| 摘要 |
PURPOSE:To relieve stress of a bead part and raise an effect of radiation and further improve endurance by rolling up a carcass ply around a bead core and providing the layer of reinforcement adjacently to the outside of a roll-up part and further providing sunken grooves or the like in the vicinity of an upper end of the layer of reinforcement and the like. CONSTITUTION:A carcass ply 5 made of metallic cord in a bead part 4 is rolled up around a bead core 6 from the inside to the outside and the reinforcement layer 7 for the metallic cord is provided adjacently to the outside of the roll-up part 5a. Further, sunken grooves 9 in the circumferential direction of the tire are provided on the outer surface of the bead part in the neighborhood of the upper end 7a of the reinforcement layer. The sunken grooves 9 are provided, from a position corresponding to the upper end 7a of the reinforcement layer, upward or downward or upward and downward at a definite width W, that is, upward by about 50mm. from the upper end 7a of the reinforcement layer and downward to the vicinity of the upper end of a rim flange 8. Thus, a strain of stress of the bead part 4 is effectively dispersed and relieved, and the effect of radiation can be raised. |
