Fuel injector for hydraulically boosted injection system has pressure boost valve for hydraulically assisted closure of nozzle needle that at least partly closes fuel feed channel when injection finishes

摘要

The fuel injector has a pressure boost valve (300) for hydraulically assisted closure of a nozzle needle (220). The valve is provided in a fuel feed channel (110) on the high pressure side of the fuel injector (1) so that fluid pressure from fuel (2) at high pressure in the feed channel acts on a rear side of the nozzle needle via the valve when injection finishes, whereby the pressure boost valve at least partly closes the fuel feed channel. An independent claim is also included for a hydraulically boosted injection system.