Patent ID: 8033269

Claim:
A fuel injection device comprising: a nozzle body in which a first fuel chamber, a second fuel chamber, a third fuel chamber, and a nozzle orifice extending from the second fuel chamber to the outside of the fuel injection device are formed; a needle valve held in a needle valve holding part in the nozzle body; a needle valve open part provided closer to the front end side than the needle valve holding part in the nozzle body, having the second fuel chamber; a needle valve close part provided closer to the rear end side than the needle valve holding part in the nozzle body, having the third fuel chamber; an injection control valve held in the nozzle body, being capable of advancing and retreating in the first fuel chamber, in which in the nozzle body, a first fuel passage extending from a fuel supply source to the first fuel chamber, a second fuel passage extending from the first fuel chamber to the second fuel chamber, a third fuel passage extending from the first fuel chamber to the third fuel chamber, and a fourth fuel passage extending from the third fuel chamber to a low pressure part at the outside of the fuel injection device are formed, the injection control valve advances to a first position, thereby allowing the first fuel passage to be communicated with the first fuel chamber and blocking access from the first fuel chamber to the third fuel passage, and the injection control valve retreats to a second position, thereby blocking access from the first fuel passage to the first fuel chamber and allowing the first fuel chamber to be communicated with the third fuel passage, the needle valve advances to contact with the nozzle body, thereby blocking access from the second fuel chamber to the nozzle orifice, and the needle valve retreats to move apart from the nozzle body, thereby allowing the second fuel chamber to be communicated with the nozzle orifice, the needle valve open part retreats the needle valve by the fuel pressure in the second fuel chamber, and the needle valve close part advances the needle valve by the fuel pressure in the third fuel chamber; and a discharge prevention part of preventing fuel in the first fuel chamber from discharging to the outside of the fuel injection device through the third fuel passage, the third fuel chamber, and the fourth fuel passage when the injection control valve shifts from the first position to the second position.