Injection device for use in e.g. diesel-type internal combustion engine, has fuel chamber separated from nozzle and counter-pressure chambers, where pressure in fuel chamber reduces force produced by pressure in counter-pressure chamber

摘要

The device has a fuel chamber (46) separated from a nozzle chamber (37) and a counter-pressure chamber (38), and defined such that a fuel flows into and flows out from the chamber (46). A pressure in the chamber (46) reduces force produced by a pressure in the chamber (38), where the force is applied on a needle (33) in a valve closing direction. The fuel flows from the chamber (46) for shifting the needle such that the pressure in the chamber (46) is reduced. Fuel passages (41, 48) are provided such that the rate of decrease of the pressure in the chamber (46) is large.