| 摘要 |
PROBLEM TO BE SOLVED: To prevent a tread part from being caught by a mold during vulcanization of an unvulcanized tire by maximizing the the thickness of a spot corresponding to the equatorial line of the tire and at the same time, minimizing the thickness of a spot corresponding to a position for a tire side part at a specified height and further, specifying the wall thickness ratio of the thickest part to the thinnest part. SOLUTION: An unvulcanized tire 2 which becomes a pneumatic bias tire is set in a mold consisting of a top force 3 and a bottom force 4 and a bladder 1 is introduced into the unvulcanized tire 2. The flange 13 of the bladder 1 is fixed to the inside dia. part 14 of the mold. In this case, the bladder center part 6, for the bladder 1, which corresponds to the tire equatorial line is of the thickest wall and a bladder side part 7 which is a spot corresponding to a tire side part position equivalent to 50-90% of the tire section height H extending in a direction from a position corresponding to the outside dia. of a bead part to a tread part 10, is of the thinnest wall. The wall thickness ratio of the thickest part to the thinnest part is set to be 1.4-1.7. |
