Noise attenuating method for e.g. air filter box, of motor vehicle, involves adding auxiliary wall to portion of surface of main wall for covering surface while forming space between walls to obtain double wall for sound insulation

摘要

The method involves adding an auxiliary wall to a portion of a surface of a main wall in an engine part, for covering the surface while forming a space between the auxiliary and main walls in a manner to obtain a multi-wall i.e. double wall for sound insulation. The main wall and the auxiliary wall are parallel with each other, and made of synthetic material. The space separating the main wall and the auxiliary wall is filled with a sound insulation material such as water, oil or synthetic foam.