Device for regulating the airflow in a ventilation device

The invention relates to a device for regulating the airflow rate in a ventilation device (1a, 1b), comprising an autonomously operating valve (2) movably provided in an air duct (3) of the ventilation device (1a, 1b) and which automatically adjusts the airflow opening with relation to the pressure difference between the inlet (4) and the outlet (5) of the air duct (3), in which the valve (2) is rotatingly suspended around a free suspension point (6) in the air duct (3), and provided in such a way that, upon rising pressure difference, the valve (2) moves in the air duct (3) first by rotating to a maximum turning angle around the free suspension point (6) and subsequently by deforming, without further rotation around the free suspension point (6).