Air/fuel ratio control system for an internal combustion engine with a function for preventing the blackening phenomenon of oxygen concentration sensor

Patent · Tue Mar 22 00:00:00 EST 1988

OSTI ID:5004376

Kawanabe, T; Asakura, M; Kimura, K; Muroya, M

An air/fuel ratio control system for an internal combustion engine is described comprising: an air supply passage connected to an air intake system of the internal combustion engine, for varying the air/fuel ratio of the mixture to be supplied to the engine; an open/close valve disposed in the air supply passage for controlling the air flow in the air supply passage; an oxygen concentration sensing unit disposed in an exhaust gas of the internal combustion engine; current supply means for supplying a pump current across the electrodes of the oxygen pump element so as to keep constant voltage generated across the electrodes of the sensor cell element thereby causing the sensing unit to monitor a magnitude of the pump current which is substantially in proportion to the oxygen concentration in the exhaust gas; valve open time period control circuit means connected to the oxygen concentration detection device; valve drive means connected to the valve open time period control circuit means for opening the open/close valve for the calculated valve open time period in each of the cycles; and control means responsive to output signals of the current supply means and the valve open time period control circuit means for stopping the supply of the pump current across the electrodes of the oxygen pump element when the valve open time period calculated by the valve open time period control circuit means exceeds a predetermined upper limit of valve open time period.

• Assignee: Honda Giken Kogyo Kabushiki Kaisha, Tokyo
• Patent Number(s): US 4732127
• OSTI ID: 5004376
• Resource Relation: Patent File Date: Filed date 10 Sep 1986
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
EXHAUST SYSTEMS
CONTROL SYSTEMS
METERING
FUEL SYSTEMS
CONTROL
OXYGEN
DETECTION
AIR FLOW
FUEL-AIR RATIO
INTERNAL COMBUSTION ENGINES
METERS
OPERATION
PUMPS
VALVES
CONTROL EQUIPMENT
ELEMENTS
ENGINES
EQUIPMENT
FLOW REGULATORS
FLUID FLOW
GAS FLOW
HEAT ENGINES
MEASURING INSTRUMENTS
NONMETALS
330100* - Internal Combustion Engines