A METERING UNIT AND A FUEL INJECTION SYSTEM THEREOF

摘要

A metering unit and a fuel injection system is disclosed. The metering unit 10 for a fuel injection system comprises a housing 12 comprising a bore 14 and a circumferential groove 15 in fluid communication with said bore 14 and a piston 16 adapted to reciprocate in the bore 14. At least a portion of the piston 16 is in fluid communication with a fuel inlet 18 in the housing 12. The piston 16 comprises at least one opening 20 on the portion of the piston 16 in fluid communication with fuel inlet 18. The profile of at least one opening 20 being such that the metering unit 10 controls the quantity of fuel flowing back to a fuel tank. Reference figure: Figure 1