| 摘要 |
PURPOSE:To keep the sealing property of a bead and prevent the contact of a green tire with the bones of a top force and a bottom force due to overexpansion by a method wherein a preliminary molding pressure is set within a specified range until a closed space is formed at the outside of the green tire. CONSTITUTION:Fluid, provided with the pressure difference of 10-100 kilo Pascal with respect to an atmospheric pressure, is sent into a bladder 4 contacted with the inside of a green tire 3 under a pressure during a period of time until a top force 1 and a bottom force 2 are connected like the telescopic tube of a telescope and a closed space is formed at the outside of the green tire 3 in order to effect the preliminary molding of the green tire 3. Subsequently, the surface of the green tire 3 is contacted with the tops of bones 1a, 2a projected on the inner surfaces of the top force 1 and the bottom force 2 while approaching the top force 1 to the bottom force 2. The pressure P of the closed space is reduced to a pressure lower than the 1/13H (here the unit of the pressure is mmHg and H is the height of the bone in mm) of the high-pressure molding pressure Ps of the fluid supplied to the bladder during a period until a space at the side of the shoulder of the contacting part is sealed tightly by this contact. |
