Patent ID: 7954475

Claim:
A fuel injector for injecting fuel into a combustion chamber of an internal combustion engine, comprising: an injector housing, a fuel inlet line that leads from a high-pressure fuel source and is hydraulically connectable to a pressure chamber, a 3/2-way directional control valve for the injection of fuel into the combustion chamber, the valve having a valve piston axially movable back and forth between a neutral position and an injection position, the valve piston having a first end surface that delimits a coupling chamber, which is hydraulically coupled to a piezoelectric actuator and activated by the piezoelectric actuator, the 3/2-way directional control valve further having a valve element in the form of a ball element that is connected to a second end surface of the valve piston and is movable in a valve control chamber against a first sealing edge in the neutral position and is movable against a second sealing edge in an injection position, the first and second sealing edges being embodied in a contour of the valve control chamber; wherein in order to achieve a pressure-balanced switching, the first end surface of the valve piston and a partial surface on the ball element situated opposite to the first end surface, which partial surface is delimited by the second sealing edge, have effective surfaces of an approximate same size exposed to pressure from the high-pressure fuel source.