Patent ID: 7093582

Claim:
A fuel injection system for internal combustion engines, comprising a fuel injector ( 26 ) that can be acted upon by a high-pressure fuel source ( 2 , 43 ), a pressure booster ( 13 ) including a work chamber ( 15 ), a high pressure chamber ( 17 ), a differential pressure chamber ( 16 ), and a movable pressure boosting element ( 14 ), the pressure booster being disposed between the fuel injector ( 26 ) and the high-pressure source ( 2 , 43 ), the pressure boosting element ( 14 ) dividing the work chamber ( 15 ), which can be made to communicate with the high-pressure source ( 2 , 43 ) via a high-pressure line ( 3 ), from the high-pressure chamber ( 17 ) that acts upon the fuel injector ( 26 ), means filling the differential pressure chamber ( 16 ) of the pressure booster ( 13 ) with fuel and evacuating the differential pressure chamber ( 16 ) of fuel during restoration and pressure boosting phases, respectively, to thereby vary the pressure in the high pressure chamber ( 17 ) a filter element ( 5 ) connected in a line portion ( 4 ) branching from high pressure line ( 3 ) upstream of at least one of the chambers ( 15 , 16 , 17 ) of the pressure booster and upstream of the flow conduits ( 10 , 20 , 23 ; 42 , 44 ) for filling at least one of the pressure chambers ( 16 , 17 ) of the pressure booster ( 13 ), wherein the line portion ( 4 ) containing the filter element ( 5 ) changes over into flow conduits ( 10 , 20 , 23 ) for filling the differential pressure chamber ( 16 ) and the high-pressure chamber ( 17 ) of the pressure booster ( 13 ).