System for detection of air/fuel ratio in IC engine by using oxygen sensor operated with supply of current

Patent · Tue Apr 03 00:00:00 EST 1984

OSTI ID:6370861

Kitahara, T; Sone, K; Uchida, M

An air/fuel ratio detection system is disclosed for an IC engine, using an oxygen sensor element of the concentration cell type which has a laminate of a measurement electrode layer exposed to the exhaust gas, a porous layer of oxygen ion conductive solid electrolyte and a reference electrode layer and requires the supply of a small DC current thereto to produce a reference oxygen partial pressure at the reference electrode by a balance between migration of oxygen ions to the reference electrode and diffusion of oxygen molecules therefrom. To prevent excessive rise in the reference oxygen partial pressure even when the engine continues to discharge exhaust gas high in the content of oxygen, the detection system has a control circuit which controls the intensity and flow direction of the current for the sensor element with reference to a voltage which is produced by adding a definite voltage to, or subtracting the definite voltage from, the sensor output voltage depending on the level of oxygen content in the exhaust gas indicated by the sensor output voltage and smoothing the voltage resulting from the addition or subtraction.

• Assignee: Nissan Motor Company, Ltd. (Japan)
• Patent Number(s): US 4440621
• OSTI ID: 6370861
• Resource Relation: Patent Priority Date: Priority date 2 Dec 1982, Japan; Other Information: PAT-APPL-446315
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
FUEL-AIR RATIO
MEASURING METHODS
INTERNAL COMBUSTION ENGINES
AIR POLLUTION CONTROL
DESIGN
DIRECT CURRENT
ELECTROLYTES
FEEDBACK
GAS FLOW
OPTIMIZATION
OXYGEN
PROBES
CONTROL
CURRENTS
ELECTRIC CURRENTS
ELEMENTS
ENGINES
FLUID FLOW
HEAT ENGINES
NONMETALS
POLLUTION CONTROL
330100* - Internal Combustion Engines