| 摘要 |
PURPOSE:To easily manufacture a high-precision core which is strong by molding a cylindrical body out of metallic powder of stainless steel, etc., sintering it into a core blank material, and running a wire for polishing through the bottom hole of the core balnk material and polishing the internal surface of the bottom hole. CONSTITUTION:When the core 24 is manufacture, metallic powder of stainless steel, etc., and a binder are prepared and those materials are mixed together to form a cylindrical body by, for example, extrusion molding. Then, the cylindrical body is heated in a heating furnace to form a cylindrical body of sintered metal. This cylindrical body is drawn and cut to specific length, and the internal surface of the bottom hole of the cut core blank material is finished into a fiber holding hole 27. In this case, wire lapping, for example, is employed and the hole is finished to a specific internal diameter. The outer peripheral surface of a part as an insert part 25 is polished and finished concentrically on the basis of the polished bottom hole. Then, the external shape and internal shape are worked. |
