US 4,231,334 A · Method and apparatus for determining the proportions of the constituents of the air-fuel mixture supplied to an internal combustion engine

Abstract

A method and apparatus for determining the proportions of the air-fuel mixture constituents supplied to an internal combustion engine from a mixture preparing device such as a carburator, a fuel injection device or other suitable mixture preparing device. The method according to the invention serves to simplify the processing of output signals that are supplied to a mixture preparing device having at least two .lambda. sensors. The invention is especially suitable for use with large engines with several exhaust conduit systems, such as so-called V-engines, in which generally there is an unequal mixture distribution between the two rows of cylinders. By employing at least two .lambda. sensors in the exhaust gas conduit system for monitoring the exhaust gas composition, one succeeds in determining the mixture composition of the air-fuel mixture applied to all cylinders, and in influencing the air-fuel mixture in a suitable supplementary manner by a feed back of the actual value signals generated by the .lambda. sensors to the fuel preparation device, so that a desirable overall exhaust gas average value can be achieved. The apparatus employs two integrators and suitable logic circuitry for applying the .lambda. sensor signals to the integrators in such a manner that one integrator regulates the entire mixture in the desired direction, according to the sensor signals supplied to it, while the other integrator sets the amplitude of the oscillation fluctuations at a value that corresponds to the .lambda. differential.

Claims14

Dependent claims

A method for determining the proportions of the air-fuel mixture constituents supplied to an internal combustion engine having an exhaust gas conduit system and a mixture preparing device associated therewith, said air-fuel mixture constituents being supplied by the mixture preparing device which has at least two oxygen sensors arranged in the exhaust gas conduit system, comprising the steps of:

detecting the rpm of and the air flow rate to the engine, calculating the air-fuel ratio which determines the fuel quantity to be delivered to the engine, and generating a signal representative of this air-fuel ratio;
integrating the output signals from each of the oxygen sensors;
and
applying the integrated output signals to the generated representative signal of the air-fuel ratio and oscillating the representative signal about a predetermined air-fuel ratio value and at a predetermined amplitude, thereby regulating the average value of the overall exhaust gas composition to the predetermined air-fuel ratio value.

1 more element

An apparatus for determining the proportions of the air-fuel mixture constituents supplied to an internal combustion engine having an exhaust gas conduit system and a mixture preparing device associated therewith, said air-fuel mixture constituents being supplied by the mixture preparing device, said apparatus comprising:

means for generating a signal representative of the air-fuel ratio, which determines the fuel quantity to be delivered to the engine, on the basis of the rpm of and the air flow rate to the engine;
at least two oxygen sensors arranged in the exhaust gas conduit system of the engine;
a first and second integrator;
means connected between the oxygen sensors and the integrators for controlling said integrators based upon the output signals from the oxygen sensors such that said first integrator generates an output signal which maintains a constant value when the output signals of the oxygen sensors are different and an output signal which is greater or less than a constant value when the output signals of the oxygen sensors are the same, and said second integrator integrates upward when the output signals of the oxygen sensors are different and downward when the output signals of the oxygen sensors are the same;
a double-throw switch connected to the output of said second integrator;
and
means for oscillating said switch between its two positions, thereby oscillating the output from the second integrator at a predetermined amplitude, said oscillating output from the second integrator being applied to the output of the first integrator and the two outputs being applied to the output from said means for generating the air-fuel ratio representative signal, producing thereby a corrected signal for the mixture preparing device.

4 more elements

Dependencies are inferred from the claim text.

Method and apparatus for determining the proportions of the constituents of the air-fuel mixture supplied to an internal combustion engine

Life of this patent

Method and apparatus for determining the proportions of the constituents of the air-fuel mixture supplied to an internal combustion engine

Life of this patent

Abstract

Claims14