Toyo Tire Rubber Co., Ltd.

Toshio Komazawa

Takeo Iwai

Yoshikazu Tsujimoto

The present invention provides a molding tool capable of forming a molding with a cylindrical core while ensuring the discharge of the air in the vicinity of an upper end portion and forming no end face burr. As the device for this molding tool, an upper mold and a lower mold , as can be clamped, are provided with insert dies and having fitting hole portions and at their centers. The lower fitting hole portion is provided with a support pin to be fitted in the cylindrical core thereby to retain the cylindrical core , and the upper fitting hole portion is provided with a core holder so that a cavity is formed around the outer circumference of the cylindrical core when in the clamped state, to charge the cavity with a molding material to be shaped. A seal ring is mounted in the fitting hole portion of the upper insert die to fit the outer circumference of the upper end portion of the cylindrical core while holding a slight air ventilation. The upper mold is provided with an injection hole for the molding material and a relief hole for the air and the molding material.

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Osaka, Japan

Toshio Komazawa