Die and method for manufacturing core

A die for manufacturing a core including a ring-shaped supporting member that is formed by a plate-like member, that is disposed inside a pneumatic tire, and that supports the pneumatic tire by allowing an inner side of a tire tread portion to be brought into contact with an outer peripheral surface of the supporting member at the time of a deformation of the pneumatic tire due to a decrease of an internal pressure of the tire;

• and ring-shaped rubber portions that are respectively joined to both widthwise direction edge portions of the supporting member, the die comprising:
• a ring-shaped core die that is brought into contact with the supporting member from radial inner side directions thereof to support the supporting member while maintaining a non-contact state with the both widthwise direction edge portions of the supporting member;
• a transfer-molding die and a compression-molding die that are disposed so as to hold the core die therebetween from the core die axial direction, and that form cavities between the transfer-molding die and the core die as well as between the compression-molding die and the core die, the cavities being used for forming the rubber portions respectively at one edge portion and at the other edge portion of the supporting member;
• a transfer part that, at the same time when rubber material is compressed by the compression molding die, causes the rubber material to be injected into runners formed at the transfer-molding die and transferred into the cavities,
• wherein the rubber material injected into the cavities are vulcanized and molded.