Nozzle Holder Assembly

The nozzle holder assembly is used for fastening the injection nozzle in the cylinder head of the engine. It establishes the connection with the injection tubing and contains a spring which determines the nozzle opening pressure.
The pressure spring in the holder body presses on the nozzle needle via the pressure spindle. The initial tension of this spring determines the opening pressure of the injection nozzle. The opening pressure is adjusted by means of pressure adjusting shims. The fuel reaches the nozzle seat via the respective inlet bore in the holder body intermediate disc and the injection nozzle. During injection the injection pressure lifts up the nozzle needle and the fuel flows into the combustion chamber through the blind hole and the spray holes. When the injection pressure drops the spring forces the nozzle needle back onto its seat, thus terminating the injection of fuel.