JP2013000234A - Golf club head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a golf club head in which with the weight reduction of its face portion maintained and the strength of its face portion maintained, the resilience property of its face center can be held within a range complying with the rule, and even if a ball is hit off the face center, the uniform resilience performance can be exerted.SOLUTION: In the golf club head having a hollow internal structure, a face portion 11 includes, on its internal surface, an intersection portion 17 located in the central portion of the face portion, a C-shaped outer peripheral portion 14 having an opening on the side of a hosel portion, four main ribs 12a to 12d extending from the intersection portion up to the outer edge of the face portion, and an intermediate portion 15 located between the intersection portion and the outer peripheral portion or the hosel portion. The intermediate portion is divided to four areas by the four main ribs. The thicknesses of a toe side area 15a and a heel side area 15d are greater than the thickness of the outer peripheral portion, and the thicknesses of a crown side area 15c and a sole side area 15d are less than the thickness of the outer peripheral portion.

Description

  The present invention relates to a golf club head, and more particularly, to a golf club head having a thickness improved on the back surface of a face portion.

Most of the heads of recent wood clubs occupy at least a face portion made of a metal material. The thickness of the face portion needs to be increased in order to maintain the strength that can withstand the impact with the ball. While progressing head size of, since that shall be smaller than the volume of the rules on 460 cm ³ + tolerance 10 cm ^3, the driver of the head occupies the large head most of 460 cm ³ very close to the upper limit Has reached.

  As the head becomes larger in this way, the weight of the face portion becomes heavier. Therefore, the face portion is lightened and the strength of the face portion is maintained. A rib is provided on the back surface. For example, Patent Document 1 describes that six ribs extending from the center of the face toward the peripheral edge of the face are provided.

  Further, in Patent Document 2, when an X-shaped rib is provided at the center of the back surface of the face portion, the resilience performance of the face portion is greater than that when the ball is hit at the face center. When the ball is hit on the side or the crown side, the thickness of the four divided surfaces of the back surface of the face divided by the ribs is set to the sole side and the crown side rather than the toe side and the heel side. It is described that the side is made thinner.

JP 2006-141806 A JP 2008-36050 A

  Conventionally, a large number of high resilience heads having a significantly increased head resilience coefficient have been developed. However, high rebound heads with a head restitution coefficient of 0.830 or higher can no longer be used in competitions since 2008. Therefore, golf club heads have been developed that suppress the coefficient of restitution at the center of the face portion. However, if the coefficient of restitution at the center of the face portion is suppressed, the resilience performance of the face surface other than the center can be improved especially on the crown side. It was found that the sole side was lower.

  Therefore, in view of the above problems, the present invention can maintain the strength of the face portion while maintaining the weight reduction of the face portion, and can suppress the resilience of the face within the rule conforming range. An object of the present invention is to provide a golf club head capable of exhibiting nearly uniform resilience performance even when the ball is hit off and hit.

  In order to achieve the above object, a golf club head according to the present invention has a hollow structure, and includes a face portion, a crown portion, a sole portion, and a hosel portion, The portion has, on its inner surface, a central portion of the face portion, a C-shaped outer peripheral portion having an opening on the hosel portion side, and at least four main ribs extending from the central portion to the outer edge of the face portion, An intermediate portion located between the central portion and the outer peripheral portion or the hosel portion, wherein the intermediate portion is defined by the at least four main ribs, toe side zone, heel side zone, crown side zone and sole side. The wall is divided into at least four sections, and the thickness of the toe side area and the heel side area of the intermediate part is larger than the thickness of the outer peripheral part, and the crown side area and the soft part of the intermediate part are thicker. Thickness of Le side section is formed to be thinner than the wall thickness of the outer peripheral portion.

  The thickness of the crown side area of the intermediate part may be formed thicker than the thickness of the sole side area of the intermediate part. Further, the thickness of the heel side area of the intermediate part may be formed thicker than the thickness of the toe side area of the intermediate part.

  The face portion may further include a reinforcing rib extending on the inner side surface thereof from the central portion toward the outer side of the face portion.

  As described above, according to the present invention, the C-shaped outer peripheral portion having the opening on the hosel portion side is provided on the inner surface of the face portion, and the intermediate portion on the center side of the outer peripheral portion is extended from the central portion to the outer edge of the face portion. Is divided into four areas by at least four main ribs extending in the middle, and the wall thickness of the intermediate toe side area and heel side area is larger than the wall thickness of the outer peripheral area, and the intermediate area crown side area and sole side area By forming the thickness to be thinner than the thickness of the outer peripheral part, while maintaining the weight of the face part, the strength of the face part is also maintained, and the rebound of the face is kept within the rule conforming range. In addition, even when the ball is hit off the face center, rebound performance that is nearly uniform can be exhibited.

1 is a front view showing an embodiment of a golf club head according to the present invention. FIG. 2 is a back view showing a face member constituting the golf club head shown in FIG. 1. It is typical sectional drawing which shows the face member of FIG. 2 along the III-III line. FIG. 4 is a schematic cross-sectional view showing the face member of FIG. 2 along the line IV-IV. FIG. 5 is a schematic cross-sectional view showing the face member of FIG. 2 along the line V-V. FIG. 5 is a schematic cross-sectional view showing the face member of FIG. 2 along the VI-VI line. It is typical sectional drawing which shows the face member of FIG. 2 along the VII-VII line. It is a front view which shows the angle of a rib in the face member of FIG. It is a front view which shows another embodiment of the golf club head based on this invention. It is a front view which shows the golf club head of a comparative example. It is a front view which shows the position of the hit point in the simulation of an Example. It is a graph which shows the simulation result of an Example. It is a graph which shows the simulation result of a comparative example.

  Hereinafter, an embodiment of a golf club head according to the present invention will be described with reference to the accompanying drawings. 3 to 7 are intended to facilitate understanding of the configuration of the present embodiment, and are not drawn to scale.

  As shown in FIG. 1, the golf club head 1 is mainly composed of a face member 10 having a face portion 11 and a main body member 20. The main body member 20 includes a sole portion 21, a crown portion 22, and a hosel portion 25, and is integrally formed. The face member 10 and the main body portion 20 are joined by welding, so that the inside of the head has a hollow structure. The front end side of the golf club head 1 is called a toe 23 and the opposite side is called a heel 24.

  In FIG. 1, a configuration appearing on the surface of the face member 10 on the hollow structure side, that is, the back surface is shown by a broken line. On the back surface of the face member 10, portions where the thickness of the face member 10 is partially thick or thin, for example, ribs 12 and 13, intersections 17 thereof, and an outer peripheral portion 14 are formed. The back surface of the face member 10 will be described.

  As shown in FIG. 2, on the back side surface of the face member 10, an intersecting portion 17 located in the center portion of the face portion 11, a C-shaped outer peripheral portion 14 having an opening on the hosel portion side, and the intersecting portion The intermediate part 15 located between 17 and the outer peripheral part 14 or the hosel part is formed. The wall thicknesses of the crossing portion 17, the outer peripheral portion 14, and the intermediate portion 15 of the face member are different from each other, as will be described in detail later.

  Four main ribs 12 extending from the intersecting portion 17 to the outer edge of the face portion 11 are formed on the back surface of the face member 10. The first main rib 12a extends from the intersecting portion 17 toward the toe side of the crown portion, and the second main rib 12b extends from the intersecting portion 17 toward the heel side of the sole portion, and the third main rib 12c. Is extended from the intersecting portion 17 in the direction of the heel side of the crown portion, particularly in the direction of the hosel portion, and the fourth main rib 12d extends from the intersecting portion 17 in the direction of the toe side of the sole portion. These main ribs 12 are connected via an intersecting portion 17 disposed in the central portion of the face portion 11. As described above, the four main ribs 12 extend from the intersecting portion 17 located at the central portion of the face portion 11, so that the resilience performance at the central portion of the face portion 11 can be suppressed.

  The intermediate portion 15 is divided into four sections by the first to fourth main ribs 12a to 12d. That is, the toe side area 15a located between the first main rib 12a and the fourth main rib 12d, and the sole side area 15b located between the second main rib 12b and the fourth main rib 12d. And a crown side area 15c located between the first main rib 12a and the third main rib 12c, and a heel side area 15d located between the second main rib 12b and the third main rib 12c. It is. On the other hand, although the outer peripheral portion 14 is divided into the main ribs 12, each of the divided areas has a common uniform thickness and is handled as an integral one.

  As shown in FIG. 3, the four main ribs 12 are thickest at the center of the main rib 12, and are adjacent to the planar outer peripheral portion and the intermediate portion, in this case, the toe side region 15 a and the sole side region in the intermediate portion. It is formed so that the wall thickness decreases toward 15b. By setting it as the main rib of such a structure, the stress concentration at the time of impact can be prevented. This reduction in thickness is preferably such that the rib surface has an arcuate curved surface. The radius of this circle is preferably 10 mm or more, for example. On the other hand, as shown in FIG. 4, the thickness of the main rib 12 is formed to be equal from the intersecting portion 17 toward the outside of the face portion 11.

  Further, the thickness of at least one of the four main ribs 12 may be different from the thickness of the other main ribs at the thickest portion. For example, as shown in FIG. 4, it is preferable to form the first main rib 12a thicker than the second main rib 12b. Alternatively, the thickness of the third main rib 12c is preferably thicker than the thickness of the fourth main rib 12d. As described above, the thickness of the main rib located on the crown side of the center of the face portion 11 is made thicker than the thickness of the main rib located on the sole side, so that the resilience performance of the entire face portion 11 is uniform. Can be approached. The thickness of the first main rib 12a and the third main rib 12c located on the crown side may be the same or different. Further, the thickness of the second main rib 12b and the fourth main rib 12d positioned on the sole side may be the same or different.

  The thickness difference between the main ribs on the crown side and the sole side is preferably about 0.2 mm or more, and more preferably about 0.3 mm or more in the thickest portion of each rib. On the other hand, the upper limit of the thickness difference is preferably about 0.7 mm or less, and more preferably about 0.6 mm or less. Further, the difference between the thickness at the thickest portion of the thinnest main rib among the first to fourth main ribs 12 to 15 and the thickness of the peripheral portion 19 adjacent thereto is at least about 0. 3 mm or more is required, preferably about 0.5 mm or more, more preferably about 0.6 mm or more. On the other hand, the upper limit of the difference in thickness is preferably about 2.0 mm or less, and more preferably about 1.8 mm or less.

  Each of the four main ribs 12 is preferably formed with a substantially uniform width. The width of the main rib 12 is preferably about 2 mm or more, and more preferably about 3 mm or more at the portion in contact with the face back surface. On the other hand, the upper limit of the width of the main rib 12 is preferably about 12 mm or less, and more preferably about 10 mm or less.

  A reinforcing rib can also be formed on the back surface of the face portion 11. As shown in FIG. 2, as the reinforcing ribs, a toe side reinforcing rib 13a extending from the intersecting portion 17 to the toe side region 15a at the intermediate portion and a heel side reinforcing rib 13b extending from the intersecting portion 17 to the heel side region 15d are formed. Has been. The toe side and heel side reinforcing ribs 13 a and 13 b are arranged in a straight line via the intersecting portion 17. For example, the reinforcing rib 13 is formed when the resilience performance of the area having the intermediate portion 15 such as the toe side area 15a and the heel side area 15d is high exceeding the rule application range, thereby suppressing the resilience performance of these areas. Can do.

  Similarly to the main rib, the reinforcing rib 13 is formed so that the thickness at the center is the thickest and the thickness decreases toward the middle portion. On the other hand, the thickness of the reinforcing rib 13 is formed so as to gradually decrease from the intersecting portion 17 toward the outside of the face portion 11 as shown in FIG. The width of the reinforcing rib 13 is also formed so as to become gradually narrower from the intersecting portion 17 toward the outside of the face portion 11. Thus, by making the reinforcing rib 13 thinner and thinner from the center toward the outside, a sudden change in rigidity can be suppressed. The tip of the reinforcing rib 13 can be formed in an arc shape. For example, the radius of this circle is preferably 10 mm or more, and more preferably 15 mm or more.

  The reinforcing rib 13 can be formed up to a middle position between the center of the face portion and the outer edge. The length of the reinforcing rib 13 is preferably about 45% or more from the center of the face portion 11 to the outer edge, and more preferably about 50% or more. On the other hand, the upper limit of the length of the reinforcing rib 13 is preferably about 90% or less, and more preferably about 85% or less. Therefore, the reinforcing rib 13 may be formed only in the intermediate portion 15 as shown in FIG. The length of the toe side and the heel side of the reinforcing rib 13 may be the same or different.

  The thickest portion of the reinforcing rib 13 can be the same thickness as the thickest portion of the thickest main ribs of the four main ribs 12, or can be made thinner or thicker. You can also. When thinning or thickening, the difference between them is preferably about 0.1 mm or more, and preferably about 0.5 mm or less. Further, the width of the reinforcing rib 13 is the thickest portion, preferably about 2 mm or more, and more preferably about 3 mm or more. On the other hand, the upper limit of the width of the reinforcing rib 13 is preferably about 12 mm or less, and more preferably about 10 mm or less.

  The outer peripheral portion 14 of the face portion 11 and the intermediate portion 15 divided into four areas, that is, the toe side area 15a, the sole side area 15b, the crown side area 15c, and the heel side area 15d are substantially in the respective regions. Although it has a uniform thickness, as shown in FIG. 6, the thickness of the sole-side area 15b and the crown-side area 15c in the intermediate part is formed thinner than the thickness of the outer peripheral part 14, and as shown in FIG. Further, the thickness of the toe side area 15a and the heel side area 15d in the intermediate part is formed to be thicker than the thickness of the outer peripheral part 14. By adopting such a thick structure, the restitution coefficient of the central portion is lowered, and the restitution coefficient of the entire face portion 11 can be made uniform.

  The width of the outer peripheral portion 14 having a C-shape is preferably about 20% or more of the distance from the intersecting portion 17 of each main rib 12 to the outer edge of the face portion, and preferably about 25% or more. On the other hand, the upper limit of this width is preferably about 40% or less, and more preferably about 35% or less.

  The difference in thickness between the toe side area 15a and the heel side area 15d of the intermediate part and the outer peripheral part 14 is preferably about 0.025 mm or more, more preferably about 0.05 mm or more, and further preferably about 0.1 mm or more. On the other hand, if this difference in wall thickness is too large, there may be cases where uniform resilience performance cannot be obtained, so the upper limit is preferably about 0.5 mm or less, more preferably about 0.4 mm or less. Further, the difference in thickness between the sole side area 15b and the crown side area 15c and the outer peripheral portion 14 is preferably about 0.025 mm or more, more preferably about 0.05 mm or more, and further preferably about 0.1 mm or more. On the other hand, if this difference in wall thickness is too large, there may be cases where uniform resilience performance cannot be obtained, so the upper limit is preferably about 0.5 mm or less, more preferably about 0.4 mm or less.

  The thickness of the sole side area 15b and the crown side area 15c may be the same or different. Preferably, in order to make the resilience coefficients on the sole side and the crown side more uniform, as shown in FIG. The thickness of the sole side area 15b is preferably thinner than that of the crown side area 15c. The difference in thickness is preferably about 0.025 mm or more, more preferably about 0.05 mm or more, and further preferably about 0.1 mm or more. On the other hand, if this difference in wall thickness is too large, there may be cases where uniform resilience performance cannot be obtained, so the upper limit is preferably about 0.5 mm or less, more preferably about 0.4 mm or less.

  The wall thicknesses of the toe side area 15a and the heel side area 15d may be the same or different. Preferably, in order to make the coefficient of restitution on the toe side and the heel side more uniform, as shown in FIG. The toe side area 15a is preferably thinner than the heel side area 15d. The difference in thickness is preferably about 0.025 mm or more, more preferably about 0.05 mm or more, and further preferably about 0.1 mm or more. On the other hand, if this difference in wall thickness is too large, there may be cases where uniform resilience performance cannot be obtained, so the upper limit is preferably about 0.5 mm or less, more preferably about 0.4 mm or less.

  As shown in FIGS. 4 to 7, the intersecting portion 17 has a thickest central portion 18 at the center thereof. Further, the intersecting portion 17 is formed so that the thickness decreases from the central portion 18 toward the intermediate portion 15 or the main rib 12. The center portion 18 includes the sweet spot of the face portion 11, that is, the position of the center of gravity of the golf club head projected onto the face surface. The central portion 18 includes the intersection of the central axis of the first and second main ribs 12a and 12b and the central axis of the third and fourth main ribs 12c and 12d. The intersection of the main ribs and the sweet spot may be the same or different. The intersection of the main ribs is an extension of a score line (not shown) formed on the surface of the face portion 11 (not shown) or partially formed on the toe side and the heel side of the face portion. Arrange them so that they do not exist on the line.

  The thickness of the central portion 18 is thicker than the thickest portion of the thickest main rib of the four main ribs 12. The difference in thickness is preferably about 0.1 mm or more, and more preferably about 0.5 mm or less. Moreover, as shown in FIG. 2, it is preferable that the center part 18 is a planar circle. The radius of the flat circular central portion 18 is preferably about 5 mm or more, and preferably about 12 mm or less. The central portion 18 is not limited to such a circle, and may be an ellipse, a rectangle such as a rectangle or a rhombus, or a polygon such as a pentagon or a hexagon.

  Moreover, as shown in FIG. 2, it is preferable that the crossing part 17 is a plane ellipse shape. The length of the major axis of the planar elliptical intersecting portion 17 is preferably about 20 mm or longer, more preferably about 30 mm or longer than the region of the central portion 18. On the other hand, the upper limit of the long axis is preferably about 50 mm or less, and more preferably about 45 mm or less. The short axis of the planar elliptical intersection 17 is preferably about 10 mm or longer, more preferably about 20 mm or longer than the region of the central portion 18. On the other hand, the upper limit of the minor axis is preferably about 40 mm or less, and more preferably about 30 mm or less.

  As described above, the thickness of the intermediate portion 15 of the face member 10 is approximately about 1. although the thickness difference exists in the toe side area 15a, the sole side area 15b, the crown side area 15c, and the heel side area 15d. 0 mm or more is preferable, and about 1.5 mm or more is more preferable. On the other hand, the upper limit of the thickness of the intermediate portion 15 is preferably about 3.0 mm or less, and more preferably about 2.5 mm or less. The thickness of the outer peripheral portion 14 of the face member 10 is preferably about 1.0 mm or more, more preferably about 1.5 mm or more, although there is a difference in thickness with the intermediate portion 15 as described above. On the other hand, the upper limit of the thickness of the outer peripheral portion 14 is preferably about 3.0 mm or less, and more preferably about 2.5 mm or less.

  The thicknesses of the thickest portions of the four main ribs 12a to 12d of the face member 10 are different from other main ribs as described above, or different from the intermediate portion 15 or the outer peripheral portion 14. However, generally, about 3.0 mm or more is preferable, and about 3.2 mm or more is more preferable. On the other hand, the upper limit of the thickness of each of the four main ribs 12a to 12d is preferably about 4.2 mm or less, and more preferably about 4.0 mm or less. Further, the thickness of the thickest portion of the reinforcing rib 13 of the face member 10 is generally preferably about 3.0 mm or more, and more preferably about 3.2 mm or more. On the other hand, the upper limit of the thickness of the reinforcing rib 13 is preferably about 4.2 mm or less, and more preferably about 4.0 mm or less. The thickness of the central portion 18 of the face member 10 is preferably about 2.5 mm or more, and more preferably about 2.7 mm or more, although there is a difference in thickness with the main rib 12 as described above. On the other hand, the upper limit of the thickness of the central portion 18 is preferably about 4.0 mm or less, and more preferably about 3.8 mm or less.

  The first main rib 12a is preferably inclined to the toe side with respect to the vertical. The second main rib 12b is preferably inclined toward the heel side with respect to the vertical. By tilting the first and second main ribs 12a and 12b in this manner, the resilience performance in the upper toe-lower heel direction where the hit points of the amateur golfer are concentrated can be maximized. Specifically, as shown in FIG. 8, the inclination θa of the center line 31 of the first and second main ribs 12a and 12b with respect to the horizontal line 30 when the golf club head 1 is placed at the normal address position is about The angle is preferably 90 ° or less, and more preferably about 85 ° or less. On the other hand, the lower limit of the rib inclination θa is preferably about 25 ° or more, and more preferably about 30 ° or more.

  The third main rib 12c is preferably inclined toward the crown side or the hosel side with respect to the horizontal. The fourth main rib 12d is preferably inclined toward the sole with respect to the horizontal. By tilting the third and fourth main ribs 12c and 12d in this way, the resilience performance in the upward direction of the tow can be maximized. Specifically, the inclination θb of the center line 32 of the third and fourth main ribs 12c, 12d with respect to the horizontal line 30 is preferably about 5 ° or more, and more preferably about 10 ° or more. On the other hand, the upper limit of the rib inclination θb is preferably about 80 ° or less, and more preferably about 70 ° or less.

  The reinforcing rib 13 has a central axis 33 that bisects the angle formed by the central axis 31 of the first and second main ribs and the central axis 32 of the third and fourth main ribs (that is, both It is preferable that each has an angle of θc with respect to the central axes 31 and 32. The inclination of the major axis of the ellipse of the intersecting portion 17 is the same as that of the central axis 33 of the reinforcing rib 13, and the central axis 31 of the first and second main ribs and the center of the third and fourth main ribs. It is preferable to make the angle formed by the shaft 32 into two equal parts.

  The first and second main ribs 12a and 12b can be smoothly curved not in a straight line but in an S shape or a Z shape along the central axis 31. Further, the third and fourth main ribs 12c and 12d can be smoothly curved not in a straight line but in an S shape or a Z shape along the central axis 32. By smoothly curving the main rib 12 in this manner, the area of both the sole side area 15b and the crown side area 15c can be increased.

  The face member 10 can be formed by either forging or casting. Further, as the material of the face member 10, titanium, a titanium alloy, stainless steel, or the like can be used. The volume of the golf club head 1 is preferably about 100 cc or more, and more preferably about 150 cc or more. On the other hand, the volume of the golf club head 1 is preferably about 500 cc or less, and more preferably about 460 cc or less. Further, the weight of the golf club head 1 is preferably about 170 g or more, and more preferably about 175 g or more. On the other hand, the weight of the golf club head 1 is preferably about 250 g or less, and more preferably about 245 g or less.

  In the above-described embodiment, the reinforcing rib 13 is provided as shown in FIGS. 1 to 7, but the present invention does not need to be provided with the reinforcing rib as shown in FIG.

  A golf club head according to the present invention was produced and evaluated for its coefficient of restitution (COR). In this example, instead of actually measuring the COR value, characteristic time (CT) was measured. The CT value is a quantitative value that allows simple and accurate measurement of the face spring effect adopted by the US Golf Association (USGA) and the British Golf Association (R & A), and is approved by R & A Rules Limited. Can be measured with a portable pendulum machine (portable pendulum type measuring instrument). In general, the better the face is bent, the lower the energy loss and the higher the initial velocity of the ball. Therefore, the CT value represents the bending as the contact time between the ball and the face. Currently, the upper limit of the rule is 257 (specified 239 + allowable error 18) μsec.

  The golf club head of the example employs the configuration shown in FIG. That is, four main ribs and two reinforcing ribs were provided, and the thickness of the intermediate portion divided into four areas by the four main ribs and the outer peripheral portion was formed differently. On the other hand, as shown in FIG. 10, in the golf club head of the comparative example, the outer peripheral portion was not provided, and the intermediate portion was a peripheral portion extending to the outer edge of the face member. Table 1 shows the thicknesses of the middle part or the peripheral part, the four main ribs, and the reinforcing ribs of the four sections divided by the central part, the outer peripheral part, and the main ribs of these examples and comparative examples.

  The common face condition is that the face width is 75 mm and the height is 43 mm, and the first to fourth main ribs are inclined in the same manner as in FIG. The length was 40 mm, the minor axis length was 30 mm, and the ellipse angle θc was 15 °. The width of the outer periphery of the C shape was in the range of 30-40 mm. The length of the reinforcing rib was 27 mm on the toe side and 25 mm on the heel side. The width of the first to fourth main ribs was 9.5 mm, and the width of the reinforcing ribs was 7.1 mm. As common golf club head conditions, the face member was made of titanium alloy (Ti-6Al-4V), the head volume was 460 cc, and the head weight was 190 g.

  About the Example and the comparative example, CT value in the hit point of a ball | bowl was measured. As shown in FIG. 11, the hitting points of the ball were examined for 15 different hitting points in the vertical direction and the horizontal direction. The center hit point 40c is assumed to be a hit ball at a sweet spot, and is in the intersection of the face members. The other 14 hitting points were assumed to be hitting balls without the sweet spot. The positions 10 mm away from the center hitting point 40 c on the toe side and heel side were designated as hitting points 40 b and 40 d, and the positions 10 mm away on the toe side and heel side were designated as hitting points 40 a and 40 e, respectively. Further, the positions 10 mm away from the crown side and the sole side of these five hit points 40a to 40e were 40aH to 40eH and 40aL to 40eL, respectively.

  Under the above conditions, the CT values at the respective hit points in the examples and comparative examples were measured. The results are shown in Tables 2 and 3. Further, the CT value of the entire face surface in the hit point area was calculated based on the measurement result of the hit point. The results are shown in FIGS. In these tables and drawings, the position of the center hit point 40c is 0 mm, the distance toward the crown side or the heel side is plus, and the distance toward the sole side or the toe side is minus. In addition, the results of the tables and drawings are shown as a ratio when the CT value of the center dot 50c is 100. A region surrounded by a thick line in the figure indicates a region having a CT value ratio of 96 or more, and the CT value ratio increases or decreases by 1 each time one thin line is exceeded.

  As shown in Tables 2 and 3 and FIGS. 12 and 13, an outer peripheral part thicker than the thickness of the sole side area and the crown side area of the middle part and thinner than the thickness of the toe side area and the heel side area is provided. In the golf club head of the example, the CT of the face part could be made more uniform than the golf club head of the comparative example in which the outer peripheral part was not provided. In particular, uniform CT could be obtained in the region of −10 mm to −20 mm from the center in the height direction of 0 mm to 10 mm, and in the region of −10 mm to 0 mm in the height direction from 10 mm to 20 mm from the center. Therefore, even when the ball is hit with the sweet spot removed, it can be seen that the resilience close to that when the ball is hit with the sweet spot can be exhibited.

DESCRIPTION OF SYMBOLS 1 Golf club head 10 Face member 11 Face part 12a 1st main rib 12b 2nd main rib 12c 3rd main rib 12d 4th main rib 13 Reinforcement rib 14 Outer peripheral part 15 Middle part 15a Toe side area 15b Sole side Area 15c Crown side area 15d Heel side area 17 Intersection 18 Central part 20 Body member 21 Sole part 22 Crown part 23 Toe part 24 Heel part 25 Hosel part 30 Horizontal line 31 Central axis of first and second main ribs 32 3rd And the central axis of the fourth main rib 33 The central axis of the reinforcing rib 40 RBI

Claims (4)

A golf club head having a hollow structure inside,
Including a face portion, a crown portion, a sole portion, and a hosel portion,
The face portion has, on its inner surface, a central portion of the face portion, a C-shaped outer peripheral portion having an opening on the hosel portion side, and at least four main ribs extending from the central portion to the outer edge of the face portion. And an intermediate portion located between the central portion and the outer peripheral portion or the hosel portion,
The intermediate portion is divided into at least four sections of a toe side area, a heel side area, a crown side area, and a sole side area by the at least four main ribs;
The wall thickness of the toe side area and the heel side area of the intermediate part is thicker than the wall thickness of the outer peripheral part, and the wall thickness of the crown side area and sole side area of the intermediate part is thinner than the wall thickness of the outer peripheral part. Golf club head that is formed to be   2. The golf club head according to claim 1, wherein a thickness of a crown side area of the intermediate portion is formed to be thicker than a thickness of a sole side area of the intermediate portion.   3. The golf club head according to claim 1, wherein a thickness of a heel side area of the intermediate part is formed to be thicker than a thickness of a toe side area of the intermediate part.   4. The golf club head according to claim 1, wherein the face portion further includes a reinforcing rib extending on an inner side surface of the face portion from the center portion toward an outer side of the face portion. 5.

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