Noise damper and pneumatic tire with compensation tread groove
A noise damper disposed in a tire cavity formed by a pneumatic tire and wheel rim is disclosed. A noise damper designed to use with a wheel rim comprises an annular body disposed around a damper-mounting portion of the wheel rim, and the annular body is made of a spongy material having an inside diameter of from 0.9 to 1.10 times an outside diameter of the damper-mounting portion. A noise damper designed to use with a pneumatic tire comprises an annular body disposed in a tire hollow, and the annular body is made of a spongy material having an outside diameter of from 1.00 to 1.10 times the maximum inside diameter of the tire hollow.
1. A pneumatic tire comprising
a tread portion,
a pair of sidewall portions,
a pair of bead portions,
a circumferentially extending noise damper made of a spongy material fixed to the inside of the tread portion with adhesive, and
a compensation groove formed in the tread portion so as to extend circumferentially along the noise damper, wherein the cross sectional area (Scg) of the compensation groove satisfies the following condition:
Scg>=(M1+M2)/( G×Dxpi )
wherein
M 1 is the mass of the damper,
M 2 is the mass of the adhesive,
G is the specific gravity of a tread rubber on which the groove is formed,
D is the tire diameter measured at the tire equator, and
pi=3.14159.
2. A pneumatic tire comprising
a tread portion,
a pair of sidewall portions,
a pair of bead portions,
a circumferentially extending noise damper made of a spongy material fixed to the inside of the tread portion with adhesive, and
a compensation groove formed in the tread portion so as to extend circumferentially along the noise damper, wherein
the compensation groove has a width (Wg) and a groove depth of not less than 4.0 mm but not more than 2.5 times the width (Wg).