Patent ID: 6886535

Claim:
A fuel injection apparatus for an internal combustion engine, comprising a high-pressure fuel pump ( 10 ) and a fuel injection valve ( 12 ) connected to it for each cylinder of the engine, the high-pressure fuel pump ( 10 ) having at least one pump piston ( 18 ) that is driven into a stroke motion by the engine and delimiting a pump working chamber ( 22 ), which is supplied with fuel from a fuel tank ( 24 ), the fuel injection valve ( 12 ) having a pressure chamber ( 40 ) connected to the pump working chamber ( 22 ) and at least one injection valve element ( 28 ) that controls at least one injection opening ( 32 ), the pressure prevailing in the pressure chamber ( 40 ) acting on the at least one injection valve element ( 28 ) in an opening direction ( 29 ) counter to a closing force in order to open the at least one injection opening ( 32 ), a control valve ( 68 ) that at least indirectly controls a connection ( 66 ) of the pump working chamber ( 22 ) to a relief chamber ( 24 ) and a pressure source ( 23 ) in order to fill the pump working chamber ( 22 ) during the intake stroke of the at least one pump piston ( 18 ), the high-pressure fuel pump ( 10 ) having two pump pistons ( 18 , 118 ) including a first pump piston ( 18 ) inside of which a second pump piston ( 118 ) is guided so that it can slide in an approximately coaxial fashion, wherein the two pump pistons ( 18 , 118 ) delimit the pump working chamber ( 22 ), in that the first pump piston ( 18 ) is driven in a stroke motion, and means optionally coupling the two pump pistons ( 18 , 118 ) to each other to move together as a unit during the delivery stroke, or decoupling the two pump pistons ( 18 , 118 ) whereby the second pump piston ( 118 ) can be fixed in a passive position so that only the first pump piston ( 18 ) executes the delivery stroke.