| 摘要 |
PURPOSE:To cast a metallic mold for forming tire without detachment at circumference of a metal piece at the time of casting even in the case of the total length of the metal piece exceeds 20mm by forming a hole to a mold body at end part of the metal piece. CONSTITUTION:In the gypsum mold 1 for casting the metallic mold for forming tire, difference of thermal expansion between the gypsum mold 1 and metal piece 2 developed caused by coming into contact with hot temp. of molten metal at time of casting, is absorbed with the hole 3 formed at end part of the metal piece 2. Therefore, the gypsum 1 at circumference of the metal piece 2 is not detached by expansion of the metal piece 2. Therefore, correction of recessing defect on the forming surface in the metallic mold needing much labor is unnecessary and the perfect metallic mold for forming the tire can be easily manufactured. |
