| 摘要 |
PURPOSE:To ensure a prescribed fuel pressure even if the discharging pressure amount of a high pressure fuel pump is insufficient by arranging an opening/ closing valve on a bypass passage for bypassing a high pressure control means for controlling a fuel pressure from the high pressure fuel pump, and controlling the opening/closing valve according to operating condition of an internal combustion engine. CONSTITUTION:Low and high pressure fuel pumps 4, 5 are respectively arranged in a fuel passage 3 for connecting the fuel injection valve 1 to the fuel tank 2 of an internal combustion engine. A check valve 12 is arranged in a first bypass passage 11 for bypassing the high pressure fuel pump 5. An opening/ closing valve 14 is arranged in a second bypass passage 13 for bypassing a high pressure fuel pump 5. Meanwhile the fuel pressure on the upstream side of the second bypass passage 13 is maintained by a fuel pressure maintaining mechanism 15 to a constant pressure or more lower than that of the high pressure control means 10. And the opening/closing valve 14 is controlled by a control means 30 so as to open/close the opening/closing valve 14 according to normal operating condition and specified operating condition of the internal combustion engine. |
