NOISE-ABSORBING COAT FOR AIR DUCTS OF VEHICLE PASSENGER COMPARTMENT (DRIVER CABIN) HEAT-AND-VENT SYSTEM (HVS) Russian patent published in 2012 - IPC B60H1/04 B60R13/08 

FIELD: transport.

SUBSTANCE: invention relates to noise-absorbing coatings designed to reduce aerodynamic noise propagating in air ducts. Proposed coat is arranged in undercuts or on surfaces of HVS air duct, control or guide elements and includes layer of porous noise-absorbing material faced with protective layer of sound-transmission gas-water-tight film or fabric on its outer surface and, on its inner surface, with adhesive layer. Structure of said porous material has punched holes of diameter d_perf=(0.1…0.5)h, where h is thickness of said porous layer with center-to-center spacing t_perf=(0.5…2.0)h. Note here that coefficient of perforation k_perf is in the range of k_perf= S_perf/S_surf=0.02…0.2, where S_perf is total area of perforated holes projection area on noise-absorbing surface, S_surf is area of face surface of noise absorbing coating.

EFFECT: intensified noise absorption, larger active noise absorption surface.

4 cl, 15 dwg