Patent ID: 8347851

Claim:
A fuel injection control apparatus comprising: a body having a first nozzle hole formed in its tip portion facing a combustion chamber of an internal combustion engine, and a second nozzle hole formed in the tip portion and located between the first nozzle hole and the tip of the body; an outer needle valve having a tubular form, slidably accommodated in the body, and adapted to open and close the first nozzle hole with its tip portion; an inner needle valve having a rodlike form, slidably accommodated in the outer needle valve, and adapted to open and close the second nozzle hole with its tip portion; a nozzle chamber which is provided on the tip side of the outer and inner needle valves and in which rail pressure, which is pressure of fuel within the nozzle chamber, applies force to the outer and inner needle valves from the tip side in a valve opening direction, the fuel within the nozzle chamber being injected into the combustion chamber through the first and second nozzle holes in a state in which the outer and inner needle valves are opened; an outer control chamber which is provided on the back side of the outer needle valve and in which outer control pressure, which is pressure of fuel within the outer control chamber, applies force to the outer needle valve from the back side in a valve closing direction; an inner control chamber which is provided on the back side of the inner needle valve and in which inner control pressure, which is pressure of fuel within the inner control chamber, applies force to the inner needle valve from the back side in the valve closing direction; a high pressure generating section for generating fuel having the rail pressure; a fuel supply channel for connecting the high pressure generating section and the nozzle chamber; a first fuel inflow channel for connecting the fuel supply channel and the outer control chamber or the inner control chamber; a communication channel for establishing communication between the outer control chamber and the inner control chamber; a fuel drain channel for connecting the inner control chamber and a fuel tank; a first control valve installed in the fuel drain channel and adapted to allow and shut off communication through the fuel drain channel; and a piece provided separately from the body, unitarily fixed to the body, and adapted to separate the nozzle chamber and the outer control chamber from each other, the piece having a stopper for limiting a lift of the outer needle valve, wherein the piece is disposed between the nozzle chamber and the outer control chamber.