Patent ID: 7140556

Claim:
A fuel injector comprising: an injection valve provided with a mobile plunger for controlling the flow of fuel; an actuator capable of displacing the plunger between a closed position and an open position of the injection valve; an injection jet having a plurality of first through-holes made starting from a chamber arranged downstream from the injection valve; a supporting body having a tubular shape and comprising a supply channel; and a sealing body in which a valve seat of the injection valve is defined and the injection jet is made; wherein the sealing body is monolithic and comprises a disc-shaped plug member, which seals the bottom of the supply channel and is passed through by the injection jet, and a guide member, which rises up from the plug member, is tubular in shape and receives within it the plunger to define a lower guide of the plunger; wherein the guide member has at least in part an external diameter smaller than the internal diameter of the supply channel so as to define an external channel for the fuel; wherein in the lower part of the guide member there are provided a number of second through-holes which open into the valve seat; wherein each second through-hole has a diameter greater than the diameter of each first through-hole so as to minimize the hydraulic resistance and improve the cooling effect in such portion and so as the total area of the second through-holes is at least three times the total area of the first through-holes.