CONTROL VALVE AND FUEL INJECTION VALVE HAVING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a control valve easy to be assembled and reducing driving energy, without high machining accuracy or positioning accuracy. SOLUTION: For boosting fuel supplied from a common rail 2 to a boosting device 4 by the drive of a boosting piston 44 and then injecting the boosted fuel from the injection nozzle 7, a hydraulic servo valve 3 for controlling boosting operation and injecting operation is provided. The hydraulic servo valve 3 of a two-position three-way valve increases/decreases hydraulic pressure of a servo valve control chamber 13 to make a boost control passage 14 and an injection control passage 15 selectively communicate with a return port 28 leading to a return passage 27 or a high pressure port 22 leading to the common rail 2. The hydraulic servo valve 3 is divided into an upper valve 31 provided with an upper seat 33 and a lower valve 32 provided with a lower seat 34 to be driven, so that its machining is facilitated and the driving energy is reduced. COPYRIGHT: (C)2006,JPO&NCIPI