Throttle valve assembly

A throttle valve assembly for an internal combustion engine comprising:

• a valve housing having a main channel and an auxiliary channel connected to the main channel,
• a main throttle valve pivotally mounted in the main channel between a fully open position (MV1) and a closed position (MV2), said main throttle valve having a main pivoting shaft extending along a main axis (A1),
• an auxiliary throttle valve pivotally mounted in the auxiliary channel between a closed position (AV1) and a fully open position (AV2), said auxiliary throttle valve having an auxiliary pivoting shaft extending along an auxiliary axis (A2),
• a common rotating actuator controlling the opening angle of both the main throttle valve and the auxiliary throttle valve through an actuating mechanism, said actuating mechanism providing a time shift between the pivoting motions of both throttle valves during actuation of the rotating actuator,
• characterized by said actuating mechanism comprising a crank mechanism connected between the auxiliary pivoting shaft and a gear train driven by the rotating actuator such that, depending on the rotational motion provided by the rotating actuator, the auxiliary throttle valve is first actuated from its closed position (AV1) to its fully open position (AV2) and secondly actuated from its fully open position (AV2) to its closed position (AV1), without need for reversing the rotation direction of the gear train.