Patent ID: 7059303

Claim:
A fuel injection system for internal combustion engines, comprising a fuel injector ( 10 ) that can be supplied from a high-pressure fuel source ( 60 ), a pressure booster ( 30 ) having a movable piston ( 36 ), the pressure booster being connected between the fuel injector and the high-pressure fuel source and the movable piston separating a chamber ( 35 ) that is connected to the high-pressure fuel source ( 60 ), from a high-pressure chamber ( 40 ) communicating with the injector ( 10 ) and from a rear chamber ( 38 ), a fuel line ( 46 ; 75 ; 88 ; 186 ) connecting the high-pressure chamber ( 40 ) in communication with the rear chamber ( 38 ) in such a way that the high-pressure chamber can be filled via the rear chamber with the high pressure of the high-pressure fuel source ( 60 ); a fill valve ( 49 ; 72 ; 140 ; 161 , 170 , 176 ), the chamber ( 35 ) communicating with the rear chamber ( 38 ) via the fill valve, and control valve means ( 31 ) connecting the rear chamber ( 38 ) for communication with a low-pressure line ( 32 ), whereby by filling the rear chamber with fuel and by evacuating the rear chamber of fuel, the fuel pressure in the high-pressure chamber can be varied.