Gold club head

Abstract

To provide a golf club head which can be increased in moment of inertia such as right and left MOI while materializing a low position of the center of gravity of the golf club head.SOLUTION: A golf club head 1 is provided, having a hollow portion therein. In a reference state, the golf club head 1 includes: a main body including a face portion, a crown portion, and a sole portion 4; and a weight object 20 fixed to the main body. The sole portion 20 includes a toe side region 4A, a heel side region 4B, and a center region 4C between the toe side region 4A and the heel side region 4B. The center region 4C comprises a bulged portion 7 bulging downward of the head from outer surfaces of each of the toe side region and the heel side region and bulging in a head front and rear direction. The bulged portion 7 includes a bottom surface 71 facing downward of the head, and a rear end surface 72 extending upward from the bottom surface 71 and facing rearward of the head. The rear end surface 72 is formed with a recessed portion 8. The weight object 20 is fixed to the recessed portion 8, and the weight object 20 is located at a position lower than the crown portion 3 and located at a position upper than the bottom surface 71 of the bulged portion 7.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a golf club head.

Background Art

[0002] Patent Document 1 below discloses a golf club head in which a weight is provided on the sole portion. In this golf club head, a holding portion for holding the weight is provided on the sole portion. The weight includes a lower surface facing the bottom surface side of the head and a first side surface extending upward from the first side portion of the lower surface to the head. The lower surface of the weight is exposed at the bottom surface of the head, and the first side surface of the weight is exposed on the sole contour line side.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Disclosure of the Invention

Problems to be Solved by the Invention

[0004] The above-described golf club head is expected to have an effect of being able to provide the head center of gravity at various positions on the sole contour line side while achieving a lower center of gravity. However, there was room for further improvement in increasing the left-right MOI, which is the moment of inertia around the vertical axis passing through the head center of gravity, in the above-described golf club head.

[0005] The present invention has been devised in view of the above problems, and the main object thereof is to provide a golf club head that can increase the moment of inertia such as the left-right MOI while achieving a lower center of gravity.

Means for Solving the Problems

[0006] The present invention relates to a golf club head having a hollow portion inside, and includes a head body having a face portion, a crown portion, and a sole portion in a reference state placed on a horizontal plane with a specified lie angle and loft angle, and a weight fixed to the head body. The sole portion includes a toe side region, a heel side region, and a center region between the toe side region and the heel side region. The center region is provided with a bulging portion that bulges downward from the outer surfaces of the toe side region and the heel side region and extends in the front-rear direction of the head. The bulging portion includes a bottom surface facing downward and a rear end surface extending upward from the bottom surface and facing the rear of the head. A recess is formed in the rear end surface, and the weight is fixed to the recess. The weight is located below the crown portion and above the bottom surface of the bulging portion.

Advantages of the Invention

[0007] By adopting the above configuration, the golf club head of the present invention can increase the moment of inertia such as the left and right MOI while achieving a lower center of gravity.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Mode for Carrying Out the Invention

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The drawings are for helping the understanding of the present invention, and may include exaggerated expressions or expressions different from the dimensional ratios of actual structures. Also, when there are a plurality of embodiments, the same or common elements are denoted by the same reference numerals throughout the specification, and redundant descriptions are omitted. Further, the specific configurations shown in the embodiments and the drawings are for understanding the content of the present invention, and the present invention is not limited to the specific configurations shown.

[0010] FIGS. 1 to 6 are a plan view, a front view seen from the face portion side, a side view seen from the toe side, a rear view seen from the rear, a bottom view, and a perspective view of the golf club head (hereinafter sometimes simply referred to as "head") 1 of the present embodiment in a reference state. In FIGS. 1 to 6, the head 1 is placed in the reference state.

[0011] [Reference State of Head] The reference state of the head 1 is a state in which the head 1 is placed with its loft angle α (shown in FIG. 3) and lie angle (shown in FIG. 2) with respect to the horizontal plane HP. In the reference state, as shown in FIG. 1, the center line CL of the shaft of the head 1 is arranged in an arbitrary vertical plane VP. In this specification, the horizontal direction along the vertical plane VP is defined as the toe - heel direction of the head 1, and the horizontal direction orthogonal to the vertical plane VP is defined as the head front - rear direction. Also, in the head 1, the face portion 2 side is conventionally described as the "front side" or "front", and the opposite side is described as the "rear side" or "rear". Also, in this specification, the direction orthogonal to the horizontal plane HP is defined as the head up - down direction. Unless otherwise specified, the head 1 is assumed to be in the reference state. The head 1 also defines a toe T and a heel H.

[0012] [Basic Configuration of the Head] In FIGS. 1 to 6, the head 1 of the present embodiment has a hollow portion i (see FIG. 8) inside and is configured as, for example, a typical wood type. The wood - type head 1 includes a fairway wood in addition to a driver (#1). Also, the head 1 of the present embodiment may be configured as a hybrid type or an iron type as long as it has a hollow portion inside.

[0013] The head 1 of the present embodiment includes a head body 10 and a weight 20 fixed to the head body 10.

[0014] The head body 10 includes, for example, a face portion 2, a crown portion 3, and a sole portion 4, and these define the hollow portion i inside the head. The head body 10 may be made of, for example, various metal materials. As the metal material, for example, various ones such as titanium, titanium alloy, stainless steel, aluminum alloy, etc. may be adopted. The head body 10 of the present embodiment is formed of, for example, a titanium alloy. A part of the head body 10 may be made of a fiber - reinforced resin.

[0015] The front surface of the face portion 2 is configured as a face 2a for hitting a ball. The face 2a may be configured as a three-dimensional curved surface that smoothly protrudes toward the outside of the head, for example. The face 2a is provided with a plurality of grooves extending in the toe-heel direction, called face lines for example, but these are omitted in the drawings of the present embodiment.

[0016] The face 2a is defined as a region surrounded by its peripheral edge E. In this specification, the peripheral edge E of the face 2a is defined as follows. First, as shown in FIG. 11(A), each cross-section s1, s2, s3... including the normal line N connecting the head center of gravity G and the sweet spot SS is specified. The sweet spot SS is the point where the normal line N drawn from the head center of gravity G to the face 2a intersects the face 2a.

[0017] Next, as shown in FIG. 11(B), in each of the cross-sections s1, s2, s3..., the position Pe where the radius of curvature r of the contour line Lf on the outer surface side of the head becomes 200 mm for the first time from the sweet spot SS side toward the outside of the face is obtained, and the connection of these positions Pe is defined as the peripheral edge E of the face 2a. Also, in this specification, the "radius of curvature" of an arbitrary point on a certain curve is obtained as the radius of a single circle passing through three points: that point, a point on the curve separated by 1 mm on one side of that point, and a point on the curve separated by 1 mm on the other side of that point. These "1 mm" are the path distances along the curve.

[0018] The crown portion 3 is an upper wall portion that continues to the face portion 2 and constitutes the upper surface of the head. Specifically, in the plan view of the head in FIG. 1, the crown portion 3 is the portion visible from the outside excluding the face 2a. As shown in FIG. 1, a neck portion 5 may be provided on the heel H side of the crown portion 3, for example. The neck portion 5 has a shaft insertion hole 5a so that a shaft (not shown) can be fixed. The axis center line of the shaft insertion hole 5a is used when specifying the shaft axis center line CL from the head 1 alone.

[0019] [Configuration of sole portion] FIG. 7 is a perspective view of the head 1 as viewed from the sole part 4 side. As shown in FIGS. 5 and 7, the sole part 4 includes a toe-side region 4A including the toe T, a heel-side region 4B including the heel H, and a center region 4C between the toe-side region 4A and the heel-side region 4B.

[0020] The center region 4C is provided with a bulging portion 7 that bulges downward from the outer surfaces of the toe-side region 4A and the heel-side region 4B under the head and extends in the head front-rear direction.

[0021] As shown in FIGS. 3, 5, and 7, the bulging portion 7 of the present embodiment includes a bottom surface 71 facing downward (i.e., facing the horizontal plane HP) under the head, and a rear end surface 72 that extends upward (crown portion 3) from the rear end of the head of the bottom surface 71 and faces the rear of the head. As particularly well shown in FIG. 5, the bulging portion 7 also includes a toe-side side surface 73 connecting the outer surface of the toe-side region 4A and the bottom surface 71, and a heel-side side surface 74 connecting the outer surface of the heel-side region 4B and the bottom surface 71. Thus, the bulging portion 7 of the present embodiment is configured to bulge locally downward in the center region 4C of the sole part 4.

[0022] As well shown in FIG. 5, in a view of the bottom surface of the head, the bottom surface 71 of the bulging portion 7 is located on the face normal FN passing through the face center FC (described later). Also, the bottom surface 71 of the bulging portion 7 continuously decreases in width W in the toe-heel direction toward the rear of the head. On the other hand, as shown in FIG. 3, the bulging portion 7 continuously increases in the bulging height h downward under the head toward the rear of the head. Although not particularly limited, the width W of the bulging portion 7 in the toe-heel direction is, for example, in the range of 20 to 50 mm, and the maximum bulging height h of the bulging portion 7 is, for example, 3 mm or more.

[0023] FIG. 8 is a partial cross-sectional view taken along line VIII-VIII of FIG. 1, FIG. 9 is a cross-sectional view taken along line IX-IX of FIG. 1, and FIG. 10 is an exploded perspective view of the head 1. As well represented in FIG. 10, a recess 8 is formed in the rear end surface 72 of the bulging portion 7. The recess 8 is a space recessed toward the hollow portion side of the head 1. The recess 8 of the present embodiment is formed so as to open at the rear end surface 72 without protruding onto either the outer surface of the crown portion 3 or the outer surface of the bottom surface 71 of the bulging portion 7.

[0024] A weight 20 is fixed to the recess 8. The weight 20 is made of, for example, a material having a specific gravity greater than that of the head body 10. As the weight 20, for example, a high specific gravity metal material is desirable. Although not particularly limited, as such a metal material, for example, an alloy containing W is desirable, and in particular, an alloy composed of W containing Ni and / or Fe is preferably used. The specific gravity of the weight 20 is, for example, 7 or more, preferably 8 or more, and more preferably in the range of 10 to 15.

[0025] As shown in FIG. 8, the weight 20 is located below the crown portion 3 and above the bottom surface 71 of the bulging portion 7.

[0026] [Advantages of the Present Embodiment] In order to further increase the moment of inertia such as the left and right MOI while achieving a lower center of gravity, it is important to distribute more weight at a lower position and on the outer peripheral side of the head. In the head 1 of the present embodiment, a bulging portion 7 is formed in the center region 4C in the toe-heel direction of the sole portion. Such a bulging portion 7 intensively distributes the weight of the center region 4C below the sole portion. On the other hand, the toe side region 4A and the heel side region 4B of the sole portion 4 are recessed relatively upward (toward the crown portion side) with respect to the bulging portion 7. Such a sole structure helps to create a volume margin with respect to the upper limit value of the head volume in the golf rules. The obtained volume margin enables further enlargement of the bulging portion 7 or further extension of the bulging portion 7 toward the rear of the head, which contributes to a lower center of gravity and a high left and right MOI.

[0027] On the rear end face 72 of the bulge portion 7, a recess 8 is formed, and a heavy object 20 is fixed to this recess 8. Further, the heavy object 20 is located below the crown portion 3 and above the bottom surface 71 of the bulge portion 7. With such a configuration, the weight of the heavy object 20 is distributed at a lower position and on the rear side of the head. This aims to lower the center of gravity of the head 1 while further increasing the moment of inertia (lateral MOI).

[0028] Generally, the bottom surface 71 of the bulge portion 7 tends to come into contact with the ground during the swing. However, in the head 1 of the present embodiment, the heavy object 20 is located above the bottom surface 71 of the bulge portion 7, and thus is not exposed on the bottom surface 71. Therefore, the head 1 of the present embodiment can solve problems such as damage, detachment, and loosening of the heavy object 20 over a long period of time.

[0029] Hereinafter, more preferred embodiments of the present invention will be described.

[0030] As shown in FIG. 1, in order to further increase the lateral MOI of the head 1, in a plan view of the head, it is desirable that the center of gravity 20G of the heavy object 20 is located between the first virtual straight line S1 and the second virtual straight line S2. Here, the first virtual straight line S1 is a straight line that passes through the face center FC and extends rearward of the head with an angle of 15 degrees toward the toe T side with respect to the face normal FN, and the second virtual straight line S2 is a straight line that passes through the face center FC and extends rearward of the head with an angle of 15 degrees toward the heel H side with respect to the face normal FN. In the structure of a typical wood-type golf club head, on the rear side of the head and in the range between the first virtual straight line S1 and the second virtual straight line S2, it can be said that the position is farther from the head center of gravity G. Therefore, by positioning the center of gravity 20G of the heavy object 20 in such a range, the weight of the heavy object 20 can be distributed at a position farther from the head center of gravity G, and thus the moment of inertia such as the lateral MOI can be further increased.

[0031] In this specification, the face center FC means the center point on the face 2a. The face center FC is a preferable striking position where a golfer attempts to strike the ball. The face center FC is determined as follows. First, in the vertical direction and the toe-heel direction of the head 1, an arbitrary point P near the approximate center of the face 2a is selected. Next, a plane is determined that passes through this point P, extends along the normal direction of the face 2a at the point P, and is parallel to the toe-heel direction. The intersection line between this plane and the face 2a is drawn, and the midpoint Px is determined. Next, a plane is determined that passes through this midpoint Px, extends along the normal direction of the face 2a at the midpoint Px, and is parallel to the vertical direction. The intersection line between this plane and the face 2a is drawn, and the midpoint Py is determined. Next, a plane is determined that passes through this midpoint Py, extends along the normal direction of the face 2a at the point Py, and is parallel to the toe-heel direction. The intersection line between this plane and the face 2a is drawn, and the midpoint Px is newly determined. Next, a plane is determined that passes through this new midpoint Px, extends along the normal direction of the face 2a at the point Px, and is parallel to the vertical direction. The intersection line between this plane and the face 2a is drawn, and the midpoint Py is newly determined. The above steps are repeated, and Px and Py are sequentially determined. During the repetition of this process, when the distance between the new midpoint Py and the immediately preceding midpoint Py first becomes 0.5 mm or less, the new position Py (the last position Py) is defined as the face center FC.

[0032] In a preferred embodiment, in the head top view as shown in FIG. 1, it is desirable that the weight 20 is located on the face normal FN passing through the face center FC. With such a configuration, the weight of the weight 20 can be intensively distributed at a position farther rearward from the head center of gravity G, and thus the moment of inertia such as the left-right MOI can be further increased.

[0033] As shown in FIG. 8, the recess 8 has a recess bottom surface 81 having a first depth D. The first depth D defines the maximum depth of the recess 8. The recess bottom surface 81 of the present embodiment is formed as a flat surface. The heavy object 20 of the present embodiment is fixed so as to contact the recess bottom surface 81, for example. The maximum thickness t of the heavy object 20 from the recess bottom surface 81 is configured to be smaller than the first depth D. Thereby, the outer surface of the heavy object 20 is located closer to the hollow portion i side of the head 1 than the rear end surface 72 of the bulging portion 7 (including the virtual rear end surface 72a when it is assumed that the opening of the recess 8 is closed).

[0034] In the case of a head such as the above Patent Document 1, in order to prevent deterioration of the head appearance, a polishing process or the like is necessary so that the outer surface of the heavy object and the outer surface of the head 1 are flush and continuous. On the other hand, as in the present embodiment, by intentionally recessing the outer surface of the heavy object 20 from the rear end surface 72 of the bulging portion 7, a polishing process or the like for making the outer surface of the heavy object 20 and the outer surface of the rear end surface 72 continuous becomes unnecessary, and problems in the manufacturing process are solved. Further, since the heavy object 20 is positioned closer to the hollow portion i side of the head 1 than the rear end surface 72, during swinging, the chance of the heavy object 20 contacting an external object is significantly reduced, and breakage, detachment, loosening, etc. of the heavy object 20 can be effectively prevented.

[0035] As shown in FIG. 10, the heavy object 20 of the present embodiment has a plate shape. In this specification, the "plate shape" means a flat member, and defines the plate plane direction and the thickness direction. The heavy object 20 of the present embodiment has a first surface 21 facing the rear of the head, a second surface 22 facing the front of the head, and an outer peripheral surface 23 connecting them. The first surface 21 and the second surface 22 define the plane direction of the plate shape, and the direction orthogonal to this is the thickness direction.

[0036] As shown in FIG. 4, the weight 20 of the present embodiment is arranged such that the first surface 21 and the second surface 22 are along the rear end surface 72 of the bulging portion 7 (that is, the plate plane direction is along the rear end surface 72). Further, in a preferred embodiment, the weight 20 is formed such that the lower end 23L side is larger than the upper end 23U side in terms of the width in the toe-heel direction. The weight 20 of the present embodiment has a flat hexagonal contour on both the first surface 21 and the second surface 22. Such a weight 20 helps to position its center of gravity 20G lower.

[0037] FIG. 8 is a longitudinal cross-section of the head extending in the head front-rear direction passing through the center of gravity 20G of the weight 20. In the longitudinal cross-section of the head in FIG. 8, it is desirable that the maximum length L1 in the head up-down direction of the weight 20 is arranged to be larger than the maximum length L2 in the head front-rear direction of the weight 20. In this way, by making the weight 20 longitudinally long with a relatively small maximum length L2 in the head front-rear direction, the left-right MOI of the head 1 can be further effectively increased.

[0038] In a preferred embodiment, in the longitudinal cross-section of the head in FIG. 8, the weight 20 is arranged such that the plate plane direction A extending vertically is tilted backward. That is, the upper part of the plate plane direction A is located behind the lower part with respect to the head. In particular, the backward tilt angle θ of the weight 20 is preferably in the range of 10 to 30°, more preferably in the range of 15 to 25° with respect to the vertical direction. The left-right MOI can be effectively increased while achieving a lower center of gravity. In this specification, the backward tilt angle θ of the weight 20 is defined as the angle formed between the plate plane direction A and the vertical line in FIG. 8.

[0039] The weight 20 may be fixed to the head body 10 in various ways. As shown in FIGS. 8 and 10, the weight 20 of the present embodiment is fixed to the head body 10 by screw means. For example, the weight 20 is formed with a through hole 24 penetrating the first surface 21 and the second surface 22. Further, on the bottom surface 81 of the recess, for example, a female screw portion 82 is formed which extends toward the hollow portion i side and has a screw groove machined on the inner peripheral surface. Then, the male screw portion 30 is fixed to the female screw portion 82 on the bottom surface 81 of the recess through the through hole 24 of the weight 20 from the outside of the head. In other embodiments, the weight 20 may be fixed to the head body 10 by an adhesive, caulking, welding, or the like. Further, as the screw means, as long as it can be engaged and disengaged by the rotation operation of the male screw portion, it includes a one-touch lock mechanism or the like that can be engaged and disengaged with a small rotation amount of about 90 degrees.

[0040] In order to improve the appearance of the head 1, a badge 40 or the like having a design, a trademark, or the like formed thereon may be fixed to the first surface 21 of the weight 20.

[0041] As shown in FIG. 3, in the head 1 of the present embodiment, the head center of gravity G is located below the face center FC, and the center of gravity 20G of the weight 20 is located below the head center of gravity G. At the time of ball hitting, the head 1 tends to rotate about the head center of gravity G. When the face center FC of the head 1 hits the ball at the loft angle, the head 1 rotates so that the loft angle increases, so the launch angle increases and the flight distance improves. Further, the center of gravity 20G of the weight is preferably located below the head center of gravity G in order to lower the center of gravity of the entire head.

[0042] The head 1 of the present embodiment has a head volume of 400 to 500 cm 3 and the head center of gravity is located in the range of 26.0 to 30.0 mm from the horizontal plane HP, and the left and right MOI is preferably 4600 to 5500 g·cm 2

[0043] ​As described above in detail, although the embodiments of the present invention have been described, the present invention is not limited to the above specific disclosure, and various modifications can be made and implemented within the scope of the technical idea described in the claims.

Example

[0044] Hereinafter, more specific examples of the present invention will be described. A head having the basic structure of FIGS. 1 to 10 was designed based on the specifications in Table 1, and the height of the head center of gravity from the horizontal plane and the left and right MOI were calculated by computer simulation. The main common specifications of the golf club head are as follows. Head volume: 460 cm 3 Head body: Titanium alloy, specific gravity 4.38 Weight: W-Ni alloy, specific gravity 12, volume 1.16 cm 3 , weight: 13.9 g The results of the computer simulation are as shown in Table 1. In Table 1, the backward tilt angle θ of the weight was adjusted with the lower left corner of the weight in FIG. 8 as the rotation center so as not to change the head shape. For Comparative Example 1, the head body has substantially the same shape as that of the example, but the weight is arranged behind the head and its plate plane direction is along the bottom surface of the bulge. Comparative Example 2 is a head in which the weight is removed from Comparative Example 1. Comparative Example 3 is a head in which the weight is moved to the center in the head front-rear direction of the sole portion from Comparative Example 1.

[0045]

Table 1

[0046] The golf club head of the example can further increase the moment of inertia such as the left and right MOI while achieving a lower center of gravity.

[0047] [Appendix] The present invention includes the following aspects.

[0048] [The present invention 1] A golf club head having a hollow portion inside, In a reference state placed on a horizontal plane with a specified lie angle and loft angle, it includes a head body having a face portion, a crown portion, and a sole portion, and a weight fixed to the head body, The sole portion includes a toe side region, a heel side region, and a center region between the toe side region and the heel side region, The center region is provided with a bulging portion that bulges downward from the outer surfaces of the toe side region and the heel side region and extends in the head front-rear direction, The bulging portion includes a bottom surface facing downward from the head and a rear end surface extending upward from the bottom surface and facing the rear of the head, A recess is formed in the rear end surface, The weight is fixed to the recess, The weight is located below the crown portion and above the bottom surface of the bulging portion, A golf club head. [The present invention 2] In a plan view of the head, the center of gravity of the weight is located between a first virtual straight line passing through the face center and having an angle of 15 degrees to the toe side with respect to the face normal and extending rearward of the head, and a second virtual straight line passing through the face center and having an angle of 15 degrees to the heel side with respect to the face normal and extending rearward of the head. The golf club head according to the first aspect of the present invention. [The present invention 3] In a plan view of the head, the weight is located on the face normal passing through the face center. The golf club head according to the first or second aspect of the present invention. [The present invention 4] The recess has a recess bottom surface having a first depth, The weight is fixed so as to abut against the recess bottom surface, The maximum thickness of the weight from the recess bottom surface is smaller than the first depth. The golf club head according to any one of the first to third aspects of the present invention. [The present invention 5] The weight has a plate shape defining a plate plane direction and a thickness direction, In a head longitudinal section extending in the head front-rear direction through the center of gravity of the weight, The weight has the plate plane direction arranged along the rear end face, and the golf club head according to any one of 1 to 4 of the present invention. [Invention 6] In the head longitudinal section, the maximum length of the weight in the head up-down direction is greater than the maximum length of the weight in the head front-rear direction, and the golf club head according to any one of 1 to 5 of the present invention. [Invention 7] In the head longitudinal section, the weight is arranged such that the plate plane direction is tilted backward, and the golf club head according to Invention 6. [Invention 8] The angle of the backward tilt is 10 to 30° with respect to the vertical direction, and the golf club head according to Invention 7. [Invention 9] The head center of gravity is located below the face center, The center of gravity of the weight is located below the head center of gravity, and the golf club head according to any one of 1 to 8 of the present invention. [Invention 10] The head volume is 400 to 500 cm 3 and the head center of gravity is located in the range of 26.0 to 30.0 mm from the horizontal plane, The left-right MOI, which is the moment of inertia around the vertical axis passing through the head center of gravity, is 4600 to 5500 g·cm 2 and the golf club head according to Invention 2 or 3.

Explanation of Signs

[0049] 1 Head 2 Face part 2a Face 3 Crown part 4 Sole part 4A Toe side region 4B Heel side region 4C center area 7 bulge 8 recess 10 head body 20 weight 20G center of gravity 71 bottom surface 72 rear end surface 81 bottom surface of recess A plate plane direction FC face center FN face normal

Claims

1. A golf club head having a hollow portion inside, including a head body having a face portion, a crown portion, and a sole portion in a reference state placed on a horizontal plane with a specified lie angle and loft angle, and a weight fixed to the head body, wherein the sole portion includes a toe side region, a heel side region, and a center region between the toe side region and the heel side region, the center region includes a bulging portion that bulges downward from the outer surfaces of the toe side region and the heel side region and extends in the head front-rear direction, the bulging portion includes a bottom surface facing downward and a rear end surface extending upward from the bottom surface and facing the rear of the head, a recess is formed in the rear end surface, the weight is fixed to the recess, the weight is located below the crown portion and above the bottom surface of the bulging portion, a golf club head.

2. In a plan view of the head, the center of gravity of the weight is located between a first virtual line passing through the face center and having an angle of 15 degrees toward the toe side with respect to the face normal and extending rearward of the head, and a second virtual line passing through the face center and having an angle of 15 degrees toward the heel side with respect to the face normal and extending rearward of the head. The golf club head according to claim 1.

3. In a plan view of the head, the weight is located on the face normal passing through the face center. The golf club head according to claim 2.

4. The recess has a bottom surface of the recess having a first depth, the weight is fixed so as to abut against the bottom surface of the recess, the maximum thickness of the weight from the bottom surface of the recess is smaller than the first depth. The golf club head according to claim 2 or 3.

5. The weight has a plate shape defining a plate plane direction and a thickness direction, in a head longitudinal section extending in the head front-rear direction through the center of gravity of the weight, the weight is arranged such that the plate plane direction is along the rear end surface. The golf club head according to claim 2 or 3.

6. In the head longitudinal section, the maximum length of the weight in the head up-down direction is larger than the maximum length of the weight in the head front-rear direction. The golf club head according to claim 5.

7. In the head longitudinal section, the weight is arranged such that the plate plane direction is tilted backward. The golf club head according to claim 6. Claim 8 The golf club head according to claim 7, wherein the backward tilt angle is 10 to 30° with respect to the vertical direction. Claim 9 The center of gravity of the head is located below the center of the face, The golf club head according to claim 2 or 3, wherein the center of gravity of the weight is located below the center of gravity of the head. Claim 10 The head volume is 400 to 500 cm ３ and The center of gravity of the head is located in the range of 26.0 to 30.0 mm from the horizontal plane, The left and right MOI, which is the moment of inertia about the vertical axis passing through the head center of gravity, is 4,600 to 5,500 g·cm ２ The golf club head according to claim 2 or 3, which is as described above.

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