| 摘要 |
PURPOSE: A fuel injector is provided to be applied with a pilot valve, thereby optimally controlling the period and amount of fuel spray. CONSTITUTION: A fuel injector includes a needle valve device (200), a needle valve actuator (230), a booster (300), a pilot valve (400), and a solenoid valve (500). The needle valve device has a needle valve (252) and a fuel chamber (254) installed in the vicinity of a nozzle portion (250). The needle valve actuator has a piston (210) in which a spring (240) is interposed. The booster has first to third chambers (310,320,330) formed at the upper, intermediate, lower portions based on a piston (350), respectively, and has only piston without a spring. The pilot valve is operated by the pressure difference between the pressure of supply fuel and the operation pressure of the solenoid valve, and has a spool (475) and a spacer (485). The solenoid valve controls the operation pressure of fuel so as to operate the needle valve actuator or the pilot valve. |
