| 摘要 |
PURPOSE:To easily pull out a liner body for a vent hole by forming a tire mold by a core, fitting the liner body made of plaster or clay for a casting on a groove of a plaster core and then forming the vent hole by removing the liner body by pressed water. CONSTITUTION:Recess parts 12, 13 are arranged on the side walls 10, 11 of the groove 8 formed on the surface 7 of the plaster core 1 having the same outer shape as the tire, and the both ends 9a, 9b of the liner body 9 made of the plaster or clay for the casting are laid as bridge on the both recess parts 12, 13 facing to each other, and fixed by fillers 14, 15 composing of the plaster, etc. The tire mold is made by pouring the molten metal, such as aluminum alloy etc., into the space, which is formed by the plaster core 1 formed by such a way and the main mold. By removing the liner body 9, remaining in this tire mold by pressed water, the vent hole is formed, and the pull-out operation of the liner body for the vent hole forming is eliminated. |
