| 摘要 |
PURPOSE:To stably perform idling operation, by controlling a solenoid valve with an injection pulse signal generated at a fixed frequency from a pulse generator circuit at idling time in a device which injects metered fuel through the solenoid valve into an intake passage. CONSTITUTION:At operation of an engine 1, an output of a speed sensor 17 is input to an injection timing control circuit 28, shaped by a waveform shaper 19 and then fed to a frequency selector circuit 29 and frequency comparator circuit 30. This output is compared in the circuit 30 with an idling speed having a preset fixed width, and an output is generated only when an engine speed is range to within said idling speed and input to a selective control circuit 34. While at ON time of an idle switch 27, said circuit 34 outputs a selective signal, and a pulse signal met to a guide ring setting speed generated by a constant frequency pulse generator circuit 35 is generated from the circuit 29 to open and control a solenoid valve 8 then inject fuel into an intake pipe 2. |
