Golf club head

Abstract

A hollow golf club head has a head body having a face aperture part and a face member held to the face aperture part by welding, the face member formed by forging a rolled material of a titanium alloy having an α phase, and the face member comprising a thick-material part positioned in the center of the face member, an outer peripheral part positioned at the periphery of the thick-material part, and a thin-material part partially positioned between the thick-material part and the outer peripheral part. The thick-material part is formed in an area having a shape obtained by depressing a substantially elliptical or substantially circular shape in a substantially arcuate shape toward the center of the ellipse at two opposite sides thereof. The thick-material part, the thin-material part, and the peripheral part are formed by the forging so as to destroy an orientation of the α-phase.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This application claims priority from Japanese Patent Application No. 2009-298199 filed Dec. 28, 2009, which is incorporated herein by reference in its entirety.BACKGROUND OF THE INVENTION[0002]The present invention relates to a golf club head, and more particularly, relates to a golf club head having improved material thickness on the back surface of the face part thereof, and also a face part formed by forging of a rolled material.[0003]The heads of a majority of recent wood clubs are formed with at least the face part made of a metallic material. The material thickness of the face part must be made thick in order to maintain the strength to be able to withstand the impact with a ball. Although heads are increasing in size, because the rules require that they have a volume less than 460 cm3 plus a tolerance of 10 cm3, the majority of heads have become large 460-cm3 driver heads that are very close to the upper limit. When the head size i...

AI Technical Summary

Benefits of technology

[0009]Given the above, in consideration of the above-noted problems, the present invention has as an object to provide a golf club head in which the restitution of the face part can be held to within a range that conforms to the rules, while maintaining the light weight and strength of the face part, the golf club head being capable of preventing a large decrease of restitution performance even in the case in which a ball is hit at a part away from the sweet spot, and capable of preventing the occurrence of cracks in the relatively low-strength thin-material part.

[0016]According to a golf club head according to the present invention, because a thin-material part having a material thickness that is thinner than the outer periphery part of the face member is formed in a region that is caused to be recessed by forging of the thick-material part of the face member, not only is it possible to maintain the light weight of the face part and suppress the restitution to within an amount that is compliant with the rules, it is also possible to prevent a large decrease in the restitution performance even in the case in which the ball is hit at a part other than the sweet spot. Additionally, by forming the face member by forging a rolled material, it is possible to weaken the characteristic directionality of strength by destroying the α-phase crystal structure of the titanium alloy, thereby preventing the occurrence of cracks in the thin-material part that has relatively low strength.

Problems solved by technology

In the case in which the material at the center of the face part, such as described in Japanese Patent Application Publication No. 9-172273, is thick, there is the problem that, if the ball is hit at a location that is removed from the sweet spot, the restitution performance of the face is greatly reduced from the case in which the ball is hit at the sweet spot, and if the restitution performance at the sweet spot is suppressed so as to be low, the restitution performance other than at the sweet spot is considerably reduced.

Also, generally there is a tendency that the thinner the material of the face is made, the greater the restitution performance of the face and the weaker the strength of the face.

For this reason, consideration must be given to the rolling direction when using a rolled material, leading to the problem of extreme difficulty of use, and there is a particular tendency for cracks to form at score line grooves in the surface of the face, the material of which has been made thin.

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