| 摘要 |
PURPOSE:To prevent a molded product from distorting by making a flow and cooling of molten plastic at a stepped place position smooth and uniform, by a method wherein a molding tool is constituted of a male mold, which is comprised of a large-diameter part and small- diameter part projected above a center line and provides a radial and uneven flow path wall on a titled stepped place, and a female mold, which is provided with a flow path wall forming a flow path in a form corresponding to the flow path wall and forms a gap between the large-diameter part and small-diameter part. CONSTITUTION:A female mold 1 is constituted of a columnar large-diameter part 3 possessing a stepped place 2 tilted downward by forming sharp angle with a center line and a columnar small-diameter part 4 projected above a center line. A flow path wall 5 where it arrives at the fringe radially from a center line in the direction of the outer fringe and the surface of a section running along the outer fringe is uneven is provided. A female mold 6 possesses a space 7 forming a thickness of a molded product 20 and parts 9, 10 forming a space 8, an uneven state flow path wall 12 is provided to a part 11 also facing on the stepped place 2 and gate 13 is provided by connecting with the stepped place of the stepped part. Molten plastic is caused to flow into spaces 7, 8 between the male mold 1 and female mold 6 and a wave-like flow path 14, cooled and a molded product 20, which is comprised of a large- diameter cylindrical part 22 possessing a stepped place 21 where grooves are formed radially on both the surfaces and a small-diameter cylindrical part 23, is molded. |
