KR20170110522A - Golf club - Google Patents

Abstract

And provides a golf club which can relatively easily judge whether or not the ball has hit the sweet spot based on the hit sound. The golf club includes a shaft and a club head installed at an end of the shaft, the club head including a head body and a plate-like face member provided along a striking surface of the head body, A part of the lower edge surface, or a part of both the upper and lower edge surfaces of the head body. The fixed position of the face member may be located in the vicinity of the node of natural vibration when the face member is freely supported. The Rockwell C scale hardness of the face member is preferably 40 or more. The face member may be fixed to the head body by a set screw. The face member may be fixed to the head body at two positions of the upper edge surface of the face member and at the lower edge surface.

Description

Golf Club {GOLF CLUB}

The present invention relates to a golf club.

When playing golf, it is important that the ball hit the center of the club head's striking surface (the so-called "sweet spot"). As a criterion of the flayer to judge whether or not the player has hit the ball in the sweet spot, a batted sound is considered. Therefore, in particular, a commercially available wood such as a driver is designed in consideration of the sound of a hit.

Among the clubs, the putter has a relatively weak force, so it is accompanied by a smaller pitch. Therefore, it is difficult to judge whether or not the ball has hit the sweet spot, based on the sound of the hit. In order to cope with such a situation, Japanese Patent Laid-Open No. 9-70460 discloses a golf putter that relatively amplifies a hit sound by employing an inverted box-shaped head whose back surface is open. However, even with the structure disclosed in Japanese Patent Application Laid-Open No. Hei 9-70460, it is difficult to sufficiently amplify the hit sound of the golf putter, and therefore, it is still difficult to judge whether or not the ball has hit the sweet spot, it's difficult.

Japanese Patent Laid-Open No. Hei 9-70460

In order to cope with the above situation, it is an object of the present invention to provide a golf club that allows a user to relatively easily judge whether or not a ball has hit a sweet spot, based on a hit sound.

According to an aspect of the present invention, a golf club includes a shaft and a club head installed at an end of the shaft. The club head includes a head body, And the face member is fixed to the head body only on a part of the upper edge face of the face member, a part of the lower edge face, or only a part of both sides of the upper and lower edge faces.

As described above, according to the golf club of the embodiment of the present invention, it is possible to relatively easily determine whether or not the ball hit the sweet spot, based on the sound of the hit.

1 is a schematic partial front view showing a golf club according to an embodiment of the present invention.
2 is a cross-sectional view taken along line AA of the golf club shown in Fig.
3 is a schematic partial front view showing a golf club according to an embodiment of the present invention, which is different from that shown in Fig.
4 is a cross-sectional view along the BB line of the golf club shown in Fig.

Hereinafter, embodiments of the present invention will be described with reference to the drawings as necessary.

A golf club according to an embodiment of the present invention includes: a club head including a head body and a plate-like face member provided along the striking face of the head body; The face member being fixed to the head body only on a part of the upper edge surface of the face member, a part of the lower edge surface, or a part of both upper and lower edge surfaces; And at least partially open upper and lower edge surfaces. Therefore, since the face member has a relatively large area capable of freely oscillating, the face member can vibrate relatively large. Therefore, the golf club can generate a relatively large hit sound, so that the user can relatively easily judge whether or not the ball has hit the sweet spot based on the hit sound.

The fixing position of the face member may be located near the node of natural vibration when the face member is freely supported. In this way, when the face member is fixed at a position near the node of the natural vibration when the face member is freely supported, it is difficult for the fixing member of the face member to damp the vibration of the face member. Therefore, the golf club of the present invention can generate a relatively long reverberation sound, so that it is possible to more easily determine whether or not the ball has hit the sweet spot based on the sound of the hit.

The Rockwell C scale hardness of the face member is preferably 40 or more. When the Rockwell C scale hardness of the face member is equal to or more than the lower limit, the vibration of the face member is less likely to be damped, so that a larger hit sound is generated and the reverberation time becomes longer. Therefore, It is easier to judge whether or not the ball has hit the sweet spot.

It is preferable that the face member is fixed to the head body by a set screw. When the face member is fixed to the head body by the set screw, the fixed portion of the face member can be made small, and damping of the sound of the hit caused by the vibration transmitted to the head body can be suppressed relatively reliably.

It is preferable that the face member is fixed to the head body at two positions of the upper edge surface of the face member and the lower edge surface. The face member can be stably fixed when the face member is fixed to the head body at two positions of the upper edge surface and the lower edge surface of the face member.

The term "free support" as used herein means an ideal support state in which the support point is not fixed and vibration is not suppressed. Means that the distance from the node of the natural vibration in the heel-to-toe direction is 1/8 or less, preferably 1/10 or less, of the wavelength of the natural vibration . Here, the "Rockwell C scale hardness" means a value measured in accordance with JIS-Z2245 (2011).

First Embodiment

The golf club according to the first embodiment of the present invention shown in Figs. 1 and 2 is a putter. The golf club has a shaft (1) and a club head (2) provided at an end of the shaft (1).

<Shaft>

As the shaft 1, a known shaft can be used. A grip (not shown) gripped by a player (user) is attached to an end of the shaft 1 opposite to the club head 2.

As this shaft 1, any shaft for a golf club can be used. That is, the material, diameter, and length of the shaft 1 are not particularly limited.

<Club Head>

The club head 2 includes a head main body 3 and a plate-like face member 4 provided along the striking face of the head main body 3. As shown in Fig. The face member 4 is fixed to the head main body 3 only at a part of the upper edge surface and a part of the lower edge surface, more specifically at two positions of the upper edge surface and the lower edge surface.

The shape and size of the club head 2 are not particularly limited as long as they can be used as golf clubs. More specifically, for example, a golf club manufactured in accordance with regulations set by a group such as a Professional Golf Association (PGA) is preferable, but it is not necessarily required to be produced in accordance with these regulations, If yes, which golf club is acceptable.

<Head body>

The head main body 3 includes a cavity 5 in which a face member 4 is provided on the front side (on the side of the ball in the hitting direction, that is, on the side of the ball which blows when hitting). The cavity 5 is preferably formed to have a longer rectangular shape in the heel tauto direction (horizontal direction parallel to the striking surface) when viewed from the front face perpendicular to the striking face (when viewed from the front side in the front-rear direction) desirable. That is, it is preferable that the head body 3 is formed in a box shape whose front side is opened. In addition, the head main body 3 may be formed in a cylindrical shape or a frame shape which is opened not only on the front side but also on the rear side.

The head main body 3 includes a pair of screw holes 6 formed to extend through the upper wall portion of the cavity 5 in the vertical direction and a pair of screw holes 6 formed in the bottom wall portion of the cavity 5 to face the screw holes 6 And a pair of fixing pins (7) installed so as to protrude in the direction of the arrow. A set screw (locking screw) 8 is screwed into the screw hole 6, respectively.

The thickness of the head body 3 in the region where the face member 4 of the upper wall portion and the bottom wall portion of the cavity 5 fit is greater than the thickness of the head body 3, As shown in Fig. More specifically, the lower limit of the average thickness of the head body 3 in the region where the face member 4 of the upper wall portion and the bottom wall portion of the cavity 5 fit is preferably 2 mm, more preferably 3 mm to be. On the other hand, the upper limit of the average thickness of the head body 3 in the region where the face member 4 of the bottom wall portion and the top wall portion of the cavity 5 fit is preferably 8 mm, more preferably 6 mm. If the average thickness of the head body 3 in the region where the face member 4 of the bottom wall portion and the top wall portion of the cavity 5 are fitted is less than the lower limit described above, the strength may become insufficient. Conversely, when the average thickness of the head body 3 in the region where the face member 4 of the upper wall portion and the bottom wall portion of the cavity 5 are fitted exceeds the upper limit, the striking face can be unnecessarily small. It should be noted that the thicknesses of the head body 3 in the upper wall portion and the bottom wall portion of the cavity 5 may be different from each other. According to the golf club of the present invention, in particular, when the thickness of the head body 3 at the bottom wall portion of the cavity 5 exceeds the upper limit, the ball placed on the ground is struck in the vertical direction with the face member 4 It can be difficult.

The lower limit of the maximum length in the longitudinal direction of the head body 3 is preferably 2 cm, more preferably 3 cm. On the other hand, the upper limit of the maximum length in the longitudinal direction of the head body 3 is preferably 15 cm, more preferably 10 cm. If the maximum length of the head main body 3 in the front-rear direction is less than the above-mentioned lower limit, the strength of the head main body 3 may be insufficient or it may be difficult to fix the head main body 3 to the shaft 1. [ Conversely, when the maximum length of the head main body 3 in the longitudinal direction exceeds the upper limit, handling of the golf club may be difficult.

The material of the head main body 3 is not particularly limited, but a metal such as stainless steel having excellent strength and workability is preferably used.

The lower limit of the effective diameter of the fixing pin 7 is preferably 1 mm, more preferably 1.4 mm. On the other hand, the upper limit of the effective diameter of the fixing pin 7 is preferably 3 mm, more preferably 2.5 mm. When the effective diameter of the fixing pin 7 is less than the above lower limit, the strength is insufficient and may be deformed or broken when the user hits the ball. Conversely, when the effective diameter of the fixing pin 7 exceeds the upper limit, the fixing pin 7 can suppress the vibration of the face member 4. Here, the "effective diameter" means the diameter of the portion contacting the face member 4.

The lower limit of the outer diameter (nominal diameter) of the set screw 8 is preferably 1.2 mm, and more preferably 1.8 mm. On the other hand, the upper limit of the outer diameter of the set screw 8 is preferably 4 mm, more preferably 3 mm. When the outer diameter of the set screw 8 is less than the above lower limit, the strength becomes insufficient and the member may be deformed or broken when hit by the ball. Conversely, when the outer diameter of the set screw 8 exceeds the upper limit, the set screw 8 can suppress the vibration of the face member 4.

<Face absence>

The face member 4 is preferably formed in a rectangular shape that is longer in the hill-to-toe direction when viewed from the front. Further, it is preferable that the face member 4 has a symmetrical shape in the heel-toothed direction and the perpendicular direction, respectively. By forming the face member 4 symmetrically in the vertical direction and the horizontal direction, the vibration of the face member 4 becomes a standing wave, and the vibration of a specific wavelength becomes large, so that a relatively large sound can be generated.

The face member 4 substantially seals the opening of the cavity 5 and forms a gap between the peripheral walls (upper wall, lower wall and side wall) of the cavity 5 and the rear wall of the cavity 5 , And is held substantially perpendicular to the striking direction by the fixing pin (7) and the set screw (8). It is preferable that the front side surface of the face member 4 is located on the same plane as the front end surface of the peripheral wall of the head body 3 or is located forward from the front end surface.

The lower limit of the average width of the face member 4 in the vertical direction is preferably 8 mm, more preferably 10 mm. On the other hand, the upper limit of the average width of the face member 4 in the vertical direction is preferably 40 mm, more preferably 20 mm. When the average width of the face member 4 in the vertical direction is less than the lower limit, it may not be easy for the ball to fit the face member 4. [ Conversely, when the average width of the face member 4 in the vertical direction exceeds the upper limit, it may be difficult to fit the ball to the center of the face member 4 in the vertical direction.

The lower limit of the average width of the face member 4 in the hill-climbing direction is preferably 4 cm, more preferably 5 cm. On the other hand, the upper limit of the average width of the face member 4 in the heel tucking direction is preferably 8 cm, more preferably 7 cm. When the average width of the face member 4 in the heel tucking direction is less than the above lower limit, the sweet spot of the face member 4 may be small. Conversely, when the average width of the face member 4 in the heel tucking direction exceeds the upper limit, the width in the heel tucking direction of the club head may be excessively large.

The lower limit of the average gap between the face member 4 and the peripheral wall of the cavity 5 is preferably 0.5 mm, more preferably 1 mm. On the other hand, the upper limit of the average distance between the face member 4 and the peripheral wall of the cavity 5 is preferably 5 mm, more preferably 3 mm. When the average distance between the face member 4 and the peripheral wall of the cavity 5 is less than the lower limit described above, the air vibration at the back side of the face member 4 is hardly conducted to the outside, . Conversely, when the average distance between the face member 4 and the peripheral wall of the cavity 5 exceeds the upper limit, the striking face may be unnecessarily small.

The lower limit of the average interval in the front-rear direction between the face member 4 and the rear wall of the cavity 5 is preferably 3 mm, more preferably 5 mm. On the other hand, the upper limit of the average distance between the face member 4 and the rear wall of the cavity 5 is preferably 5 cm, more preferably 3 cm. The air layer between the face member 4 and the rear wall of the cavity 5 can suppress the vibration of the face member 4 when the average distance between the face member 4 and the rear wall of the cavity 5 is less than the lower limit described above . Conversely, if the average distance between the face member 4 and the rear wall of the cavity 5 exceeds the upper limit, the club head 2 may be excessively large.

The face member 4 is formed on the upper edge surface of the face member 4 in order to reliably fix the face member 4 to the head main body 3 and a pair of the set screws 8 An upper counter bore 9 and a pair of lower counter bores 10 formed on the lower edge surface of the face member 4 and to which the fixing pin 7 is engaged.

One of the upper counter bore 9 and the lower counter bore 10 has a concave portion in the shape of a round surface with a reduced sectional area such as a conical shape or a spherical shape and the upper counter bore 9 and the lower counter bore 10, It is preferable that the other of them has a groove shape in which the width of the V-groove shape or the like is monotonously decreased. Therefore, when one of the upper counter bore 9 and the lower counter bore 10 is formed in a groove shape, a dimensional error in the hill tuck direction along the striking face of the head body 3 and the face member 4 is absorbed .

The lower limit of the average width of the upper counter bore 9 and the lower counter bore 10 is preferably 1 mm, and more preferably 1.5 mm. On the other hand, the upper limit of the average width of the upper counter bore 9 and the lower counter bore 10 is preferably 5 mm, and more preferably 3 mm. When the average width of the upper counterbore 9 and the lower counterbore 10 is less than the lower limit, engagement with the set screw 8 or the fixing pin 7 may be insufficient. Conversely, when the average width of the upper counterbore 9 and the lower counterbore 10 exceeds the upper limit, the face member 4 can not be positioned correctly or it can interfere with the vibration of the face member 4 have.

The lower limit of the maximum depth of the upper counterbore 9 and the lower counterbore 10 is preferably 0.3 mm, more preferably 0.5 mm. On the other hand, the upper limit of the maximum depth of the upper counter bore 9 and the lower counter bore 10 is preferably 1.5 mm, more preferably 1 mm. When the maximum depth of the upper counter bore 9 and the lower counter bore 10 is less than the lower limit, engagement with the set screw 8 or the fixing pin 7 may be insufficient. Conversely, when the maximum depth of the upper counter bore 9 and the lower counter bore 10 exceeds the upper limit, the vibration of the face member 4 can be prevented.

The position of the upper counterbore 9 and the lower counterbore 10 in the heel tucking direction, that is, the fixed position of the face member 4, is located near the node of natural vibration when the face member 4 is freely supported . The structure for fixing the face member 4 does not hinder the vibration of the face member 4 by supporting the face member 4 in the vicinity of the node of the natural vibration when the face member 4 is freely supported. That is, by providing the set screw 8 and the fixing pin 7 at the node of the natural vibration, the vibration energy is not diffused to the head main body 3 through the set screw 8 and the fixing pin 7. Therefore, attenuation of the vibration of the face member 4 can be suppressed. Therefore, the face member 4 of the embodiment of the present invention makes the reverberation generated when the player hits the ball with the golf club longer, so that the player can easily identify the hit sound.

Further, by supporting the face member 4 in the vicinity of the node of the natural vibration when the face member 4 is freely supported, the center of the face member 4 as seen from the front corresponds to a vibration multiplication. The position corresponding to the vibration of the face member 4 can be easily obtained by the elasticity of the face member 4 so that the kinetic energy of the club head 2 can be accurately transmitted to the ball. The position corresponding to the vibration is also a position at which the face member 4 can vibrate most efficiently.

Therefore, when the ball is hit by the golf club, when the ball is hit by the sweet spot, the face member 4 vibrates at a larger amplitude, resulting in a louder sound having a longer reverberation time. Further, as the hit position of the ball deviates from the sweet spot, the vibration having a frequency component different from the resonance frequency of the natural vibration is likely to be generated at first. Therefore, according to the present golf club, it is possible to relatively easily determine whether or not the ball has hit the sweet spot, based on the tone of the hit sound, the sound pressure and the length of the reverberation.

It is preferable that the natural frequency at which the fixed position of the face member 4 is located at the node is the odd order vibration mode. In the odd order vibration mode, when the face member 4 is homogeneous and has a uniform thickness, the central portion of the face member 4 in the heel tucking direction corresponds to a vibration multiplication, that is, a sweet spot. Clubs can be used conveniently.

It is particularly preferable that the natural vibration in which the fixed position of the face member 4 is located at the node is the primary vibration mode. Among the vibration modes of each order, the primary vibration mode has the largest node interval, so that the greatest amplitude can be obtained for the striking energy. Therefore, by fixing the face member 4 to the head main body 3 at the node of the primary vibration mode, the sweet spots can be made larger, and a larger hit sound can be generated. More specifically, when the face member 4 is a homogeneous and uniformly rectangular rectangular plate, the nodes of the natural vibration are about 0.224 times the length of the face member 4 from both ends of the face member 4 .

The lower limit of the average thickness between the fixed positions of the face member 4 (the area along the line between the opposing upper counterbore 9 and lower counterbore 10) is preferably 1 mm, more preferably 1.5 mm to be. On the other hand, the upper limit of the average thickness between the fixing positions of the face member 4 is preferably 10 mm, and more preferably 8 mm. When the average thickness between the fixing positions of the face member 4 is less than the above lower limit, the strength of the face member 4 may be insufficient. Conversely, when the average thickness between the fixed positions of the face member 4 exceeds the upper limit, the natural frequency of vibration of the face member 4 (that is, the frequency of the hit sound) can be reduced, It can be difficult.

The thickness of the face member 4 may be entirely constant or may be partially different. For example, when the thickness of the face member 4 in the vicinity of both end portions in the heel tucking direction is made larger than the thickness of the center portion in the heel tucking direction, the mass of both ends in the heel tucking direction becomes larger, The node of the natural vibration of the face member 4 is closer to both ends in the hill tortoise direction than when the thickness of the face member 4 is constant. Therefore, the range of the amplitude of the natural vibration can be extended, so that the sweet spot of the golf club can be large.

The nodes of the natural vibration of the face member 4 can be moved by attaching weights in the vicinity of both ends in the heel taut direction of the face member 4. [ It is also preferable that the thickness (weight) of the face member 4 is not changed in the vertical direction. When the thickness of the face member 4 changes in the vertical direction, components of the natural vibration are generated in the vertical direction to form a traveling wave, so that the sound may be distorted or the sound pressure may be lowered.

As the material of the face member 4, steel having a comparatively large hardness is preferable, and steel subjected to the quenching treatment is more preferable. By forming the face member 4 with such a high hardness material, the natural frequency of the vibration of the face member 4 can be made relatively high, so that it becomes easy to hear the sound of the hit. The surface of the face member 4 may be subjected to a rust-proof treatment such as solid chromium plating.

The lower limit of the Rockwell C scale hardness (HRC) of the face member 4 is preferably 40, more preferably 50, and still more preferably 55. [ On the other hand, the upper limit of the Rockwell C scale hardness of the face member 4 is preferably 80, more preferably 75. When the Rockwell C scale hardness of the face member 4 is less than the lower limit described above, the natural frequency of vibration of the face member 4 (that is, the frequency of the hit sound) can be small and the vibration is easily attenuated, It can be difficult to hear. On the other hand, when the Rockwell C scale hardness of the face member 4 exceeds the upper limit, machining of the face member 4 may be difficult, so that the golf club may be unnecessarily expensive.

<Advantages>

As described above, according to the golf club of the embodiment of the present invention, since the face member 4 is fixed to the head main body 3 only at the upper edge face and a part (4 positions) of the lower edge face, ) Is easily vibrated, resulting in a relatively large sound with a long reverberation. In addition, when the ball is hit on the double of natural vibration corresponding to the sweet spot of the face member 4, the hit sound has less distortion and a larger sound pressure. Therefore, according to the golf club of the embodiment of the present invention, it is possible to relatively easily determine whether or not the ball hit the sweet spot, based on the sound of the hit.

[Second Embodiment]

A golf club according to another embodiment of the present invention shown in Figs. 3 and 4 includes a shaft 1 and a club head 2a provided at an end of the shaft 1. [

The shaft 1 of the golf club shown in Fig. 3 may be similar to the shaft 1 of the golf club shown in Fig.

<Club Head>

The club head 2a includes a head main body 3a and a plate-shaped face member 4a provided along the striking face of the head main body 3a. The face member 4a is fixed to the head body 3a only at two positions on the upper edge surface of the face member 4a. That is, the lower edge surface of the face member 4a is not fixed to the head main body 3a.

The configuration of the head main body 3a and the face member 4a of the golf club shown in Fig. 3 is the same as that of the head main body 3a of the golf club shown in Fig. 1 except for the configuration related to fixing the face member 4a to the head main body 3a 3 and the face member 4, respectively.

Two fixing protrusions 11 are provided on the face member 4a so as to protrude upward from the positions of two nodes of the natural vibration of the upper edge face of the face member 4a. The fixing protrusion 11 can be cut integrally with the face member 4a, for example, from a plate-shaped material. Alternatively, the fixing protrusion 11 may be fixed to the face member 4a by welding or the like.

The face member 4a is fixed so as to substantially seal the opening of the cavity 5 by attaching the fixing protrusion 11 to the front end surface of the upper wall of the cavity 5 of the head body 3a. The fixing protrusion 11 is preferably fitted to the fitting recess formed in the front end surface of the upper wall of the head main body 3a.

As a method for fixing the fixing protrusion 11 to the head main body 3a, for example, welding or the like can be used, but a method using the screw 12 can be preferably employed as shown in Fig. The fixing protrusion 11 may be provided with a fixing hole 13 into which the screw 12 is inserted. As shown in the figure, the fixing hole 13 preferably includes a counter bore into which the head of the screw 12 is fitted.

The width of the portion of the fixing protrusion 11 extending from the upper edge surface in the heel-toothed direction may be further shortened as shown in the drawing so that the vibration of the face member 4a is difficult to be restricted.

[Other Embodiments]

The above-described embodiments do not limit the configuration of the present invention. Therefore, it should be understood that omission, substitution and / or addition of constituent elements of each component in the above embodiments may be made based on the description and technical knowledge of the present specification, and thus all such modifications are to be construed as being within the scope of the present invention do.

The present invention may be applied to a golf club other than a putter, for example, a wood (e.g., a driver) and an iron (e.g., an approach wedge).

The shape of the face member according to the golf club of another embodiment of the present invention when viewed from the front is not limited to a rectangular shape and may be any shape such as a long oval shape, a semi-elliptical shape, or a triangular shape. However, in consideration of the diameter of the ball, the face member has a shape in which the lower edge of the face member extends linearly in the heel-toothed direction so that the club head does not contact the ground and the user can align the ball to the center of the face member Or a shape slightly convex downward.

The method of fixing the face member in the golf club according to the other embodiment of the present invention is not limited to the method according to the above-described embodiment, and any method can be adopted.

For example, the face member may be fixed to the head body using a pin penetrating from the head body to the upper edge surface of the face member. When the set screw is used, the lower side of the face member may be fixed with a set screw, or both the upper side and the lower side may be fixed with a set screw.

Further, even when the fixing protrusions are provided on the face member, fixing protrusions may be provided on the upper and lower sides so as to fix both the upper edge and the lower edge. In this case, the lower fixing protrusion can be simply fitted to the fitting concave portion of the head body without screwing. According to this configuration, the bottom wall of the head main body can be easily thinned.

In addition, the face member in the golf club of the embodiment of the present invention may be fixed to only one position of the upper edge face, a single position of the lower edge face, or each single position of the upper and lower edge faces with respect to the head body. The fixed position in the horizontal direction of the upper edge surface and the fixed position in the horizontal direction of the lower edge surface may be different. For example, the upper end of one of the two resonance points of the face member and the lower end of the other of the two resonance points of the face member may be fixed, while the lower end of one resonance point and the upper end of the other resonance point may not be fixed.

Further, according to the golf club of the embodiment of the present invention, the head body may include a through hole through which the sound can pass, on the peripheral wall or the rear wall of the cavity.

The golf club according to the present invention can be preferably used particularly as a putter.

1: shaft 2, 2a: club head
3, 3a: head body 4, 4a: face member
5: cavity 6: screw hole
7: Fixing pin 8: Set screw
9: upper counter bore 10: lower counter bore
11: Fixing projection 12: Screw
13: Fixing hole

Claims (5)

A golf club comprising a shaft and a club head mounted at an end of the shaft,
The club head includes a head main body and a plate-like face member provided along the striking surface of the head main body,
Wherein the face member is fixed to the head body only on a part of the upper edge surface of the face member, a part of the lower edge surface, or a part of both sides of the upper and lower edge surfaces. The method according to claim 1,
And the position of the face member is located near the node of the natural vibration when the face member freely supports. 3. The method according to claim 1 or 2,
And the Rockwell C scale hardness of the face member is 40 or more. 3. The method according to claim 1 or 2,
Wherein the face member is fixed to the head body by a set screw. 3. The method according to claim 1 or 2,
Wherein the face member is fixed to the head body at two positions of the upper edge surface of the face member and the lower edge surface.

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