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

Patent · Tue Oct 19 04:00:00 EDT 1982

OSTI ID:6669310

Kenji, O; Sone, K

A system for feedback control of air/fuel ratio in an IC engine is disclosed, utilizing a recently developed 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 one side and a reference electrode on the other side facing a substrate. There is a circuit to supply a heating current to the heater and force a dc current to flow in the solid electrolyte layer to cause migration of oxygen ions through the solid electrolyte toward the reference electrode to thereby establish a reference oxygen partial pressure on the reference side of the solid electrolyte layer. To prevent lowering of this oxygen partial pressure while the engine is operated under a high-load condition and the feedback control is discontinued to feed the engine with a fuel-enriched mixture, the control system includes operating condition sensor means and switching means to interrupt the supply of the current to the heater in response to a command signal from the sensor means and, optionally, current regulating means to increase the intensity of current flowing in the solid electrolyte also in response to the command signal.

• Assignee: Nissan Motor Co Ltd (Japan)
• Patent Number(s): US 4354468
• OSTI ID: 6669310
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330100* -- Internal Combustion Engines
CONTROL SYSTEMS
DESIGN
ELECTROLYTES
ENGINES
FEEDBACK
FUEL-AIR RATIO
HEAT ENGINES
INTERNAL COMBUSTION ENGINES
MEASURING INSTRUMENTS
METERS
OXYGEN METERS
SOLID ELECTROLYTES