| 摘要 |
PURPOSE:To improve impact resilience and durability by performing core arrangement accurately and realizing strong unification, by a method wherein a top and bottom forces are made into a molding tool set by inserting a middle frame having a male- shaped part in the same form with a core material at the center of the same between the top and bottom forces, an outer shell which is in an unvulcanized or semicured state is formed by filling an outer shell material and vulcanization molding is performed by inserting and leaving the core material by removing the middle frame. CONSTITUTION:To begin with, an outer shell 4 form is formed by filling a cavity shaped in the same form with the outer shell 4 form by a top and bottom forces 1a, 1b and a middle frame 2 with an outer shell material 3 of an elastic material base. In this instance, as for the outer shell 4, it is restricted to a state of a material to be used anterior to completion of molding, that is, an unvulcanized state in case of rubber and a semi-cured state in case of synthetic resin. Then after the middle frame has been removed from the top and bottom forces 1a, 1b and the outer shell 4 has been joined spherically by inserting a core material 5 into female-shaped core traces 6 shaped inside the outer shell 4, a spherical form A integrally shaped by vulcanizing or curing the same is obtained. |
