| 摘要 |
PROBLEM TO BE SOLVED: To prevent the seizure of a high pressure pump in an extremely low speed region while allowing normal operation to some extent during a failure in an electric system for a solenoid valve. SOLUTION: The common-rail fuel injection control device for allowing the forcible feed to a common rail 2 of a fuel supplied from a feed pump 6 and pressurized by the high pressure pump 3 and controlling the amount of the fuel to be supplied to the high pressure pump 3 with the normally opened solenoid valve 7 comprises fuel supply shut-off means 60 for mechanically shutting off the supply of the fuel to the high pressure pump 3 until the feeding pressure of the feed pump 6 reaches a preset value or more during deenergizing the solenoid valve. During deenergization due to the failure in the electric system for the solenoid valve 7, when an engine speed is low down to the extremely low speed region and the feeding pressure of the feed pump 6 is less than the preset value, the fuel supply to the high pressure pump 3 is mechanically shut off and so the pressure pump 3 is in a non-forcibly-fed condition which precludes the operation of a high pressure on the pressure generating part thereof. Thus, the seizure of the high pressure pump 3 is prevented. |
