Fuel injector and in-cylinder direct-injection gasoline engine

摘要

A fuel injector comprising: a plunger (6) for opening/closing a fuel path to control the amount of fuel to be injected; a seat portion (4) for the plunger (6); a plurality of nozzle holes (29) for injecting fuel passed through between the plunger (6) and the seat portion (4), and the fuel injector (100) further comprising:a nozzle plate (1) provided with the seat portion (4), and a taper-fuel inlet hole whose diameter is gradually reduced from the seat toward its outlet; anda orifice plate (25) arranged downstream the taper-fuel inlet hole (3), and provided with a concave portion opposite to the nozzle plate, and a plurality of nozzle holes being formed concentrically at a bottom of the concave (26),wherein the plurality of nozzle holes (29) are formed so that each nozzle hole (29) has an inclined angle in the direction of the plate thickness within the concave area (26).