Common-Rail-Injektor

摘要

The invention relates to a common rail injector for injecting fuel in a common rail injection system of an internal combustion engine. The common rail injector has an injector housing (1) with a fuel inlet (21) that is connected to a central high pressure fuel accumulator outside the injector housing (1) and a pressure chamber (24) inside the injector housing (1). Fuel is injected out of said pressure chamber at high pressure in accordance with the position of a control valve (33). This control valve ensures that a nozzle needle (8) that can be moved axially back and forth in a longitudinal bore (6) of the injector, against the prestressing force of a nozzle spring (19) located in a nozzle spring chamber (20), is lifted up from a seat when the pressure in the pressure chamber (24) is greater than the pressure in a control chamber (30), said control chamber being connected to the fuel inlet (21) by a fuel intake throttle (31). The aim of the invention is to provide a common rail injector of small construction volume and with a simple construction that is also economical to produce. To this end, the control chamber (30) is delimited by a sleeve (28) which is sealingly displaceable on the end of the nozzle needle (8) furthest from the combustion chamber and can be held in a position in which it rests against the injector housing (1) with the help of the nozzle spring (19).