KR20080034392A - Metal golf club head - Google Patents

Abstract

A metal golf club head is provided to dampen vibrations of the golf club head effectively generated by hitting a golf ball with an anti-corrosion screw made of a magnesium alloy, and to improve both feeling of hitting and hitting sound. A metal golf club head comprises: a metal head main body; and an anti-corrosion screw which is made of a magnesium alloy and fastened to predetermined location on the metal head main body, wherein the anti-corrosion screw is coated with an oxide film, recess portions(24,26) are formed in side portions(16,18,20) of the metal head main body, and the anti-corrosion screw is fastened to the inside of the recess portion not to protrude from the recess portion.

Description

Metal Golf Club Head {METAL GOLF CLUB HEAD}

TECHNICAL FIELD The present invention relates to a metal golf club head having good feel and sound.

The metal golf club head which has a hollow part is enlarged, and the so-called driver head which has a loft angle of 13 degrees or less has become the mainstream that the head volume exceeds 300 cc and is 350 cc-500 cc. In the case of a driver head, the head weight is 200 g or less, preferably about 180 g to 195 g, and the specific gravity of the titanium alloy is 4.2 to 5.0, so that the thickness of the crown part, the side part and the soul part is made thin. In some cases, the thickness of the face portion is also partially reduced.

Previously, a driver head having a hollow part made of a titanium alloy (for example, Ti-6Al-4V) manufactured by casting has a thickness of about 1.2 mm for the crown part, the soul part and the side part, and the thickness of the face part. It was about 3 mm. In recent years, the sheet material is press-molded with β-type titanium alloy or the like to produce each part of the golf club head (such as the sole part, the side part, the crown part, the face part, or two or more of these parts integrated). And fixing these by welding to manufacture a golf club head having a hollow portion (see, for example, Japanese Unexamined Patent Application Publication No. 2003-52866). In casting, a method of melting a metal by a lost wax manufacturing method (investment casting method) and introducing it into a ceramic mold is difficult, and it has been difficult to thin each part. Since the thickness of each part can be made thin by the method of manufacturing each part of a head, the thickness of 1 mm or less becomes possible and it becomes possible to manufacture a larger golf club head.

However, the thinning and enlargement of the golf club head has caused the vibration of the golf club head to become large when the golf ball is hit, resulting in undesirable effects on hitting and hitting.

This invention is made | formed in view of the above-mentioned situation, and an object of this invention is to provide the metal golf club head which improved both a hitting and a hitting sound.

In order to achieve the above object, the present invention provides a metal golf club head, wherein a screw of a magnesium alloy subjected to anticorrosion treatment is attached to a predetermined portion of the metal head body.

In the metal golf club head of the present invention, the vibration of the golf club head when the golf ball is hit by the screw of the magnesium alloy subjected to the anticorrosion treatment is effectively attenuated, so that both the feel and the sound are improved.

According to the metal golf club head of the present invention, it is possible to obtain desirable feeling and sound.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail. In the present invention, the material of the metal head body is not limited, but examples thereof include titanium alloys, stainless steels, aluminum alloys, and low carbon steels (for example, S15C and S25C). In addition, the metal head main body may be integrally molded by casting, or may be what joined several parts by welding.

Although there is no limitation in the kind of the metal head main body used for this invention, a thin and light driver head is especially preferable, For example, a titanium alloy (for example, specific gravity about 4.5) or an aluminum alloy (for example, about specific gravity about A driver head having a head volume of 2.7) of 300 to 500 cc can be suitably used. In addition, in a head made of stainless steel having a high specific gravity (for example, specific gravity 7.8), a driver head having a head volume of 200 to 300 cc can be suitably used. It is preferable that the thickness of the head is 0.5 to 1.0 mm, particularly 0.6 mm to 0.9 mm, for the thinnest portions of the crown portion, the sole portion and the side portion. The metal head body used in the present invention may be not only a hollow golf club head but also a solid golf club head such as an iron club head.

Although the kind of magnesium alloy is not limited in this invention, What added aluminum and zinc to magnesium can be used suitably. More specifically, the AZ31 alloy which added 3 mass% of aluminum and 1 mass% of zinc to magnesium, the AZ61 alloy which added 6 mass% of aluminum and 1 mass% of zinc to magnesium, and 9 mass% of aluminum to magnesium Although the AZ91 alloy etc. which added 1 mass% of these can be used suitably, it is not limited to these.

It is preferable that the weight of the screw of the magnesium alloy used for this invention is 1-5 g per piece. If the screw is too light, it is not effective for suppressing the vibration of the head, and if it is too heavy, it will not affect the weight of the head. In addition, the magnesium alloy has a specific gravity of about 1.7 to 2.0. In addition, the magnesium alloy has a Young's modulus of 44 to 45 kPa, which is less than half the value of titanium alloy and about 6 to 70% of aluminum alloy.

Since magnesium alloys are easy to corrode, the surface of a screw is subjected to anticorrosive treatment. Specifically, the anticorrosive treatment of the screw surface is performed by chromate (hexavalent chromate) treatment, permanganate treatment, anodizing treatment, zinc phosphate treatment, or the like, or by coating an insulating paint or an insulating resin on the screw surface. The process can be performed. In addition, in this invention, an anticorrosive process shall include an antirust process.

Particularly preferred as an anticorrosive treatment is to form an oxide film on the screw surface by using an anodizing treatment method or the like. Moreover, since magnesium alloy tends to cause electrolytic corrosion by contact with dissimilar metals, it is preferable to coat at least the male threaded portion of the screw of the magnesium alloy. Moreover, it is preferable to coat also the female screw part of the head main body which the screw of a magnesium alloy contacts. As for painting, it is suitable to use the epoxy-type paint with good adhesiveness with the magnesium alloy which formed the oxide film on the surface.

In the present invention, the screw of the magnesium alloy can be produced by machining using a round rod of the magnesium alloy. Magnesium alloys have a lower cutting resistance than aluminum alloys and stainless steels, and therefore are easy to machine. The screw of the magnesium alloy is produced by machining, and after the contamination of the surface is removed by alkali washing, acid washing can be performed for anticorrosive treatment.

In the present invention, the adhesive can be applied to the male threaded portion of the screw of the magnesium alloy or the female threaded portion of the head body to which the male threaded portion of the screw of the magnesium alloy is screwed, thereby effectively removing the magnesium alloy screw from the head body. You can prevent it. As an adhesive agent, an epoxy adhesive can be used, for example. Moreover, in this invention, adhesiveness of a screw and a head main body can be improved by giving anticorrosive treatment to the screw of a magnesium alloy.

In this invention, after attaching the screw of a magnesium alloy to a head main body, it can paint on the surface of a head main body. In this case, since the coating film covers the gap between the head body and the screw of the magnesium alloy, dust and water can be prevented from entering the gap. Moreover, you may inject the anaerobic adhesive excellent in permeability, such as an acrylic adhesive, into the clearance gap between the head main body and the screw of a magnesium alloy. Since the anaerobic adhesive enters the gap between the head body and the screw of the magnesium alloy and hardens, it is possible to obtain an effect of preventing loosening of the screw and entry of dust or moisture into the gap.

In the present invention, the screw of the magnesium alloy is attached to the side portion of the metal head body, particularly, the recess is provided in the side portion of the metal head body, and the screw of the magnesium alloy is mounted so as not to protrude from the recess. It is preferable. When the magnesium alloy screw is attached to the sole portion, the sole portion contacts the ground during the swing. Thus, the magnesium alloy screw is scratched, the oxide film or paint is peeled off, and the magnesium alloy screw is corroded from the scratch portion. Although there is a possibility, when the magnesium alloy screw is attached to the side part, the problem as mentioned above does not arise. In addition, by attaching the screw of the magnesium alloy so that the screw of the magnesium alloy does not protrude from the recess in the recess provided in the side portion of the head main body, it is possible to effectively prevent the scratch of the screw of the magnesium alloy. In this case, it is preferable to form a thick thick part in the side part of a metal head main body, and to provide the said recessed part in this thick part. In addition, the concave portion preferably protrudes from the outer surface of the head body to the hollow portion of the head body.

EMBODIMENT OF THE INVENTION Hereinafter, although embodiment of this invention is described with reference to drawings, this invention is not limited to the following example. Fig. 1A is a perspective view showing a head body of a metal golf club head according to an embodiment of the present invention, and Fig. 1B is a sectional view taken along line T1-T1 of Fig. 1 of the head body. 2A is a perspective view of the head main body from a direction different from that of FIG. 1A, and FIG. 2B is a sectional view taken along the line T2-T2 of FIG.

The head body 10 of this example includes a sole portion 12, a crown portion 14, a toe side portion 16, a hill side side portion 18, and a back side side portion ( 20, the hollow part 22 is formed in the inside, and the opening part 23 closed by the face member is formed in the face side. In the head main body 10 of the present example, recesses 24 and 26 are provided in the toe side portion 16 and the heel side side portion 18, respectively. The recessed parts 24 and 26 protrude from the outer surface of the head main body 10 to the hollow part 22 of the head main body 10, and the tip is open. Further, the recesses 24 and 26 have a large diameter portion 28 on the outer surface side of the head main body 10, have a small diameter portion 30 in front of the head body 10, and a female screw (on the peripheral surface of the small diameter portion 30). 39) is formed. In addition, 38 is a shaft insertion part in a figure.

And the screw 32 of magnesium alloy is fitted in the recessed part 24 and 26, respectively. As shown in Fig. 3, the screw 32 has a large diameter portion 28 of the recesses 24 and 26, a large diameter portion 34 corresponding to the small diameter portion 30, and a small diameter portion 36. The head body by screwing the small diameter part 36 to the female screw 39 formed in the small diameter part 30 of the recessed part 24 and 26, and the male screw 37 formed in the peripheral surface of the neck part 36. As shown in FIG. It is fixed to (10). In this example, a slight gap is formed between the inner circumferential surface of the large diameter portion 28 of the concave portions 24 and 26 and the outer circumferential surface of the large diameter portion 34 of the screw 32.

In this example, an oxide film is formed on the surface of the screw 32 by anodizing, and an epoxy paint is applied thereon. In addition, an epoxy paint is applied to the inner circumferential surfaces of the recesses 24 and 26. In addition, an anaerobic adhesive 41 is injected into the gap between the head main body 10 and the screw 32 (the gap between the stepped portions of the recesses 24 and 26 and the stepped portions of the screw 32). have.

In addition, although the screw was arrange | positioned in the toe side side part and the heel side side part in the said example, the arrangement | positioning part of the screw in this invention is not limited to this, Toe side side part 16, the heel side side part 18, and Screws can be appropriately arranged in one or two or more places selected from the back side side portions 20.

<Example>

The head body of the metal golf club head of the embodiment shown in FIG. 1 and FIG. 2 was produced. In this case, the head body was produced by investment casting using Ti-6Al-4V titanium alloy. The face member was produced by press molding using a β-type titanium alloy. The screws were made of magnesium alloy (AZ61 alloy). The screw had a total length of 15.5 mm, a large diameter portion of 10 mm, a large diameter portion of 9.8 mm, a small diameter portion of 5.75 mm, and a mass of 1.5 g. The face member was fixed to the head body by welding, and screws were respectively fixed to two recesses of the head body to complete the golf club head. In the metal golf club head of this example, the head volume was 460 cc, the thickness of the thinnest part of the crown part was 0.6 mm, the thickness of the thinnest part of the soul part was 0.9 mm, and the thickness of the thinnest part of the side part was 0.7 mm. The face member was a face member with a partially thick portion having a thickness of 2.6 to 3.6 mm. In addition, the part which provided the recessed part of the side part was thickened.

The golf club was produced using the said metal golf club head, and a hitting and a hitting sound were evaluated by the golfer's rudder. Further, a hollow iron golf club head (first comparative example) in which nylon screws are fixed as screws to two recesses, and a hollow iron golf club head in which stainless steel screws are fixed as screws to two recesses, respectively. The same evaluation was performed using 2 comparative examples). The weight of the magnesium alloy screw was 1.5 g / piece, the weight of the nylon screw was 0.9 g / piece, and the weight of the stainless steel screw was 6.5 g / piece. As a result, evaluation by the golfer became as follows.

(Metal golf club head of the Example)

• The middle of the club head using stainless steel screws and the club head using nylon screws.

· The sound is clear and high notes are heard.

· Feeling sounds only.

・ There is elasticity of ball on face side and is just right.

(Metal golf club head of the first comparative example)

The sound is not clear.

· Mild feeling but somewhat lacking.

· The feeling of attack is not clearly transmitted.

・ There is no ringing feeling, and there is little elasticity, so the ball does not feel flying away.

(Metal golf club head of the second comparative example)

Sound sounds, head feels hard

High sound

・ There is a sense of elasticity of the ball on the face of the ball, so the ball pops up quickly.

· It feels difficult to control the ball and fly.

In addition, the relationship between the vibration frequency of the head and the damping ratio was investigated by modal analysis using the golf club heads of the examples, the first comparative example and the second comparative example. Modal analysis is the analysis method demonstrated below. That is, when a force is applied from the outside of the structure, the structure starts to vibrate and continuously vibrates. This vibration has an inherent shape (unique mode), vibrates at a unique frequency (unique vibration), and attenuates (mode damping ratio). Modal analysis is an analysis method for obtaining this intrinsic dynamic property (modal parameter), that is, intrinsic mode, natural vibration, and mode damping ratio. In this experiment, the vibration characteristics of the golf club head were evaluated by modal analysis using an impact hammer. The results are shown in the graph of FIG.

The golf club head of the example using the magnesium alloy screw has a higher damping ratio than the golf club head of the second comparative example using the stainless steel screw in the low frequency region, and the golf club of the second comparative example using the stainless steel screw in the high frequency region of 5000 Hz or higher. It can be seen that the head and the damping ratio are equivalent, and have appropriate vibration damping characteristics. On the other hand, it turns out that the golf club head of the 1st comparative example using a nylon screw has a high damping ratio in the whole frequency range, and the vibration suppression effect is too high. Moreover, it turns out that the golf club head of the 2nd comparative example using a stainless steel screw has a low damping ratio in the whole frequency range, and its vibration suppression effect is low.

1A is a perspective view showing a head body of a metal golf club head according to an embodiment of the present invention, and FIG. 1B is a sectional view taken along the line T1-T1 of FIG.

FIG. 2A is a perspective view of the head main body as seen from a direction different from FIG. 1A, and FIG. 2B is a sectional view taken along the line T2-T2 of FIG.

3 is an enlarged cross-sectional view showing a state where a screw of magnesium alloy is attached to a head body;

Fig. 4 is a graph showing the relationship between the vibration frequency of the head and the damping ratio in the golf club heads of Examples and Comparative Examples.

<Explanation of symbols for the main parts of the drawings>

10: head body

12: soul part

14: crown portion

16: toe side part

18: heel side part

20: back side part

22: hollow part

24, 26: recess

32: screw

Claims (7)

A metal golf club head, wherein a screw of a magnesium alloy subjected to anticorrosion treatment is attached to a predetermined portion of the metal head body. The metal golf club head according to claim 1, wherein the screw of the magnesium alloy subjected to the anticorrosion treatment has an oxide film formed on its surface. The metal golf club head according to claim 1 or 2, wherein the screw of the magnesium alloy subjected to the anticorrosion treatment is formed with an oxide film on the surface after the male thread is formed by machining. The metal golf club head according to any one of claims 1 to 3, wherein the screw of the magnesium alloy subjected to the anticorrosion treatment is coated on the male thread portion. The metal golf club according to any one of claims 1 to 4, wherein after the screw of the magnesium alloy subjected to anticorrosion treatment is attached to a predetermined portion of the metal head body, the surface of the metal head body is coated. head. The metal golf club head according to any one of claims 1 to 5, wherein a screw of a magnesium alloy subjected to anticorrosion treatment is attached to a side portion of the metal head body. The metal golf ball according to any one of claims 1 to 6, wherein a recess is provided in a side portion of the metal head body, and a screw of magnesium alloy is mounted in the recess so as not to protrude from the recess. Club head.

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