| 摘要 |
PURPOSE:To permit to reduce the dynamic range of a pressure regulator and lower the operating sound of the engine in a low revolution area by a method wherein the fuel pump is driven in accordance with the amount of suction air on the operating condition of the engine to discharge the optimum amount of fuel. CONSTITUTION:A suction air amount signal 15, outputted by an airflow meter, is compared with respective reference values V1, V2 of the suction air amount, which are corresponding to the low speed and high speed operating conditions of the engine, in comparators 16, 17 and when the suction air amount signal VQ is larger than the reference value V1, an analog switch 18 is put ON and the motor 12 of the fuel pump 11 is driven by a voltage Vc of a constant voltage electric source 19. When V1>=VQ>=V2, the analog switch 21 is put ON and the pump motor 12 is driven by the output of a function voltage generator 22. When VQ<V2, the analog switch 23 is put ON and the pump motor 12 is driven by the voltage Vb of a constant voltage electric source 24. According to this method, the dynamic range of the pressure regulator 8 may be reduced and the operating sound in the low-load, low-revolution area may be lowered. |
