Among many potential problems associated with automobiles, the problem regarded as most sensitive and important to the customers is the automobile’s quietness. In particular, because the trend toward the high-performance automobiles is increasing, the quietness should be considered reflecting the increasing demand of the customers for the comfort of automobile ride. Road noise is the low-frequency range in the region of 20Hz to 350Hz, generated when the tires are making contacts with the rough road surface while the automobile is running, in which the noises are resonating within the passenger compartment or with the automobile suspension. In this research, among the factors related to the road noise, the influencing factors associated with the suspension and the tire design were investigated. In particular, among the tire design factors, the structure and the rubber material were investigated as the influencing factors, and for the investigative purpose, experimental tires were manufactured and road noise evaluations were conducted thorough actual feeling tests. Then the test results and correlations were analyzed using the 6-Sigma statistical method. Results from this study shows that, among the tire design factors, the apex is the most influencing factor, in which the height of the apex is the key. The influential factors were found out to be apex height, belt angle, and tread hardness, in that order, and when the suspension is of a same kind, the tendency of the road noise was found to be similar.

Abstract
 1. 서론
 2. 통계적인 기법
  (1) Road Noise 비교평가를 위한 타이어 설계 인자 선정
  (2) 실험
 3. 결과 분석
  (1) 에이펙 높이, 에이펙 경도에 따른 도로소음
  (2) 벨트 각, 트레드 경도, 에이펙 높이에 따른 도로소음 분석
  (3) 차종에 따른 도로소음 분석
 4. 결론
 후기
 References

• 김병삼(원광대학교 공과대학 기계자동차공학부) | Byoung-Sam Kim
• 이태근(대덕대학교 정밀기계공학과) | Tae-Keun Lee Corresponding Author
• 이영욱(원광대학교 대학원 기계공학과) | Young-Uk Lee