| 摘要 |
The invention relates to a high pressure fuel pump comprising an evacuation orifice assembly, comprising: a first member (30) adapted to be disposed across the evacuation orifice (12) and comprising at least one opening (32) therein, a second member (40) with a lead portion (42) adapted to be disposed within said opening(s) (32), wherein the assembly is adapted to provide a first predetermined flow-rate of fluid through the opening(s) (32) when the lead portion (42) is in a first position within the opening(s) (32), and to selectively enlarge the opening(s) (32) to provide a second predetermined flow- rate of fluid through the opening(s) (32) when the lead portion is in a second position within said opening(s) (32). The invention also provides an evacuation orifice arrangement adapted to be fitted within an existing bore in the pump comprising: a body (11) adapted to fit within the existing bore, comprising an open-ended evacuation orifice (12); an evacuation assembly and a resilient compression member (14) set to yield (compress) upon exposure to pressure above a predetermined level and adapted to exert force on the first member (30). |
