| 摘要 |
PROBLEM TO BE SOLVED: To suppress the generation of large combustion sound at the time of controlling fuel pressure in accumulator piping from a high state to a low state in a fuel injection control device for an accumulator type engine provided with a contraflow regulating means. SOLUTION: An injector 2 of a diesel engine 1 is connected to a common rail 4 common to each cylinder 4, and the common rail 4 is connected to a supply pump 6 through feed piping 5. A check valve 7 is provided at an intermediate part of the feed piping 5. A pressure control valve 10 for controlling the pressure of discharged fuel is provided near a discharge port 6a of the supply pump 6. The common rail 4 is provided with a relief valve 12. In case of the engine 1 being put in a complete explosion state, the relief valve 12 is put in an on state by an electronic control unit 51, and high pressure fuel in the common rail 4 is returned to a fuel tank 8 via return piping 11, so that fuel pressure in the common rail 4 is rapidly lowered. |
