Air/fuel ratio control apparatus for an internal combustion engine

Patent · Tue May 02 04:00:00 EDT 1989

OSTI ID:6053870

Osuga, M; Oyama, Y

This patent describes an apparatus for controlling an air/fuel ratio of fuel mixture to be supplied for an internal combustion engine so as to follow a desired value thereof, comprising: fuel supply means for supplying a predetermined amount of fuel for the engine in response to a fuel supply signal; oxygen sensor means, a sensing portion of which is heated at a constant operating temperature, for producing an output voltage in proportion to an air/fuel ratio of fuel mixture supplied for the engine; and microprocessor means, in which the desired value of the air/fuel ratio is set on the basis of load of the engine and a reference of the sensor output voltage is determined. There is further provided means for producing a signal representative of the combustion state in the engine, which is derived from the oxygen sensor means and depends on an amount of unburnt gas discharged from the engine; and the microprocessor means further executes the following steps: comparing a value of the combustion state signal produced by the signal producing means with a reference value thereof; changing the value of the desired air/fuel ratio to a new value thereof in accordance with the result of the comparing step; and correcting the reference of the sensor output voltage on the basis of the new value of the desired air/fuel ratio.

• Assignee: Hitachi, Ltd., Tokyo
• Patent Number(s): US 4825838
• OSTI ID: 6053870
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330100* -- Internal Combustion Engines
99 GENERAL AND MISCELLANEOUS
990220 -- Computers
Computerized Models
& Computer Programs-- (1987-1989)
COMPUTERIZED CONTROL SYSTEMS
CONTROL SYSTEMS
DESIGN
ENGINES
ENRICHMENT
FUEL SYSTEMS
FUEL-AIR RATIO
HEAT ENGINES
INTERNAL COMBUSTION ENGINES
METERING
OXYGEN ENRICHMENT