Method of manufacturing a curved metal plate, and golf club head

#1. Field of the Invention

#The present invention relates to a method of manufacturing a curved metal plate made of titanium or titanium alloy, and a golf club head using a plate of metal such as titanium alloy with ribs formed thereon manufactured by the press-bending technique.

#2. Discussion of the Background

#FIG. 1 is a reference perspective view illustrating one embodiment of a die assembly used for the manufacturing method of the present invention.

#FIG. 2 is a reference perspective view illustrating a modified example of a die segment.

#FIG. 3 is a reference perspective view illustrating another modified example of the die segment.

#The present invention is directed to a method of manufacturing a metal plate made of a plate material selected from titanium or titanium alloy having a predetermined shape by plastically deforming the metal plate under pressure by utilizing a convex surface formed in a die. Because the titanium or titanium alloy can have a varying composition, a conventional titanium or titanium alloy may be used. For example, it can be cited pure titanium, beta-titanium alloy, alpha-beta titanium alloy, or beta-titanium alloy having the following composition (wt. %): V 15-25, Al 2.5-5, Sn 0.5-4, O 0.12 or less, and Ti and unavoidable impurities constitute the residue (as disclosed in Japanese Patent No. 2669004), or V 10-25, Al 2-5, Cr 2-5, Sn 2-4, O 0.25 or less, and Ti and unavoidable impurities constitute the residue (as disclosed in Japanese Patent No. 2640415). Of these compositions, it is preferable to use the beta-titanium alloy having the following composition (wt. %): V 15-25, Al 2.5-5, Sn 0.5-4, O 0.12 or less, and Ti and unavoidable impurities constitute the residue, because it exhibits excellent product strength and workability for plastic deforming.

#A metal plate used in the present invention can be obtained from titanium or titanium alloy which is cold- or hot-rolled, additionally subjected to solution treatment thereafter, or cold- or hot-rolled after it is subjected to solution treatment. The thickness of the metal plate is not necessarily limited to a specific value, provided that the metal plate formed can be plastically deformed with pressure. For example, it can be cited a metal plate having a thickness of about 0.1-15 mm, and preferably about 0.5-5 mm.

#As a die used in the manufacturing method of the present invention, it can be cited, for example, a die assembly provided with a concave surface and a convex surface with only the convex surface forming recesses thereon, between which surfaces the metal plate is pressed into a curved shape.