Patent ID: 7320310

Claim:
A fuel injector for injecting fuel into a combustion chamber ( 23 ) of an internal combustion engine the injector comprising a pressure booster ( 3 ) having a booster piston ( 4 ) which separates a work chamber ( 5 ), permanently subjected to fuel via a pressure source ( 1 , 2 ), from a pressure-relievable differential pressure chamber ( 6 ), and a servo valve ( 24 ) actuatable to effect a change in pressure in the differential pressure chamber ( 6 ), the servo valve opening or closing a hydraulic connection ( 21 , 39 , 42 ) of the differential pressure chamber ( 6 ) to a low-pressure-side return ( 28 ), the servo valve ( 24 ) having a servo valve piston ( 32 , 65 ), which is guided between a control chamber ( 36 ) and a first hydraulic chamber ( 38 ) and on which an operative hydraulic face ( 44 ), constantly urged in the opening direction of the servo valve piston ( 32 ) by a system pressure, and a first sealing seat ( 40 ), which seals off the servo valve ( 24 ) from a low-pressure-side return ( 28 ) wherein the servo valve piston ( 32 ) comprises a first sealing seat ( 40 ), which opens or closes the low-pressure-side return ( 28 ), and a control edge ( 41 ), which separates the first hydraulic chamber ( 38 ) from a second hydraulic chamber ( 39 ).