Patent attributes
Fuel injection equipment is provided which realizes characteristics of fuel injection proper for all over the operation range of an engine, can further reduce nitrogen oxide(NOx) emission, and is high in mechanical durability. The fuel injection equipment for an internal combustion engine comprises an injection pump having a plunger part and a fuel passage equipped with a main electromagnetic valve, a fuel supply part for supplying the fuel to the fuel injection pump, a fuel injection pipe for sending the fuel to an injection nozzle part, and a secondary electromagnetic valve attached to an overflow pipe for returning to said fuel supply part the redundant fuel not to be injected from said unit injector, wherein an orifice is attached to said overflow pipe.