| 摘要 |
PURPOSE:To flush and remove foreign substances as well as to prevent any hindrance of fuel injection from occurring by dividing a spool storage chamber to be interconnected to a pump pressure chamber into a spill chamber and a transformer chamber, and connecting a spill passage, leading to the pump pressure chamber, to the spill chamber. CONSTITUTION:At the time of fuel injection, a solenoid valve 100 is closed, pressure in a pump pressure chamber 19 goes up whereby fuel is sprayed out of a fuel injection nozzle 20. At the time of stopping the fuel injection, the solenoid valve 100 is opened, and a transformer chamber 115 is opened as well. A spool 110 is moved by a pressure drop in the transformer chamber 115 and thereby fuel in the pump pressure chamber 10 is split into a pump low pressure chamber 5 by way of a spill chamber 125 and a spill passage 126, thus the fuel injection comes to an end. At this time, pressure in this spill chamber 125 is equal to that in the pump low pressure chamber 5, while the transformer chamber 115 is interconnected to a lower pressure part than the pump low pressure chamber 5 via the opening. Consequently, spill's displacement becomes large enough by a pressure differential between the spill chamber 125 and the transformer chamber 115 so that foreign substances held between an end face of the spool 110 and a seat surface of the spill chamber 125 can be flushed and removed.
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