| 摘要 |
A fuel injector nozzle 102 comprises a needle 106 having an extension 116 in a reduced cross-section part 120 of the nozzle body 104. When the needle 106 is in a closed position, fig.4, an edge seal 140 prevents fuel from flowing into a sac 130, and a secondary seal 142 formed between a needle extension 116 and a nozzle bore 124 prevents fuel from being ejected from the sac 130. The nozzle may have two sets of spray holes 132, 134 such that when the needle 106 is in a partially open position (fig.5), the secondary seal 142 is partially open allowing fuel to flow into the sac 130 via a needle bore 128 and vents 126 and into only the first row of spray holes 132, the second set of spray holes 132 being obstructed by the needle extension 116. When the needle is fully open (fig.6), neither set of spray holes 132, 134 are obstructed and fuel is ejected from both sets of spray holes. |
