| 摘要 |
PROBLEM TO BE SOLVED: To reduce transmitted sound from an engine room to a vehicle cabin.SOLUTION: In a transmitted sound reduction structure 10, a cooler pipe 24 penetrates a pipe through-hole 32 of a dash panel 18 and an opening 40 of a dash insulator 20. In this cooler pipe 24, an expansion valve 58 is fitted into an insertion hole 78 formed at center of a shield material 28. This shield material 28 is a multilayer structure in which a sound absorbing layer 74 and a sound insulation layer 76 are stacked, and exhibits a transmitted sound reduction performance equivalent to that of the dash insulator 20. Further, this shield material 28 comprises: a water cutoff portion 28A compressed in a longitudinal direction of a vehicle between an edge 18A of the pipe through-hole 32 and an air conditioning case 48; and a transmitted sound reduction portion 28B compressed between an edge 20A of the opening 40 and the air conditioning case 48, and a water-cutoff inner peripheral portion 74A and a sound insulation outer peripheral portion 74B of the sound absorbing layer 74 can be compressed and deformed in the longitudinal direction of the vehicle, independently. |
