| 摘要 |
A fuel injection valve of an internal combustion engine is opened at a predetermined crank angle position. A counter starts to count pulses from a clock pulse signal generator at the predetermined crank angle position, and produces a signal to close the fuel injection valve when the accumulated count in the counter reaches an integer value which corresponds to the ratio of Ti to Tc where Ti is the fuel injection time duration, calculated by a calculating means from engine operational parameters, and Tc is the period of the signal from the clock pulse signal generator. The clock pulse signal generator is controlled by the calculating means, and the period Tc of its output signal is thereby varied. The ratio of Ti to Tc should preferably be selected so as to be as close to the capacity of the counter as possible. A voltage controlled oscillator may be used as the clock pulse signal generator, together with a digital to analog converter which converts the fuel injection time interval Ti to a voltage value which is inputted to the voltage controlled oscillator so as to control its output frequency.
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