| 摘要 |
PROBLEM TO BE SOLVED: To conduct stable close control without being influenced by the fluctuation of nozzle back pressure and improve the controllability of an injection amount with respect to a command pulse in an injector having a two-control valve structure. SOLUTION: There is provided a hydraulic servo valve 4 comprising a valve 41 and a servo piston 42 formed integrally with the valve 41. The valve is disposed in a first back pressure chamber 6 arranged between a nozzle back pressure chamber 12 and a low pressure source 3. The servo piston has on its one end face side a volume chamber 8 communicating with a high pressure source and on the other end face side a second back pressure chamber 7 the pressure of which is controlled by a two-way electromagnetic valve 5. The hydraulic servo valve 4 is operated by the application of the hydraulic pressure of the second back pressure chamber 7 controlled by the two-way electromagnetic valve 5, the hydraulic pressure of the first back pressure chamber 6, and the hydraulic pressure of the volume chamber 8. The stable operation of the hydraulic servo valve is enabled by the application of the hydraulic pressure of one of the second back pressure chamber 7 and the volume chamber 8 in the same direction as the hydraulic pressure of the first back pressure chamber 6 without being influenced by the pressure fluctuation of the nozzle back pressure chamber 12. COPYRIGHT: (C)2009,JPO&INPIT
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