Patent ID: 7252070

Claim:
A fuel injection system for an internal combustion engine, comprising a respective high-pressure fuel pump ( 10 ) and a fuel injection valve ( 12 ) connected to it for each cylinder of the internal combustion engine, the high-pressure fuel pump ( 10 ) having a pump piston ( 18 ) driven into a stroke motion and delimiting a pump working chamber ( 22 ), which can be connected to a low-pressure region ( 25 ) via a connection ( 21 ) that is controlled by an electrically actuated control valve ( 60 ), the fuel injection valve ( 12 ) having an injection valve element ( 28 ) that controls at least one injection opening ( 32 ) and is acted on in an opening direction ( 29 ) by the pressure prevailing in a pressure chamber ( 40 ), which can be connected to the pump working chamber ( 22 ), an electrical control element ( 64 ) controlling an opening and closing motion of the injection valve element ( 28 ), a pressure reservoir ( 68 ) communicating with the pump working chamber ( 22 ) via a connection ( 66 ) through which fuel is delivered into the pressure reservoir ( 68 ) during the delivery stroke of the pump piston ( 18 ) and also communicating with the pressure chamber ( 40 ) of the fuel injection valve ( 12 ) via the connection ( 66 ) through which the pressure chamber ( 40 ) can be supplied with fuel from the pressure reservoir ( 68 ) for a fuel injection via the fuel injection valve ( 12 ) independent of the delivery stroke of the pump piston ( 18 ), the connection ( 66 ) of the pressure reservoir ( 68 ) to the pump working chamber ( 22 ) and pressure chamber ( 40 ) containing a coupling device ( 70 ; 170 ; 270 ), which contains a sliding piston ( 74 ; 174 ; 274 ) that is acted on at one end by the pressure prevailing in the pressure reservoir ( 68 ) and is acted on at the other end by the pressure prevailing in the connection ( 66 ), the piston ( 74 ; 174 ; 274 ) executing a delivery stroke oriented toward the pressure chamber ( 40 ) in order to execute a fuel injection, and the coupling device ( 70 ; 170 ; 270 ) containing a bypass connection ( 76 , 77 ; 176 ; 276 , 277 ) via which the connection ( 66 ) communicates with the pressure reservoir ( 68 ).