Fuel metering valve for IC engine - has pressure equalising groove between metering and leakage return grooves

摘要

The valve has a plug (2) in a cylinder (1). Fuel enters through a bore (4) in the plug and leaves through circumferential grooves (5) which communicate with the bore. Each groove overlaps an outlet port (7) in the cylinder and is profiled so that the volume flow varies as the plug is rotated. A further groove (11) below the metering grooves collects leakage past the plug and returns it through a port (12) in the cylinder. An additional groove (13) communicates with the central bore (4) to alter the pressure distribution and prevent leakage from the metering grooves.