System for controlling air-fuel ratio in an internal combustion engine

Patent · Tue Jan 06 04:00:00 EST 1987

OSTI ID:6838256

Egami, T; Saito, T; Kohama, T; Saito, K; Sato, K; Takahashi, H

A system is described for controlling the air-fuel ratio to a predetermined value in an internal combustion engine comprising: first sensor means for sensing an actual air-fuel ratio and issuing a signal having two levels, one level corresponding to an air fuel ratio larger than the predetermined value, the other level corresponding to an air-fuel ratio smaller than the predetermined level; second sensor means for detecting a change in engine conditions from a steady state to a transient state; processing means for performing the following functions: (a) calculating a basic amount of fuel to be supplied to the engine, which amount is determined in accordance with engine operating conditions; (b) in response the signal from the first sensor means, increasing a first correcting factor for correcting the basic fuel amount when the signal has one level, and decreasing the first factor when the signal has another level, in order to maintain the actual fuel ratio to the predetermined value; (c) calculating the difference in value between the value of the first corresponding factor during the preceding steady state and the value of the first correcting factor when a change to the transient state is sensed by the second sensor means; (d) calculating a second correcting factor for correcting the basic fuel amount based on the value of the difference; and (e) calculating a final fuel amount from the basic fuel amount and the first correcting factor but not the second correcting factor during the steady state and from the basic fuel amount and at least the second correcting factor during the transient state, the second correcting being calculated to eliminate the difference during the transient state; and means for providing a supply of fuel to the engine so that the calculated final fuel amount is supplied to the engine.

• Assignee: Nippon Soken, Inc., Nishio
• Patent Number(s): US 4635200
• OSTI ID: 6838256
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330100* -- Internal Combustion Engines
COMPUTER CALCULATIONS
COMPUTERIZED CONTROL SYSTEMS
CONTROL SYSTEMS
CORRECTIONS
DATA PROCESSING
ENGINES
FUEL INJECTION SYSTEMS
FUEL SYSTEMS
FUEL-AIR RATIO
HEAT ENGINES
INTERNAL COMBUSTION ENGINES
MEASURING INSTRUMENTS
MONITORS
PROCESSING
SIGNALS
STEADY-STATE CONDITIONS
TRANSIENTS
VEHICLES