To provide a ball for sports wherein a core covered by a skin is not eccentric, and its manufacturing method.
A partial forming process for the skin and a remaining part forming process of the skin are performed in order. The partial forming process of the skin is a process for forming the skin 2a into a semi-spherical shape on the surface of another semi-sphere of the spherical core 1 under a state wherein the surface of a semi-sphere of the core 1 is tightened to a first die 6. The remaining part forming process of the skin is a process for forming the skin 2b on the surface of the remaining semi-sphere of the core 1 under a state wherein the semi-spherical skin 2a formed by the partial forming process of the skin is tightened to a second die 7. The skin 2 of a specified thickness can be formed with a skin material which is press-fitted in a space between the external surface of the core 1 and the die surface of the die. As a result, this ball for sports of an even quality in which the core 1 and the skin 2 are built-in under an inside-outside concentric state can be obtained.
NISHIDA HIROTOSHI
IMAZATO KATSUHIRO
ASICS CORP