Patent ID: 6925988

Claim:
A fuel injection system for internal combustion engines, comprising a high-pressure accumulation chamber ( 7 ), which contains highly pressurized fuel, at least one fuel injection valve ( 15 ), which is connected to the high-pressure accumulation chamber ( 7 ) and which can inject the highly pressurized fuel through injection openings ( 41 , 42 ), which constitute an injection cross section, into a combustion chamber of the engine, a control chamber ( 62 ), which is defined by a longitudinally mobile piston ( 60 ) and is operationally connected to the fuel injection valve ( 15 ) so that the injection cross section of the fuel injection valve ( 15 ) is controlled as a function of the hydraulic pressure in the control chamber ( 62 ), and a low-pressure accumulation chamber ( 72 ) which can be connected to the control chamber ( 62 ), in which a predetermined fuel pressure is maintained in the low-pressure accumulation chamber ( 72 ) that is lower than the pressure in the high-pressure accumulation chamber ( 7 ), wherein in order to control the injection openings ( 41 ; 42 ), at least one valve needle ( 35 ; 37 ) is disposed so that it can move longitudinally in a bore ( 30 ) of the fuel injection valve ( 15 ), counter to a closing force, each at least one valve needle having a pressure surface ( 39 ; 48 ), which is disposed in a pressure chamber ( 32 ) that can be connected to the high-pressure accumulation chamber ( 7 ) so that the pressure in the pressure chamber ( 32 ) can move the valve needle ( 35 ; 37 ) longitudinally, counter to the closing force, in which the valve needle ( 35 ; 37 ) is connected to the piston ( 60 ), and wherein the high-pressure accumulation chamber ( 7 ), the low-pressure accumulation chamber ( 72 ), and the pressure chamber ( 32 ) are connected to a high-pressure valve ( 11 ) so that in a first position of the high-pressure valve ( 11 ), the high-pressure accumulation chamber ( 7 ) is connected to the pressure chamber ( 32 ) while the connection to the low-pressure accumulation chamber ( 72 ) is closed off, and in a second position of the high-pressure valve ( 11 ), the low-pressure accumulation chamber ( 72 ) is connected to the pressure chamber ( 32 ), while the connection to the high-pressure accumulation chamber ( 7 ) is closed off.