with a preset reference value; and correction coefficient setting means for, when deterioration of the sensing elements is detected by the deterioration detecting means, setting a coefficient for correcting an air/fuel ratio signal detected when the engine is running with fuel supply on the basis of both the air/fuel ratio signal detected during engine operation without fuel supply and the reference value.
- Assignee:
- NGK Spark Plug Co., Ltd. Nagoya
- Patent Number(s):
- US 4753203
- OSTI ID:
- 6948635
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
33 ADVANCED PROPULSION SYSTEMS
330100* -- Internal Combustion Engines
CONTROL SYSTEMS
CORRECTIONS
ELECTRIC MEASURING INSTRUMENTS
ELECTRICAL EQUIPMENT
ELECTROLYTES
ENGINES
EQUIPMENT
FUEL SYSTEMS
FUEL-AIR RATIO
HEAT ENGINES
INTERNAL COMBUSTION ENGINES
MEASURING INSTRUMENTS
METERING
METERS
PUMPS
SIGNALS
SOLID ELECTROLYTES
330100* -- Internal Combustion Engines
CONTROL SYSTEMS
CORRECTIONS
ELECTRIC MEASURING INSTRUMENTS
ELECTRICAL EQUIPMENT
ELECTROLYTES
ENGINES
EQUIPMENT
FUEL SYSTEMS
FUEL-AIR RATIO
HEAT ENGINES
INTERNAL COMBUSTION ENGINES
MEASURING INSTRUMENTS
METERING
METERS
PUMPS
SIGNALS
SOLID ELECTROLYTES