| 摘要 |
PURPOSE:To shorten the time for evacuating the inside of a mold, while the risk of occurrence of bare on a molded tire surface is prevented by a method in which in the sipping molding plate partitioning the recessed portion for molding the block of a tire tread, the notch part or connecting hole connecting the both side parts of the recessed portion is provided, and on the other hand, the height from the bottom surface of the recessed portion in said connecting part is set at a prescribed height or lower. CONSTITUTION:While air exhausting is continued, when a bladder is pressurized, a green tire is expanded, and its tread part is press fitted into the recessed portion 9 for molding its block. Until the surface of the tread part of the green tire reaches the lowest position of the recessed portion 9 for molding the block or a passage 12, all spaces in the recessed portion 9 for molding the block, are connected to an exhaust hole 13, and air exhausting is continued at a prescribed pressure, but when the green tire is further pushed, and the notch part 11 of a sipping molding plate 10 or the passage 12 are blocked, the little lower pressure air trapped in the space partitional by the sipping molding plate 10 has no outlet already. But if the height H from the bottom surface 13 of the notch part 11 of the sipping molding plate 10 or the passage 12 is caused to be 2mm or lower, the air volume closed in the space and retained there becomes small, and it is absorbed in the rubber of the tire during vulcanization. |
