20130255623 | FUEL INJECTOR - A fuel injector according to the present invention includes a needle valve mechanism including a needle valve provided near a nozzle portion, and a fuel chamber; a needle valve actuator mounted with a piston, wherein a spring is disposed into the piston; a booster formed with first through third chambers in an upper portion, a middle portion, and a lower portion, respectively, based on a piston, and having only the spring-free piston; a pilot valve operating by a pressure difference between pressure for injection of the fuel chamber and working pressure of a solenoid, having a spool and a spacer mounted above the spool and formed with a second orifice on one side thereof; and a solenoid valve controlling working pressure of fuel to operate the needle valve actuator or the pilot valve. | 10-03-2013 |