FORCED VENTILATION SYSTEM FOR MOTOR VEHICLES

摘要

A method is disclosed for making a forced ventilation apparatus (1) for equalizing a pressure difference between a passenger compartment and surroundings of a motor vehicle. The apparatus (1) includes a frame (2) made of hard plastics and delimiting an aperture (3), and a flat ventilation flap (7) made of an elastomer material and secured to the frame (2). A resilient restoring force counteracts opening movement of the ventilation flap (7) from a closed position in which the ventilation flap (7) rests on the frame (2) and closes the aperture (3) in the frame. The method comprises the step of injection-moulding the ventilation flap (7) to the frame (2) in an opened position. To this end, the elastomer material is pressed from a free end of the ventilation flap (7) into a common contact area (8) of the ventilation flap (7) with the frame (2).