| 摘要 |
PURPOSE:To enable to perform pilot injection at an arbitrary time and in an arbitrary quantity, by a method wherein a fuel injection pump and a pump, having an about constant discharge pressure, are connected to a common fuel injection nozzle, and a switching valve and a booster device are located in the connection line. CONSTITUTION:When a compression stroke nears its terminal, a switching valve 7 is changed over to communicate a line 52 on the electric pump 3 with a low pressure chamber 82 of a booster device 8. In which case, a discharge pressure from the electric pump 3 is exerted on the low pressure chamber 82 and a high pressure chamber 83. But, since the upper and the lower pressure receiving surface of a piston 81 are different from each other, the piston 81 is pressed toward the high pressure chamber 83 side and fuel in the high pressure chamber 83 is pressurized. As a result, a chuck valve 9 is closed, and when fuel in the high pressure chamber 83 is increased in a pressure to a given value, fuel is injected through a nozzle 4. The amount of the fuel injected is determined by the volume of the high pressure chamber 83 and a timing, at which a switching valve 7 is charged over to close the line 52. Fuel injection from the booster device 8 is pilot injection in prior to main injection from a pump 2.
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