Patent ID: 7850435

Claim:
A fuel injection apparatus for an internal combustion engine, the apparatus comprising a high-pressure pump ( 10 ) that delivers fuel into a reservoir ( 12 ) from which fuel is drawn for injection into the engine, a fuel-supply pump ( 22 ) that delivers fuel from a fuel tank ( 24 ) to the high-pressure pump ( 10 ), the high-pressure pump ( 10 ) having a housing ( 30 ) with an internal chamber ( 31 ) containing a drive unit ( 32 , 34 ) for at least one pump element ( 36 ) of the high-pressure pump ( 10 ), the pump element ( 36 ) having a pump piston ( 38 ) driven into a stroke motion by the drive unit ( 32 , 34 ) and delimiting a pump working chamber ( 42 ) into which fuel is supplied via an inlet ( 60 ) during an intake stroke of the pump piston ( 38 ) and from which fuel is displaced via an outlet ( 64 ) into the reservoir ( 12 ) during a delivery stroke of the pump piston ( 38 ), the pump piston ( 38 ) moving into the internal chamber ( 31 ) during its intake stroke and out from the internal chamber ( 31 ) during its delivery stroke, wherein during its intake stroke, the pump piston ( 38 ) causes a pressure increase in the internal chamber ( 31 ), a connection ( 23 ) containing a check valve ( 52 ) which connection directly delivers fuel from the fuel-supply pump ( 22 ) through the check valve and into the internal chamber ( 31 ), the check valve ( 52 ) being disposed in the housing between the fuel-supply pump and the internal chamber and opening toward the internal chamber ( 31 ) of the housing ( 30 ) such that the check valve ( 52 ) opens toward the internal chamber ( 31 ) and closes in an opposite direction, and means ( 62 ) for connecting the inlet ( 60 ) of the pump working chamber ( 42 ) to the internal chamber ( 31 ) so that during the intake stroke of the pump piston ( 38 ), fuel displaced from the internal chamber ( 31 ) by the movement of the piston toward the internal chamber ( 31 ) is drawn into the pump working chamber ( 42 ).