Sound Insulator For The Passenger Compartment Of A Motor Vehicle
A sound insulator for a motor vehicle passenger compartment is disclosed. The aim of the invention is to develop a sound insulator which makes it possible to obtain an improved damping effect within a frequency range less than 300 Hz. In that respect, the invention relates to a sound insulator for a motor vehicle passenger compartment, which comprises an air cushion consisting of a dampingly active envelope which is made of an elastic material and disposed between a sound-generating component and the compartment internal space. The invention provides for a sound damping layer ( 25 ) which matches the shape of said component ( 13 ), acts as a spring material system and is covered on the compartment side by a heavyweight film ( 26 ), thereby forming the first shell of the air cushion ( 29 ). The invention also provides for the second shell of the air cushion ( 29 ) which is tightly connected to the heavyweight film ( 26 ), consists of an elastic, preferably pre-shaped, film ( 27 ) which forms the cushion air between the first and second shell.
1 - 5 . (canceled)
6 . A sound insulator for a passenger compartment of a vehicle, comprising:
an active damping envelope including an elastic material and having an air cushion disposed between a sound-emitting component and an interior of the passenger compartment; and
a sound-absorption layer adapted to a shape of the component and acting as a spring-mass system;
the envelope including a first shell having a heavyweight film sealing the sound-absorption layer on the passenger-compartment side and a second shell made of an elastic film sealingly bonded to the heavyweight film, the air cushion being formed between the first and second shells; and
7 . The sound insulator as recited in claim 6 wherein the sound-absorption layer made of a porous, sound-insulating material resting directly against the component and bonded to the heavyweight film.
8 . The sound insulator as recited in claim 7 wherein the porous, sound-insulating material is made of foam, nonwoven material or glass wool.
9 . The sound insulator as recited in claim 6 wherein the elastic film forming the second shell is adapted to the shape of at least one surrounding component.
10 . The sound insulator as recited in claim 6 wherein the mass per unit area of the elastic film forming the second shell is less than or equal to the mass per unit area of the heavyweight film.
11 . The sound insulator as recited in claim 6 wherein at least one opening is provided in the sound-emitting component and in the sound-absorption layer, the elastic film forming the second shell surrounding a second component extending through the opening.