Injector for injecting fluid

摘要

An injector comprises a valve needle comprising at its downstream end a closing element (7). The closing element (7) extends to an outer edge (14) and has a rounded portion (16) with a contact area (13) upstream of the outer edge (14). The injector further comprises a cartridge (4). The cartridge (4) comprises a seat cone (18) arranged at a seat cone half angle. The seat cone (18) forms a valve seat and extends to a downstream edge (10) at a downstream end of the cartridge (4). The cartridge (4) comprises a recess (5) in which the valve needle is arranged axially moveable and comprises an outer surface (11) directly adjacent to the edge (10) of the cartridge (4). The outer surface (11) is on the same level with the outer edge (14) of the closing element (7) of the valve needle (6) when the closing element (7) is seated with its contact area (13) on the valve seat of the cartridge (4). The cartridge comprises an upstream cone (19) arranged directly upstream of the seat cone (18) and arranged at an upstream cone half angle being smaller than the seat cone half angle and differing less than 15 degrees from the seat cone half angle.