SOUND INSULATION STRUCTURE OF VEHICULAR FLOOR

摘要

PROBLEM TO BE SOLVED: To provide a sound insulation structure of a floor part effectively insulating road noises generated when a vehicle travels on a rough road surface. SOLUTION: An urethane layer 13 having good adhesion with a floor plate is placed on a steel vehicular floor plate as a part constituting the vehicle and a lower part mass layer is put on the urethane layer, and additionally a carpet 17 is put on a layer made of fiber effectively lowering secondary resonance frequency or a low elastic urethane layer 15 via an upper part mass layer to form the sound insulation structure with two degrees of freedom.