1. Field of the Invention
The invention is based on a fuel injector for injecting fuel into a combustion chamber of an internal combustion engine.
2. Description of the Prior Art
DE-A 103 35 340 has disclosed a fuel injector that includes a control valve for a pressure booster. The pressure booster has a working chamber that is separated from a differential pressure chamber by a pressure booster piston. The pressure change in the differential pressure chamber of the pressure booster is carried out by means of a servo valve that is activated by an associated switching valve. The differential pressure chamber contains a spring element that encompasses a lower section of the pressure booster piston, which has a diameter that is smaller than the upper section of the pressure booster piston. One end of the spring element is supported on the upper section of the pressure booster piston and the other end is supported on the injector housing. The spring element produces a restoring movement of the pressure booster piston. The disadvantage of this design is that it is not possible to pre-assemble the pressure booster piston and spring element. In addition, this embodiment has spatial disadvantages since it is necessary to select the outer diameter of the spring element to be smaller than the large piston diameter.