| 摘要 |
PURPOSE:To reduce the size and the manufacturing cost of a valve device, by a method wherein, in a unit injector, a difference pressure between sections before and behind an orifice is produced by causing a part of high pressure fuel to flow, and the differential pressure produces a driving force to effect the opening motion of a weighing valve. CONSTITUTION:The high pressure fuel in a pressure chamber 26 is transferred to a needle chamber 27D through a fuel passage 29, and when the pressure exceeds the energizing force of a spring 27B, a needle valve 27C is energized upward to open a nozzle 27E, and the fuel in the pressure chamber 26 is injected through the nozzle 27E. A weighing valve 35 and an electromagnetic valve 36, serving as a valve device and located subsequent to the weighing valve, are situated on a fuel feed passage 28 communicated with the pressure chamber 26. The fuel feed passage 28 is communicated with a fuel passage 29 also, and since the high pressure fuel in the pressure chamber 26 is kept from flowing through the weighing valve 35 with the electromagnetic valve 36 closed, the high pressure fuel to a nozzle 27. With the electromagnetic valve 36 opened, a differential pressure between parts located before and behind an orifice 35E opens the weighing valve 35. |
