Closed loop air-fuel ratio control system for use with internal combustion engine
First Claim
1. A closed loop fuel control system for a multi-cylinder internal combustion engine including an intake passage leading to the cylinders, air fuel supply conduit means for supplying air and fuel to said intake passage in variable ratio, and exhaust means, the system comprising:
- an exhaust gas sensor provided in said exhaust means for generating a first signal representing the concentration of a composition of gases in said exhaust means;
means for generating a second signal representing the deviation of said first signal from a reference level indicating a desired air-fuel ratio;
a variable frequency oscillator for generating a third signal of which the frequency is variable in dependence upon the speed of said engine;
a pulse width converter responsive to said second and to said third signal for generating a train of pulses of which the duration is dependent upon the magnitude of said second signal and the frequency is dependent upon the frequency of said third signal from said variable frequency oscillator; and
electromechanical flow control means disposed in said air fuel supply conduit means and responsive to said train of pulses for controlling the air-fuel ratio to said desired value.
0 Assignments
0 Petitions
Accused Products
Abstract
In an electronic closed loop control system for controlling the air-fuel ratio of an air-fuel mixture fed to an internal combustion engine to an optimum, the frequency of a dither signal is discretely or continuously changed to change a repetition rate of a pulsating signal in order to prevent engine vibration discomfortable to a driver, the pulsating signal being applied to at least one electromagnetic valve provided for regulating the air-fuel ratio of the air-fuel mixture.
18 Citations
9 Claims
-
1. A closed loop fuel control system for a multi-cylinder internal combustion engine including an intake passage leading to the cylinders, air fuel supply conduit means for supplying air and fuel to said intake passage in variable ratio, and exhaust means, the system comprising:
-
an exhaust gas sensor provided in said exhaust means for generating a first signal representing the concentration of a composition of gases in said exhaust means; means for generating a second signal representing the deviation of said first signal from a reference level indicating a desired air-fuel ratio; a variable frequency oscillator for generating a third signal of which the frequency is variable in dependence upon the speed of said engine; a pulse width converter responsive to said second and to said third signal for generating a train of pulses of which the duration is dependent upon the magnitude of said second signal and the frequency is dependent upon the frequency of said third signal from said variable frequency oscillator; and electromechanical flow control means disposed in said air fuel supply conduit means and responsive to said train of pulses for controlling the air-fuel ratio to said desired value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
Specification