Layer body with flexible partial areas for a reduction of the bodies - and / or airborne sound in acoustically excited by a helicoidal guide

摘要

1. Sandwich construction with flexible subsections to reduce structure-borne noise and/or airborne noise from acoustically exited surfaces characterized by : a simple spring/mass system consisting of a heavy layer (5) attached to a synthetic foam layer (2) ; in the areas of the acoustically exited surface (6) emitting an extreme noise level a supplementary element (3) is added to the spring/mass system ; the supplementary element (3) is suspended resiliently, being an integral part of the foam layer (2) ; the supplementary element (3) suspended resiliently to the foam layer (2) forms a damped spring together with the foam layer (2) ; the hard plane shaped supplementary element (3) is kept at a defined distance from the acoustically exited surface (6) both the surface (6) and the hard plane shaped supplementary element (3) forming an acoustic double wall ; the hard plane shaped supplementary element (3) over an intermediate thin foam layer abuts on the surface (6) to seal the cavity between the supplementary element (3) and the exited surface (6).