Fuel injection system

Abstract

A fuel injection system for an internal combustion engine includes electromagnetic injection valves controlled by a fuel control unit which receives signals from a camshaft actuated switch, a position-dependent throttle transducer and an oxygen sensor. When the oxygen sensor changes output levels, the transmission of this information is delayed, by the action of a switching transistor controlled by a monostable multivibrator, for a period of time equal to the internal time constant of the multivibrator.

What is claimed is:  .[.1. A fuel-air control system for an internal combustion engine, including a controller with integral control characteristic for controlling the fuel-air mixture admitted to the engine (λ-control process) and including 
     
        predetermined time period. .Iaddend. .Iadd. 8.  A fuel-air control system for an internal combustion engine, including a controller with integral control characteristic for controlling the fuel-air mixture admitted to the engine (λ-control process) and including (A) an oxygen sensor, located in the exhaust system of the engine, and capable of providing an output signal; the improvement in said fuel-air system comprising:   (B) a comparator circuit, for comparing said output signal from said oxygen sensor with a reference value and providing an output signal;   (C) an integrating circuit, whose sole control signal input is connected to the output from said comparator circuit and which delivers a changeable output signal;   (D) a timing circuit connected to the output from said comparator circuit and which delivers an output signal that in addition to the output of the comparator circuit is continuously connected to the input of said integrating circuit, the output signal from said timing circuit inhibits the transmission of said output signal from said comparator to said integrating circuit for delaying the change of its output signal in one direction for a predetermined period of time thereby delaying in one direction the response of said integrating circuit to changes in the output signal from said oxygen sensor;   (E) a control unit, connected to the output from said integrating circuit, for providing injection valve control signals;   (F) an air-fuel rate adjusting device connected to said control unit; and   (G) signal generator means, connected to said engine for delivering an rpm-dependent output signal which is connected to said timing circuit to determine the duration of said predetermined period of time. .Iaddend.