Method and apparatus for determining an injection moment during a start process in an internal combustion engine

An apparatus for determining a moment of injection of fuel during a start in an internal combustion engine with an intermittent fuel injection and provided with a main power supply, a battery, a crankshaft and a fuel injection valve, the apparatus comprising means for shifting a time point for the injection valve for a delay-period of time (Zo) depending upon the number of revolutions of the crankshaft so that said time point respectively occurs approximately within a following maximum value of a cyclically fluctuating voltage of the main power supply depending upon the number of revolutions of the crankshaft, said means including at least one adder circuit block (16, 33) operative for adding the delay-period of time (Z1+Zo) depending upon the number of revolutions of the crankshaft to a time point of the occurrence of an ignition signal defined by reference marks so that an actual time point of injection occurs within the maximum value of the pulsating battery voltage U.sub.B.

An apparatus for determining a moment of injection of fuel during a start in an internal combustion engine with an intermittent fuel injection and provided with a main power supply, a battery, a crankshaft and a fuel injection valve, the apparatus comprising means for shifting a time point for the injection valve for a delay-period (t.sub.v) depending upon the number of revolutions of the crankshaft so that said time point respectively occurs approximately within a following maximum value of a cyclically fluctuating voltage of the main power supply depending upon the number of revolutions of the crankshaft, said means comprising a differential circuit block (25) for forming a time differential of the battery voltage and releasing a time point of the fuel injection start if start conditions are present.

A method for determining a moment of injection of fuel during a start in an internal combustion engine with an intermittent fuel injection and provided with a main power supply, a battery, a crankshaft and a fuel injection valve, the method comprising the step of controlling a time point for the injection valve control for a delay-angle (t.sub.v) depending upon the voltage of the battery so that said time point respectively occurs approximately within a maximum value of a pulsating battery voltage.

An apparatus for determining a moment of injection of fuel during a start in an internal combustion engine with an intermittent fuel injection and provided with a main power supply, a battery, a crankshaft and a fuel injection valve, the apparatus comprising means for shifting a time point for the injection valve for delay-angle (t.sub.v) depending upon the voltage of the battery, so that said time point respectively occurs approximately within a following maximum value of a pulsating battery voltage, said means including at least one adder circuit block (16, 33) operative for adding the delay-angle (t.sub.v) depending upon the number of revolutions of the crankshaft to a time point of the occurrence of an ignition signal defined by reference marks so that an actual time point of injection occurs within the maximum value of the pulsating battery voltage (u.sub.B).

An apparatus for determining a moment of injection of fuel during a start in an internal combustion engine with an intermittent fuel injection and provided with a main power supply, a battery, a crankshaft and a fuel injection valve, the apparatus comprising means for shifting a time point for the injection valve for a delay-angle (Zo) depending upon the voltage of the battery so that said time point respectively occurs approximately within a maximum value of a pulsating battery voltage, said means comprising a differential circuit block (25) for forming a time differential of the battery voltage and releasing a time point of the fuel injection start if start conditions are present.