| Popis: |
At present, fuel efficiency improvement technologies for example weight, engine efficiency improvement, design modification, and eco-friendly car are being proceed due to the tightened international regulations. Therefore, production of eco-friendly cars specially electric car has increased. Due to that, the main noise source has changed from engine to motor noise and road noise as it has been changed from engine cars that have led engine technology to eco-friendly cars. As the noise source has changed, it is necessary to manufacture sound absorption/insulation structure for the noise characteristics generated by electric vehicles. In this work, the elastomer sheet was applied to the Dash outer as automotive terior parts for reducing engine noise. We applied the elastomer sheets for generation Dash outer layers (nonwooven/PU foam/nonwooven) to improve sound insulation properties. The elastomer sheet showed surface wetting between PU foam and elastomer sheets by optical microscopy. The acoustic properties were measured by APAMAT-II and BUCK tests. |
