PURPOSE: To reduce the temperature of the wall surface of a communicating hole in a vortex chamber so as to prevent generation of crank, melting, loss and the like which are caused by thermal fatigue by providing an electronic control type unit injector, a temperature detecting means, and a control means.
CONSTITUTION: The fuel injection device of an auxiliary chamber type diesel engine is provided with an auxiliary chamber (a vortex chamber) 10. And it is also provided with an electric control type unit injector 11 capable of injecting fuel into the vortex chamber 10 and changing an injection pressure, and a temperature detecting means 37 for detecting the wall surface temperature of a communicating hole 14 for communicating the vortex chamber 10 with a combustion chamber 13. And also it is provided with a control means 23 for carrying out auxiliary injection of a small amount of fuel in addition to the injection by means of the electric control unit injector 11, when the wall surface temperature of the communicating hole 14 detected by the temperature detecting means 37 is a prescribed value or more. Fuel injected by this auxiliary injection is stuck on the wall surface of the communicating hole 14, and also the fuel is gasified so as to reduce a wall surface temperature. It is thus possible to reduce a thermal load around the communicating hole 14.
TERASAWA YASUYUKI
SAKIMOTO MASATSUGU
KONDO MITSUNORI
