Fuel injection valve protecting apparatus and fuel pressure increase preventing apparatus in LPG injection type engine

摘要

A fuel injection valve protecting apparatus for an LPG injection type engine operates when an excessive current passes through the fuel injection valve, or when an abnormality of the fuel injection valve occurs. An electrical fuse is inserted in a driving current supply line of the fuel injection valve. An electronic control apparatus has an abnormality diagnostic unit to detect any abnormality of the fuel injection valve by monitoring a check signal sent back from a fuel injection valve driving circuit, to thereby close a fuel shutoff valve and shut off the liquefied petroleum gas. Relief valves are connected in parallel between a petroleum gas supply line and an intake manifold so as to directly discharge any petroleum gas in the petroleum gas supply line into the intake manifold when the pressure difference between the petroleum gas supply line and the intake manifold reaches a set differential pressure.