Air-to-fuel ratio detector for engines

Patent · Tue May 06 04:00:00 EDT 1986

OSTI ID:5543081

Asayama, Y; Kominami, S

An air-to-fuel ratio detector for an engine is described which consists of: an air-to-fuel ratio sensor having an oxygen pump and an oxygen sensor disposed opposite to each other with a minute gap therebetween in an exhaust gas passage of the engine and each consisting of a flat plate of a solid electrolyte and electrodes attached to the opposite sides of the flat plate respectively; means for supplying a pump current to the oxygen pump; means for detecting the magnitude of an electromotive force of the oxygen sensor generated proportionally to the difference between the oxygen partial pressure within the minute gap and the oxygen partial pressure outside the minute gap by the oxygen pump supplied with a predetermined pump current; means for controlling the pump current to be supplied to the oxygen pump so that the electromotive force detected by the electromotive force detecting means is maintained at a fixed level; means for generating an air-to-fuel ratio detection output signal which is proportional to the pump current; and means for changing over the direction of the pump current supplied to the oxygen pump and the polarity of the output signal of the oxygen sensor simultaneously.

• Assignee: Mitsubishi Denki Kabushiki Kuisha, Tokyo
• Patent Number(s): US 4586476
• OSTI ID: 5543081
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330603* -- Vehicle Design Factors-- Engine System
ELECTRODES
ELECTROLYTES
ELECTROMOTIVE FORCE
ELEMENTS
ENGINES
EXHAUST GASES
EXHAUST SYSTEMS
FLUIDS
FUEL-AIR RATIO
GASEOUS WASTES
GASES
MEASURING INSTRUMENTS
METERS
NONMETALS
OXYGEN
OXYGEN METERS
PARTIAL PRESSURE
PUMPING
PUMPS
SIGNALS
SOLID ELECTROLYTES
VEHICLES
WASTES