JP7211076B2 - golf club head - Google Patents

Description

The present invention relates to a golf club head, and more particularly to a golf club head having a hollow inside.

A golf club head with a hollow inside, especially a golf club head called a fairway wood or a hybrid golf club head, which often hits a ball placed on the ground directly, must have a low sweet spot in order to obtain a large flight distance. is required.

Patent Literature 1 listed below describes a golf club head suitable as a fairway wood or utility (hybrid). This golf club head has a weight portion on the sole portion facing the hollow portion. The weight portion extends in the toe-heel direction near the face portion. Such a golf club head brings the center of gravity (sweet spot) on the face closer to the hitting point of the ball by lowering the center of gravity. We expect the effect of increasing the distance.

Japanese Patent No. 5842904

In the golf club head of Patent Literature 1, the weight portion is fixed in a state of being lifted from the sole portion. Therefore, in the above golf club head, the center of gravity of the weight portion tends to be high, and there is room for further improvement in providing a low sweet spot.

A golf club head suitable for a fairway wood or hybrid has a smaller head volume than a driver or the like. Therefore, the moment of inertia around the vertical axis passing through the center of gravity of the golf club head (right and left moment of inertia) also tends to be small. With such a golf club head, the orientation of the golf club head tends to change when the ball is hit at a position shifted to the left or right from the sweet spot, and there is room for further improvement in the directionality of the hit ball.

The present invention has been devised in view of the above circumstances, and is suitable for golf club heads, especially fairway woods and hybrids, which can achieve high resilience, a low sweet spot, and a large lateral moment of inertia. The main issue is to provide the club head.

The present invention provides a golf club head having a hollow portion therein, comprising a face portion for hitting a ball and a sole portion extending rearward of the head from the face portion, the hollow portion side of the sole portion. A first weight portion is provided on the face portion side of the inner surface facing toward the face portion, and the first weight portion extends upward from the inner surface and extends toward the face portion side without contacting the face portion. The rear edge of the first weight portion, which protrudes and connects the first weight portion and the inner surface of the sole portion on the rear side of the head in a plan view of the head, has a concave edge recessed toward the face portion. and the center of gravity of the head is positioned on the head rear side of the recess edge.

In another aspect of the present invention, in a plan view of the sole portion, the center of gravity of the head is located in a recessed region surrounded by the recessed portion edge and a straight line connecting both ends of the recessed portion edge in the toe-heel direction. Also good.

In another aspect of the present invention, in plan view of the sole portion, the edge of the recess may be arc-shaped having a center on the rear side of the head of the edge of the recess.

In another aspect of the present invention, the front edge of the first weight portion, where the first weight portion and the inner surface of the sole portion are connected on the face portion side, and the leading edge of the front edge of the head in the front-rear direction of the head. The distance (A) may be 14-23 (mm).

In another aspect of the present invention, a second weight portion may be provided on the inner surface of the sole portion on the rear side of the head relative to the center of gravity of the head.

In another aspect of the present invention, in a reference state in which the golf club head is placed on a horizontal plane with a specified lie angle and loft angle, the second weight part is located in an area (B ) may be placed in

In another aspect of the present invention, in a plan view of the sole portion, the front edge of the second weight portion where the second weight portion and the inner surface of the sole portion are connected on the side of the center of gravity of the head It may be curved in an arc shape centered on the center of gravity side.

In another aspect of the present invention, a third weight portion may be provided on the inner surface of the sole portion on the toe side of the center of gravity of the head.

In another aspect of the present invention, in a plan view of the sole portion, the inner edge of the third weight portion where the third weight portion and the inner surface of the sole portion are connected on the side of the center of gravity of the head is located at the center of gravity of the head. It may be curved in an arc with the center on one side.

In another aspect of the present invention, a fourth weight portion may be provided on the inner surface of the sole portion on the heel side of the center of gravity of the head.

In another aspect of the present invention, in a plan view of the sole portion, the inner edge of the fourth weight portion where the fourth weight portion and the inner surface of the sole portion are connected on the side of the center of gravity of the head is located at the center of gravity of the head. It may be curved in an arc with the center on one side.

In another aspect of the present invention, the depth of the center of gravity may be 29-32 (mm).

In another aspect of the present invention, the height of the center of gravity may be 11 to 16 (mm).

In another aspect of the present invention, the height of the sweet spot is in the range of 17 to 22 (mm) from the horizontal plane in a reference state in which the golf club head is placed on a horizontal plane with a specified lie angle and loft angle. You can

In another aspect of the present invention, in a reference state in which the golf club head is placed on a horizontal plane with a specified lie angle and loft angle, the lateral moment of inertia, which is the moment of inertia about the vertical axis passing through the center of gravity of the head, is 2200. It may be up to 2800 (g·cm ² ).

In the golf club head of the present invention, the first weight portion is provided on the face portion side of the inner surface of the sole portion. The first weight portion extends upward from the inner surface and protrudes toward the face portion without contacting the face portion. Since such a first weight portion is located away from the face portion, the thickness of the sole portion in the vicinity of the face portion can be reduced. Therefore, when hitting a ball, the portion of the sole portion near the face portion can be easily deflected, and the golf club head can have a high resilience.

In addition, since the first weight portion protrudes and extends from the inner surface of the sole portion toward the face portion, a large weight can be placed on the face portion side of the golf club head, and the center of gravity of the head is shallowed (closer to the face portion). )be able to. As such, the golf club head of the present invention provides a low sweet spot. With such a golf club head, when hitting a ball placed directly on the ground, the hitting position and the sweet spot are close to each other, so that high resilience and low spin of the hit ball can be achieved to increase flight distance. can.

Further, in a plan view of the sole portion 4, a recess edge recessed toward the face portion is provided at the rear edge of the first weight portion where the first weight portion and the inner surface of the sole portion are connected on the rear side of the head. is provided, and the center of gravity of the head is located on the head rear side of the edge of the recess. Therefore, in the golf club head of the present invention, a large weight of the first weight portion is distributed to a position distant from the center of gravity of the head, so that a large lateral moment of inertia can be obtained, and the directionality of the hit ball can be improved. .

1 is a perspective view of a golf club head showing one embodiment of the present invention; FIG. 2 is a plan view of the golf club head of FIG. 1; FIG. 3 is a cross-sectional view taken along line III-III of FIG. 2; FIG. FIG. 4 is a cross-sectional view taken along line IV-IV of FIG. 3; FIG. 5 is a perspective view of FIG. 4; (A) to (C) are plan views of sole portions showing other embodiments.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described based on the drawings. The same reference numerals are assigned to the same members or portions throughout all the embodiments, and overlapping descriptions are omitted.

1 is a perspective view of a golf club head (hereinafter sometimes simply referred to as "head") 1 of this embodiment, FIG. 2 is a plan view thereof, and FIG. 3 is a sectional view taken along line III-III of FIG. show.

[Reference condition, etc.]
1 to 3, the head 1 is in a reference state. Unless otherwise specified, the head 1 is assumed to be in this reference state.

The reference state is a state in which the head 1 is placed on the horizontal plane HP at the lie angle (not shown) and the loft angle α (shown in FIG. 3) determined for the head 1 . More specifically, as shown in FIG. 2, the reference state is a state in which the shaft axis center line CL of the head 1 is arranged in the reference vertical plane VP and is inclined at the lie angle. is held at the loft angle α (shown in FIG. 3). The shaft centerline CL is defined by the shaft centerline of the shaft insertion hole 6 a formed in the hosel portion 6 of the head 1 .

[Head coordinate system]
Here, head 1 is associated with an xyz coordinate system. The x-axis is perpendicular to the reference vertical plane VP and parallel to the horizontal plane HP, the y-axis is parallel to both the reference vertical plane VP and the horizontal plane HP, and the z-axis is both the x-axis and the y-axis. orthogonal axes. With respect to the head 1, the direction along the x-axis is defined as the front-rear direction of the head, the direction along the y-axis is defined as the toe-heel direction, and the direction along the z-axis is defined as the vertical direction of the head.

[Example of basic form of head]
The head 1 of this embodiment is configured to have a hollow portion i therein. In a preferred embodiment, the head 1 of this embodiment is configured as a golf club head suitable for hitting the ball directly on the ground. Examples of such include, for example, fairway woods or hybrids. These heads typically have a loft angle α of 15 degrees or more, a head volume of the order of 100-200 cc, and a head weight of the order of 200-240 g.

Fairway woods include, for example, spoon (#3), buffy (#4), creek (#5) and other woods (#7, #9).

Hybrids, for example, are known in the art as having a shape intermediate between a wood and an iron head.

The head 1 includes a face portion 2, a crown portion 3, a sole portion 4, side portions 5, etc. so as to define a hollow portion i.

For example, the hollow portion i may be used as a space as it is, or a gel agent for weight adjustment or the like may be placed in a portion thereof.

The face portion 2 is formed on the front side of the head 1 to hit the ball, and has a face 2a which is the surface that comes into direct contact with the ball. Although not shown, the face 2a is provided with a plurality of grooves called face lines extending in the toe-heel direction.

The crown portion 3 extends rearward of the head from the upper side of the face portion 2 to form the upper surface of the head. The hosel portion 6 described above is provided on the heel side of the crown portion 3 . The hosel portion 6 has a shaft insertion hole 6a for fixing a golf club shaft (not shown).

The sole portion 4 extends rearward of the head from the lower side of the face portion 2 to form the bottom surface of the head.

The side portion 5 connects between the crown portion 3 and the sole portion 4 . The toe side and heel side of the side portion 5 are connected to the toe side and heel side of the face portion 2, respectively.

In this embodiment, the face portion 2, the crown portion 3, the sole portion 4, and the side portions 5 are made of, for example, a metal material. Suitable metal materials include, for example, stainless steel, maraging steel, titanium alloys, magnesium alloys, and aluminum alloys. Alternatively, a portion of the head 1 (eg, the crown portion 3) may be made of a non-metallic material such as fiber reinforced resin.

4 shows a cross-sectional view taken along line IV-IV of FIG. 3, and FIG. 5 shows a perspective view of FIG. As shown in FIGS. 3 to 5, a first weight portion 10 is provided on the inner surface 7 of the sole portion 4 facing the hollow portion i side.

[First part by weight]
The first weight portion 10 is provided on the inner surface 7 of the sole portion 4 on the face portion 2 side in the head front-rear direction. As is clear from the cross section shown in FIG. 3, the first weight portion 10 extends upward from the inner surface 7 of the sole portion 4 and protrudes toward the face portion 2 without contacting the face portion 2. . More specifically, the first weight portion 10 of the present embodiment extends upward from the inner surface 7 of the sole portion 4 at a position spaced rearward of the head from the face portion 2 , and then extends obliquely toward the face portion 2 . It is a protuberance that extends inward and ends at a position where its tip does not come into contact with the face portion 2 .

The first weight portion 10 is positioned apart from the face portion 2 . Therefore, the thickness of the portion of the sole portion 4 near the face portion 2 (that is, the sole front side portion 4a of the sole portion 4 sandwiched between the face portion 2 and the first weight portion 10) can be reduced. . As a result, when the ball is hit, the portion of the sole portion 4 near the face portion 2 is easily flexed, and the head 1 can have a high resilience.

In addition, since the first weight portion 10 extends obliquely from the inner surface 7 of the sole portion 4 toward the face portion 2, a large weight can be placed on the face portion 2 side of the head 1, and the center of gravity of the head can be shallowed (face part 2). Therefore, the head 1 of this embodiment can provide a low sweet spot SS. With such a head 1, when hitting a ball placed directly on the ground, the hitting position and the sweet spot SS are close to each other, so that high resilience and low spin of the hit ball can be achieved, and the flight distance can be increased. can. The sweet spot SS is the intersection of a perpendicular line N drawn from the center of gravity G of the head to the face 2a and the face 2a.

In a preferred embodiment, in the sole portion 4 , the circumference of the first weight portion 10 is formed with a thickness t sufficiently smaller than that of the first weight portion 10 . As a result, more weight is centrally distributed to the first weight section 10, enhancing the effects described above.

The thickness t of the sole portion 4 around the first weight portion 10 is not particularly limited, but is, for example, 2.0 mm or less, more preferably 1.8 mm or less. In order to maintain the durability of the sole portion 4, the thickness t of the sole portion 4 is desirably 0.6 mm or more, for example.

The height of the center of gravity G of the head and the position in the front-rear direction of the head can be adjusted by changing the volume, cross-sectional shape, and the like of the first weight section 10 . For example, the center of gravity height, which is the height from the horizontal plane HP to the center of gravity G of the head, is preferably 11 to 16 mm. Further, the depth of the center of gravity, which is the distance in the front-rear direction of the head from the leading edge Le of the head 1 to the center of gravity G of the head, is preferably 29 to 32 mm. Furthermore, the height of the sweet spot SS from the horizontal plane HP is, for example, 17-22 mm. As a result, when hitting a ball placed directly on the ground, the hitting position and the sweet spot SS are closer, and the flight distance can be increased.

As shown in FIG. 4, the first weight portion 10 extends in the toe-heel direction. In the first weight portion 10 of the present embodiment, the toe side end 10a is located on the toe side of the center of gravity G of the head, and the heel side end 10b is located on the heel side of the center of gravity G of the head. Further, the toe-side end 10a of the first weight portion 10 does not reach the side portion 5 and terminates in front of the side portion 5, for example, and the heel-side end 10b of the first weight portion 10 is connected to the hosel portion 6, for example. be. In such a mode, it is possible to bring the center of gravity closer to the heel side. As a result, the ball can be better gripped when hit.

[Trailing edge of first weight part]
The first weight portion 10 has a rear edge 11 that defines the edge on the rear side of the head. The rear edge 11 is a connection portion on the rear side of the head between the first weight portion 10 and the inner surface 7 of the sole portion 4. In other words, in the cross section of the first weight portion 10 parallel to FIG. The edge 11 defines the rear end of the first weight portion 10 in the head front-rear direction.

As is clear from FIG. 4 , the first weight portion 10 is located on the front side of the head with respect to the trailing edge 11 . In a plan view of the sole portion 4 , the rear edge 11 of the first weight portion 10 is provided with a recess edge 12 recessed toward the face portion 2 side. To position. In such a mode, since a large weight of the first weight portion 10 is distributed to a position away from the center of gravity G of the head, the head 1 has a large moment of inertia in the left and right direction, and the directivity of the hit ball can be improved. can.

In a preferred embodiment, in plan view of the sole portion 4 , the recessed portion edge 12 has an arcuate shape with its center on the head rear side of the recessed portion edge 12 . In such a manner, the weight distribution effect described above can be optimized and further enhanced. The term "arc-shaped" is not limited to a single arc, but may be a compound arc formed by connecting a plurality of arcs (the same shall apply hereinafter). Particularly preferably, the recessed portion edge 12 may be an arc whose center is the projected center of gravity PG (shown in FIG. 5) obtained by projecting the center of gravity G of the head onto the inner surface 7 of the sole portion 4 . Although the radius of curvature of the arc is not particularly limited, it is preferably 20 mm±5 mm, for example.

In a preferred embodiment, in a plan view of the sole portion 4, the center of gravity G of the head may be positioned within the recessed area surrounded by the recessed portion rim 12 and a straight line S connecting both ends of the recessed portion rim 12 in the toe-heel direction. As a result, the lateral moment of inertia can be reliably increased while the center of gravity G of the head is located on the front side (face portion side). In a preferred embodiment, the center of gravity G of the head is desirably 10 mm±2 mm from the straight line S toward the face portion 2 side.

In a preferred embodiment, the lateral moment of inertia, which is the moment of inertia about the vertical axis passing through the center of gravity G of the head, is 2200 to 2800 (g·cm ² ). As a result, the directivity of the hit ball is improved more reliably.

The trailing edge 11 of the first weight portion 10 of the present embodiment is provided with, for example, a toe side edge 13 and a heel side edge 14 extending substantially along the toe-heel direction on the toe side and the heel side of the recess edge 12. It is Here, the term "substantially" allows the toe side edge 13 and the heel side edge 14 to be inclined within an angle range of 10 degrees or less with respect to the toe-heel direction. Such toe-side edge 13 and heel-side edge 14 are suitable for distributing more weight to the toe side and heel side of the head 1, and serve to further increase the lateral moment of inertia.

[Front edge of the first weight part]
The first weight portion 10 has a front edge 15 that defines the edge on the front side of the head. A front edge 15 of the first weight portion 10 is a connection portion between the first weight portion 10 and the inner surface 7 of the sole portion 4 on the front side of the head. In this embodiment, the front edge 15 extends substantially along the toe-heel direction of the head 1, as indicated by the dashed line in FIG. Here, the term "substantially" allows the front edge 15 to be inclined within an angle range of 10 degrees or less with respect to the toe-heel direction.

In a preferred embodiment, as shown in FIG. 3, the distance A in the head front-rear direction between the front edge 15 of the first weight portion 10 and the leading edge Le of the head 1 is, for example, 14 to 23 mm, more preferably 16 to 21 mm. In such a mode, the center of gravity G of the head is moved toward the face portion 2, while the sole front portion 4a between the face portion 2 and the first weight portion 10 is formed sufficiently large, so that when hitting a ball, the sole front portion 4a is formed sufficiently large. 4a can be greatly bent to achieve even higher resilience. In addition, when the distance A changes in the toe-heel direction, it is desirable that the minimum distance satisfies the preferable numerical range.

[Manufacturing method of the first weight part]
The first weight portion 10 may be integrally formed with the sole portion 4 in advance by, for example, casting or cutting. In this case, the first weight portion 10 is made of the same metal material as the sole portion 4 . Alternatively, the first weight portion 10 may be provided as a separate and independent member from the sole portion 4 and secured to the inner surface 7 of the sole portion 4 using welding or screw means or the like. In this case, the first weight portion 10 may be made of a metal material (high specific gravity metal material) different from that of the sole portion 4 .

[Modified example of the first weight part]
FIG. 6 shows a plan view of the inner surface 7 of the sole portion 4 as a modification of the first weight portion 10. As shown in FIG. As shown in FIG. 6(A), the rear edge 11 of the first weight portion 10 may be entirely formed of the recessed edge 12 from the toe side to the heel side. Further, as shown in FIGS. 6B and 6C, the recess edge 12 may be a combination of straight lines. That is, in FIG. 6B, the recess edge 12 is a V-shaped polygonal line that defines a triangular recess, and in FIG. It may be composed of a polygonal line that defines the recess.

Next, modified examples of the sole portion 4 will be described.

[Second weight part]
As shown in FIG. 4, the inner surface 7 of the sole portion 4 may be provided with a second weight portion 20 on the rear side of the head relative to the center of gravity G of the head. The second weight portion 20 distributes a large weight to the rear of the sole portion 4 intensively to increase the depth of the center of gravity of the head 1 while keeping the center of gravity G of the head low. In addition, the second weight portion 20 helps to further increase the left and right moments of inertia.

In this embodiment, the second weight portion 20 is formed of a thick portion that is locally thicker than the thickness t of the sole portion 4 . Although the thickness of the second weight portion 20 is not particularly limited, it is preferably 1.4 mm or more, more preferably 1.8 mm or more. In the sole portion 4, the circumference of the second weight portion 20 is formed with the thickness t sufficiently smaller than that of the second weight portion 20 (see FIG. 3). As a result, more weight is centrally distributed to the second weight section 20, enhancing the effects described above. In another aspect, the second weight portion 20 may be made of a metal material different from that of the sole portion 4 .

In a preferred embodiment, as shown in FIG. 3, the second weight section 20 is arranged within a region (B) of 6 (mm) or less from the horizontal plane HP. In general, the sole portion 4 has a shape that curves upward toward the rear of the head. Therefore, if the second weight section 20 is arranged closer to the rear side of the head, the center of gravity G of the head may become higher. Such defects are prevented.

In a preferred embodiment, as shown in FIG. 4, in a plan view of the sole portion 4, the front edge of the second weight portion 20 where the second weight portion 20 and the inner surface 7 of the sole portion 4 are connected on the side of the center of gravity G of the head. 22 is preferably curved in an arc whose center is on the side of the center of gravity G of the head. In this manner, the weight of the second weight portion 20 can be placed far from the center of gravity G of the head, optimizing the above-described weight distribution effect and further increasing the left and right moment of inertia.

In the present embodiment, in plan view of the sole portion 4, the rear edge 24 of the second weight portion 20 where the second weight portion 20 and the inner surface 7 of the sole portion 4 are connected on the side of the head outer contour line is also located at the center of gravity G of the head. It is curved in an arc with the center on the side. More specifically, the rear edge 24 of the second weight portion 20 extends along the outline of the head when viewed from above. Thereby, the second weight portion 20 can effectively distribute a large weight to the toe-side peripheral portion of the sole portion 4 .

[Third part by weight]
As shown in FIG. 4, the inner surface 7 of the sole portion 4 may be provided with a third weight portion 30 on the toe side of the center of gravity G of the head. The third weight portion 30 concentrates a large amount of weight on the toe side of the sole portion 4 and serves to further increase the left and right moment of inertia while maintaining a low center of gravity G of the head.

In this embodiment, the third weight portion 30 is formed of a thick portion that is locally thicker than the thickness t of the sole portion 4 . Although the thickness of the third weight portion 30 is not particularly limited, it is preferably 1.0 mm or more, more preferably 1.3 mm or more. In the sole portion 4 , the circumference of the third weight portion 30 is formed with the thickness t sufficiently smaller than that of the third weight portion 30 . As a result, more weight is centrally distributed to the third weight section 30, enhancing the effects described above. In another aspect, the third weight portion 30 may be made of a metal material different from that of the sole portion 4 .

The third weight section 30 is provided, for example, apart from the first weight section 10 and the second weight section 20 . In other words, between the third weight portion 30 and the first weight portion 10 and between the third weight portion 30 and the second weight portion 20, the portion having the small thickness t is interposed. ing. As a result, the rigidity of the sole portion 4 is prevented from increasing excessively, and deterioration of resilience performance and the like is suppressed.

In a preferred embodiment, in a plan view of the sole portion 4, the inner edge 32 of the third weight portion 30 where the third weight portion 30 and the inner surface 7 of the sole portion 4 are connected on the side of the center of gravity G of the head is centered on the side of the center of gravity G of the head. It is preferable to curve in an arc shape having In this manner, the weight of the third weight portion 30 can be placed far from the center of gravity G of the head, optimizing the weight distribution effect described above and further increasing the left and right moment of inertia.

In the present embodiment, in plan view of the sole portion 4, the outer edge 34 of the third weight portion 30 where the third weight portion 30 and the inner surface 7 of the sole portion 4 are connected on the side of the head outer contour line also It is curved in an arc with the center on the side. More specifically, the outer edge 34 of the third weight portion 30 extends along the outer contour of the head. Thereby, the third weight portion 30 can effectively distribute a large weight to the toe side peripheral portion of the sole portion 4 .

[Fourth weight part]
As shown in FIG. 4, the inner surface 7 of the sole portion 4 may be provided with a fourth weight portion 40 on the heel side of the center of gravity G of the head. The fourth weight portion 40 concentrates a large amount of weight on the heel side of the sole portion 4 and serves to further increase the left and right moment of inertia while maintaining a low center of gravity G of the head.

In this embodiment, the fourth weight portion 40 is formed of a thick portion that is locally thicker than the thickness t of the sole portion 4 . Although the thickness of the fourth weight portion 40 is not particularly limited, it is preferably 1.2 mm or more, more preferably 1.5 mm or more. In the sole portion 4 , the circumference of the fourth weight portion 40 is formed with the thickness t sufficiently smaller than that of the fourth weight portion 40 . As a result, more weight is centrally distributed to the fourth weight section 40, enhancing the above effect. In another aspect, the fourth weight portion 40 may be made of a metal material different from that of the sole portion 4 .

The fourth weight section 40 is provided, for example, apart from the first weight section 10 and the second weight section 20 . In other words, between the fourth weight portion 40 and the first weight portion 10, and between the fourth weight portion 40 and the second weight portion 20, the portion having the small thickness t is interposed. ing. As a result, as described above, the rigidity of the sole portion 4 is prevented from increasing excessively, and deterioration of the resilience performance and the like is suppressed.

In a preferred embodiment, in a plan view of the sole portion 4, the inner edge 42 of the fourth weight portion 40, where the fourth weight portion 40 and the inner surface 7 of the sole portion 4 are connected on the side of the center of gravity G of the head, is centered on the side of the center of gravity G of the head. It is preferable to curve in an arc shape having In this manner, the weight of the fourth weight section 40 can be placed far from the center of gravity G of the head, optimizing the above-described weight distribution effect and further increasing the lateral moment of inertia.

In the present embodiment, in a plan view of the sole portion 4, the outer edge 44 of the fourth weight portion 40 where the fourth weight portion 40 and the inner surface 7 of the sole portion 4 are connected on the head outer contour side is also on the head center of gravity G side. is curved in an arc with its center at . More specifically, the outer edge 44 of the fourth weight portion 40 extends along the outer contour of the head. Thereby, the fourth weight portion 40 can effectively distribute a large weight to the heel-side peripheral portion of the sole portion 4 .

[Combination of each weight part]
In the embodiment of FIG. 4 , the sole portion 4 is provided with a second weight portion 20 , a third weight portion 30 and a fourth weight portion 40 in addition to the first weight portion 10 . However, the second weight section 20, the third weight section 30, and the fourth weight section 40 are optional elements, and needless to say, they may be omitted. Further, as for the second weight part 20, the third weight part 30, and the fourth weight part 40, only one of them may be applied, or two or more of them may be applied in various combinations. For example, third weight part 30 is preferably greater than second weight part 20 and fourth weight part 40 . As a result, more weight is distributed to the position on the side opposite to the hosel portion 6, optimizing the weight balance of the head.

Although several embodiments of the present invention have been described in detail above, the present invention is not limited to the specific embodiments described above, and can be implemented in various modifications.

A hollow fairway wood (#3) shown in FIGS. 1 to 5 was manufactured based on the specifications in Table 1, and the performance of the head was tested.

As a comparative example, a golf club head in which the trailing edge of the first weight portion substantially extends in the toe-heel direction and does not have a concave edge (the length of the first weight in the toe-heel direction is was the same as in the example.) was also tested. Throughout the examples and comparative examples, each head employs the same structure except for the trailing edge of the first weight section. Then, the height of the sweet spot, the height of the center of gravity, the depth of the center of gravity, and the right and left moments of inertia were measured for the example and the comparative example. Table 1 shows the test results.

As a result of the test, it was confirmed that the head of the example achieves a low sweet spot and a large lateral moment of inertia. In addition, since the ball has a low sweet spot, the sweet spot and the hitting position are close to each other when hitting a ball placed directly on the ground.

1 golf club head 2 face portion 2a face 4 sole portion 7 inner surface of sole portion 10 first weight portion 11 trailing edge of first weight portion 12 recess edge 20 second weight portion 22 front edge of second weight portion 30 third weight Part 32 Inner edge 40 of third weight part Fourth weight part 42 Inner edge SS of fourth weight part Sweet spot i Hollow part

Claims (14)

A golf club head having a hollow inside,
having a face portion for hitting a ball and a sole portion extending rearward of the head from the face portion;
A first weight portion is provided on the face portion side of the inner surface of the sole portion facing the hollow portion side,
the first weight portion extends upward from the inner surface and protrudes toward the face portion without contacting the face portion;
In a plan view of the sole portion, the rear edge of the first weight portion where the first weight portion and the inner surface of the sole portion are connected to each other on the rear side of the head is provided with a concave edge recessed toward the face portion. and
The center of gravity of the head is located on the rear side of the recessed edge of the head,
The depth of the center of gravity is 29 to 32 (mm),
golf club head. 2. The golf club head according to claim 1, wherein, in a plan view of the sole portion, the recessed edge has an arc shape having a center on the head rear side of the recessed edge. 3. The center of gravity of the head according to claim 1, wherein in a plan view of the sole portion, the center of gravity of the head is positioned within a recessed region surrounded by the edge of the recessed portion and a straight line connecting both ends of the edge of the recessed portion in the toe-heel direction. golf club head. The distance (A) in the front-rear direction of the head between the leading edge and the front edge of the first weight portion where the first weight portion and the inner surface of the sole portion are connected on the face portion side is 14 to 14. 4. The golf club head according to claim 1, which is 23 (mm). 5. The golf club head according to any one of claims 1 to 4, wherein the inner surface of the sole portion is provided with a second weight portion on the rear side of the head relative to the center of gravity of the head. In a standard state in which the golf club head is placed on a horizontal plane at a prescribed lie angle and loft angle, the second weight portion is located within a region (B) of 6 (mm) or less from the horizontal plane. 6. The golf club head of claim 5. In a plan view of the sole portion, the front edge of the second weight portion where the second weight portion and the inner surface of the sole portion are connected on the side of the center of gravity of the head has an arc shape having a center on the side of the center of gravity of the head. 7. A golf club head according to claim 5 or 6, which is curved in an upward direction. 8. The golf club head according to any one of claims 1 to 7, wherein the inner surface of the sole portion is provided with a third weight portion on the toe side of the center of gravity of the head. In a plan view of the sole portion, the inner edge of the third weight portion, where the third weight portion and the inner surface of the sole portion are connected on the side of the center of gravity of the head, has an arc shape having a center on the side of the center of gravity of the head. 9. The golf club head of claim 8, which is curved. 10. The golf club head according to any one of claims 1 to 9, wherein the inner surface of the sole portion is provided with a fourth weight portion on the heel side of the center of gravity of the head. In a plan view of the sole portion, the inner edge of the fourth weight portion where the fourth weight portion and the inner surface of the sole portion are connected to each other on the side of the center of gravity of the head is shaped like an arc whose center is on the side of the center of gravity of the head. 11. The golf club head of claim 10, which is curved. 12. The golf club head according to claim 1, wherein the height of the center of gravity is 11-16 (mm). 13. In a reference state in which the golf club head is placed on a horizontal plane with a specified lie angle and loft angle, the height of the sweet spot from the horizontal plane is in the range of 17 to 22 (mm). The golf club head according to any one of 1. In a standard state in which the golf club head is placed on a horizontal plane at a specified lie angle and loft angle, the lateral moment of inertia, which is the moment of inertia about the vertical axis passing through the center of gravity of the head, is 2200 to 2800 (g cm). ² ), the golf club head of any of claims 1-13.

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