Mixing valve of an internal combustion engine

A mixing valve (6) of an internal combustion engine (1) of a motor vehicle has a single actuator (9) and a differential gear (16). A flap (13) arranged in an intake duct (4) and a flap (14) arranged in an exhaust duct (5) are driven via the differential gear (16). Spring elements (17, 18) bias the flaps (13, 14) into a basic position against stops (19, 20) and determine which of the flaps (13, 14) is driven in which adjustment range of the actuator (9).