| 摘要 |
PURPOSE:To prevent a ceramic part from occurrence of cracks during processing by cooling and solidifying a holding part holding a raw molded item and/or a processing part and processing the processing part when a raw ceramic molded item before degreasing and calcining is processed. CONSTITUTION:When e.g. a turbin wheel is prepd., for processing central hole, a molded item having a central hole 100 is injection-molded at an apex part of a shaft which is to be a holding part 10. After drying, this hole 100 is inserted in a projection 211 of an apex of a core pushing center 21 of a processing apparatus. Then, the side peripheral face 111 of a shaft part of the processing part 11 side is supported by means of a positioning plate 22. Then, liq. nitrogen etc., is injected from a nozzle 242 on the holding part 10 to cool and solidify it and a central hole is perforated on the processing part 11 by means of a drill 23. A hardness being durable to a repulsive force is given thereby to the holding part 10 where the repulsive force is most strongly applied to prevent a ceramic part from occurrence of cracks etc., and to keep processing accuracy. |
