JP2002165904A - Face structure of hollow metallic club head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To especially improve distance by providing a face part with a thin region, and to provide a face structure having high stability of the carry and lateral directional property of a ball hit out of its centroid, in relation to the face structure of a hollow metallic club head formed by fixing a crown part and a sole part to the laterally long face part. SOLUTION: In the face part 11, a thick region 15a with a constant thickness projecting from the rear surface of the face 15 is extended and formed in a range from a heel to a toe including a hitting region 16a in the center of the face part 11. The upper and lower parts of the thick region are formed as thin regions 15b and 15c, and the respective thin regions are formed with a constant thickness. An extending part 17 for fixing the crown part and the sole part is formed backward from the peripheral edge of the rear surface of the face 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a face structure of a hollow metal club head in which a crown portion and a sole portion are fixed to a horizontally long face portion.

[0002]

2. Description of the Related Art Conventionally, a wood-type driver emphasizing a flight distance has used a metal head having a hollow structure in which a crown portion and a sole portion are fixed to a back surface of a face portion by welding. By various improvements, the resilience of the face portion is enhanced, and the flight distance is remarkably improved.

[0003] For example, a titanium alloy is applied to a head material, and the face portion is made thinner by its high strength, thereby improving the resilience. This is because by making the face thinner, it is possible to increase the elastic deflection δ of the face portion rearward at the time of impact, as shown by the solid line in FIGS. 2B and 2C. This is because the elastic elongation λ (indicated by λv and λh in FIG. 2) in the vicinity of the back surface can be increased as a whole, and the total elastic energy Et stored in the face portion, which is abbreviated to the equation (1), can be increased. .

Et = α × (k × λ ² ) / 2 + β (1) where k is a spring constant of the face surface in the direction of the elastic extension λ, and α is a distribution of the elastic extension in the thickness direction. The coefficient β that changes accordingly is the elastic energy of other factors.

On the other hand, as an improvement of the face structure, FIG.
As shown in (1), there is one in which the thickness around the impact area 23 at the center of the face portion 21 is reduced to improve resilience (Japanese Patent Application Laid-Open No. 9-192273). This is the hit area 23
The thin region 25 is provided around the perimeter of the face portion 21. The strength of the striking region 23 is maintained high so as to withstand the impact at the time of striking, and the elastic deformation of the face portion 21 rearward at the time of striking is increased as a whole. Things.

[0006]

However, in general, the face portion including the face structure having the thin region 25 is formed in a horizontally long shape, that is, as shown in FIG. Since the side is formed longer, the elastic extension at the time of impact on the face surface, especially near the back surface of the face, is large in the vertical direction and small in the horizontal direction. Therefore, the elastic energy Ev stored by the vertical elastic expansion λv is large, and the horizontal elastic expansion λ
The elastic energy Eh stored by h is small, that is, the total elastic energy Et stored in the face portion 21 at the time of impact is not evenly distributed between the elastic energy Ev in the vertical direction and the elastic energy Eh in the horizontal direction.

For this reason, the total elastic energy Et stored in the face portion 21 is different between the case where the ball serving as the hitting area 23 is removed in the horizontal direction and the case where the ball is hit in the vertical direction.
Are different, resulting in a difference in flight distance. In other words, the flight distance of the off-centered hit ball is affected not only by the deviation amount of off-centering but also by the direction of off-centering. I have

[0008] In general, a ball hit off-center spins by a so-called gear effect. For example, FIG.
As shown in the figure, the ball hit on the heel side 23a of the face portion 21 performs spin rotation in a slice system, and the ball hit on the toe side 23b performs spin rotation in a hook system. The gear effect generally decreases as the thickness of the face portion 21 increases, and the ball stabilizes straight.

However, as shown in FIG. 3, the face structure including the thin region 25 around the hitting region 23 is particularly suitable for the left and right portions 25 sandwiching the hitting region 23.
Since the thickness of the a and 25b is thin, the heel side 25
When hitting at a, the spin of the slice system is further increased by a large gear effect, and when hit at the toe side 25b, the spin of the hook system is further increased. In other words, the ball muscle of the ball hit by removing the core in the left-right direction is destabilized, and the left-right directionality of the hit ball is deteriorated.

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a face structure which has a thin portion in a horizontally long face portion and improves a flight distance. An object of the present invention is to provide a face structure that is excellent in stability of flight distance of a hit ball and in left-right directionality.

[0011]

In order to achieve the above object, the present invention provides a face structure of a hollow metal club head in which a crown portion and a sole portion are fixed to a horizontally long face portion. There is a thick region of a constant thickness protruding from the back surface of the face,
It is characterized by being formed to extend from the heel to the toe, including the hitting area at the center of the face portion, and to make the upper and lower parts of the thick area thin, and the thin areas are formed to have a constant thickness. .

According to the present invention, since the thin regions are formed above and below the thick region extending from the heel to the toe of the horizontally long face portion, the spring constant k in the left-right direction of the face portion is formed.
The spring constant kv in the vertical direction can be made relatively smaller than h. Therefore, due to the above-described horizontally long shape of the face portion, the elastic elongation in the left-right direction at the time of impact and the up-down direction become uneven, and the total elastic energy of the face portion is higher in the up-down direction Ev than in the left-right direction Eh. The non-uniform distribution of the larger distribution toward
By making the spring constant kv in the vertical direction relatively small, the spring constant kv can be evenly distributed and solved. Therefore, it is possible to make the total elastic energy stored in the face portion when the core is removed in the left-right direction and hit the head portion substantially equal to the total elastic energy when the core is removed in the vertical direction. Variations in flight distance can be suppressed. In addition, since the thick region is formed to have a constant thickness and extends from the heel to the toe, even when the core hitting region is removed and hit at the left and right sides, the thickness of the portion is large. The gear effect is suppressed. Therefore, spin is unlikely to occur in the hit ball, and the ball muscle can be straightened while suppressing the increase in the slice and hook.

According to a second aspect of the present invention, in the face structure of the hollow metal club head according to the first aspect, the thick region occupies 30 to 40% of the area of the back surface of the face. According to the above invention, the thick region is 3
Since it is 0% or more, a decrease in the durability of the face portion due to a narrow thick region can be suppressed. on the other hand,
Since the thick region is set to 40% or less, a reduction in resilience due to a narrow thin region can be suppressed, and good resilience can be maintained.

According to a third aspect of the present invention, in the face structure of the hollow metal club head according to any one of the first and second aspects, the vertical thickness of the thick region is 15 to 20.
mm. According to the above invention, since the vertical width of the thick region is set to 15 mm or more, the vertical width of the thick region that can withstand the impact at the time of impact is wide, the durability of the face portion is excellent, and the gear effect is suppressed. The area where you can hit the ball is wide and it is easy to hit a straight hit ball. On the other hand, since the upper and lower widths are set to 20 mm or less, a decrease in resilience due to a narrow thin region can be suppressed, and good resilience can be maintained.

According to a fourth aspect of the present invention, in the face structure of the hollow metal club head according to any one of the first to third aspects, the face portion is formed so as to extend rearward from a peripheral edge of the face back surface. An extension portion for fixing the crown portion and the sole portion is formed. According to the invention, the crown portion and the sole portion are fixed to the extending portion, and the fixed portion is separated from the face surface. Therefore, for example, when the fixing method is welding, it is possible to prevent a weld defect or a heat-affected zone of the weld from being generated on the face surface, and to suppress a decrease in strength and toughness of the face surface where impact resistance is required. Can be. In addition, the thickness of the face portion can be further reduced by the suppression of the decrease in strength and toughness, and the resilience can be further improved.

According to a fifth aspect of the present invention, in the face structure of the hollow metal club head according to the fourth aspect, an extension width of the extension portion is set in a range of 15 to 25 mm. I do. According to the above invention, since the extension width is set to 15 mm or more, the fixing portion is located far enough from the face surface to reliably prevent the welding defect and the heat affected zone of the welding from being generated on the face surface. it can. Therefore, it is possible to reliably suppress a decrease in the strength and toughness of the face surface. On the other hand, since the extension width is set to 25 mm or less, the extension portion can be drawn and formed integrally with the face surface by a press or the like, and cost can be reduced.

According to a sixth aspect of the present invention, in the face structure of the hollow metal club head according to the fourth or fifth aspect, the included angle between the face back surface and the extended portion is more than 90 ° and 100 °. ° or less. According to the above invention, the included angle between the face back surface and the extended portion is set to an obtuse angle of more than 90 ° and 100 ° or less. The span with the end is large. Therefore, the head speed can be increased by reducing the air resistance of the face surface during the swing, and the bending moment of the face portion due to the impact load can be increased, so that the resilience is excellent.

[0018]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG.
FIG. 1 shows a face structure according to an embodiment of the present invention, and FIG.
FIG. 1A is a front view of a face portion, and FIG.
It is sectional drawing of the BB line arrow in (a).

As shown, the face portion 11 of the golf club head according to the present embodiment includes a neck portion 13 for connecting a shaft, a face 15, and an extension extending rearward from the entire periphery of the back surface of the face. And a projecting portion 17, which are integrally forged with a titanium alloy. Then, a crown portion and a sole portion (not shown) are fixed to the extension portion 17 by welding, and finally a golf club head having a hollow structure is obtained.

The face 15 has a horizontally long shape like a normal face, that is, the width in the left and right directions is longer than the width in the upper and lower directions. In the face 15, a thick region 15a having a constant thickness protruding from the back surface thereof is formed to have a constant vertical width from the heel to the toe, including the hitting region 16a at the center of the face. And the other face 1
The portion 5 is thin regions 15b and 15c having the same thickness, and is located above and below the thick region 15a as shown in the figure, and these thin regions 15b and 15c occupy substantially the same area as each other.

The thickness of the thick region 15a is 2.3 to 2.
The thickness is set to an appropriate value of 7 mm, and the vertical width is set to an appropriate value of 15 to 20 mm.
Area is 30 to 40%. The thickness of the thin regions 15b and 15c is set to an appropriate value of 1.8 to 2.2 mm. The appropriate values, that is, the distribution of the areas of the thick region and the thin region in the face, and the respective thicknesses are determined by the elastic extension of the face 15 in the vertical direction when the intended impact load is applied to the impact region 16a. The elastic energy Ev based on λv and the elastic energy Eh based on the elastic elongation λh in the left-right direction are determined to be substantially equal. The intended impact load used at that time is appropriately set according to the user of the golf club. For example, in the case of a general-purpose golf club, the average hitting load of an amateur golfer is used as the hitting load. In the case of a custom golf club, the average hitting load of the individual is used.

In the face 15 set to such an appropriate value, the elastic energy stored in the face 15 when the core is removed in the left-right direction and the elastic energy when the face is removed in the vertical direction are substantially equal. Therefore, variation in the flight distance due to the difference in the direction in which the core is removed is suppressed to a small value.

It should be noted that the face 15 according to the present embodiment can be adjusted so that the elastic energy Eh of the elastic extension λh in the left-right direction is substantially equal to the elastic energy Ev of the elastic extension λv in the vertical direction as described above. For the following reasons.

The face 15 has a thick region formed from the heel to the toe, and thin regions are formed above and below the thick region. The spring constant kv in the vertical direction is smaller. Therefore, due to the horizontally long shape of the face 15,
The difference Ev-Eh in elastic energy due to the longer elastic extension λv in the vertical direction than in the horizontal direction λh at the time of impact can be compensated for by the difference between the spring constants kh and kv in the horizontal direction and the vertical direction. As a result, the total elastic energy Et stored in the face 15 at the time of the impact can be equally distributed to the elastic energy Eh due to the elastic extension λh in the left-right direction and the elastic energy Ev due to the elastic extension λv in the vertical direction.

The thick region 15a is formed to have a constant thickness on the left and right from the heel to the toe. For this reason,
Remove the core hitting area 16a and its left and right portions 16b,
Even when the ball is hit with 16c, the gear effect is suppressed because the portions 16b and 16c are thick, and spin is unlikely to occur in the hit ball. Therefore, the ball muscle is easily straightened without increasing the length of the slice or hook, and the hit ball is excellent in the left-right directionality.

The extending portion 17 is formed to protrude rearward from the entire peripheral edge of the face back surface, and has a substantially cylindrical appearance.
Its extension width is 20 mm. And, the extension portion 17
In the uppermost part, the included angle D1 with the back surface of the face is 100 °.
In the lowermost portion, the included angle D2 is 91 °, and in the extending portion 17 between the uppermost portion and the lowermost portion, the included angle D increases from 100 ° to 9 from the uppermost portion to the lowermost portion.
It gradually decreases to 1 °.

The extension ends 17a, 17 of the extension portion 17
b, the crown portion and the sole portion are fixed by welding. At this time, since the welded portion is separated from the face 15 by the extension width, welding defects and a heat affected zone at the time of welding may occur on the face 15. Face 1
5 can surely be prevented from decreasing in strength and toughness.

The back surface of the face 15 and the extension 1
Since the included angle D with 7 is set to an obtuse angle of more than 90 ° and not more than 100 °, the span between the striking region 16a and the end portions 17a and 17b of the face portion 11 is set for the size of the face 15 surface. Can be bigger. Therefore, the head speed can be increased by reducing the air resistance of the face 15 during the swing, and the bending moment of the face 15 due to the impact load can be increased, so that the resilience thereof can be improved. Therefore, the flight distance can be further increased.

As described above, the included angle at the top is 100
The reason why the angle is increased to 0 ° and the included angle of the lowermost portion is decreased to 91 ° is to reduce the air resistance at the lowermost portion, which is the fastest at the time of the swing, and to suppress the deceleration of the head speed.

The face 1 of the present embodiment described above
5 thickness is 2.3-2.7mm even in thick region,
Face thickness of normal cast titanium alloy is 2.8 ~
Although the thickness is 3.0 mm, the thickness is significantly thinner than this, but there is no problem in the strength of the face 15 due to this. This is because the face portion 11 of this embodiment is forged and has a strength about 20% higher than that of the casting, and as described above, the extension portion 17 is provided with a crown portion and a sole portion. This is because the strength and toughness of the face 15 are relatively higher than that of the cast product due to welding.
The resilience of the face portion 11 is further improved by the thinning, and the flight distance is further improved.

Although the embodiment according to the present invention has been described above, the present invention is not limited to the embodiment, and the following modifications can be made without departing from the gist of the present invention. In the present embodiment, the upper and lower thin regions have the same thickness, but the present invention is not limited to this as long as the elastic energy is equally distributed in the vertical direction and the left and right direction. Is also good. For example, the thickness of the lower thin region may be thicker than the upper thin region,
In this case, there is an advantage that the ball has a low center of gravity and the ball easily rises.

[0032]

As described above, according to the first aspect of the present invention, the dispersion of the flight distance due to the difference in the direction in which the center is removed is suppressed, and the stability of the flight distance is excellent. Is easy to be straight and has excellent left and right directionality of the hit ball.

According to the second aspect of the present invention, since the resilience and durability of the face portion can be satisfactorily provided, the head life can be extended without impairing the flight distance.

According to the third aspect of the present invention, the durability of the face portion is excellent, so that the life of the head can be extended, and a straight hit ball can be easily hit, so that the right and left directionality is excellent.
Furthermore, it has excellent resilience, so it is excellent in flight distance.

According to the fourth aspect of the present invention, since the strength and toughness of the face can be prevented from lowering, the durability is excellent and the head life can be extended. Further, the face portion can be made thinner and the resilience can be further increased, so that the flight distance can be further increased.

According to the fifth aspect of the present invention, the reduction in strength and toughness of the face can be reliably suppressed, so that the life of the head can be prolonged.

According to the sixth aspect of the present invention, the head speed during the swing can be increased, and the resilience of the face portion also increases, so that the flight distance can be further increased.

[Brief description of the drawings]

FIG. 1 is a view showing a face structure of a golf club head according to an embodiment of the present invention, wherein FIG. 1 (a) is a front view of a face portion, and FIG. 1 (b) is a view in FIG. FIG. 4 is a sectional view taken along line BB of FIG.

FIG. 2 is a diagram for explaining a rearward elastic deflection δ generated at the time of hitting in a conventional horizontally long face portion, and a face surface, in particular, elastic stretches λv and λh of a face back surface,
2A is a front sectional view of the head, FIG. 2B is a sectional view taken along line BB in FIG. 2A, and FIG.
It is sectional drawing in the CC line arrow in (a).

FIG. 3 is a view showing a conventional hollow metal club head having a thin portion in a horizontally long face portion, and FIG.
3A is a side sectional view of the head, and FIG.
It is sectional drawing of the BB line arrow in (a).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Face part 13 Neck part 15 Face 15a Thick area 15b, 15c Thin area 17 Extension part

Claims (6)

[Claims] 1. A face structure of a hollow metal club head in which a crown portion and a sole portion are fixed to a horizontally long face portion, wherein the face portion has a constant thickness protruding from a back surface of the face. A thick region is formed extending from the heel to the toe, including the hitting region in the center of the face portion, and the thin region is formed to have a constant thickness by making the upper and lower portions of the thick region thin. The face structure of a hollow metal club head characterized by the following. 2. The method according to claim 1, wherein the thick region has an area of 3
The face structure of a hollow metal club head according to claim 1, wherein the face structure occupies 0 to 40%. 3. The vertical width of the thick region is 15 to 20 mm.
The face structure of a hollow metal club head according to any one of claims 1 to 2, wherein the face structure is set in the range of: 4. The face portion according to claim 1, wherein an extension portion for fixing the crown portion and the sole portion is formed rearward from a peripheral edge of the face rear surface. A face structure of a hollow metal club head according to any one of the first to third aspects. 5. An extension width of the extension portion is 15 to 25 mm.
The face structure of a hollow metal club head according to claim 4, wherein the face structure is set in the range of: 6. The hollow metal club head according to claim 4, wherein an included angle between the face back surface and the extending portion is set to be more than 90 ° and 100 ° or less. Face structure.