Golf club head

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to a golf club head capable of increasing the moment of inertia while lowering the center of gravity.

【0002】

[Problems to be solved by conventional techniques and inventions]

For example, in a metal wood type golf club head having a hollow portion formed inside, a material having high strength and low specific gravity such as titanium or a titanium alloy has been preferably used in recent years. Such a golf club head can have a larger head volume than a conventional head using persimmon wood. Increasing the head volume means an increase in the moment of inertia (the term "moment of inertia" as used herein refers to the left and right moments of inertia about the vertical axis passing through the center of gravity of the head, unless otherwise specified). It is possible to improve the directional stability of the hit ball by increasing the sweet area and suppressing the head shake at the time of a missed shot.

【0003】

Further, in recent years, as shown in FIG. 7, a weight member c made of a metal material having a large specific gravity such as copper alloy or tungsten is fixed to the sole portion b of the head a, and the center of gravity g of the head a is designed to be low. (Refer to Japanese Patent Application Laid-Open No. 2000-116825). By lowering the center of gravity of the head in this way, the flight distance can be increased by increasing the launch angle of the hit ball and appropriately reducing the backspin amount.

【0004】

On the other hand, in order to increase the moment of inertia of the head, it is effective to distribute more weight around the head away from the center of gravity g, more specifically around the side portion d and the sole portion b. However, although the head a having the weight member c fixed to the sole portion b can achieve a lower center of gravity, the sole portion b is locally heavier, so that the weight distribution effect around the head a is relative. There is a drawback that the moment of inertia becomes small because it fades away.

【0005】

The present invention has been devised in view of the above problems, and is composed of a crown plate forming the main part of the crown portion on the upper surface of the head and a head main body portion on which the crown plate is arranged, and the crown. The plate is formed from a low specific gravity metal material with a specific gravity of 5.0 or less, and the head body is formed using a high specific gravity metal material with a specific gravity of 7.0 or more, and these are joined by brazing to lower the center of gravity. It is an object of the present invention to provide a golf club head which can prevent a decrease in the moment of inertia, improve the directional stability of a hit ball, and have excellent durability.

【0006】

[Means for solving problems]

The invention according to claim 1 of the present invention is a golf club head having a hollow inside, from a crown plate forming a main portion of a crown portion on the upper surface of the head and a head main body portion on which the crown plate is arranged. The crown plate is formed of a low specific gravity metal material having a specific gravity of 5.0 or less, and the head main body is formed of a high specific gravity metal material having a specific gravity of 7.0 or more, and the crown plate and the head main body are formed. It is characterized by joining with and by brazing.

【0007】

The invention according to claim 2 is the golf club head according to claim 1, wherein the weight of the crown plate is 10 to 30% of the weight of the head main body.

【0008】

Further, according to the third aspect of the present invention, the head main body portion has a face portion for hitting a ball, a sole portion connected to the lower edge of the face portion to form a head bottom portion, and a face portion rising from the periphery of the sole portion. The golf club head according to claim 1 or 2, which includes a side portion extending from the toe side of the golf club to the heel side of the face portion and a shaft insertion portion to which a shaft can be mounted.

【0009】

The golf club head according to claim 4, wherein the crown plate is made of titanium or a titanium alloy, and the head body portion contains stainless steel. Is.

【0010】

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of a golf club head according to an embodiment of the present invention, and FIG. 2 is an exploded perspective view thereof. In FIG. 1, a golf club head (hereinafter, may be simply referred to as a head) 1 is connected to a face portion 2 having a face surface F for hitting a ball on the surface and an upper edge 2a of the face portion 2. The crown portion 3 which forms the upper surface of the head, the sole portion 4 which is connected to the lower edge 2b of the face portion 2 and forms the bottom surface of the head, and which rises from the periphery of the sole portion 4 and passes through the back face from the toe t side of the face portion 2. An example thereof includes a side portion 5 extending to the heel e side of the face portion 2 and a shaft insertion portion 6 to which a shaft can be mounted. Further, the head 1 of this example is exemplified by a wood type head 1 made of a metal material and having a hollow portion i inside.

【0011】

As shown in FIG. 2, the head 1 is composed of a crown plate 7 forming a main portion of the crown portion 3 and a head main body portion 9 on which the crown plate 7 is arranged. In this example, the crown portion 3 forms a region on the upper surface of the head surrounded by the contour line formed by the upper edge 2a of the face portion 2 and the upper edge 5a of the side portion 5, and the shaft insertion portion 6 is formed. It is composed of substantially excluded parts. As shown in FIG. 4, a smooth joint surface 11 formed by a recessed surface recessed toward the inside of the head is formed between the shaft insertion portion 6 and the crown portion 3.

【0012】

In this example, the crown plate 7 is exemplified as a single plate formed in a shape in which a small distance L is separated inward from the contour line of the crown portion 3. The small distance L is not particularly limited, but is preferably about 2 to 10 mm, preferably about 2 to 5 mm, for example, so that the crown plate 7 substantially covers the entire area of the crown portion 3 in this example. Can be configured.

【0013】

Further, in this example, the head main body portion 9 includes the face portion 2, the sole portion 4, the side portion 5, the shaft insertion portion 6, and the crown peripheral portion 3e forming a small width. It is desirable that each part of the head body 9 is integrally formed by, for example, lost wax precision casting, and each part previously divided into two or more is integrally formed by welding. You can also do it. As described above, the head main body 9 can be manufactured by using various methods, and the method is not particularly limited. Further, in the present embodiment, the face portion 2, the sole portion 4, the side portion 5, and the shaft insertion portion 6 are exemplified by being formed of the same metal material.

【0014】

As shown in FIGS. 2 and 4 to 6, the crown peripheral edge 3e is formed with a receiving portion 12 that holds the face plate 7 substantially flush with the crown peripheral edge and supports it from below. The receiving portion 12 of the present embodiment is shown to be formed over the entire peripheral edge of the crown plate 7. The width A (shown in FIG. 5) of the receiving portion 12 is not particularly limited, but is preferably, for example, 2 to 7 mm, more preferably 3 to 5 mm. Such a receiving portion 12 can easily and accurately mount the crown plate 7 when attaching the crown plate 7 to the head main body portion 9, and also helps to increase the joint strength of brazing described later.

【0015】

Further, in the present invention, the crown plate 7 is formed of a low specific gravity metal material M1 having a specific gravity of 5.0 or less, while the head body 9 is formed of a high specific gravity metal material M2 having a specific gravity of 7.0 or more. In this way, by using the low specific gravity metal material M1 for the crown plate 7 which forms the main part of the crown portion 3, the weight on the upper side of the head 1 can be reduced, and as a result, the center of gravity G of the head 1 is further reduced. It can be set low. Further, by using the high specific gravity metal material M2 for the head body portion 9 on which the crown plate 7 is arranged, the center of gravity of the head 1 can be further lowered, and the head 1 such as the side portion 5 as well as the sole portion 4 can be further lowered. As a result of being able to distribute more weight to the peripheral part of the head 1, the moment of inertia of the head 1 can also be increased. As described above, in the head 1 of the present invention, not only the sole portion 4 is made relatively heavy, but the parts other than the crown portion 3 are made heavy in a well-balanced manner, so that lowering the center of gravity and increasing the moment of inertia are more effective. Can be compatible with.

【0016】

In the present embodiment, the sole portion 4 is not compounded with a massive weight member or the like, but such a weight member can be attached within a range that does not cause deterioration of the moment of inertia of the head 1.

【0017】

Here, when the specific gravity of the metal material constituting the crown plate 7 exceeds 5.0, the weight of the crown portion 3 forming the upper side of the head 1 tends to increase relatively, and the weight of the head main body portion 9 alone has a low center of gravity. It becomes difficult to achieve the conversion. From this point of view, it is desirable that the specific gravity of the low specific gravity metal material M1 of the crown plate 7 is as small as possible, and more preferably 4.5 or less.

【0018】

The low specific gravity metal material M1 forming such a crown plate 7 is not particularly limited, but for example, pure titanium (specific gravity about 4.5), titanium alloy (specific gravity about 4.4 to 4.7), magnesium alloy (specific gravity about). 1.8 ~ 2.3), duralumin (specific gravity about 2.8) or aluminium-lithium (Al-Li) alloy (specific gravity about 2.6), etc. can be mentioned. Above all, it is desirable to use a material such as a titanium alloy or an aluminum alloy (duralumin) for the crown plate 7 from the viewpoint of ensuring specific strength and low specific gravity, and in this embodiment, a titanium alloy (Ti-6Al-4V) is used. It exemplifies the thing.

【0019】

The thickness of the crown plate 7 is not particularly limited, but is preferably 0.7 to 1.2 mm, more preferably 0.9 to 1.1 mm in view of the balance between weight reduction and strength. Needless to say, such a crown plate 7 can be formed by various processing methods such as forging, casting, and rolling.

【0020】

It is also conceivable to use a low specific gravity composite material such as a fiber reinforced resin for the crown plate 7. However, when such a material is used for the crown plate 7, the hitting sound is extremely different from that of a general head, and the rigidity of the crown portion 3 is insufficient, so that it is necessary to take measures such as increasing the thickness. It is difficult to adopt because there is a problem that the repulsive performance of the head is significantly reduced.

【0021】

On the contrary, if the specific gravity of the metal material constituting the head body 9 is less than 7.0, it becomes difficult to distribute more weight to the periphery of the head 1 (side portion 5) or the bottom portion of the head (sole portion 4). , It becomes difficult to lower the center of gravity of the head 1 and increase the moment of inertia.

【0022】

Examples of the high specific gravity metal material M2 forming the head body 9 include stainless steel (specific gravity about 7.8 to 8.0) such as SUS630 (specific gravity 7.8) and CUSTOM450 (manufactured by Carpenter, USA, specific gravity 7.8), and nickel-copper. Alloys (specific gravity about 8.9), tungsten alloys (specific gravity about 12 to 15) or tungsten (specific gravity about 18), platinum (specific gravity about 21.3), copper alloys (specific gravity about 8 to 13), maraging alloys (specific gravity about 7.0 to 8.2) And so on. Above all, it is desirable to use a material such as SUS630 or CUSTOM450 for the head main body 9 from the viewpoint of strength, ease of processing, economy, etc., and in this example, the one using SUS630 is exemplified. From a practical point of view, the specific gravity of the high specific gravity metal material M2 is preferably about 7.0 to 10, more preferably about 7 to 8.5. Further, the head main body 9 can be formed by using two or more kinds of metal materials as long as it is formed from the high specific gravity metal material M2.

【0023】

The thickness of each part of the head body 9 is not particularly limited, but for example, the sole part 4 has a thickness of 1.0 mm or more, more preferably 1.5 mm or more, and the side part 5 has a thickness of, for example, 0.7 mm or more. More preferably, it is 0.7 to 1.0 mm. The thickness of the face portion 2 is preferably, for example, 2.2 to 3.0 mm, more preferably 2.4 to 2.6 mm.

【0024】

If the head volume is too small, the effect of increasing the moment of inertia of the head is reduced, and if it is too large, the head weight may become excessive or the center of gravity of the head may become high. From this point of view, the head volume of the head 1 is, for example, 100 to 200 cm.³, More preferably 120-170 cm³Is desirable.

【0025】

The weight of the crown plate 7 is preferably 10 to 30%, more preferably 10 to 25%, still more preferably 10 to 17% of the weight of the head body 9. When the weight of the crown plate 7 exceeds 30% of the weight of the head main body 9, the weight of the upper side of the head 1 tends to increase and the height of the center of gravity of the head 1 tends to increase, and conversely, 10%. If it is lower than that, the thickness of the crown plate 7 tends to be substantially reduced, and it may be difficult to obtain the durability required for practical use.

【0026】

Further, in the present invention, since the crown plate 7 and the head main body 9 are made of dissimilar metals, the crown plate 7 and the head main body 9 are joined by brazing. Brazing involves melting a metal or alloy having a melting point lower than that of the base metal in order to join dissimilar metals, that is, brazing, and filling the gaps between the base materials with the brazing material using, for example, a capillary phenomenon to fill and solidify the dissimilar metals. This is a method of joining metals together. Such brazing can increase the bonding strength as compared with the case of bonding using an adhesive, whereby the durability of the head can be maintained.

【0027】

When such brazing is performed, the peripheral edge 7e of the crown plate 7 is provided by providing the receiving portion 12 around the crown peripheral edge portion 3e as shown in an enlarged manner in FIG. 5, although the brazing is not particularly limited. It is desirable to form a lap joint J that overlaps inside and outside. By using such a lap joint J, for example, when a low-strength wax is used or even if some defects occur, a sufficient lap allowance is secured to improve the strength of the joint portion and improve the strength of the joint portion, and the crown plate 7 and the head. It is possible to prevent the main body 9 from coming off.

【0028】

Further, when brazing the crown plate 7 and the crown peripheral portion 3e, it is desirable to form the lap joint J as described above, but in particular, the joint area between the crown plate 7 and the head main body portion 3 is 200 mm, for example.²Above, preferably 300 mm²Above, more preferably 400 mm²Above, more preferably 400 to 800 mm²Is desirable. The joint area is obtained as the sum of the overlapping area of the receiving portion 12 and the crown plate 7 and the area of the end surface 7a of the crown plate 7.

【0029】

The joint area is 200 mm²If it is less than, the strength at the joint between the crown plate 7 and the head body 9 is not sufficiently obtained, and the durability of the head 1 tends to decrease. On the contrary, the width of the receiving portion 12 is increased. Joint area 800 mm²If it is made larger than, the rigidity of the crown portion 3 is remarkably increased, and as a result, the shot feeling and the hitting sound of the head 1 tend to be deteriorated. In particular, when the rigidity of the crown portion is increased, the reverberation sound is shortened among the hitting sounds and the feeling is deteriorated.

【0030】

The brazing used for brazing is variously selected depending on the metal material to be joined, its melting point, etc., but silver brazing (Ag-Al, Ag-Cu (Ag-Al, Ag-Cu) is preferable for the reason of optimizing the strength and brazing conditions. BAg-19), Ag-Al-Mn, Ti-Zr-Ni, Ti-Cu-Ni, Ti-Cu-Ni-Zr, Ag-Pb-Ga, Pb-Ag-Si) should be used.

【0031】

The silver wax contains a silver-copper alloy as a main component, and can be suitably used for brazing a wide range of metal materials other than magnesium and aluminum, such as steel materials, nickel and their alloys. Examples of the additive component include elements of Cd, Ni, Sn, and Li. For example, JIS Z 3261 describes various elements. The melting point is approximately 620 to 800 ° C, and it can be suitably used because it has a lower melting point than the titanium alloy and SUS630 used in this embodiment.

【0032】

In the present embodiment, the crown plate 7 and the head main body 9 as shown in FIG. 2 are prepared, and the crown plate 7 is positioned and placed on the receiving portion 12 of the crown peripheral portion 3e. At this time, if necessary, the crown plate 7 and the head body 9 are pressed with a jig or the like to temporarily fix them. If the pressing force at this time is too low, the brazing material is not sufficiently filled and appearance defects such as gaps are likely to occur. On the contrary, if it is too high, the head body itself may be damaged or deformed. From this point of view, the pressing force is preferably 0.1 to 1.0 MPa, more preferably 0.3 to 0.7 MPa.

【0033】

Then, as shown by the alternate long and short dash line in FIGS. 3 and 5, the paste-like wax 13 is applied in this example around the gap between the crown plate 7 and the crown peripheral edge portion 3e of the head main body portion 9. Then, by heating the head 1 in a furnace in a vacuum atmosphere, for example, the melted wax 13 penetrates into the gap of the joint portion by a capillary phenomenon. After that, the head 1 is taken out from the furnace and the joint is polished, painted, etc. to manufacture the head 1.

【0034】

The temperature at which the head 1 is brazed is lower than the melting point of the crown plate 7 and the head body 9 and higher than the melting point of the brazing 13, but the combination of the materials of the present embodiment is preferable. It is desirable that the temperature is 620 to 900 ° C, more preferably 650 to 850 ° C. If it is less than 620 ° C, the brazing does not melt and brazing becomes difficult. Conversely, if it exceeds 900 ° C, β transformation occurs during brazing, such as when a Ti alloy that undergoes β transformation is used for the crown plate. This is because it will be stored.

【0035】

In addition to the in-furnace brazing method, there are various brazing methods such as a gas brazing method, a high frequency brazing method, an arc brazing method, and an optical beam brazing method, and any method may be used. However, the brazing method in a furnace, which is preferably suitable for mass production, is particularly desirable. When brazing is performed in a place other than a vacuum atmosphere, flux or the like is applied first to suppress oxidation of the joint surface. Further, the crown plate 7 and the head main body 9 may be a butt joint, for example, in addition to the lap joint.

【0036】

As described in detail above, the present invention is not limited to the illustrated wood type golf club head, and is intermediate between the iron type and the wood type and the iron type as long as it has a hollow portion inside. Needless to say, it can be applied to various heads such as a utility type having a head shape and a putter type.

【0037】

[Example]

Hereinafter, more specific examples of the present invention will be described. A wood-type golf club head was prototyped with the specifications shown in Table 1, and the moment of inertia, height of the center of gravity, durability, and feeling when hitting the ball were tested. The head shape has a head volume of 170 cm.³, The head mass was unified to 225g. In Comparative Examples 1, 2 and 4, the crown plate and the head body were integrally formed. The contents of the test are as follows.

【0038】

<Moment of inertia of the head> Each test head is placed on the horizontal plane with the specified lie angle and loft angle, and the moment of inertia around the vertical axis passing through the center of gravity is calculated by MOMENT OF INERTIA MEASURING INSTRUMENT manufactured by INERTIA DYNAMICS Inc. It was measured using MODEL NO.005-002.

【0039】

<Durability> A wood-type golf club is prototyped by attaching the same shaft to each head, and each club is attached to a swing robot, and a trial hit test of 1000 shots is performed at the center of the face at a head speed of 50 m / s. Then, it was confirmed that the crown plate and the head body were not joined to each other. Those that did not come off at the joint and did not have cracks were evaluated as , and others were evaluated as x.

【0040】

<Feeling at the time of hitting> For each of the wood-type golf clubs, a trial hit test was conducted by 10 golfers, and the shot feeling and hitting sound were evaluated by a 5-point method, and the average score of 10 people was obtained. The larger the number, the better. Table 1 shows the test results.

【0041】

[table 1]

<img file="JP2002165902A_D0001.tif" />【0042】

As a result of the test, it can be confirmed that in the example, the moment of inertia is increased while lowering the center of gravity of the head as compared with the comparative example. In the head of the embodiment, the moment of inertia is set to X (g · mm).²), When the height of the center of gravity is Y (mm), the ratio (X / Y) can be set to 130 or more, preferably 140 or more, more preferably 150 or more, and the moment of inertia per unit center of gravity height is made larger. Obtainable.

【0043】

On the other hand, in Comparative Example 1, since the head body is made of a low specific gravity material and the weight member is arranged on the sole to concentrate the weight, the weight is biased to the sole and the moment of inertia is generated. It can be confirmed that it is getting worse. Further, in Comparative Example 2 or 4, since the crown plate is formed of a material having a high specific gravity, the center of gravity cannot be lowered. Further, in Comparative Example 3, since the crown plate is made of fiber reinforced resin and the joining method with the head main body is also adhesive, the durability is low and the hitting feeling is deteriorated. Further, in Comparative Example 5, although a low heavy metal material is used for the crown plate and a high heavy metal material is used for the head body, sufficient durability is not obtained because both are joined by an adhesive. .. Further, in the example, in the fifth embodiment in which the joint area was increased, the hitting feeling was slightly inferior. This is considered to be the result of the rigidity of the crown portion being excessively increased.

【0044】

[Effect of the invention]

As described above, in the invention according to claim 1, the golf club head is composed of a crown plate forming a main part of the crown portion on the upper surface of the head and a head main body portion on which the crown plate is arranged. The head body is formed of a low heavy metal material having a specific gravity of 5.0 or less, and the head body is formed of a high metal material having a specific gravity of 7.0 or more, and the crown plate and the head body are joined by brazing. As a result, the moment of inertia can be increased while lowering the center of gravity of the head, and the durability required for the head can be ensured.

【0045】

Further, in the invention according to claim 2, by limiting the weight of the crown plate 7 to a certain range with respect to the weight of the head main body portion, it is possible to more effectively lower the center of gravity and increase the moment of inertia.

【0046】

Further, in the invention according to claim 4, the conventional head material is used by using high-strength and low-specific gravity titanium or the like for the crown plate and high-strength and high-specific gravity stainless steel for the head body. A golf club head having a low center of gravity and a large moment of inertia can be easily manufactured.

[Simple explanation of drawings]

[Figure 1]

It is a perspective view which illustrates the golf club head of this embodiment.

[Figure 2]

It is an exploded perspective view.

[Fig. 3]

It is a perspective view which shows the state which wax was applied to the boundary part between a crown plate and a head body part.

[Fig. 4]

It is sectional drawing of a head.

[Fig. 5]

It is an enlarged view of the A part.

[Fig. 6]

It is sectional drawing of a head.

[Fig. 7]

It is sectional drawing which illustrates the conventional head.

[Explanation of symbols]

1 golf club head 2 Face part 3 Crown part 3e Crown rim 4 Sole part 5 Side part 6 Shaft insertion part 7 Crown plate 9 Head body 12 receiving part 13 Rowe M1 low specific gravity metal material M2 high specific gravity metal material