JP7004927B2 - Golf club head and golf club set - Google Patents

Description

The present invention relates to a golf club head and a golf club set.

Improving the directionality of the ball when hitting the ball with the golf club head is advantageous in improving the flight distance, and for that purpose, it is necessary to secure the moment of inertia around the center of gravity of the golf club head. is important.
Patent Document 1 discloses that in a golf club head having a hollow structure, a weight (solid portion) is provided at a portion on the face back side to improve the moment of inertia.

Patent No. 5183156

However, in the above-mentioned prior art, the center of gravity point on the face surface of the golf club head is not particularly considered.
That is, when the weight is provided, the position of the center of gravity of the golf club head is affected by the position and weight of the weight, and therefore the position of the center of gravity on the face surface is also affected by the position and weight of the weight.
Therefore, in the above-mentioned conventional technique, the moment of inertia around the center of gravity can be improved by providing the weight, but there is a concern that the center of gravity on the face surface is separated from the center point of the face surface and the flight distance is reduced.
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a golf club head and a golf club set which are advantageous in improving the flight distance while improving the moment of inertia. be.

In order to achieve the above object, the present invention has a face portion having a vertical height and extending to the left and right, a crown portion extending rearward from the upper part of the face portion, and a lower portion of the face portion. A head body including a sole portion extending rearward and a side portion extending through a face back between the toe side edge and the heel side edge of the face portion between the crown portion and the sole portion. A weight portion is provided integrally with the side portion at the face back portion of the side portion, and the inside surrounded by the face portion, the crown portion, the sole portion, the side portion, and the weight portion is provided. A hollow golf club head as a space, and a normal line passing through the center point of the face surface in a reference state in which the golf club head is installed according to a predetermined lie angle and loft angle with respect to a horizontal plane. The cross section of the head body that is included and orthogonal to the horizontal plane is defined as the face center reference cross section, and the plane that is orthogonal to the horizontal plane and the face center reference cross section and abuts on the leading edge in the reference state is defined as the first plane. The plane parallel to the first plane and abutting on the outer surface of the face back is defined as the second plane, and the distance between the first plane and the second plane when the head body is viewed in a plan view is the maximum head width W. The point where the second plane intersects with the outer surface of the face back is projected onto the horizontal plane as the head maximum width point N1, and the weight is viewed in a plan view in the reference state. The maximum thickness that is the maximum length of the projected lines that are projected on the horizontal plane by a straight line extending in the thickness direction of the portion. When the point N2 is set, the weight maximum thickness point N2 is a third plane that is parallel to the face center reference cross section and passes through the maximum head width point N1 in a state where the head body is viewed in a plane in the reference state. It is located in the weight specified range between the third plane and the fourth plane 30 mm away from the third plane in the toe direction, and passes through the center of gravity of the golf club head in the reference state to the horizontal plane. When the magnitude of the inertial moment with the orthogonal vertical straight line as the rotation axis is MI (g · cm ² ), the inertial moment MI is 5000 g · cm ² or more and 5900 g · cm ² or less, and the volume of the head body. Is 400 cc or more and 470 cc or less, and the weight portion is made of the same material as the head body. In the weight portion, the wall portion having a wall thickness larger than the wall thickness of the wall portion constituting the face portion, the crown portion, and the sole portion is formed from the sole portion at the face back portion of the side portion. The face center reference is formed between the third plane and the fifth plane parallel to the face center reference cross section and passing through the weight maximum thickness point N2, which is formed to extend over the crown portion. The first point is a point on the outer surface of the head body located at a position farthest from the face portion in the face back direction in an arbitrary cross section obtained by breaking the head body in a plane parallel to the cross section. When the outer surface of the head body separated from the face portion by 2 mm is set as the second point, the length of the straight line connecting the first point and the second point is 5 mm or more and 25 mm or less . It is characterized in that at least one cross section exists (however, the length of the straight line connecting the first point and the second point is excluded in the range of 8.5 mm or less) .
Further, in the present invention, the weight portion is connected to the crown portion via a gradually changing portion for the crown portion whose wall thickness gradually decreases toward the crown portion side, and is a plane parallel to the face center reference cross section. In the fracture surface of the head body including the gradually changing portion for the crown portion, the length of the gradually changing portion for the crown portion is 3 mm or more and 10 mm or less, and in the fracture surface, the wall thickness of the crown portion is formed. Is characterized in that the range within 30 mm from the boundary between the crown portion and the gradually changing portion for the crown portion is 0.3 mm or more and 0.8 mm or less.
Further, in the present invention, when the point where the normal of the face surface passing through the center of gravity point of the golf club head intersects the face surface is defined as the center of gravity point on the face surface, the center of gravity point on the face surface is the face surface. It is characterized in that it is located within a range of 5 mm from the center point of.
Further, the present invention is characterized in that the maximum thickness of the weight portion is 3% or more and 14% or less of the maximum head width W.
Further, in the present invention, among the projected contour lines obtained by projecting the outer contour line of the cross section obtained by breaking the head body in a plane parallel to the horizontal plane in the reference state onto the horizontal plane, the protrusion most protruding toward the toe side in the toe heel direction. The intersection is defined as the intersection of the first straight line that passes through the point and extends in the front-rear direction of the head body and the second straight line of the projected contour line that passes through the head maximum width point N1 and extends in the toe heel direction. When, the projected contour line is characterized in that it is located outside the range of 20 mm from the intersection.
Further, the present invention is a golf club set comprising a plurality of golf clubs having the golf club heads according to any one of claims 1 to 5 and having different counts.

According to the first aspect of the present invention, since the weight maximum thickness point N2 is located in the weight specified range, the moment of inertia MI of the golf club head can be largely secured by the weight portion, so that the directionality of the hit ball is improved. It will be advantageous on.
Further, since the weight maximum thickness point N2 is located within the weight specified range, the center of gravity on the face surface of the head body including the weight portion is located near the center point of the face surface, so that the flight distance of the hit ball is improved. It will be advantageous in planning.
According to the inventions of claims 2 to 9, it is more advantageous to enhance the effect of claim 1.
According to the tenth aspect of the present invention, when the golf club head is manufactured by casting, it is advantageous in suppressing the deformation of the wall portion of the crown portion and ensuring the appearance of the golf club head.
The invention according to claim 11 is advantageous in ensuring the effect of claim 1 in a plurality of golf clubs having different counts constituting the golf club set.

It is a front view which looked at the golf club head which concerns on embodiment from the front of the face surface. It is the A arrow view of FIG. It is a B arrow view of FIG. It is a top view of the golf club head which shows the modification of the weight part. It is sectional drawing which the golf club head was broken by the face center reference cross section Pfc, and shows the part which is close to a face back. (A) is a plan view of a golf club head when the weight portion includes a first weight portion and a second weight portion, and (B) is a cross-sectional view of the golf club head of (A) cut at a face center reference cross section Pfc. (C) is a view taken along the line C of (B). It is sectional drawing which the golf club head was broken by the face center reference cross section Pfc, and shows the structure of the gradual change part for a crown. (A) and (B) are explanatory views explaining the 1st point α1, the 2nd point α2, and the straight line Lα. It is a top view which shows the relationship between the projection contour line B of a golf club head, and an intersection N12. It is 1st explanatory drawing which shows the method of defining the center point Pc of a face surface. It is a 2nd explanatory drawing which shows the method of defining the center point Pc of a face surface. It is a 3rd explanatory view which shows the method of defining the center point Pc of a face surface. It is a 4th explanatory view which shows the method of defining the center point Pc of a face surface. It is sectional drawing of the golf club head which shows the relationship between the center of gravity point G0 of a golf club head, and the center of gravity point FG on a face surface. It is a front view of the golf club head explaining the definition of the contour line I of a face surface. It is sectional drawing of the golf club head explaining the definition of the contour line I of a face surface. It is a front view of the golf club head explaining the definition of the center point Pc of a face surface. It is sectional drawing of the golf club head explaining the regulation method which defines the start end K1 and the end end K2 of a gradual change part for a crown part. (A) is a cross-sectional view of a golf club head explaining the regulation of the start end K1 of the gradual change portion for the crown portion, and (B) is a cross-sectional view of the golf club head explaining the regulation of the end K2 of the gradual change portion for the crown portion. be. It is a schematic perspective view which shows the moment of inertia measuring instrument which measures the moment of inertia of a golf club head. (A) and (B) are schematic views showing the method of measuring the moment of inertia in the order of processes. (A) to (C) are schematic views for explaining the fixing position which fixes a golf club head to a jig at the time of measuring a moment of inertia. It is a schematic diagram for demonstrating the preferable form of the fixing position which fixes a golf club head to a jig at the time of measuring a moment of inertia. It is a figure which shows the evaluation result of the experimental example under condition 1. It is a figure which shows the evaluation result of the experimental example under condition 2. It is a figure which shows the evaluation result of the experimental example under condition 3. It is a figure which shows the evaluation result of the experimental example under condition 4. It is a figure which shows the evaluation result of the experimental example under condition 5. It is a figure which shows the evaluation result of the experimental example under condition 6.

Next, an embodiment of the present invention will be described.
As shown in FIGS. 1 to 3 and 5, in the present embodiment, the golf club head 10 is a hollow wood type golf club head (driver), and includes a head body 12.
The head body 12 is mainly made of a metal material.
As the metal material, for example, one kind or two or more kinds such as stainless steel, maraging steel, pure titanium, titanium alloy or aluminum alloy are used.
The head main body 12 includes a face portion 14, a crown portion 16, a sole portion 18, and a side portion 20, and the head main body 12 is provided with a weight portion 30 described later.
The face portion 14 has a vertical height and extends to the left and right.
The crown portion 16 extends rearward from the upper portion of the face portion 14.
The sole portion 18 extends rearward from the lower portion of the face portion 14.
The side portion 20 extends between the crown portion 16 and the sole portion 18 through the face back 28 between the toe 22 side edge and the heel 24 side edge of the face portion 14.
As shown in FIG. 5, the weight portion 30 is provided integrally with the side portion 20 at the position of the face back 28 of the side portion 20, and the details of the weight portion 30 will be described later.
The head body has a hollow shape (hollow structure) with a space 13 (FIG. 5) inside surrounded by a face portion 14, a crown portion 16, a sole portion 18, a side portion 20, and a weight portion 30.
The outer surface exposed to the outside of the face portion 14 is the face surface 14A for hitting the ball, and the inner surface of the face portion 14 facing the space 13 is the face inner surface 14B.
The outer surface exposed to the outside of the crown portion 16 is the crown surface 16A, and the inner surface of the crown portion 16 facing the space 13 is the crown inner surface 16B.
The outer surface exposed to the outside of the sole portion 18 is the sole surface 18A, and the inner surface of the sole portion 18 facing the space 13 is the sole inner surface 18B.
Further, the inner surface of the weight portion 30 facing the space 13 is the weight inner surface 3010.
In the figure, reference numeral 19 indicates a leading edge.

As shown in FIGS. 1 to 3, the crown portion 16 is provided with a hosel 31 connected to the shaft S on the face surface 14A side and at a position closer to the heel 24, and the shaft S is connected to the hosel 31. The golf club 100 according to the present invention is configured.

Next, a method of defining the center point Pc of the face surface 14A will be described.
The center point Pc of the face surface 14A is the geometric center of the face surface 14A, and various conventionally known methods of defining the center point Pc include the first defining method and the second defining method exemplified below. The method can be adopted.

[A] First method of defining the center point Pc of the face surface 14A:
When the boundary between the face surface 14A and the portion of the other golf club head 10 is clear, in other words, it is a method of defining the center point Pc when the peripheral edge of the face surface 14A is specified by the ridge line. In this case, the face surface 14A is clearly defined.
10 to 13 are explanatory views showing a method of defining the center point Pc of the face surface 14A.

(1) First, as shown in FIG. 10, the golf club head 10 is placed on the horizontal plane HP so that the lie angle and the face angle become specified values. The state of the golf club head 10 at this time is used as a reference state. The set values of the lie angle and the face angle are, for example, the values described in the product catalog.

(2) Next, the temporary center point c0 in the direction connecting the crown portion 16 and the sole portion 18 is obtained.
That is, as shown in FIG. 10, a perpendicular line f0 that intersects the approximate center point of a line parallel to the horizontal plane HP connecting the toe 22 and the heel 24 (hereinafter referred to as a horizontal line) is drawn.
The midpoint of the a0 point where the perpendicular line f0 and the upper edge of the face surface 14A intersect and the b0 point where the perpendicular line f0 and the lower edge of the face surface 14A intersect is defined as a temporary center point c0.

(3) Next, as shown in FIG. 11, a horizontal line g0 passing through the temporary center point c0 is drawn.
(4) Next, as shown in FIG. 12, at the d0 point where the horizontal line g0 and the edge of the face surface 14A on the toe 22 side intersect, and the e0 point where the horizontal line g0 and the edge of the face surface 14A on the heel 24 side intersect. The midpoint is the temporary center point c1.

(5) Next, as shown in FIG. 13, a perpendicular line f1 passing through the temporary center point c1 is drawn, and the perpendicular line f1 and the lower edge of the face surface 14A intersect with the perpendicular line f1 and the upper edge of the face surface 14A. Let the midpoint of the b1 point where the two intersect is the temporary center point c2.
Here, if the temporary center points c1 and c2 match, that point is defined as the center point Pc of the face surface 14A.
If the temporary center points c1 and c2 do not match, the steps (2) to (5) are repeated.
Since the face surface 14A has a curved surface, the length of the horizontal line g0 and the lengths of the perpendicular lines f0 and f1 when the midpoint of the horizontal line g0 and the midpoint of the perpendicular lines f0 and f1 are obtained is the curved surface of the face surface 14A. Along the length shall be used.
The face center line CL is defined by a straight line that passes through the center point Pc and extends in a direction orthogonal to the toe 22-heel 24 direction.

[B] A second method for defining the center point Pc of the face surface 14A:
Next, the definition of the center point Pc when the peripheral edge of the face surface 14A and the portion of the other golf club head 10 are connected by a curved surface and the face surface 14A cannot be clearly defined will be described.

As shown in FIG. 14, the golf club head 10 is hollow, the reference numeral G0 indicates the center of gravity point of the golf club head 10, and the reference numeral Lp is a straight line connecting the center of gravity point G0 and the center of gravity point FG on the face surface, in other words. The straight line Lp is a perpendicular line (normal line) of the face surface 14A passing through the center of gravity point G0.
That is, the point where the center of gravity point G0 of the golf club head 10 is projected onto the face surface 14A is the center of gravity point FG on the face surface.
Here, as shown in FIG. 15, consider a large number of planes H1, H2, H3, ..., Hn including a straight line Lp connecting the center of gravity point G0 and the center of gravity point FG on the face surface.

As shown in FIG. 16, the radius of curvature r0 of the outer surface of the golf club head 10 is measured in the cross section when the golf club head 10 is broken along the planes H1, H2, H3, ..., Hn.
When measuring the radius of curvature r0, it is treated as if there is no face line, punch mark, etc. on the face surface 14A.
The radius of curvature r0 is continuously measured outward (upward and downward in FIG. 16) from the center point Pc of the face surface 14A.
Then, in the measurement, the portion where the radius of curvature r0 is first or less than a predetermined value is defined as the contour line I representing the peripheral edge of the face surface 14A.
The predetermined value is, for example, 200 mm.
A region surrounded by contour lines I determined based on a number of planes H1, H2, H3, ..., Hn is defined as the face surface 14A, as shown in FIGS. 15 and 16.

Next, as shown in FIG. 17, the golf club head 10 is placed on a horizontal ground (horizontal plane HP) so that the lie angle and the face angle become specified values.
The straight line LT passes through the toe side point PT of the face surface 14A and extends in the vertical direction.
The straight line LH passes through the heel side point PH of the face surface 14A and extends in the vertical direction.
The straight line LC is parallel to the straight line LT and the straight line LH. The distance between the straight line LC and the straight line LT is equal to the distance between the straight line LC and the straight line LH.
Reference numeral Pu indicates an upper point of the face surface 14A, and reference numeral Pd is a lower point of the face surface 14A. The upper point Pu and the lower point Pd are both intersections of the straight line LC and the contour line I.
The center point Pc is defined by the midpoint of the line segment connecting the upper point Pu and the lower point Pd.

(Head maximum width point N1, weight maximum thickness point N2, weight specified range LW)
Next, the provisions of each part of the golf club head 10 will be described in detail.
As shown in FIGS. 1 to 3, the golf club head 10 is set in a reference state in which the golf club head 10 is installed according to a predetermined lie angle and loft angle with respect to the horizontal plane HP.
A cross section obtained by breaking the head body 12 on a plane X including a normal line passing through the center point Pc of the face surface 14A and orthogonal to the horizontal plane HP is referred to as a face center reference cross section Pfc. In other words, the face center reference cross section Pfc is a cross section in which the head body 12 is broken at a plane X including the face center line CL and orthogonal to the horizontal plane HP in the reference state.

As shown in FIG. 3, in the reference state, the plane orthogonal to the horizontal plane HP and the face center reference cross section Pfc and abutting on the leading edge 19 is defined as the first plane P1, which is parallel to the first plane P1 and hits the outer surface of the face back 28. The plane in contact is defined as the second plane P2, and the distance between the first plane P1 and the second plane P2 when the head main body 12 is viewed in a plan view is defined as the head maximum width W.
Further, the point where the point where the second plane P2 and the outer surface of the head main body 12 intersect is projected onto the horizontal plane HP is defined as the head maximum width point N1.
With the head body 12 viewed in a plan view in the reference state, the projection line having the longest length of the projection lines extending in the thickness direction of the weight portion 30 projected onto the horizontal plane HP is referred to as the maximum thickness projection line A. do.
The intersection where the maximum thickness projection line A intersects with the contour line D projected from the head body 12 on the horizontal plane HP is defined as the weight maximum thickness point N2.
The length of the maximum thickness projection line A is the maximum thickness dmax of the weight portion 30.

The third plane P3 is a plane parallel to the face center reference cross section Pfc and passing through the maximum head width point N1 in a state where the head main body 12 is viewed in a plane in the reference state.
The plane parallel to the third plane P3 and separated from the third plane P3 in the toe direction by 30 mm is referred to as the fourth plane P4.
The weight defined range LW is defined between the third plane P3 and the fourth plane P4.
The weight maximum thickness point N2 is located in the weight specified range LW in a state where the head main body 12 is viewed in a plan view in the reference state.
When the weight maximum thickness point N2 is located in the weight specified range LW, as shown in FIG. 1, the center of gravity point FG on the face surface of the head body 12 including the weight portion 30 is close to the center point Pc of the face surface 14A. It is located at a location, or the center of gravity point FG on the face surface coincides with the center point Pc of the face surface 14A.

The above-mentioned regulation of the head maximum width point N1, the weight maximum thickness point N2, and the weight regulation range LW will be described.
As a result of investigating the shape of a commercially available wood-type golf club head 10, when the golf club head 10 is viewed in a plan view at the reference position of the golf club head 10, the head maximum width point N1 is the head maximum width point N1 with respect to the face center reference cross section Pfc. It was found that the golf club was displaced toward the toe 22 side.
This is a remnant of the old Persimmon era, and when making a golf club head with a solid single material, the mass is taken up by the hosel of the heel, and the center of gravity point FG on the face surface is set to the face surface 14A. The only way to bring it near the center point Pc was to increase the shape of the toe 22 side. In this case, the contour of the golf club head has a pear shape when viewed in a plan view.

Currently, the golf club head has a hollow structure, and a large number of materials can be used, so that the center of gravity point FG on the face surface can be set without shifting the head maximum width point N1 toward the toe 22 side. It is possible to bring it near the center point Pc of the face surface 14A, but since the shape of the wood type golf club head retains the above-mentioned old remnants, the head maximum width point N1 is still the toe 22. The reality is that it is biased to the side.
Further, when the golf club head is viewed in a plan view, the degree of curvature of the curve of the side portion 20 from the face center reference cross section Pfc to the toe 22 side is the degree of curvature of the curve of the side portion 20 from the face center reference cross section Pfc to the heel 24 side. It is gradual compared to.
These things are due to the peculiar shape of the wood type golf club head influenced by the shape of the old Persimmon era mentioned above, and by making such a peculiar shape, the golfer can make the golf club head. It is designed so that you do not feel any visual discomfort when you look at it.

Then, as shown in FIG. 3, in order to increase the moment of inertia MI most efficiently, the center of gravity point G in the state without the weight portion 30 (internal weight) (the state without the internal weight of the golf club head 10). It is necessary to place the weight of the weight 30 at a position as far away from the weight as possible.
In the following, the center of gravity point without the internal weight of the golf club head 10 is referred to as the center of gravity point G, and the center of gravity point with the internal weight of the golf club head 10 is referred to as the center of gravity point G0.
Then, in order to arrange the center of gravity point FG on the face surface in the vicinity of the center point Pc of the face surface 14A in accordance with the shape of the golf club head 10, the weight portion 30 is centered on the weight maximum thickness point N2. It is necessary to arrange a large amount of mass in the face back 28 and to position the weight maximum thickness point N2 at the face back 28 near the head maximum width point N1.
That is, locating the weight portion 30 at the position of the face back 28 slightly displaced toward the toe 22 is to efficiently increase the moment of inertia MI, and the center of gravity point FG on the face surface is the center of the face surface 14A. It is advantageous to place it near the point Pc.
Further, in order to bring the center of gravity point FG on the face surface closer to or coincide with the center point Pc of the face surface 14A according to the shape of the golf club head 10 and increase the moment of inertia MI, the weight maximum thickness point N2 It has been found that it is important that is located in a specific range, that is, the weight specified range LW.
From these things, the head maximum width point N1, the weight maximum thickness point N2, and the weight regulation range LW are defined as described above.

Therefore, by defining the head maximum width point N1, the weight maximum thickness point N2, and the weight regulation range LW as described above, the weight portion 30 causes the moment of inertia MI around the center of gravity point G0 (FIG. 14) of the golf club head 10. It is advantageous to improve the directionality of the hit ball by securing a large amount of ball, and since the center of gravity FG on the face surface is close to the center point Pc, the center point Pc of the face surface 14A having the highest hit probability is near the center point Pc. The coefficient of restitution becomes high, which is advantageous in improving the flight distance of the hit ball.
According to the investigation by the present inventors, the hitting point position on the face surface 14A varies around the center point Pc of the face surface 14A, and the hitting point position having the highest hitting probability is the center point Pc of the face surface 14A. I know that.
Further, in the present specification, the moment of inertia MI around the center of gravity point G0 of the golf club head 10 is the moment of inertia having a straight line perpendicular to the horizontal plane HP passing through the center of gravity point G0 of the golf club head 10 in the reference state as the axis of rotation. It is a moment, and is simply referred to as the moment of inertia MI below. The method of measuring the moment of inertia MI will be described later.

Further, when the weight maximum thickness point N2 is located outside the weight specified range LW, the center of gravity point FG on the face surface of the head body 12 including the weight portion 30 is located at a position largely separated from the center point Pc of the face surface 14A. It will be placed.
Therefore, the weight portion 30 cannot secure a large moment of inertia MI of the golf club head 10, and the center of gravity point FG on the face surface is arranged at a position greatly separated from the center point Pc (average position of the hitting point position by a person) of the face surface 14A. It is disadvantageous in improving the flight distance of the hit ball when a person hits it.

Note that FIG. 3 shows a case where the weight inner surface 3010 facing the space 13 has a flat surface, but as shown in FIG. 4, the weight inner surface 3010 extends along the outer surface of the side portion 20. It may be a curved surface that is convex toward the outside of the existing head body 12. In this case, the weight portion 30 has a shape (internal weight shape) that follows the outer surface shape of the golf club head 10.
By doing so, since the weight portion 30 is arranged at a position farther from the center of gravity point G of the golf club head 10, it is advantageous for the weight portion 30 to secure a large moment of inertia MI of the golf club head 10.

Here, a method of measuring the moment of inertia MI of the golf club head 10 will be described in detail with reference to FIGS. 20 to 23.
Here, FIG. 20 is a schematic perspective view showing a moment of inertia measuring instrument of the golf club head 10. The moment of inertia MI is measured by the moment of inertia measuring instrument shown in FIG.

The moment of inertia measuring device 60 includes a measuring unit 62, a calculation unit 64, a start lever 66, a display unit 68, and an operation button 69, and an object to be measured for the moment of inertia MI is placed on the measuring unit 62, and the start lever 66. After picking and displacementing by hand, let go and twist and vibrate, measure the moment of inertia MI through the calculation unit 64 by measuring the period of the torsional vibration at this time, and display the value of the moment of inertia MI on the display unit 68. It is a display device.
As the moment of inertia measuring device 60, Model MOI-005-014 manufactured by Inertia Dynamics Co., Ltd. is exemplified. Such a moment of inertia measuring instrument may be a known one, and is not particularly limited in the present invention.

As shown in FIG. 21 (A), the jig 70 is fixed to the moment of inertia measuring device 60, and the moment of inertia Ia of the jig 70 is measured.
Next, as shown in FIG. 21B, the sole portion 18 of the golf club head 10 is fixed to the upper surface portion 72 of the jig 70, and the total moment of inertia Ib of the golf club head 10 and the jig 70 is measured. .. Next, the moment of inertia MI of the golf club head 10 is obtained from (Ib-Ia) from the obtained moments of inertia Ia and Ib.
In the normal moment of inertia measuring instrument 60, the numerical value of Ia is automatically tare by a series of procedures by making full use of the operation button 69, and the numerical value of (Ib-Ia) is displayed.

In order to fix the golf club head 10 and the jig 70, for example, fixing with a double-sided tape, an adhesive such as clay, fixing with an adhesive, fixing with a magnetic force, or the like can be mentioned.
For fixing, the sole portion 18 of the golf club head 10 is fixed to the upper surface portion 72 of the jig 70. However, if the sole portion 18 has a convex curved surface, the upper surface portion 72 is preferably a concave curved surface that matches the convex curved surface, and if the sole portion 18 is a flat surface, the upper surface portion 72 is It is preferably a flat surface. That is, it is preferable that both sides to be fixed match.
When the sole portion 18 of the golf club head 10 has a curved surface, an adhesive body (not shown) is provided so as to match the sole portion 18 and the upper surface portion 72, and the golf club head 10 is fixed. In this case, it goes without saying that a sticky body having an internal mass of an adhesive or the like is included in a part of the jig, and in tare pulling, it is pulled as a tare like the jig.

The golf club head 10 passes through the center of gravity point G0 of the golf club head 10 shown in FIG. 22 (A), has a first straight line V orthogonal to the horizontal plane B, and the moment of inertia measuring instrument 60 shown in FIG. 22 (B) is twisted. It is preferable that the rotation axis R of the vibration is fixed to the moment of inertia measuring instrument 60 so as to coincide with or substantially coincide with the rotation axis R as shown in FIG. 22 (C).
Approximately the same means that the distance between the point where the rotation axis R passes through the horizontal plane B and the point p where the first straight line V passes through the horizontal plane B is within 3 mm, preferably within 2 mm, and more preferably within 1 mm. ..
By fixing the sole portion 18 of the golf club head 10 within this range, the moment of inertia MI of the golf club head 10 can be measured more accurately.

Further, it is not always necessary that the distance between the point where the rotation axis R passes through the horizontal plane B and the point p where the first straight line V passes through the horizontal plane B is within the above range, and the distance is known to automatically tare. It can be corrected by subtracting the product of the mass of the golf club head 10 multiplied by the self-squared of this distance from the numerical value of (Ib-Ia) obtained in the above steps.
The moment of inertia MI of the golf club head 10 may be obtained by this correction method. As described above, the method for measuring the moment of inertia MI of the golf club head 10 is not particularly limited.

The point where the rotation axis R of the moment of inertia measuring device 60 and the rotation axis R pass through the sole portion 18 is determined by the moment of inertia measuring device 60. The rotation axis R is preferably vertical or substantially vertical.
Here, the term "vertical" means that the inclination with respect to the vertical direction is within 2 °, preferably within 1 °. In order to set the rotation axis R vertically or almost vertically, adjust the level of the measuring instrument with the spirit level provided in the moment of inertia measuring instrument 60 as a guide, or adjust the measuring instrument horizontally. It may be installed on top.
By setting within the above range, the moment of inertia MI around the rotation axis with the first straight line V passing through the center of gravity G of the golf club head 10 and orthogonal to the horizontal plane B as the first rotation axis can be measured more accurately. Can be done.

Further, it is preferable that the plane supported by the upper surface portion 72 of the jig 70 is horizontal or substantially horizontal. Approximately horizontal in the present invention means that the inclination with respect to the horizontal plane is within 2 °, preferably within 1 °.
By setting it within the above range, the moment of inertia MI of the golf club head 10 can be measured more accurately.

Further, it is preferable that the jig 70 is mounted on the moment of inertia measuring device 60 so that the position of the center of gravity of the jig itself coincides with or substantially coincides with the rotation axis R. In general, when the center of gravity position of the jig 70 is C as shown in FIG. 23, the distance δ between the center of gravity position C and the rotation axis R is within 2 mm, preferably within 1 mm.
By setting the position C of the center of gravity of the jig 70 within the above range, the moment of inertia MI of the golf club head 10 can be measured more accurately.

In the present embodiment, the moment of inertia MI of the golf club head 10 is 5000 g · cm ² or more and 5900 g · cm ² or less.
When the moment of inertia MI is within the above range, it is advantageous in improving the directionality of the hit ball.
If the moment of inertia MI is below the above range, it is disadvantageous in improving the directionality of the hit ball.
Further, according to the Rules of Golf, the upper limit of the moment of inertia MI is 5900 g · cm ² .
The volume of the head body 12 is 400 cc or more and 470 cc or less.
When the volume of the head body 12 is within the above range, it is advantageous in securing the moment of inertia MI.
If the volume of the head body 12 is less than the above range, it is disadvantageous in securing the moment of inertia MI.
Further, according to the Rules of Golf, the volume of the head body 12 is limited to 470 cc.

As shown in FIG. 5, the weight portion 30 is made of the same material as the head body 12.
By doing so, the weight portion 30 can be formed by casting at the same time as the head main body 12, which is advantageous in reducing the manufacturing cost.
Further, in the weight portion 30, the wall portion 11B having a wall thickness larger than the wall thickness of the wall portion 11A constituting the face portion 14, the crown portion 16, and the sole portion 18 has a sole portion at the position of the face back 28 of the side portion 20. It is configured to be formed extending from 18 to the crown portion 16.
The weight portion 30 may be provided such that the wall portion 11B is provided at a portion of the face back 28 of the side portion 20 from the sole portion 18 to an intermediate portion between the sole portion 18 and the crown portion 16. In other words, a gap may be formed between the upper end of the weight portion 30 and the crown portion 16.
However, as in the present embodiment, the weight portion 30 is composed of the wall portion 11B formed continuously extending from the sole portion 18 to the crown portion 16 at the portion of the face back 28 of the side portion 20. The weight portion 30 can also be formed in the above gap portion.
Therefore, since the heavier weight portion 30 can be provided, the weight portion 30 can secure a large moment of inertia MI of the golf club head 10, which is more advantageous in improving the directionality of the hit ball.

Further, as shown in FIG. 7, the weight portion 30 is connected to the crown portion 16 via a gradually changing portion 32 for the crown portion whose wall thickness gradually decreases toward the crown portion 16 side.
The length ΔL of the gradually changing portion 32 for the crown portion is 3 mm or more and 10 mm or less in the fracture surface in which the head main body 12 including the gradually changing portion 32 for the crown portion is broken in a plane parallel to the face center reference cross section Pfc.
The length ΔL of the gradual change portion 32 for the crown portion is the distance from the start end K1 to the end K2 of the gradual change portion 32 for the crown portion along the shape of the inner surface of the gradual change portion 32 for the crown portion facing the space 13. Is.
In the fracture surface, the wall thickness d of the crown portion 16 is 0.3 mm or more and 0.8 mm or less in a range within 30 mm from the boundary K (termination K2) between the crown portion 16 and the gradually changing portion 32 for the crown portion.

The start end K1 and the end end K2 of the gradually changing portion 32 for the crown portion are defined as follows.
That is, as shown in FIG. 18, in an arbitrary cross section parallel to the face center reference cross section Pfc, the cross section near the cross section where the wall thickness of the weight portion 30 is maximum or the cross section where the wall thickness is maximum is closer to the crown portion 16. The contour line of the weight inner surface 3010 in the above is specified at three measurement points at a pitch of 1 mm from the sole portion 16 toward the crown portion 16, and the radius R of the circle defined by the three measurement points is measured.
This measurement is performed while moving by 1 mm pitch, and the value R1 / R0 obtained by dividing the currently measured radius R1 by the previously measured radius R0 is calculated.
Then, as shown in FIG. 19A, the midpoint of the three measurement points when R1 / R0 is less than 0.5 is defined as the starting end K1 of the gradually changing portion 32 for the crown portion.
Further, as shown in FIG. 19B, the midpoint of the three measurement points when R1 / R0 is less than 0.4 is defined as the terminal K2 of the gradually changing portion 32 for the crown portion.

If the gradual change portion 32 for the crown portion is not provided, a step is formed between the wall portion 11A of the crown portion 16 and the wall portion 11B of the weight portion 30, so that the wall portion 11A of the crown portion 16 and the weight at the time of casting are formed. The wall portion 11A of the crown portion 16 is dented toward the space 13 due to the difference in shrinkage ratio from the wall portion 11B of the portion 30, which is disadvantageous in ensuring the appearance of the golf club head 10.
However, when the gradually changing portion 32 for the crown portion is provided as in the present embodiment, the wall portion 11A of the crown portion 16 and the wall portion 11B of the weight portion 30 are smoothly connected without a step, and therefore, at the time of casting. The deformation of the wall portion 11A of the crown portion 16 due to the difference in shrinkage ratio between the wall portion 11A of the crown portion 16 and the wall portion 11B of the weight portion 30 can be suppressed, and the appearance of the golf club head 10 can be improved. It is advantageous to secure it.

Further, when the length ΔL of the gradually changing portion 32 for the crown portion is within the range of 3 mm or more and 10 mm or less, it is advantageous in suppressing the deformation of the wall portion 11A of the crown portion 16 during casting.
If the length ΔL of the slowly changing portion 32 for the crown portion is less than the range of 3 mm or more and 10 mm or less, the length ΔL of the slowly changing portion 32 for the crown portion is too short, so that the wall portion 11A of the crown portion 16 is deformed during casting. The effect of suppressing is reduced. In other words, the wall portion 11A tends to be dented.
If the length ΔL of the slowly changing portion 32 for the crown portion exceeds the range of 3 mm or more and 10 mm or less, the length ΔL of the slowly changing portion 32 for the crown portion is too long, and the mass is excessively taken by the crown portion 16. The mass of the weight portion 30 (internal weight) is reduced, and the effect of securing the moment of inertia MI of the golf club head 10 is reduced.
When the wall thickness d of the crown portion 16 is within a range of 0.3 mm or more and 0.8 mm or less within a range of 30 mm from the boundary K, the weight portion 30 (internal weight) is not excessively taken by the crown portion 16. ) Can be secured, and the effect of increasing the moment of inertia MI of the golf club head 10 is great.
If the wall thickness d of the crown portion 16 is less than 0.3 mm or more and 0.8 mm or less within a range of 30 mm from the boundary K, the wall thickness d of the crown portion 16 is too thin and the wall of the crown portion 16 at the time of casting is formed. The effect of suppressing the deformation of the portion 11A is reduced.
If the wall thickness d of the crown portion 16 exceeds the range of 0.3 mm or more and 0.8 mm or less within a range of 30 mm from the boundary K, the wall thickness d of the crown portion 16 is too thick and the weight of the crown portion 16 becomes heavy. , The effect of securing the moment of inertia MI of the golf club head 10 is reduced.

Although the case where the weight portion 30 is formed of the same material as the head main body 12 has been described, the weight portion 30 is formed including a material having a heavier specific gravity than the head main body 12, as in the modified example shown below. It may have been.
That is, as shown in FIGS. 6A to 6C, the weight portion 30 includes a lower portion 3002 connected to the sole portion 18, an upper portion 3004 connected to the crown portion 16, and the lower portions 3002 and the upper portion 3004. It is provided with an intermediate portion 3006 located between the two and provided with a recess 3008 on the outer surface of the face back 28.
The weight portion 30 includes a first weight portion 30A composed of a lower portion 3002, an upper portion 3004, and an intermediate portion 3006, and a second weight portion 30B in which a material having a higher specific density than that of the head body 12 is embedded in the recess 3008. It is composed of.
The second weight portion 30B is located inside both ends of the first weight portion 30A in the toe heel direction in a state where the head body 12 is viewed in a plan view in the reference state, and at least a part of the second weight portion 30 is within the weight specified range. It is located in LW.
When the weight portion 30 is formed by the first and second weight portions 30A and 30B in this way, the weight portion 30 contains a material having a heavier specific gravity than the head main body 12, so that the weight portion 30 is not provided. It is advantageous in arranging the weight of the weight portion 30 at a position more distant from the center of gravity point G of the golf club head 10 and more advantageous in securing the moment of inertia MI of the golf club head 10.
Various conventionally known metal materials can be used as materials having a heavier specific gravity than the material of the head body 12.
For example, when the head body 12 is made of a titanium alloy, tungsten or the like having a heavier specific gravity than the titanium alloy can be used as the material for forming the second weight portion 30B.

Further, the weight portion 30 may be formed by joining a material having a heavier specific gravity than the head main body 12 to the inner surface of the face back 28 in the space 13 without embedding it in the recess 3008.
In this case as well, it is advantageous to arrange the weight of the weight portion 30 at a position more distant from the center of gravity point G of the golf club head 10, and it is more advantageous to secure the moment of inertia MI of the golf club head 10.
However, as described above, when the weight portion 30 is made of the same material as the head main body 12, different materials are used as compared with the case where the weight portion 30 is made of the same material as the head main body 12. Since it is not necessary to join the parts, it is advantageous in reducing the parts cost and the manufacturing cost.

In the present embodiment, as shown in FIG. 1, the center of gravity point FG on the face surface is located within a range of 5 mm from the center point of the face surface 14A.
When the center of gravity point FG on the face surface is located within a range of 5 mm from the center point of the face surface 14A, it is advantageous in improving the flight distance of the hit ball.
If the center of gravity point FG on the face surface is located outside the range within 5 mm from the center point of the face surface 14A, the effect of improving the flight distance of the hit ball is reduced.

Further, in the present embodiment, the maximum thickness dmax of the weight portion 30 is 3% or more and 14% or less of the maximum head width W.
When the maximum thickness dmax of the weight portion 30 is within the range of 3% or more and 14% or less of the maximum head width W, it is more advantageous to secure the moment of inertia MI of the golf club head 10.
When the maximum thickness dmax of the weight portion 30 is less than the range of 3% or more and 14% or less of the maximum head width W, the weight of the weight portion 30 is small, so that the effect of securing the moment of inertia MI of the golf club head 10 is reduced. ..
When the maximum thickness dmax of the weight portion 30 exceeds the range of 3% or more and 14% or less of the head maximum width W, the volume occupied by the weight portion 30 increases, so that the rigidity of the head body 12 increases and the effect of ensuring resilience is achieved. Decreases.

Further, in the present embodiment, as shown in FIG. 3, a plane parallel to the face center reference cross section Pfc and passing through the weight maximum thickness point N2 is defined as a fifth plane P5.
As shown in FIGS. 8A and 8B, in an arbitrary cross section in which the head body 12 is broken in a plane parallel to the face center reference cross section Pfc between the third plane P3 and the fifth plane P5 described above. The point on the outer surface of the head body 12 located at the farthest point in the face back 28 direction from the face portion 14 is defined as the first point α1, and the point on the outer surface of the head body 12 located 2 mm away from the first point α1 in the face portion 14 direction. Is the second point α2.
There is at least one arbitrary cross section having a length of a straight line Lα connecting the first point α1 and the second point α2 of 5 mm or more and 25 mm or less .
In this case, since the second point α2 exists at two points, there are also two straight lines Lα, but the straight line Lα having the larger length is defined as a target.
This is advantageous in securing a large space for arranging the weight portion 30 in the vertical direction connecting the crown portion 16 and the sole portion 18 inside the head main body 12 (space 13), and is advantageous for the golf club head 10. It is more advantageous in securing the moment of inertia MI.
Further, if there is no arbitrary cross section in which the length of the straight line Lα connecting the first point α1 and the second point α2 is 5 mm or more and 25 mm or less , it is disadvantageous in securing a large space for arranging the weight portion 30. Therefore, the effect of securing the moment of inertia MI of the golf club head 10 is reduced.

Further, in the present embodiment, as shown in FIG. 9, the toe heel of the projected contour line B in which the contour line outside the cross section obtained by breaking the head body 12 in a plane parallel to the horizontal plane HP in the reference state is projected onto the horizontal plane HP. The point most protruding toward the toe 22 in the direction is defined as the protruding point C.
The point where the first straight line L1 extending in the front-rear direction of the head body 12 passing through the protrusion point C and the second straight line L2 extending in the toe heel direction through the head maximum width point N1 in the projected contour line B intersect. The intersection is N12.
The projected contour line B is located outside the range of 20 mm from the intersection N12. In other words, the distance β between the projected contour line B and the intersection N12 is 20 mm or more.

The golf club head formed so that the projected contour line B is located within a range of 20 mm from the intersection N12 is called a quadrangular driver because it has a quadrangular shape when viewed in a plan view. A square driver generally has a larger area of a sole portion 18 and a side portion 20 than a non-square golf club head.
That is, since the quadrangular driver has a quadrangular shape when viewed in a plan view, the golfer tends to feel a sense of discomfort in the shape when visually recognizing the golf club head, it is difficult to swing, the head speed is reduced, and the flight distance is secured. The effect of hitting is likely to decrease, and the feel of hitting is also likely to decrease due to the rectangular shape.
On the other hand, the golf club head 10 in which the projected contour line B is located outside the range of 20 mm from the intersection N12 has no discomfort in shape when viewed by a golfer, is easy to swing, and does not reduce the head speed. , It is advantageous in securing the flight distance.

Further, when the length obtained by projecting a straight line connecting the center of gravity point G0 of the golf club head 10 and the leading edge 19 onto the horizontal plane HP in the face center reference cross section Pfc of the head body 12, the center of gravity depth is 40 mm. More than 60 mm is preferable.
When the depth of the center of gravity is within the above range, the golf club head 10 rotates so that the face surface 14A faces upward at the time of hitting, which is advantageous in obtaining the effect of launching the ball, which leads to an increase in flight distance.

Further, it is preferable that the wall thickness of the crown portion 16 facing the space 13 is 0.3 mm or more and less than 2.0 mm in order to secure the resilience and durability of the golf club head 10.
If the wall thickness of the crown portion 16 is less than the above range, the effect of ensuring durability is reduced.
If the wall thickness of the crown portion 16 exceeds the above range, the effect of ensuring resilience is reduced.
Further, it is preferable that the wall thickness of the sole portion 14 facing the space 13 is 0.5 mm or more and less than 4.0 mm in order to secure durability and freedom of design.
If the wall thickness of the sole portion 14 is less than the above range, the effect of ensuring durability is reduced.
If the wall thickness of the sole portion 14 exceeds the above range, the weight of the head body 12 becomes large, and the degree of freedom in design for setting the center of gravity point G0 of the golf club head 10 is restricted.

The maximum head width W of the head body 12 is preferably 100 mm or more and 127 mm or less.
When the head maximum width W is less than the above range, the boundary point between the face portion 14 and the sole portion 16 and the boundary point between the sole portion 16 and the weight portion 30 approach each other. Since the stress of the above is concentrated, the effect of ensuring durability is reduced.
Further, according to the Rules of Golf, the maximum head width W is set to 127 mm.

Further, the weight of the head body 12 is preferably 180 g or more and 210 g or less, which secures the moment of inertia MI and improves the directionality of the hit ball.
When the head weight is lower than the above range, the head weight is small, so that the moment of inertia MI is small, and the effect of improving the directionality of the hit ball is reduced.
When the head weight exceeds the above range, the head weight is large, so that the swing speed is lowered and the effect of securing the flight distance is lowered.

As described above, according to the present embodiment, as shown in FIGS. 3 and 4, the maximum weight thickness point N2 is located in the weight specified range LW, so that the weight portion 30 causes the golf club head 10 to have a weight. It is advantageous in securing a large moment of inertia MI and improving the directionality of the hit ball.
Further, since the weight maximum thickness point N2 is located in the weight specified range LW, the center of gravity point FG on the face surface of the head body 12 including the weight portion 30 is located near the center point Pc of the face surface 14A. It is advantageous in improving the flight distance of the hit ball.

Further, the present invention is applied to a golf club set including a plurality of golf clubs 100 having such golf club heads 10 having different counts.

Hereinafter, experimental examples of the present invention will be described.
24 to 29 are views showing the experimental results of the golf club head 10 according to the present invention.
A golf club head 10 as a sample was prepared for each experimental example, and the following four evaluation items were measured to obtain an index (evaluation point), and a total score of the four indexes was obtained.
In the following experimental example, a driver was used as the golf club head 10 as an experimental target.

(1) Average flight distance The average value of the flight distances of 20 subjects when a golf ball was actually hit using the golf club head 10 of each experimental example was evaluated by an index. The index of the experimental example corresponding to the comparative example is set to 100, and the larger the index, the longer the average flight distance and the better the evaluation.
Specifically, a target point is set in the hitting field and the golfer hits the ball toward the target point. Ten balls are played for one golf club, and the average value of the flight distance is measured as the evaluation data of the average flight distance.

(2) Variation in flight distance The variation in flight distance measured during the average flight distance test was evaluated by an index.
Here, the variation in flight distance is obtained as follows.
The difference between the maximum value and the minimum value of the flight distance is obtained as the variation of the flight distance.
The evaluation data of the flight distance variation was obtained for each of the 20 subjects using the golf clubs of each experimental example, and the average value of the evaluation data of the flight distance variation of 20 persons was obtained for each of the golf clubs.
Then, the average value of the evaluation data of the experimental examples corresponding to the comparative examples is set to 100, and the experimental examples other than the comparative examples are indexed ((the average value of the evaluation data of the experimental examples corresponding to the comparative examples / the experimental examples other than the comparative examples). It was evaluated by the average value of the evaluation data) × 100). That is, the higher the index, the smaller the variation in flight distance and the better.

(3) Left-right variation The left-right variation of 20 subjects when a golf ball was actually hit using the golf club head 10 of each experimental example was evaluated by an index.
Here, the left-right variation is obtained as follows.
That is, a target point is set in the hitting field and the golfer hits the ball toward the target point. Then, the distance between the straight line connecting the hitting point and the target point and the stopping point of the hit ball is recorded as the directional blur width (yard).
The amount of deviation to the right with respect to the target flight line Lg is displayed as a positive (+) value, and the amount of deviation to the left is displayed as a negative (-) value. Was calculated as the evaluation data of the left-right variation.
Here, the evaluation data of the left-right variation was obtained for each of the 20 subjects using the golf clubs of each experimental example, and the average value of the evaluation data of the left-right variation of 20 subjects was obtained for each of the golf clubs. Then, the average value of the evaluation data of the experimental examples corresponding to the comparative examples is set to 100, and the experimental examples other than the comparative examples are indexed ((the average value of the evaluation data of the experimental examples corresponding to the comparative examples / the experimental examples other than the comparative examples). It was evaluated by the average value of the evaluation data) × 100). That is, the higher the index, the smaller the left-right variation and the better.

(4) Hit feeling The hit feeling when a golf ball was actually hit using the golf club head 10 of each experimental example for 20 subjects was evaluated by an index.
The index of the experimental example corresponding to the comparative example is set to 100, and the larger the index, the better the feel of hitting and the better the evaluation.
In the evaluation of the feel of hitting, 20 golfers actually hit a golf ball 10 times at a time with respect to one golf club head 10, and the average value was calculated.
The hitting feeling is dominated by the hitting sound when the ball is hit. Generally, when the reverberation is long, it is expressed as having a feeling of playing, and when the reverberation is short, it is expressed as having a soft feel.

(5) Total score The total score is the sum of the above-mentioned four indexes of average flight distance, flight distance variation, left-right variation, and hit feeling.
The total score of the experimental examples corresponding to the comparative examples is set to 400, and the larger the total score, the better the evaluation.

The golf club head of the experimental example will be described below.
The golf club head used in the experimental examples is a driver, and the following conditions are common except for the parameters specified in each experimental example.
Material of head body 12: Titanium alloy Ti-8Al-1Mo-1V
Material of weight portion 30: Titanium alloy same as the material of head body 12. However, in Experimental Examples 30 and 31, the weight portion 30 is the first weight portion 30A made of titanium alloy, and the specific gravity is heavier than that of titanium alloy, as will be described later. It is provided with a second weight portion 30B made of tungsten.
Loft angle 10.5 °
Rye angle 59 °
Weight 200g

(Condition 1)
As shown in FIG. 24, the conditions specified in claim 1 are changed, and the conditions specified in claims 6 to 8 and 10 are set to constant conditions outside the specified range.
Further, the distance β between the projected contour line B and the intersection N12 defined in claim 9 is set to 25 mm, and the provision that the projected contour line B is located outside the range of 20 mm from the intersection N12 is set as a constant condition.

As shown in FIG. 24, Experimental Example 1 corresponds to a comparative example, and is a conventional golf club head (driver) having a weight portion on the face back side.
In Experimental Example 1, although the volume V of the head body 12 and the moment of inertia MI specified in claim 1 are satisfied, the maximum weight thickness point N2 is outside the range of the weight specified range LW.

In Experimental Example 2, the maximum weight thickness point N2 specified in claim 1 is within the range of the weight specified range LW, and the volume V of the head body 12 is 395 cc, which is less than the range of 400 cc or more and 470 cc or less. It is outside the scope of the present invention.
The moment of inertia MI is 4600 g · cm ² , which is in the range of 5000 g · cm ² or more and 5900 g · cm ² .
In Experimental Example 3, the maximum weight thickness point N2 specified in claim 1 is within the range of the weight specified range LW, and the volume V of the head body 12 is 480 cc, which exceeds the range of 400 cc or more and 470 cc or less. It is outside the scope of the present invention.
The moment of inertia MI is 5230 g · cm ² , which is in the range of 5000 g · cm ² or more and 5900 g · cm ² .
In Experimental Example 4, the maximum weight thickness point N2 specified in claim 1 is within the range of the weight specified range LW, the volume V of the head body 12 is 410 cc, and the volume V is within the range of 400 cc or more and 470 cc or less.
The moment of inertia MI is 5050 g · cm ² , which is in the range of 5000 g · cm ² or more and 5900 g · cm ² .
In Experimental Example 5, the maximum weight thickness point N2 specified in claim 1 is within the range of the weight specified range LW, the volume V of the head body 12 is 465 cc, and the volume V is within the range of 400 cc or more and 470 cc or less.
The moment of inertia MI is 5750 g · cm ² , which is in the range of 5000 g · cm ² or more and 5900 g · cm ² .
In Experimental Example 6, the weight maximum thickness point N2 specified in claim 1 is outside the range of the weight specified range LW and is outside the range of the present invention, and the weight portion 30 is not appropriately provided.
Further, the volume V of the head body 12 is 460 cc, which is within the range of 400 cc or more and 470 cc or less.
Further, the moment of inertia MI is 4800 g · cm ² , which is less than the range of 5000 g · cm ² or more and 5900 g · cm ² , which is outside the range of the present invention.
In Experimental Example 7, the maximum weight thickness point N2 specified in claim 1 is within the range of the weight specified range LW, the volume V of the head body 12 is 460 cc, and the volume V is within the range of 400 cc or more and 470 cc or less.
Further, the moment of inertia MI is 6000 g · cm ² , which exceeds the range of 5000 g · cm ² or more and 5900 g · cm ² , which is outside the range of the present invention.
Therefore, Experimental Example 7 violates the Rules of Golf, and the thickness of the crown portion 16 is too thin, so that the durability is lowered, the hitting sound is too low, and the hitting feeling is likely to be lowered.
Therefore, in Experimental Examples 4 and 5 satisfying the provisions of claim 1, the average flight distance, flight distance variation, left-right variation, hit feeling, and total score exceed Experimental Examples 1, 2, 3, 6, and 7.

(Condition 2)
As shown in FIG. 25, the conditions specified in claim 1 are changed within the specified range, the conditions specified in claim 6 are changed, and the conditions specified in claims 7, 8 and 10 are out of the specified range. It was set as a certain condition.
Further, the distance β between the projected contour line B and the intersection N12 defined in claim 9 is set to 25 mm, and the provision that the projected contour line B is located outside the range of 20 mm from the intersection N12 is set as a constant condition.

Experimental Example 8 does not satisfy the provision that the center of gravity point HG on the face surface is separated from the center point Pc of the face surface by 6 mm on the heel side, and the distance Δg specified in claim 6 is within 5 mm.
Experimental Example 9 does not satisfy the provision that the center of gravity point HG on the face surface is separated from the center point Pc of the face surface by 6 mm on the toe side, and the distance Δg specified in claim 6 is within 5 mm.
In Experimental Examples 8 and 9, since the distance Δg between the center of gravity point HG on the face surface and the center point Pc of the face surface is too far apart, the feel of hitting tends to decrease.
Experimental Example 10 satisfies the provision that the center of gravity point HG on the face surface is separated from the center point Pc of the face surface by 4 mm on the heel side, and the distance Δg specified in claim 6 is within 5 mm.
Experimental Example 11 satisfies the provision that the center of gravity point HG on the face surface is separated from the center point Pc of the face surface by 4 mm on the toe side, and the distance Δg specified in claim 6 is within 5 mm.
Therefore, in Experimental Examples 10 and 11 satisfying the provisions of claims 1 and 6, the average flight distance, flight distance variation, left-right variation, hit feeling, and total score are higher than those of Experimental Examples 8 and 9.

(Condition 3)
As shown in FIG. 26, the conditions specified in claim 1 are changed within the specified range, the conditions specified in claim 7 are changed, and the conditions specified in claims 8 and 10 are constant outside the specified range. It was a condition.
Further, the distance Δg between the center of gravity point HG on the face surface and the center point Pc of the face surface specified in claim 6 is set to 0 mm, which is a constant condition satisfying the specification.
Further, the distance β between the projected contour line B and the intersection N12 defined in claim 9 is set to 25 mm, and the provision that the projected contour line B is located outside the range of 20 mm from the intersection N12 is set as a constant condition.

In Experimental Example 12, the maximum thickness dmax of the weight portion 30 is 2% of the maximum head width W, which is less than the range of 3% or more and 14% or less specified in claim 7.
In Experimental Example 12, since the thickness of the weight portion 30 is thin, the weight portion 30 is arranged in a wide range along the toe heel direction, so that the hitting sound changes and the hitting feeling tends to deteriorate.
In Experimental Example 13, the maximum thickness dmax of the weight portion 30 is 16% of the maximum head width W, which exceeds the range of 3% or more and 14% or less specified in claim 7.
In Experimental Example 13, since the weight portion 30 is thick, the weight portions 30 are arranged in a narrow range along the toe-heel direction, so that the hitting sound changes and the hitting feeling tends to decrease.
In Experimental Example 14, the maximum thickness dmax of the weight portion 30 is 5% of the maximum head width W, which is within the range of 3% or more and 14% or less specified in claim 7.
In Experimental Example 13, the maximum thickness dmax of the weight portion 30 is 13% of the maximum head width W, which is within the range of 3% or more and 14% or less specified in claim 7.
Therefore, in Experimental Examples 14 and 15 satisfying the provisions of claims 1, 6 and 7, the average flight distance, flight distance variation, left-right variation, hit feeling, and total score are higher than those of Experimental Examples 12 and 13.

(Condition 4)
As shown in FIG. 27, the conditions specified in claim 1 are changed within the specified range, the conditions specified in claim 8 are changed, and the conditions specified in claims 9 and 10 are constant outside the specified range. It was a condition.
Further, the distance Δg between the center of gravity point HG on the face surface and the center point Pc on the face surface specified in claim 6 is set to 0 mm, which is a constant condition satisfying the specification, and the maximum thickness dmax of the weight portion 30 specified in claim 7. Is 10% of the maximum head width W, which is a constant condition that satisfies the regulation.
Further, the distance β between the projected contour line B and the intersection N12 defined in claim 9 is set to 25 mm, and the provision that the projected contour line B is located outside the range of 20 mm from the intersection N12 is set as a constant condition.

In Experimental Example 16, the length of the straight line Lα connecting the first point α1 and the second point α2 is 3 mm, which is less than the range of 5 mm or more and 25 mm or less specified in claim 8.
Therefore, in Experimental Example 16, since the space in the vertical direction in which the weight portion 30 is arranged is small in the space 13 of the head body 12, the effect of securing the moment of inertia MI is reduced, and the moment of inertia MI is also the lower limit of 5000 g · cm ² . It is a value.
In Experimental Example 17, the length of the straight line Lα connecting the first point α1 and the second point α2 is 26 mm, which exceeds the range of 5 mm or more and 25 mm or less specified in claim 8.
Therefore, in Experimental Example 17, the space in the vertical direction in which the weight portion 30 is arranged in the space 13 of the head body 12 becomes too large, and the surface area of the weight portion 30 becomes too large, making it difficult to secure the weight of the weight portion 30. The effect of efficiently securing the moment of inertia MI is reduced, and the moment of inertia MI is also the lower limit of 5000 g · cm ² .
In Experimental Example 18, the length of the straight line Lα connecting the first point α1 and the second point α2 is 7 mm, which is within the range of 5 mm or more and 25 mm or less specified in claim 8.
In Experimental Example 19, the length of the straight line Lα connecting the first point α1 and the second point α2 is 23 mm, which is within the range of 5 mm or more and 25 mm or less specified in claim 8.
Therefore, in Experimental Examples 18 and 19 satisfying the provisions of claims 1, 6, 7, and 8, the average flight distance, flight distance variation, left-right variation, hit feeling, and total score are higher than those of Experimental Examples 16 and 17.

(Condition 5)
As shown in FIG. 28, the conditions specified in claim 1 are changed within the specified range, the conditions specified in claim 9 are changed, and the conditions specified in claim 10 are fixed conditions outside the specified range. did.
Further, the distance Δg between the center of gravity point HG on the face surface and the center point Pc of the face surface specified in claim 6 is set to 0 mm, which is a constant condition satisfying the specification, and the maximum thickness dmax of the weight portion 30 specified in claim 7. Is 10% of the maximum head width W, which is a constant condition that satisfies the regulation, and the length of the straight line Lα connecting the first point α1 and the second point α2 specified in claim 8 is 7 mm, which is a constant condition that satisfies the regulation. It was a condition.

Experimental Example 20 does not satisfy the condition that the distance β between the projected contour line B and the intersection N12 is 17 mm, and the projected contour line B defined in claim 9 is located outside the range of 20 mm from the intersection N12. ..
That is, since the experimental example 20 has a square shape when viewed in a plan view, the golfer tends to feel a sense of discomfort in the shape when the golf club head 10 is visually recognized, it is difficult to swing, the head speed is lowered, and the flight distance is increased. The effect of securing is reduced. In addition, the feel of hitting is likely to deteriorate.
Experimental Example 21 satisfies the condition that the distance β between the projected contour line B and the intersection N12 is 25 mm, and the projected contour line B defined in claim 9 is located outside the range of 20 mm from the intersection N12. ..
Therefore, the experimental example 21 satisfying the provisions of claims 1, 6, 7, 8 and 9 has an average flight distance, a flight distance variation, a left-right variation, a hit feeling, and a total score higher than those of the experimental example 20.

(Condition 6)
As shown in FIG. 29, the conditions specified in claim 1 are changed within the specified range, and the conditions specified in claim 10 are changed.
Further, the distance Δg between the center of gravity point HG on the face surface and the center point Pc of the face surface specified in claim 6 is set to 0 mm, which is a constant condition satisfying the specification, and the maximum thickness dmax of the weight portion 30 specified in claim 7. Is 10% of the maximum head width W, which is a constant condition that satisfies the regulation, and the length of the straight line Lα connecting the first point α1 and the second point α2 specified in claim 8 is 7 mm, which is a constant condition that satisfies the regulation. As a condition, the distance β between the projected contour line B specified in claim 9 and the intersection N12 was set to 25 mm, which was a constant condition satisfying the specified condition.

In Experimental Example 22, the length ΔL of the gradually changing portion 32 for the crown portion is 1 mm, which is less than the range of 3 mm or more and 10 mm or less specified in claim 10.
Further, the wall thickness d of the crown portion 16 within a range of 30 mm from the boundary K between the crown portion 16 and the gradually changing portion 32 for the crown portion is 0.4 mm, and the wall thickness d of the crown portion 16 is 0.3 mm or more and 0.8 mm specified in claim 10. It is within the following range.
In Experimental Example 22, since the length ΔL of the gradually changing portion 32 for the crown portion is too short, the crown surface 16A of the crown portion 16 near the weight portion 30 is likely to be deformed to be dented during casting.
In Experimental Example 23, the length ΔL of the gradually changing portion 32 for the crown portion is 13 mm, which exceeds the range of 3 mm or more and 10 mm or less specified in claim 10.
Further, the wall thickness d of the crown portion 16 within a range of 30 mm from the boundary K between the crown portion 16 and the gradually changing portion 32 for the crown portion is 0.4 mm, and the wall thickness d of the crown portion 16 is 0.3 mm or more and 0.8 mm specified in claim 10. It is within the following range.
In Experimental Example 23, since the length ΔL of the slowly changing portion 32 for the crown portion is too long, the ratio of the weight of the slowly changing portion 32 for the crown portion to the weight of the weight portion 30 becomes excessively large, in other words, the weight portion. The margin of the weight of 30 is reduced, and the effect of securing the moment of inertia MI is reduced. Further, when the distance from the horizontal plane HP to the center of gravity point FG on the face surface is defined as the height of the center of gravity on the face surface, the height of the center of gravity on the face surface tends to be high, and the effect of ensuring the flight distance is reduced.

In Experimental Example 24, the length ΔL of the gradually changing portion 32 for the crown portion is 4 mm, which is within the range of 3 mm or more and 10 mm or less specified in claim 10.
Further, the wall thickness d of the crown portion 16 within a range of 30 mm from the boundary K between the crown portion 16 and the gradually changing portion 32 for the crown portion is 0.4 mm, and the wall thickness d of the crown portion 16 is 0.3 mm or more and 0.8 mm specified in claim 10. It is within the following range.
In Experimental Example 25, the length ΔL of the gradually changing portion 32 for the crown portion is 8 mm, which is within the range of 3 mm or more and 10 mm or less specified in claim 10.
Further, the wall thickness d of the crown portion 16 within a range of 30 mm from the boundary K between the crown portion 16 and the gradually changing portion 32 for the crown portion is 0.4 mm, and the wall thickness d of the crown portion 16 is 0.3 mm or more and 0.8 mm specified in claim 10. It is within the following range.

In Experimental Example 26, the length ΔL of the gradually changing portion 32 for the crown portion is 6 mm, which is within the range of 3 mm or more and 10 mm or less specified in claim 10.
Further, the wall thickness d of the crown portion 16 within a range of 30 mm from the boundary K between the crown portion 16 and the gradually changing portion 32 for the crown portion is 0.2 mm, and the wall thickness d of the crown portion 16 is 0.3 mm or more and 0.8 mm specified in claim 10. It is below the following range.
In Experimental Example 26, since the wall thickness d of the crown portion 16 is too thin, the effect of ensuring durability is reduced, the hitting sound is low, and the hitting feeling is lowered.
In Experimental Example 27, the length ΔL of the gradually changing portion 32 for the crown portion defined in claim 10 is 6 mm, which is within the range of 3 mm or more and 10 mm or less.
Further, the wall thickness d of the crown portion 16 within a range of 30 mm from the boundary K between the crown portion 16 and the gradually changing portion 32 for the crown portion is 1.0 mm, and the wall thickness d of the crown portion 16 is 0.3 mm or more and 0.8 mm specified in claim 10. It exceeds the following range.
In Experimental Example 27, since the wall thickness d of the crown portion 16 is too thick, the ratio of the weight of the crown portion 16 to the weight of the head body 12 becomes excessively large, in other words, the weight margin of the weight portion 30. Is reduced, and the effect of securing the moment of inertia MI is reduced. In addition, the height of the center of gravity on the face surface tends to be high, and the effect of ensuring the flight distance is reduced.

In Experimental Example 28, the length ΔL of the gradually changing portion 32 for the crown portion defined in claim 10 is 6 mm, which is within the range of 3 mm or more and 10 mm or less.
Further, the wall thickness d of the crown portion 16 within a range of 30 mm from the boundary K between the crown portion 16 and the gradually changing portion 32 for the crown portion is 0.7 mm, and the wall thickness d of the crown portion 16 is 0.3 mm or more and 0.8 mm specified in claim 10. It is within the following range.
In Experimental Example 29, the length ΔL of the gradually changing portion 32 for the crown portion is 6 mm, which is within the range of 3 mm or more and 10 mm or less specified in claim 10.
Further, the wall thickness d of the crown portion 16 within a range of 30 mm from the boundary K between the crown portion 16 and the gradually changing portion 32 for the crown portion is 0.4 mm, and the wall thickness d of the crown portion 16 is 0.3 mm or more and 0.8 mm specified in claim 10. It is within the following range.

In Experimental Examples 30 and 31, as shown in FIGS. 6A to 6C, a first weight portion 30A in which the weight portion 30 is made of a titanium alloy and a second weight portion made of tungsten having a specific gravity heavier than that of the titanium alloy are used. It is equipped with 30B.
In Experimental Examples 30 and 31, the length ΔL of the gradually changing portion 32 for the crown portion is 6 mm, which is within the range of 3 mm or more and 10 mm or less specified in claim 10.
Further, the wall thickness d of the crown portion 16 within a range of 30 mm from the boundary K between the crown portion 16 and the gradually changing portion 32 for the crown portion is 0.4 mm, and the wall thickness d of the crown portion 16 is 0.3 mm or more and 0.8 mm specified in claim 10. It is within the following range.
Therefore, in Experimental Examples 24, 25, 28 to 31, which satisfy the provisions of claims 1, 6, 7, 8, 9, and 10, the average flight distance, flight distance variation, left-right variation, hit feeling, and total score are experimental examples. It exceeds 22, 23, 26 and 27.
Further, in Experimental Examples 30 and 31, the weight portion 30 includes a first weight portion 30A made of a titanium alloy and a second weight portion 30B made of tungsten having a specific gravity heavier than that of the titanium alloy. Is more advantageous in securing the moment of inertia MI as compared with Experimental Examples 24, 25, 28, and 29, which are made of the same titanium alloy as the head body 12.

100 Golf Club 10 Golf Club Head 11A Wall 11B Wall 12 Head Body 13 Space 14 Face 14A Face 16 Crown 18 Sole 20 Side 22 Toe 24 Heel 28 Face Back 30 Weight 3002 Bottom 3004 Top 3006 Middle 3008 Recess 30A 1st weight part 30B 2nd weight part 32 Slow change part for crown part K1 Start end K2 End point Pc Center point Pfc Face center reference cross section FG Face center of gravity point P1 First plane P2 Second plane P3 Third plane P4 4th plane P5 5th plane A Maximum thickness Projection line B Projection contour line C Protrusion point D Contour line W Head maximum width N1 Head maximum width point N2 Weight maximum thickness point LW Weight specified range dmax Maximum thickness of weight portion 30 K boundary ΔL Length of gradual change part for crown part

Claims (6)

A face portion having a vertical height and extending to the left and right, a crown portion extending rearward from the upper part of the face portion, a sole portion extending rearward from the lower portion of the face portion, and the crown portion. A head body including a side portion extending between the sole portion and the toe side edge and the heel side edge of the face portion through the face back.
A weight portion is provided integrally with the side portion at the face back portion of the side portion.
A hollow golf club head having a space inside surrounded by the face portion, the crown portion, the sole portion, the side portion, and the weight portion.
In a reference state in which the golf club head is installed according to a predetermined lie angle and loft angle with respect to the horizontal plane, the head body is broken at a plane including a normal passing through the center point of the face surface and orthogonal to the horizontal plane. The cross section is used as the reference cross section for the center of the face.
In the reference state, the plane orthogonal to the horizontal plane and the face center reference cross section and in contact with the leading edge is defined as the first plane, and the plane parallel to the first plane and in contact with the outer surface of the face back is defined as the second plane. When the head body is viewed in a plane, the distance between the first plane and the second plane is defined as the head maximum width W, and the point where the second plane intersects with the outer surface of the face back is defined as the horizontal plane. The projected point is set as the head maximum width point N1.
In the state where the head body is viewed in a plan view in the reference state, the maximum thickness projection line having the maximum length among the projection lines projected on the horizontal plane by the straight line extending in the thickness direction of the weight portion is the head body. When the intersection intersecting with the contour line projected on the horizontal plane is defined as the weight maximum thickness point N2.
The weight maximum thickness point N2 is parallel to the face center reference cross section and is parallel to the third plane and the third plane passing through the maximum head width point N1 in the state where the head main body is viewed in a plane in the reference state. It is located in the weight specified range between the third plane and the fourth plane 30 mm away from the third plane in the toe direction.
^When the magnitude of the moment of inertia about the axis of rotation is a straight line that passes through the center of gravity of the golf club head and is orthogonal to the horizontal plane in the reference state, the moment of inertia MI is 5000 g. cm ² or more and 5900 g · cm ² or less,
The volume of the head body is 400 cc or more and 470 cc or less.
The weight portion is made of the same material as the head body, and is formed of the same material.
In the weight portion, a wall portion having a wall thickness larger than the wall thickness of the wall portion constituting the face portion, the crown portion, and the sole portion is formed from the sole portion to the crown at the face back portion of the side portion. It is composed of being formed extending over a part,
Any plane in which the head body is broken along a plane parallel to the face center reference cross section between the third plane and a fifth plane parallel to the face center reference cross section and passing through the weight maximum thickness point N2. In cross section
The point on the outer surface of the head body located at the farthest point in the face back direction from the face portion is set as the first point.
When the location on the outer surface of the head body separated from the first point by 2 mm in the face portion direction is defined as the second point,
There is at least one arbitrary cross section having a length of a straight line connecting the first point and the second point of 5 mm or more and 25 mm or less (however, a straight line connecting the first point and the second point). Except for the range of 8.5 mm or less),
A golf club head that features that. The weight portion is connected to the crown portion via a gradual change portion for the crown portion whose wall thickness gradually decreases toward the crown portion side.
The length of the gradually changing portion for the crown portion is 3 mm or more and 10 mm or less in the fracture surface in which the head body including the gradually changing portion for the crown portion is broken in a plane parallel to the face center reference cross section.
In the fracture surface, the wall thickness of the crown portion is 0.3 mm or more and 0.8 mm or less in a range within 30 mm from the boundary between the crown portion and the gradually changing portion for the crown portion.
The golf club head according to claim 1. When the point where the normal of the face surface passing through the center of gravity point of the golf club head intersects the face surface is defined as the center of gravity point on the face surface.
The center of gravity point on the face surface is located within a range of 5 mm from the center point of the face surface.
The golf club head according to claim 1 or 2. The maximum thickness of the weight portion is 3% or more and 14% or less of the maximum head width W.
The golf club head according to any one of claims 1 to 3. In the reference state, the head main body passes through the most protruding point toward the toe side in the toe heel direction among the projected contour lines obtained by projecting the outer contour line of the cross section obtained by breaking the head main body in a plane parallel to the horizontal plane onto the horizontal plane. When the point where the first straight line extending in the front-rear direction and the second straight line extending in the toe heel direction through the head maximum width point N1 of the projected contour lines intersect is defined as an intersection, the projected contour line Is located outside the range of 20 mm from the intersection,
The golf club head according to any one of claims 1 to 4, wherein the golf club head is characterized by the above. A plurality of golf clubs having golf club heads according to any one of claims 1 to 5 and having different counts.
A golf club set featuring that.

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