JP2006223331A - Club head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a club head which is inexpensive and achieves a lower center of gravity while accomplishing an increase in the inertial moment. <P>SOLUTION: The club head has a wooden head body 20 fixed at the tip of the club shaft 1, a metallic sole 30 disposed on the bottom part of the head body 20 and weight parts 50 which are fixed on the sole 30 with a specific gravity larger than that of the metal for forming the sole 30. The sole 30 is provided with a through-hole 33 piercing it almost vertically and a bolt 52 having the head part engaged with the lower surface of the sole 30 is inserted into the through-hole 33 and the through-hole 33 is closed with the head part while a nut 55 is provided having a female thread part 54 to be screwed with the male thread part 53 of the bolt 52, sticking into the sole 30 and the bolt 52 and the nut 53 have the weight parts 50 formed on them. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to club heads such as park golf and ground golf (hereinafter referred to as park golf).

2. Description of the Related Art Conventionally, a club head such as a golf club is known in which a weight is provided in order to increase the moment of inertia (Patent Document 1).
JP 2004-65810 A (FIG. 6)

  However, in this prior art, the weight is provided in the head via the sole and the plate, so that not only the cost is increased, but the weight is positioned upward by an amount corresponding to the thickness of the sole or the plate. Therefore, the club head cannot have a low center of gravity.

  On the other hand, in park golf and ground golf, the ball is captured near the center of gravity by lowering the center of gravity for reasons such as the face height being higher than the ball diameter and not using the tee after the second shot. is important.

  Accordingly, an object of the present invention is to provide a club head that can increase the moment of inertia, is inexpensive, and can achieve a low center of gravity.

  In order to achieve the above object, the present invention provides a wooden head main body fixed to the tip of a club shaft, a metal sole disposed at the bottom of the head main body, and the sole fixed to the sole to form the sole. A club head having a weight portion having a specific gravity greater than that of the metal, wherein the sole is provided with a through-hole penetrating in a generally vertical direction, and a bolt having a head portion engaged with the lower surface of the sole The nut is inserted into the through-hole to close the through-hole by the head, the male screw portion of the bolt protrudes to the inside of the sole, and a nut having a female screw portion that is screwed into the male screw portion of the bolt is provided, Both bolts and nuts form the weight portion.

  According to the present invention, since the weight part having a large specific gravity penetrates the sole vertically, the weight part is arranged up to the lowest part of the sole, so that the center of gravity can be lowered as the moment of inertia increases.

  Further, since the nut is screwed into the bolt constituting the weight part, the structure of the weight part is simple, and therefore the cost can be reduced.

  In addition, since the weight portion is fixed to the sole, the weight portion is not screwed into the wooden head main body or the like, so that the durability of the wooden head main body is not deteriorated.

In the present invention, when a plurality of fastening members for fastening the sole are provided at the bottom of the head main body, the center of gravity of the weight portion is more than the center of gravity of one of the plurality of fastening members. Is preferably disposed at a position close to the outer peripheral edge of the sole.
Although it is possible to increase the moment of inertia and to lower the center of gravity by using the fastening member, the weight portion is easy to add weight freely because of the original function of the fastening member. Therefore, the moment of inertia is larger when the weight portion is disposed at a position near the outer peripheral edge of the sole than when the fastening member is disposed at a position near the outer peripheral edge of the sole.

In a preferred embodiment of the present invention, the nut has a hexagonal or more polygonal column or substantially cylindrical outer surface, and an accommodation space in which the nut is accommodated is formed in the head body. Adhesive is embedded.
In this embodiment, since the weight portion has an outer surface of a polygonal column or a substantially cylindrical shape, it is possible to reduce the gap between the head body and the weight portion by drilling a circular hole in the wooden head body. It is. In addition, by filling an adhesive between the head body and the weight portion, it is possible to prevent the wooden head from being cracked or chipped.

  In the present invention, in order to sufficiently exert the function as the weight portion, it is necessary that the nominal diameter of the male screw portion and the female screw portion is 3 mm or more and 20 mm or less and the outer diameter of the nut is 10 mm or more and 30 mm or less. It is.

  In a preferred embodiment of the present invention, the bolt head is not provided with an engaged portion capable of engaging a tool. Thereby, it can be prohibited that the user (user) replaces the bolt as a weight by himself / herself. Therefore, it is possible to prevent illegal acts such as remodeling in violation of the competition rules.

In a further preferred embodiment of the present invention, an engaged portion capable of engaging with a tool is formed on the tip surface opposite to the head portion of the bolt.
When trying to rotate the weight nut, a large tool such as a spanner is required and difficult to handle, but the bolt head is smaller than the nut and can be rotated with a small tool. Improved workability.

In another preferred embodiment of the present invention, the bolts and nuts are provided so that the weight on the toe side is increased rather than the heel side at the center of the figure projected on the plane of the head body.
Increasing the weight on the toe side not only increases the moment of inertia I _G about the center of gravity, but also significantly increases the moment of inertia I _S about the shaft.

In a preferred embodiment of the present invention, the weight of the club head is set to 300 g to 500 g, the weight portion is disposed on at least a part of the outer peripheral portion of the sole, and the weight around the vertical line passing through the center of gravity of the club head is set. The inertia moment I _G is set to 4,500 gcm ² or more.
If moment of inertia I _G around the center of gravity is large, the sweet area is increased.
If moment of inertia I _G around the vertical line passing through the center of gravity of the club head is less than 4,500Gcm ^2, heavy weight of the balls, because the contact time is short, less effect of the sweet area is increased.

In another preferred embodiment of the present invention, the weight of the club head is set to 300 g to 500 g, and the weight portion is disposed on at least a part on the toe side of the outer peripheral portion of the sole, the moment of inertia I _S is set to 4,800gcm ² or more.
When the moment of inertia I _S around the shaft is large, the rotational speed of the moment of the head striking the ball at the time of hitting is increased.
In the moment of inertia I _S is less than 4,800Gcm ² about the axis of the club shaft, the rotational speed of the head is increased, it acts in a direction opposite to the direction in which force during movement the center of gravity blow the rotational speed of the head The effect of the increase on the initial velocity of the ball is reduced.

The club head weight is more preferably 330 g to 450 g, and most preferably 350 g to 430 g.
Further, the moment of inertia I _G around the center of gravity is more preferably 4,600Gcm ² or more, 4,700Gcm ² or more is most preferred.
On the other hand, the moment of inertia I _S around the shaft, more preferably 5,000Gcm ² or more, 5,400Gcm ² or more is most preferred.

Further, the inertia moment ratio I _S / I _G obtained by dividing the inertia moment I _S around the shaft by the inertia moment I _G around the center of gravity is preferably 1.1 times or more, and more preferably 1.2 times or more.
Thus, to obtain a large moment of inertia ratio is realized by arranging the weight portion at a position close to the toe.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, a club head 2 is fixed to the tip of a club shaft 1 for park golf.

FIG. 2 is an exploded perspective view of the club head 2.
As shown in FIG. 2, the club head 2 includes a wooden head main body 20 fixed to the tip of the club shaft 1, a metal sole 30 fixed to the bottom B of the head main body 20, and the head main body 20. A face 40 fixed to the front surface 20f is provided. The player swings the club shown in FIG. 1, swings the club head 2 in the front-rear direction X, and hits the ball with the front surface 40 f of the face 40.

First, the relationship between the head body 20 and the sole 30 will be described.
The sole 30 shown in FIG. 3 is formed in a bowl shape having a depth of, for example, 10 mm or more, and covers almost the entire bottom portion B of the head body 20. A plurality of bosses 31 projecting upward are integrally formed on the upper surface of the sole 30. Each boss 31 is provided at a position away from the center of gravity G (FIG. 8) of the club head 2. Each boss 31 may be integrally provided on the side surface around the sole 30.

  5 and 6 are exploded perspective views of the club head 2 as seen from the bottom surface side. As shown in FIG. 5, an engagement hole 21 is formed at a position corresponding to each boss 31 (FIG. 2) in the bottom B of the head body 20. As shown in FIG.

FIG. 7A is a longitudinal sectional view in the vicinity of the boss 31.
As shown in FIG. 7A, a boss 31 is inserted into the engagement hole 21, and an adhesive 35 is filled between the engagement hole 21 and the boss 31. Therefore, the inner side surface 21f of the engagement hole 21 and the outer side surface 31f of the boss 31 are firmly engaged with each other in the front-rear direction X in which the head 2 is swung through the adhesive 35 without any gap.

  As shown in FIG. 3, each boss 31 is formed with a female screw 32. The female screw 32 opens forward and penetrates the boss 31 in the front-rear direction X. On the other hand, a screw insertion hole 22 for inserting a fastening bolt 24 (male screw member) to be screwed into the female screw 32 of FIG. The metal fastening bolt 24 is screwed into the female screw 32 from the screw insertion hole 22, whereby the sole 30 is fastened to the bottom of the head body 20.

  The screw insertion hole 22 opens at the front surface 20f of the head main body 20, but the rear of the club head 2 is covered by the sole 30 and the head main body 20.

  Here, the screw insertion hole 22 is drilled backward from the front surface 20f of the head body 20, and the fastening bolt 24 is between the front surface 20f of the head body 20 and the rear female screw 32. The head body 20 is fastened to the sole 30. Therefore, it is not necessary to form the screw insertion hole 22 for inserting the fastening bolt 24 in the wooden head main body 20 in the vertical direction, and the fastening bolt 24 in the direction of the force acting between the sole 30 and the head main body 20 at the time of impact. Since the axial force coincides with the working direction, the durability of the head body 20 is improved.

  Since the front surface 20f of the head main body 20 covered with the face 40 in FIG. 6B is processed flat, the operation of drilling the screw insertion hole 22 in the head main body 20 is performed above the head main body 20. Compared to drilling holes from below or from behind, it is significantly easier and more reliable.

  From this point of view, the axis of the screw insertion hole 22 or the fastening bolt 24 may be inclined to about 30 ° (preferably to about 15 °) with respect to the axis L perpendicular to the front surface 40f of the face 40. That is, the screw insertion hole 22 may be formed slightly obliquely rearward, and in this case, the screw insertion hole 22 in FIG. 3 opens obliquely forward.

  In FIG. 2, the fastening bolts 24 are disposed below a horizontal line Lh passing through the center Fo of the face 40. Therefore, the center of gravity of the club head 2 can be lowered by the heavy fastening bolts 24. The center Fo of the face 40 refers to the center (centroid) of the figure formed by the outline of the face 40.

  From this point of view, it is most preferable to arrange all the fastening bolts 24 below the horizontal line Lh. However, the lowering of the center of gravity is because the weight of the fastening bolt 24 arranged below the upper and lower center Fo of the face 40 is higher than the upper and lower center Fo or the center Fo of the face 40. If it is heavier than the weight of the fastening bolt, it can be achieved to some extent.

In FIG. 8, a point G is the actual center of gravity of the club head 2, and a point O is the center (centroid) of the figure obtained by projecting the club head 2 on a plane. By increasing the moment of inertia I _G around the vertical line V passing through the center of gravity G of the club head of FIG. 7 (b), the increase in the so-called sweet area can be achieved.

On the other hand, by increasing the moment of inertia I _S about the axis S of the club shaft 1 in FIG. 1, the speed of the head is increased relative to the ball when hit. That is, the club head 2 about the axis S of the shaft 1 in Figure 1 when hit is to rotate, the movement of the center of gravity to the toe side T, the moment of inertia I _S is increased, the head relative to the ball when hit Speed increases.

  Note that the distal end portion 11 of the club shaft 1 is firmly fitted in the shaft insertion hole 29 of the head main body 20 of FIG.

In the present embodiment, the head portion 24 h in which the male screw 24 s in the male screw member 24 of FIG. 7A is not formed is accommodated in the insertion hole 22 and provided near the back surface 40 b of the face 40. Thus, because the weight of the heavy head 24h is located near the outer periphery of the head 2, the obtained aims to increase the moment of inertia I _G, the adhesive 25 is reduced to be filled in the insertion hole 22.

  An adhesive 25 is provided in the gap between the head 24 h and the back surface 40 b of the face 40.

In this embodiment, the number of bosses 31 provided on the toe side T is larger than the number of bosses 31 provided on the heel side H of the graphic center O of the club head 2 in FIG. The total weight of the fastening bolts 24 ₃ provided on the toe side T is heavier than the total weight of the fastening bolts 24 ₁ and 24 ₂ provided on the heel side H of the figure center O. Thus, the center of gravity G of the head can be moved to the toe side T by arranging the boss 31 and the fastening bolt 24 so as to be offset from the toe side T.

Next, an example of a structure for further increasing the inertia moments I _G and I _S will be described.
For example, the specific gravity of the metal constituting the fastening bolt 24 is set to be larger than the specific gravity of the metal constituting the sole 30 in FIG. 8, or the outer peripheral edge 30e of the sole 30 is located more than the position where the boss 31 is provided. The inertia moments I _G and I _S can be increased by disposing the weight portion 50 made of a metal having a specific gravity larger than that of the sole 30 at a position close to the toe side T. In particular, by disposing one or more weight portions 50 on the toe side T in the vicinity of the curved outer peripheral edge 30e of the sole 30, the inertia moments I _G and I _S can be increased, and further, the curved outer peripheral edge 30e. By disposing a plurality of weight portions 50 on the toe side T in the vicinity of, the inertia moments I _G and I _S are remarkably increased.

  As the metal constituting the sole 30, an aluminum alloy (for example, an aluminum casting) can be used. On the other hand, as the metal constituting the fastening bolt 24 and the weight part 50, brass (alloy of copper and zinc, So-called brass) can be used. As the sole 30 and the fastening bolt 24, other metals (for example, tungsten, titanium alloy, magnesium alloy, copper alloy, stainless steel, steel, etc.) may be used.

Next, an example of the structure of the weight part 50, which is a main part of the present invention, will be described.
In FIG. 8, the weight portion 50 is disposed at a position so as to be sandwiched between the outer peripheral edge 30 e of the sole 30 and the boss 31.
3 is provided with a plurality of through holes 33 penetrating substantially vertically. As shown in FIG. 7B, in the through hole 33, a weight bolt 52 having a head 51 that engages with the lower surface of the sole 30 is inserted into the through hole 33 to close the through hole 33. . The male screw portion 53 of the weight bolt 52 projects into the space inside the sole 30.
A weight nut 55 having a female threaded portion 54 is screwed into the male threaded portion 53 of the weight bolt 52. The weight bolt 52 and the weight nut 55 form the weight portion 50.
In addition, between each bolt nut 52,55 etc., it joins with the well-known adhesive agent (Loctite (trademark)) which prevents the looseness of a screw | thread.

  The weight nut 55 shown in FIG. 4B preferably has a regular hexagonal or more polygonal column or substantially cylindrical outer surface. As shown in FIG. 6A, an accommodation space S in which the weight nut 55 is accommodated is formed in the head body 20. An adhesive 56 is embedded in the accommodation space S of the head main body 20 in FIG. Thereby, the strength reduction of the wooden head main body 20 can be prevented.

The head 51 of the weight bolt 52 in FIG. 6B is not provided with an engaged portion capable of engaging a tool, while the tip of FIG. 4A opposite to the head 51 is provided. An engaged portion (for example, a groove) 57 that can engage the tool is provided on the surface. By rotating the engaged portion 57 with a tool, the reliability of fastening the weight bolt 52 and the nut 55 is improved.
A plurality of sets of the weight bolts 52 and nuts 55 are provided. Further, as shown in FIG. 6B, the head 51 of the weight bolt 52 may be provided with a design such as a recess or a print in order to improve the aesthetic appearance.

9A to 9D show modified examples of the weight portion 50. FIG.
As shown in these drawings, the sole 30 has a first screw portion 37 for fixing the weight portion 50, and a fixing portion 38 protruding upward from the sole 30 is integrally formed. Has been. The weight portion 50 has a second screw portion 58 that is screwed into the first screw portion 37.
An adhesive is filled between the fixed portion 38 and / or the weight portion 50 and the head main body 20 (FIG. 7B).

  9 (a), 9 (b), and 9 (d), torque adding portions 57 and 57A for applying a rotational force to the weight portion 50 when the weight portion 50 is attached to the sole 30 are weight portions. 50 is provided in a space inside the sole 30. Thereby, the weight part 50 cannot be removed from the outside of the sole 30. 9 (a) and 9 (b) is formed with a groove, while the torque application portion 57A in FIG. 9 (d) is a knurling process or a process with which a spanner is engaged. Also good.

  As shown in FIG. 9A, the torque adding portion 57 is provided in a space inside the sole 30 in the weight portion 50 exposed toward the inside of the sole 30, and the sole 30 is The first screw portion 37 is not opened, and the weight portion 50 can be screwed only from the inside of the sole 30. Thereby, the replacement of the weight part 50 by the user can be prevented, and intrusion of water or the like can be prevented.

  In FIG. 9C, the first screw portion 37 is provided in a hole facing the outside of the sole 30, and the weight portion 50 is screwed from the outside of the sole 30.

As described above, the preferred embodiments have been described with reference to the drawings. However, those skilled in the art will readily understand various changes and modifications within the obvious scope by looking at the present specification.
For example, the axis of the fastening member may be set in the vertical direction, or may be stopped with a male screw or the like from the lower surface of the sole.
Moreover, it is not necessary to provide a fastening member.
Further, the moment of inertia may be increased by providing a weight portion integrally with the sole and using the same kind of metal as the sole.
Furthermore, a cross-shaped groove or the like may be formed as the engaged portion.
Accordingly, such changes and modifications are to be construed as within the scope of the invention as defined by the claims.

  The present invention can be applied to ground golf and golf sports in addition to park golf. In park golf, the minimum shaft diameter is set to 14 mm or more (preferably 16 mm or more), while in ground golf, the club shaft is made of wood. Therefore, since these club golf club shafts have higher bending rigidity than ordinary golf club shafts, they do not bend as much when hit.

It is the front view and side view of the club for park golf which have the club head concerning one Example of this invention. It is a disassembled perspective view of the club head. It is a disassembled perspective view which shows a head main body and a sole. It is a perspective view which shows the state in which a weight part is attached to a head main body. It is the perspective view which looked at the sole and the head main body from the bottom. (A) is a perspective view of the head main body which shows arrangement | positioning of a male screw member and a weight part, (b) is a disassembled perspective view of the club head seen from the bottom face side. (A) is a longitudinal cross-sectional view which shows the fastening structure of a sole and a head main body, (b) is a longitudinal cross-sectional view which shows the attachment state of the weight part with respect to a sole. It is a top view of the sole which shows arrangement | positioning of a male screw member, a boss | hub, and a weight part. It is sectional drawing which shows the modification of a weight part.

Explanation of symbols

1: Club shaft 2: Club head 20: Head body 24: Fastening bolt (fastening member)
30: Sole 40: Face 50: weight 52: weight Bolt 53: male screw part 54: internal thread portion 55: mass nut 57: the engaged portion H: heel T: toe side I _S: moment of inertia I _G: Moment of inertia G: Center of gravity V: Vertical line

Claims (25)

A wooden head main body fixed to the tip of the club shaft, a metal sole disposed at the bottom of the head main body, and a weight portion having a specific gravity larger than that of the metal fixed to the sole and forming the sole. A club head,
The sole is provided with a through hole penetrating in a generally vertical direction,
A bolt having a head that engages with the lower surface of the sole is inserted into the through hole to close the through hole with the head, and a male screw portion of the bolt projects to the inside of the sole,
A nut having a female thread portion that is screwed into the male thread portion of the bolt is provided,
A club head in which both the bolt and the nut form the weight portion.   2. The plurality of fastening members for fastening the sole to the bottom of the head main body according to claim 1, wherein the center of gravity of the weight portion is more than the center of gravity of one of the plurality of fastening members. A club head located near the outer periphery of the sole. The nut according to claim 1, wherein the nut has a regular hexagonal or more polygonal column or substantially cylindrical outer surface,
An accommodation space for accommodating the nut is formed in the head body,
A club head in which an adhesive is embedded in a housing space of the head body.   2. The club head according to claim 1, wherein a nominal diameter of the male screw portion and the female screw portion is 3 mm or more and 20 mm or less, and an outer diameter of the nut is 10 mm or more and 30 mm or less.   2. The club head according to claim 1, wherein an engaged portion capable of engaging with a tool is not provided on a head of the bolt.   5. The club head according to claim 4, wherein an engaged portion capable of engaging a tool is provided on a tip surface opposite to the head of the bolt.   2. The club head according to claim 1, wherein a plurality of sets of the bolt and nut are provided.   8. The club head according to claim 1, wherein the bolt and the nut are provided so that a weight on a toe side is increased rather than a heel side at a center of a figure obtained by projecting the head main body on a plane. 9. The vertical line passing through the center of gravity of the club head according to any one of claims 1 to 8, wherein the weight of the club head is set to 300 g to 500 g, the weight portion is disposed on at least a part of the outer peripheral portion of the sole. club head moment of inertia I _G around is set to 4,500gcm ² or more. 9. The club shaft according to claim 1, wherein the weight of the club head is set to 300 g to 500 g, the weight portion is disposed on at least a part on the toe side of the outer peripheral portion of the sole, and the axis of the club shaft is A club head in which the moment of inertia I _S around is set to 4,800 gcm ² or more. 9. The vertical line passing through the center of gravity of the club head according to any one of claims 1 to 8, wherein the weight of the club head is set to 300 g to 500 g, the weight portion is disposed on at least a part of the outer peripheral portion of the sole. moment of inertia I _G around is set to 4,500Gcm ² or more, and the club head moment of inertia I _S about the axis of the club shaft is set to 4,800Gcm ² or more. The club head comprises a wooden head main body fixed to the tip of the club shaft, a metal sole disposed at the bottom of the head main body, and a weight portion provided on the sole, and the weight of the club head is 300 g to 500 g. A club golf club head set to ## EQU2 ## where the weight portion is disposed on at least a part of the outer periphery of the sole, and an inertia moment I _G around a vertical line passing through the center of gravity of the club head is 4, Club head set to 500gcm ² or more. The club head comprises a wooden head main body fixed to the tip of the club shaft, a metal sole disposed at the bottom of the head main body, and a weight portion provided on the sole, and the weight of the club head is 300 g to 500 g. a club head for park golf set in, the weight portion is disposed on at least a portion of the toe side of the outer peripheral portion of the sole, the inertia moment I _S about the axis of the club shaft 4,800gcm Club head set to ² or higher. The club head comprises a wooden head main body fixed to the tip of the club shaft, a metal sole disposed at the bottom of the head main body, and a weight portion provided on the sole, and the weight of the club head is 300 g to 500 g. A club golf club head set to ## EQU2 ## where the weight portion is disposed on at least a part of the outer periphery of the sole, and an inertia moment I _G around a vertical line passing through the center of gravity of the club head is 4, It is set to 500Gcm ² or more, and the club head moment of inertia I _S about the axis of the club shaft is set to 4,800Gcm ² or more.   The club head according to any one of claims 12 to 14, wherein a specific gravity of a metal constituting the weight portion is larger than a specific gravity of a metal constituting the sole.   16. The club head according to claim 12, wherein the weight portion is screwed and fixed to the sole. A wooden head main body fixed to the tip of the club shaft, a metal sole disposed at the bottom of the head main body, and a weight portion having a specific gravity larger than that of the metal fixed to the sole and forming the sole. A club head,
A plurality of fastening members for fastening the sole are provided at the bottom of the head main body, and the center of gravity of the weight portion is located on the outer peripheral edge of the sole than the center of gravity of one of the plurality of fastening members. The club head is located in a close position. A wooden head main body fixed to the tip of the club shaft, a metal sole disposed at the bottom of the head main body, and a weight portion having a specific gravity larger than that of the metal fixed to the sole and forming the sole. A club head,
The sole has a first screw portion for fixing the weight portion, and a fixing portion protruding upward from the sole is integrally formed,
The weight portion has a second screw portion that is screwed into the first screw portion,
The fixed portion and / or the weight portion protruding upward from the bottom surface of the sole is accommodated in an accommodating space formed in the head body,
A club head in which an adhesive is filled between the fixed portion and / or the weight portion and the head body.   In Claim 18, when attaching the weight part to the sole, a torque addition part for applying a rotational force to the weight part is provided inside the sole in the weight part, whereby the weight part is provided on the sole. Club head provided so that it cannot be removed from the outside.   The first screw portion according to claim 18, wherein the first screw portion is provided on the inner side of the sole in a fixing portion that protrudes toward the inner side of the sole, and the sole is not opened in the first screw portion. A club head in which the weight portion can be screwed only from the inside of the sole.   19. The club head according to claim 18, wherein the first screw portion is provided in a hole portion facing the outside of the sole, and the weight portion is screwed from the outside of the sole. 23. The club head for park golf according to claim 17, wherein the weight of the club head is set to 300 g to 500 g, and the weight portion is disposed on at least a part of an outer peripheral portion of the sole. Te, club head moment of inertia I _G around the vertical line passing through the center of gravity of the club head is set to 4,500Gcm ² or more. 24. The club head for park golf according to claim 17, wherein the weight of the club head is set to 300 g to 500 g, and the weight portion is at least a part on the toe side of the outer peripheral portion of the sole. are arranged, the club head moment of inertia I _S about the axis of the club shaft is set to 4,800Gcm ² or more. 23. The club head for park golf according to claim 17, wherein the weight of the club head is set to 300 g to 500 g, and the weight portion is disposed on at least a part of an outer peripheral portion of the sole. The inertia moment I _G around the vertical line passing through the center of gravity of the club head is set to 4,500 gcm ² or more, and the inertia moment I _S around the axis of the club shaft is set to 4,800 gcm ² or more. Club head. In any one of claims 1 to 24, by the weight portion is disposed offset to the toe side, the moment of inertia I _S about the axis of the club shaft, the inertia around the vertical line passing through the center of gravity club head, which is set to be equal to or greater than 1.1 times the moment I _G.

Images