| 摘要 |
PURPOSE:To reduce the number of steps of forming a drum-shaped core and to improve the yield of forming the core by filling material powder in a mold to form a projection in the center axial direction of the portion to become a collar, pressing only the projection in the middle moled and press molding it with outer mold disposed around the periphery. CONSTITUTION:Frame molds 10A, 10B divided, for example, into two are fromed in tapered shape on the outer peripheral surfaces, are then tightened integrally at both molds by a tapered ring 11 engaged with the molds, and a mortar 12 is formed. The mortar 12 forms a rolled core molding cavity 13, a large-diameter collar molding upper cavity 14A and a collar molding lower cavity 14B. An upper outer mold 21 is inserted from above to the cavity 14A, and a lower outer mold 31 is inserted from below to the cavity 14B, and a core having a projection at the center axial direction of the collar is formed. After the material powder is thrown from a throwing tube 15, an upper middle mold 22 is press-fitted from above, a lower middle mold 32 is press-fitted from below, into the upper outer mold 21 to upper projection and into the lower outer mold 31 to the lower projection, respectively to form a planar collar. |
