Sound insulation insert for decentralized living space ventilation systems or for outside air passage systems as well as punching tool and method for producing such a sound insulation insert

摘要

The invention relates to a sound insulation insert (10) which is designed in particular for the interior sound reduction in a living space ventilation system that can be inserted into a wall opening with an axial fan having a central motor hub or for an outside air passage. The sound insulation insert (10) is made of an acoustically absorbent material and, starting from an inner element (14), has webs (16a-c) which either connect to an annular outer element (12) for insertion into a wall duct, or which form the outer boundary of the sound insulation insert. According to the invention, the cross-sectional profile of at least one web (16a-c) changes within the sound-insulating insert (10) over its longitudinal extent. For example, the webs (16a-c) can have a helical shape, as a result of which the sound insulation insert becomes less light and sound permeable without significant impairment of the flow properties.