JPS6478902A - Low noise tire wheel - Google Patents

Abstract

PURPOSE:To suppress resonance in the cavity part of a tire by providing a sound absorbing layer which has a defined area and a thickness and whose sound absorption coefficient in a frequency range of 200-300Hz is 5% or more, on the inner face of the tread part of the tire or the outer peripheral face of a rim. CONSTITUTION:A sound absorbing layer 4 is provided on the inner face of the tread 2 of a tire 1 or the well face of a rim 3. And, a sound absorbing material having a sound absorption coefficient of 5% or more in a frequency range of 200-300Hz and, particularly, a normal incident absorption coefficient of 5% or more in a frequency range of 1/3 octave band of 250Hz and having a thickness of approx. 30mm or less is used for this sound absorbing layer 4. Here, the thickness of 30mm or less is for preventing the deformation of the sound absorbing layer 4. And, the installing area of the absorbing layer 4 is defined as approx. 4% or more of the area of combining the inner face of the tire with the outer peripheral face of the rim. Thereby, the resonance of air in the cavity part of the tire caused by the reflection of sound wave on the part of no absorbing layer 4 can be suppressed.