System for feedback control of air/fuel ratio in ic engine with means to control current supply to oxygen sensor

Patent · Tue Dec 28 04:00:00 EST 1982

OSTI ID:6434685

Sone, K

A system for feedback control of air/fuel ratio in an ic engine, utilizing an oxygen-sensitive device which is provided with a heater and disposed in exhaust gas to provide a feedback signal. This device has a porous solid electrolyte layer with a measurement electrode layer on the outside and a reference electrode layer on the inside facing a substrate. The control system includes a sub-system to apply a voltage to the heater and force a dc current to flow through the solid electrolyte layer to cause migration of oxygen ions therethrough to thereby establish a reference oxygen partial pressure on the inner side of the solid electrolyte layer. To prevent great changes in the reference oxygen partial pressure by the influence of the exhaust gas temperature, the sub-system comprises sensors to detect the engine operating condition and control means for gradually varying both said voltage and said current according as the detected operating condition varies. For example, the voltage and current may be varied each by using a combination of a variable resistor and a stepping motor or a combination of fixed resistances and electrically controllable switches connected respectively in parallel with the resistances.

• Assignee: Nissan Motor Co Ltd (Japan)
• Patent Number(s): US 4365604
• OSTI ID: 6434685
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330100* -- Internal Combustion Engines
CONTROL SYSTEMS
CURRENTS
DETECTION
ELECTRIC CURRENTS
ELECTROLYTES
ELEMENTS
ENGINES
EXHAUST GASES
FEEDBACK
FLUIDS
FUEL-AIR RATIO
GASEOUS WASTES
GASES
HEAT ENGINES
INTERNAL COMBUSTION ENGINES
NONMETALS
OXYGEN
PRESSURE MEASUREMENT
SIGNALS
SOLID ELECTROLYTES
WASTES