| 摘要 |
PROBLEM TO BE SOLVED: To control the fuel injecting pressure accurately with good responsiveness. SOLUTION: From a high pressure fuel supply pump 5, fuel is supplied to an aux. pressure accumulation chamber 33 inside a common rail 3, and high pressure fuel is stored in the aux. pressure accumulation chamber. A control circuit (ECU) 20 detects the intra-aux. chamber fuel pressure using a sensor 23 and controls the intra-aux. chamber fuel pressure to the predetermined value by controlling the pressure feed amount of fuel of the fuel supply pump 5. The aux. chamber is connected with the main pressure accumulating chamber 31 through a solenoid valve 25, and the solenoid valve 25 is opened each time a fuel injection valve 10 connected with the main chamber injects the fuel into the main chamber, and the fuel is supplied from the aux. to the main chamber. The ECU detects the fuel pressure in the main chamber using a sensor 21 and controls the opening time of the solenoid valve 25 so that the internal pressure of the main chamber becomes the set pressure in accordance with the engine load conditions. Because the internal pressure of the aux. chamber is controlled to constant value, the controllability for the internal pressure of the main chamber (fuel injection pressure) is enhanced. |
