JPH06254182A - Head of golf club and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide a metal wood of a golf club which can easily control the flying direction of a golf ball. CONSTITUTION:At least a face part 1 is formed from a plate shaped member which is made through the forging and rolling by using the NiTi alloy material having ultraelasticity, and the part 2 other than the face part 1 is formed through casting, and a head is formed integrally through the welding in which NiTi alloy is used as welding material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal wood golf club head and a method for manufacturing the same.

[0002]

2. Description of the Related Art As a metal wood for a golf club wood, a metal wood made of stainless steel or titanium alloy has been tried.

The inventor has found that among the Ni-Ti alloys, those having an atomic ratio of about 1: 1 forming the intermetallic compound NiTi exhibit superelasticity together with shape memory characteristics and are suitable as a golf club material. Focusing attention, NiT by casting
I have already proposed an i-alloy golf club. (Patent application 3-
277586)

[0004]

Since the NiTi alloy cast product has a rather coarse crystal grain, its strength is slightly inferior to that of a rolled material or the like. Therefore, it is necessary to increase the thickness of the face portion of the club head, which requires particularly strong strength.
However, in order to stabilize the flight direction of the golf ball, it is preferable that the face be thin.

An object of the present invention is to harmonize this point and provide a metal wood made of a NiTi alloy having a thin and strong face.

[0006]

The golf club head of the present invention is a superelastic NiTi alloy metal wood, and as shown in FIGS. 1 and 2, at least the face portion (1) is forged. It is characterized in that it is formed of a plate-shaped material according to 1. and the remaining portion (2) is formed of a hollow material by casting, and both are integrally welded.

The "forged" plate-shaped material also includes a plate-shaped material obtained by rolling. In FIG. 2, reference numeral (3) is a welded portion.

In addition to the face part (1), the sole part
It is advantageous to form (2A) also from a plate-shaped material. This is because it is easier to cast the portion (2B) excluding the sole portion than to integrally cast all except the face portion. The sole portion (2A) may be cast separately,
Depending on the design, it may be manufactured by processing from a rolled material or a forged material.

In the golf club manufacturing method of the present invention for manufacturing the above-mentioned NiTi alloy metal wood, a NiTi alloy having a martensitic structure at room temperature is used as a welding material, and the welding is performed in an inert gas atmosphere or under vacuum. It is characterized in that

[0010]

The fact that the thinner metal wood face portion is more advantageous in stabilizing the flight direction of the golf ball is because the face is bent more when hitting the ball and the impact time to the ball (usually about 0.5 msec. This is because it is possible to ensure control of the flight direction by extending ().

For simplification, when considering an example of a peripheral fixed disk that receives a concentrated load in the center, the amount of deflection Z (mm)
Is expressed by the following equation.

[0012] Z = Wa ² / 16πD W: Load (kg), a: diameter disc (mm), D: flexural rigidity (kg · mm) D = Em 2 t 3/12 (m 2 -1) E : Young's modulus (kg / mm ² ), t: Plate thickness (mm), m: Poisson number If the radius is constant, select a material with a small Young's modulus E and increase the plate thickness t to increase the deflection. It is effective to do. It should be noted that the Poisson number m is almost the same for all metal materials and shows a value of about 3.

The NiTi alloy has a Young's modulus of 7,000 kg / m.
As described in the previous proposal, it is suitable as a material for metal wood because it has a low m ² of metal materials and a specific gravity of 6.5, which is not so large.
Since the strength of the forged (including rolled) material reaches 100 kg / mm ² , if this is used for the face portion where strength is required, it can be made thinner than the cast product. As seen in the above equation, the influence of the plate thickness on the amount of deflection is large,
By making it thin, effective flight direction control can be performed. The rest, which does not require much strength, is practically cast by easy molding.

The use of a NiTi alloy having a composition that forms a martensitic structure at room temperature as a welding material is nothing but the selection of a material that exhibits high ductility so that the welded portion can withstand impact. Such NiTi alloys have Ni and T
The atomic ratio of i is in a narrow range near 1: 1.

[0015]

EXAMPLES NiTi alloy (Ni: Ti atomic ratio is almost 1)
Was melted by cold crucible induction melting while preventing contamination, and a metal wood sole portion and a back body were separately cast using a zirconia ceramic mold. The sole portion has a thickness of about 2.0 mm, and the back body has an average thickness of 1.5 mm. Separately, the face portion was cut out from the same NiTi alloy rolled into a plate having a thickness of 2.8 mm.

The above three parts were welded and integrated using the same NiTi alloy as a welding material and argon gas as a shield gas to manufacture a head portion of metal wood.

A head cast entirely from the same NiTi alloy (Comparative Example 1), a commercial titanium alloy cast (Comparative Example 2) and a stainless steel cast (Comparative Example 3).
The following is a comparison of various characteristics of each club.

Examples Comparative Example 1 Comparative Example 2 Comparative Example 3 Face material NiTiNiTiTi6A14V 17-49H Face manufacturing method Rolling Casting Casting Casting Tensile strength (kg / mm ² ) 100 80 80 90 Young's modulus (kg / mm ² ) 7000 7000 12000 20000 Plate thickness (mm) 2.8 3.5 3.5 3.1 Poisson number 3 3 3 3 Flexural rigidity (kg ・ mm) 14400 28200 48300 55900 Deflection amount (relative ratio%) 100 51 30 26

[0019]

According to the present invention, the face portion of the metal wood head can be configured to be thin and yet have sufficient strength, so that a driver shot with stable ball streak can be performed.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a metal wood head of the present invention.

2 is a cross-sectional view of the head of FIG.

[Explanation of symbols]

 1 face part 2 part other than face part 2A sole part 2B part other than face and sole 3 welded part

Claims (3)

[Claims] 1. A metal wood manufactured from a NiTi alloy exhibiting superelasticity, in which at least a face portion is formed of a plate-shaped material by forging and the remaining portion is formed of a hollow material by casting, and both are integrally welded. A golf club head that is characterized by: 2. The golf club head according to claim 1, wherein the sole portion is also formed of a plate-shaped material, and the face portion and the remaining portion are welded and integrated. 3. A method for producing a metal wood using the NiTi alloy according to claim 1 or 2 as a material, wherein the NiTi has a martensitic structure at room temperature as a welding material.
A method for manufacturing a golf club, which comprises using an alloy and performing welding in an inert gas atmosphere or under vacuum.