Patent ID: 6988489
Filing Date: 2006-01-24
Classification: F02D,F02M,Y02T

Abstract:
1. A fuel injection valve protecting apparatus in an LPG injection type engine which includes an intake manifold, a fuel injection valve, a vaporizer for vaporizing a liquefied petroleum gas fed from a liquefied petroleum gas cylinder and converting it into a petroleum gas of a predetermined pressure so as to be supplied to the fuel injection valve, a fuel injection valve driving circuit for applying a driving current to the fuel injection valve, an electronic control apparatus for controlling the fuel injection valve driving circuit so as to open and close a fuel injection port of the fuel injection valve with the driving current from the fuel injection valve driving circuit, whereby the petroleum gas is injected into the intake manifold, the fuel injection valve protecting apparatus comprising: a fuel shutoff valve provided in a liquefied petroleum gas supply line connecting the liquefied petroleum gas cylinder to the vaporizer; and an electrical fuse inserted in a driving current supply line connected between the fuel injection valve driving circuit and the fuel injection valve; wherein the electronic control apparatus has an abnormality diagnostic means incorporated therein which detects an abnormality of the fuel injection valve by monitoring a check signal of the driving current sent back from the fuel injection valve driving circuit; and wherein when the driving current applied to the fuel injection valve exceeds a predetermined value, the electrical fuse melts to interrupt the driving current to the fuel injection valve, and when the abnormality diagnostic means of the electronic control apparatus detects the abnormality of the fuel injection valve, the engine is stopped by closing the fuel shutoff valve to shut off supplying of the liquefied petroleum gas and the operation of the fuel injection valve is halted by stopping applying a control signal to the fuel injection valve driving circuit from the electronic control apparatus.