| 摘要 |
PURPOSE:To reduce the cost of a formed ring by manufacturing many rings at a time by a small molding machine through such an arrangement wherein a formed product is formed so that multiple ringlike portions are molded in layers on the outer circumference of a cylindrical member with a gap provided between adjoining ringlike portions respectively, and the formed product is cut in the direction of its diameter at each gap side. CONSTITUTION:For example, forming material is poured into a metal mold composed of a sprue bush 4 having a sprue runner 2, an outer core 7 and an inner core 9, etc. and a formed product 1 composed of a sprue runner portion 12 formed by the sprue 2, a cylindrical portion 11 and ringlike portions 10 formed in layer on the outer circumference of the cylindrical portion with a gap provided respectively, and then the formed product 1 is cut in the direction of its diameter at the gap side 13 of each ringlike portion 10 by using a blade 22 of a lathe, etc and the desired ring 23 is thus obtained. EFFECT:The occurrence of a defective product is prevented. |
