| 摘要 |
PURPOSE:To have high pressure fuel injection with a unit injector to make fuel injection steppedly by hindering secondary injection likely to occur owing to the spill pressure of the fuel. CONSTITUTION:The top of an injection plunger guide 17 is coupled by screw to the bottom of a booster plunger guide 18. Booster plunger 13 is arranged in a booster plunger bore 33 reciprocatively in sliding so that a booster pumping chamber 38 is formed in said booster plunger bore in its side near an injection plunger bore 32, which is in connection with the booster plunger bore 33, so as to open and shut the first stage injections cut-off port 39 open to the booster plunger bore 33 and main injection cut-off port 40. Spill fuel communication channel 51 is connected to the return hole of the fuel tank through a spill fuel piping 56, which is provided with a solenoid valve 57 controlled by a control unit 58 receiving signals from a number-of-revolutions sensor 61 and acceleration sensor 62. |
