CONTROL VALVE FOR A FUEL INJECTOR

The invention relates to a control valve (10) for a fuel injector (100) for internal combustion engines, which control valve comprises a valve piece (11), which has a valve seat (12) and a valve closing armature (20), which interacts with the valve seat (12) and can be moved in a reciprocating manner. A discharge bore (30) having a circular cross-section is formed in the valve piece (11). The discharge bore comprises a first region having a diameter d1, which first region serves as a throttle (31), a second region, which serves as a diffuser (32), and a third region having a diameter d3, which third region serves as a following flow geometry (33). The second region has at least one segment having a diameter d2, and the following applies: d1 < d2 < d3. The third region B3 serving as a following flow geometry (33) has a length l3, wherein the following applies to the ratio l3/d3: 2 < l3/d3 < 4, l3/d3 preferably being approximately equal to 2.5.