To provide a bladder for tire vulcanization in which change of an expansion state or the like in a bladder circumferential direction is kept in minimum, shape change of a bladder sagging in a lower side by time is suppressed, deviation of a vulcanization state by difference of a location of a tire can be prevented; and a production method of a pneumatic tire using the bladder for the tire vulcanization.
A film thickness Gb of a cylindrical bladder body part 2 is set to have a constant thickness, two or more rubber made ribs 4 extending in a cylinder axial direction are formed at an upper side part of a bladder inner face in a circumferential direction to open a space, in cylinder axial direction rigidity of a bladder 1, the rigidity of an upper side part is made larger than that of a lower side part, thereby a shape change of the bladder 1 sagging to a lower side by time is suppressed, and circumferential direction rigidity of the bladder 1 by the rib 4 is improved, a change of thermal conductivity is made minimum, and the bladder 1 is expanded in inside of a green tire G set in a horizontal-state in a mold 10, and thereby the green tire G is performed by vulcanization.
KITAI HIRONAO
Takayoshi in the daytime
Shinichi Ogawa
Takashi Noguchi
Kenji Sato
Isao Hirai
Masao Sakaizawa
Kazuhiko Saishita