| 摘要 |
PURPOSE:To enhance the control accuracy in the starting timing of fuel injection by constituting so that after fuel has been forced into an accumulator fuel injector, it is depressurized by a timing set valve to release it to a pressure-reducing chamber so that an injection start command valve is opened, and thereby the internal pressure of a valve closing pressure chamber is reduced to open the fuel injection valve. CONSTITUTION:In the device comprising a fuel tank 1, a metering unit M, and a unit injector U which is made up of a fuel injection pump 6, an accumulator fuel injector 7, and the like, an injection start command valve 21 and a pressure reducing chamber 22 for injection start both incorporated in the unit injector U, and an injection start command means 18 incorporated in the metering unit M are provided. And by the injection start command means 18, a timing set valve 19 is opened to communicate a pressure-receiving chamber 36 with a pressure-reducing chamber 20, thereby the internal pressure in the pressure-receiving chamber 36 is reduced, so that the injection start command valve 21 is controlled to be opened. Thus, the internal pressure in a valve closing pressure chamber 12 is depressurized so as to be released to the pressure reducing chamber 22, so that the injection valve 15 is opened. |
