| 摘要 |
PURPOSE:To uniformize the quality by arranging a chip in a mold, fitting the tip part thereof in a recessed part on the bottom part of the mold, preliminarily pouring molten cast iron around the bottom part of the mold to preheat the chip and pouring the molten cast iron into the mold after sufficiently preheating the tip. CONSTITUTION:This mold is composed of a cylindrical mold 14 combined with the upper end opening edge part of a cupped mold 13. An outer shell 11, supporting plate 12 and the cylindrical mold 14 are made of chamotte material (mixtured of Al2O3 and SiO2) of low thermally conductive material molded with a sand mold by a carbon dioxide process, and the cupped mold 13 is made of carbon of high thermally conductive material. In the center of the bottom part in the inner surface of the cupped mold 13, the recessed part 13a for fitting the tip part of the chip 1 is formed. By preliminarily pouring the molten cast iron around the bottom part of the mold 13, the chip 1 is preheated, and after sufficiently preheating the chip 1, the molten iron is further poured into the mold 13 and rapidly cooled. By this method, as the chip is integrated with a shank by inserting as cast-in, the number of processes is reduced and the fixed strength is improved. |
