Throttle valve arrangement for internal combustion engines

The throttle valve assembly has a housing (2) with air duct (3) and disc-like throttle valve (4) swivel mounted on a drive shaft (7) and with a bore (5) and an at least partially rounded sleeve face (8) with two surface parts and two transition faces. The surface parts are spot-symmetrical relative to the rotary axis (10) of the valve and the transition faces are in the drive shaft area. The surface parts have two edge members whereby the edge member facing the air duct wall (9) when the valve is closed is rounded.