Tire vulcanization bladder and tire manufacturing method using the tire vulcanization bladder

摘要

PPROBLEM TO BE SOLVED: To provide a tire vulcanizing bladder capable of enhancing the operative stability of a tire by reducing the coefficent of friction with the inner wall surface of a green tire at the time of vulcanizing molding of the tire, and a tire molding method using it. PSOLUTION: A bladder main body 1 is formed so that its upper and lower parts have a truncated cone shape across the central part in the longitudinal direction of the bladder main body 1 and has a large number of projections 3, which are brought into point contact with the inner surface of the green tire, formed on its surface. The occupying area of the projections 3 exceeds 50% of the total surface area of the bladder main body 1 and is preferably below 100%. When the occupying area is below 50%, that is, the surface part of the bladder main body 1 is 50% or above, the ratio of the point contact with the inner surface of the green tire is reduced and the marked difference from a standard is eliminated in tire capacity. Further, if the occupying area ratio of the projections 3 becomes near to 100% of the total surface area of the bladder main body 1, exhaust efficiency becomes bad. It is preferable to set the height from the surface of the bladder main body 1 to the apex of each of the projections 3 to 0.3-3.0 mm. PCOPYRIGHT: (C)2007,JPO&INPIT