Fuel injection device for e.g. diesel prime mover, has needle displaced in valve closing and opening directions if reinforcing mechanism stops strengthening and strengthens fuel such that needle closes and opens hole, respectively

摘要

The device has a nozzle (3) with a needle (8), which opens and closes an injecting hole (7). The nozzle defines nozzle and dynamic pressure chambers (10, 9), where fuel applying pressure on the needle flows into and out of the chamber (9). The needle is displaced in a valve opening direction by the fuel in the chamber (10) if a reinforcing mechanism (4) strengthens the fuel such that the needle opens the hole. The needle is displaced in a valve closing direction by a return spring (11) if the mechanism stops strengthening of the fuel such that the needle closes the hole.