Method and apparatus for fuel/air mixture adjustment
First Claim
1. A method for adjusting the operating point of a fuel mixture control system of an internal combustion engine, said mixture control system including a fuel mixture generator, an exhaust gas sensor for providing an actual value signal and a set-point signal generator, said actual valve signal and said set-point signal being compared in a comparator circuit which generates a comparator signal which is used by a final control element within said fuel mixture generator and wherein the improvement comprises the steps of:
- (a) generating a correction signal which contains information related to the frequency of amplitude alternations in the actual value signal provided by said exhaust gas sensor; and
(b) applying said correction signal to an input of said comparator to thereby adjust said set-point signal;
whereby, when the engine load changes, the fuel-mixture ratio is changed from a first value to at least one second value distinct from said first value.
0 Assignments
0 Petitions
Accused Products
Abstract
A method and apparatus for adjusting the reference or set-point value which is used in a closed-loop fuel control system for comparison with the actual value signal from an exhaust gas analyzer or sensor. The frequency of amplitude alternations of the sensor signal is a measure of engine speed and gas throughput rate. Accordingly, the invention provides generation of a quasi-D.C. signal whose amplitude is related to the frequency of sensor signal alternations. This signal is then used to change the supply voltage for a voltage-dividing circuit that supplies the reference voltage to the comparator circuit. The invention describes continuous and discrete adjustments of the reference signal.
72 Citations
8 Claims
-
1. A method for adjusting the operating point of a fuel mixture control system of an internal combustion engine, said mixture control system including a fuel mixture generator, an exhaust gas sensor for providing an actual value signal and a set-point signal generator, said actual valve signal and said set-point signal being compared in a comparator circuit which generates a comparator signal which is used by a final control element within said fuel mixture generator and wherein the improvement comprises the steps of:
-
(a) generating a correction signal which contains information related to the frequency of amplitude alternations in the actual value signal provided by said exhaust gas sensor; and (b) applying said correction signal to an input of said comparator to thereby adjust said set-point signal;
whereby, when the engine load changes, the fuel-mixture ratio is changed from a first value to at least one second value distinct from said first value. - View Dependent Claims (2, 3)
-
-
4. An apparatus for adjusting the operating point of a fuel mixture control system of an internal combustion engine, said mixture control system including a fuel mixture generator, an exhaust gas sensor for providing an actual value signal and a set-point signal generator, said actual value signal and said set-point signal being compared in a comparator circuit which generates a comparator signal which is used by a final control element within said fuel mixture generator and wherein the improvement comprises:
-
a pulse generator for generating an electrical pulse whenever said comparator signal crosses the zero voltage level; an integrator for integrating said electrical pulses from said pulse generator, the output from said integrator being fed to said set-point generator;
whereby the set-point signal is adjusted in dependence on the rate of mass flow through said engine. - View Dependent Claims (5, 6, 7, 8)
-
Specification