Tire preheating apparatus, tire vulcanizing system, tire preheating method, and tire manufacturing method

A tire manufacturing method, comprising:

• a tire preheating step of heating a green tire having an easy vulcanization region and a difficult vulcanization region from an outer surface side of the green tire from a normal temperature to a preheating temperature less than temperature at which vulcanization of the green tire is promoted by a heating value which is relatively smaller with respect to the easy vulcanization region and is relatively greater with respect to the difficult vulcanization region;
• a bladder preheating step of heating a bladder disposed inside the green tire to vulcanize the green tire such that a surface of the bladder coming into contact with the easy vulcanization region has a relatively low temperature and a surface of the bladder coming into contact with the difficult vulcanization region has a relatively high temperature;
• and
• a vulcanizing step of disposing the green tire heated to the preheating temperature in a tire mold, allowing an inner surface of the green tire heated to the preheating temperature to come into contact with the bladder, heating the green tire such that the temperature of the green tire exceeds the preheating temperature, and vulcanizing the green tire in the tire mold.