| 摘要 |
PROBLEM TO BE SOLVED: To provide a pneumatic tire of such a structure that a rim cushion rubber part is installed in the bead part, with which it is practicable to improve compatibly the ultra-low frequency road noise near 40 cycle and establish good comfortableness in sitting in car cabin without bringing about a significant drop of the productivity and durability. SOLUTION: A first rubber part G1 is installed as extended toward the tire periphery from near the peripheral end 5a of bead core along a carcass layer 4, and a second rubber part G2 is installed as a rim cushion rubber part in such a way as extended toward the tire periphery of the first rubber part G2 from the bead heel, and a third rubber part G3 is continued to the second rubber part G2 on the tire outside of the first rubber part G1 and extended to the tread part, wherein the hardnesses should be conditioned as the first rubber part >= second rubber part > third rubber part. The peripheral end G1a of the first rubber part G1 is made below 60% of the height SH of the tire cross- section, and the wall thickness T of the third rubber part G3 on the tire peripheral side more than 20mm from the bead heel is made 1mm or more. |
