| 摘要 |
<p>Blocks of silicone rubber are used to suppress low or medium frequency (up to 5 kHz) sound wave propagation to vehicle interiors. Pref. the blocks are at least 1 cm thick and made of matl. having a Shore hardness of at least 60 and a "Zwich" (RTM) resilience (rebound) coefficient of not more than 30, e.g. grade EVC 771-70 (RTM). The blocks may be mounted between bodywork and chassis or suspension members, to reduce vehicle interior sound levels by 10-20 dB at frequencies up to about 2 kHz, by 1-10 dB at frequencies in the range 2-5 kHz.</p> |
