Fuel supplying device for internal combustion engine

Claim 1

In a fuel supplying device for an internal combustion engine comprising: a fuel supply passage for introducing fuel fed from a fuel pump at a substantially constant pressure to a fuel injector operative at a predetermined constant pressure, the improvement comprising: said fuel injector installed at a congregated portion of engine intake manifolds, a spool type metering valve including drive motor means receiving fuel from said fuel pump, a differential regulator receiving fuel from said fuel pump and said metering valve wherein a flow pressure drop to said fuel injector is maintained substantially constant by said differential regulator, said spool type metering valve being disposed in an intermediate portion of said fuel supply passage, calculating means including a servo signal generator for calculating an injection flow amount for a predetermined air/fuel ratio on the basis of signals of various engine running factors, said calculating means producing an operational signal output from said servo signal generating circuit to said drive motor means for driving said metering valve to thereby regulate fuel injected into the intake manifolds by said fuel injector, and a cooling air passage from the outside and a gas/liquid passage serving also as an exhaust passage for a leaking fuel are connected to each other between the drive motor means and the spool type metering valve and, an exhaust end of the gas/liquid passage is connected to a suitable portion of the intake system of the engine whereby cooling air and a fuel drain are absorbed at negative pressure.