| 摘要 |
PURPOSE:To improve the yield of molding material, reduce the manufacturing cost and prevent the deformation of intermediate cylinders by forming the intermediate cylinder of rounded punch metal provided with numerous transparent holes and filling the molding material of an elastic body among the respective cylinders through the transparent holes. CONSTITUTION:Intermediate cylinders 3 formed of cylindrically rounded plate- like punch metal provided with numerous transparent holes 4 are coaxially disposed between an inner cylinder 1 and an outer cylinder 2 placed coaxially. These cylinders are incorporated into a cavity mold, and rubber material forming an elastic body 5 is injected to be vulcanization-molded. Before injecting the material, spaces among the respective cylinders 1, 3, 3, 2 are communicated through numerous transparent holes 4 provided at the intermediate cylinders 3, 3, so that the injection of the material into all the spaces can be performed successively by providing only one material injecting passage to the mold. Yield is thereby improved, and a molding cost can be reduced, as well as the deformation of the intermediate cylinders 3, 3 based on pressure deviation can be suppressed as the material pressure of each layer is balanced through the transparent holes 4. |
