Patent ID: 6550457
Filing Date: 2003-04-22
Classification: F02D

Abstract:
An electronic fuel injection control apparatus for controlling a quantity of fuel injected from an injector into an intake pipe of an internal combustion engine, comprising:intake air amount arithmetical operation means for arithmetically operating an intake air amount from an intake pipe pressure of said internal combustion engine and a rotational speed of the internal combustion engine; basic injection time arithmetical operation means for arithmetically operating a basic injection time of the fuel based on said intake air amount; correction variable arithmetical operation means for arithmetically operating a correction variable which is used for determining an actual injection time by performing a correction operation on said basic injection time; synchronous injection control means for performing an actual injection time processing in which the actual injection time is arithmetically operated by performing said correction operation using the correction variable arithmetically operated by said correction variable arithmetical operation means at every time a predetermined synchronous injection timing is detected and for performing a processing in which the synchronous injection is effected by actuating said injector during the arithmetically operated actual injection time; load detecting parameter map storing means for storing a load detecting parameter map which provides a relation among a load detecting parameter which varies depending on a change in a load applied to said internal combustion engine, an throttle valve opening degree of said internal combustion engine, and a rotational speed of said internal combustion engine; map retrieval means for arithmetically operating a map retrieval value on said load detecting parameter map, based on the throttle valve opening degree of said internal combustion engine and the rotational speed of said internal combustion engine, at least at each synchronous injection timing or at the immediately preceding timing; and map retrieval value variation arithmetical operation means in which, at every time the map retrieval value is arithmetically operated by said map retrieval means, the map retrieval value arithmetically operated by said map retrieval means at the previous synchronous injection timing or at the immediately preceding timing is used as a comparative reference value and a difference between a map retrieval value newly obtained by the map retrieval means and said comparative reference value is arithmetically operated as a map retrieval value variation, wherein said correction variable arithmetical operation means is comprised such that said correction variable is arithmetically operated relative to the map retrieval value variation when said map retrieval value variation arithmetically operated at said synchronous injection timing or the immediately preceding timing exceeds a set value, and wherein said synchronous injection control means is comprised such that said actual injection time processing is performed by using the correction variable arithmetically operated by said correction variable arithmetical operation means at said synchronous injection timing or the immediately preceding timing.