| 摘要 |
PURPOSE:To secure an optimum fuel injection rate over the whole running range, by installing a injection pressure controlling device, variable in relief pressure, in a range of a highpressure feul flow passage from a fuel injection pump to a injection nozzle, while controlling this according to a running condition. CONSTITUTION:A bosh-form distributor type fuel injection pump 5 applies pressure to fuel drawn in a high pressure chamber 56 by a plunger 48 to be reciprocated and rotated with rotation of a pump driving shaft, and distributes and feeds it to each cylinder via a passage 53 and a delivery valve 54. In this case, there is provided with an injection pressure controlling solenoid valve 70 electrically variable in relief pressure in relation to a flow passage 71b putting fuel in the high pressure chamber 56 back to a fuel sump 45. This solenoid valve 70 controls injection pressure by an electrical control circuit (unillustrated herein) in accordance with the desired injection pressure to be set on the basis of output of a running condition detector and the actual injection pressure to be detected at a pressure detector 21 whereby an optimum fuel injection rate is secured over the whole running range. |
