IC engine fuel injection valve - has ducted valve needle end giving increasing free outflow area through nozzle ducts as needle lift increases

摘要

The fuel injection valve has a needle valve (2) which opens against the direction of flow. Near the valve seat (3) the needle has a cylindrical end (4) with fuel ducts (5) which enters into a blind bore (12) of the injector housing, a number of outlet nozzle ducts (7) extending from this bore. The arrangement is such that, with increasing lift of the needle, the available free flow area through the ducts gradually increases. The ducts (5) may be inclined relative to the needle centre line (6) whilst their outlet orifices (10) are adjacent to a flow-controlling shoulder (8, 9) on the end (4).