JP5238628B2 - Golf club - Google Patents

Description

  The present invention relates to a golf club having a hollow metal club head.

  Generally, when a golf ball is hit with a sweet spot of a club head, the longest flight distance can be obtained, but the area of the sweet area including this sweet spot is small. Further, rules are set for the characteristics of the face portion of the golf club, and a golf club with high repulsion where the ball flies too much violates the rule.

  In recent years, a head characteristic time (Characteristic Time), that is, a CT value obtained from a contact time at the time of collision in the “Pendulum Test” has been introduced as a standard for determining rule conformity regarding the rebound characteristics of the face portion. When the CT value of the face portion obtained by the “Pendulum Test” exceeds the prescribed upper limit value, it is determined that the rule is violated.

  For this reason, by changing the thickness of the face portion, the repulsive force is adjusted, the overall flight distance performance is improved, and the durability is improved.

  In such a golf club, the face portion has a central thickness gradually changing portion that gradually decreases in thickness around the central thick portion toward the outer peripheral side, and a maximum thickness surrounding the central thickness gradually changing portion. The thickness of the band-like gradually changing portion surrounding the edge of the upper thick portion and the lower thick portion formed at the crown side and sole side ends is changed to the upper thick portion. In addition, there is one formed so as to become thinner from the lower thick part toward the thin part (see, for example, Patent Document 1).

Japanese Patent No. 4165282

  In such a conventional golf club, it is possible to reduce the resilience of the central portion by forming the thickest central portion, but for the peripheral portion, the resilience is increased and the central portion is increased. Cannot be as high as In particular, the upper and lower thick parts with a thickness less than or equal to the central thick part are formed on the crown side and the sole side end, so that the resilience in these upper and lower thick parts Becomes extremely low, and the flight distance decreases.

  The present invention has been made based on such circumstances, and an object of the present invention is to provide a golf club having a stable flight distance and excellent strength and durability even if the hit points vary.

In order to achieve the above object, according to the present invention, a golf ball is formed with a face portion formed with a ball hitting surface on the front surface, a crown portion, a sole portion, a toe side and heel side portion, and a back portion at the rear. A golf club comprising a hollow metal club head having a shell and an internal space formed in the outer shell, wherein the golf club is formed at a central portion of the face portion and in a toe-heel direction rather than a crown-sole direction. A first region surrounded by a long oval edge and an ellipse that is thinner than the first region and surrounds the first region and is longer in the toe-heel direction than in the crown / sole direction A second region having an outer peripheral edge, a peripheral region formed thinner than the second region to surround the second region and forming a peripheral portion of the face portion, and a toe of the second region Inside along the heel direction At the position, recessed from the outer edge side of the crown side or the sole side of the second region to the first region side, and being formed thinner than the second region and continuing to the peripheral region, wherein the thin portion is formed on the crown side and the sole side of the second region, the crown side golf club is provided that will be widely formed a elongated or area in the toe-heel direction than the sole side.

  The CT value of the thin portion is preferably formed to be equal to or greater than the value of the toe side or heel side portion of the center line on the center line passing through the center position in the toe / heel direction.

  It is preferable that the thickness change rate of the boundary portion between the thin portion and the peripheral region is smaller than the thickness change rate of the boundary portion between the first region and the second region.

According to the golf club of the present invention, the first region formed in the central portion of the face portion is suppressed in resilience due to the thickness thereof, and the peripheral region is improved in resilience, whereby the hit points vary and the periphery Even when a ball is hit in an area, a decrease in flight distance can be prevented. Further, the thin portion having a thickness thinner than that of the second region is formed in a state of being recessed from the outer edge side of the second region on the crown side or the sole side to the first region side, whereby the crown of the second region is formed. -The resilience along the sole direction can be improved, and the flight distance can be stabilized even if the hit points vary. Furthermore, the thin part is formed on the crown side and the sole side of the second region, and the thin part on the crown side is formed longer in the toe / heel direction than the sole side, so that the hit point is shifted to the crown side and is launched. Even if the angle becomes large (high), the flying distance can be prevented from being lowered, and even a general player can improve the flying distance of the hit ball and stabilize it.

  When the CT value of the thin part is formed on the center line passing through the center position in the toe / heel direction to be greater than the value of the part on the toe side or the heel side of this center line, in addition to the above, usually the CT value A reduction in the resilience of the center line position where the value is lowered can be prevented, and thereby the resilience on the crown side or the sole side can be improved relatively, and the height of the face portion is not formed to a sufficient height. Even in this case, the resilience on the crown side or the sole side can be increased, thereby improving the flight distance and stabilizing the distance.

  When the thickness change rate of the boundary portion between the thin portion and the peripheral region is made smaller than the thickness change rate of the boundary portion between the first region and the second region, the strength of the club head, particularly the face portion. The durability can be improved and the face portion can be made thinner and lighter.

The front view seen from the face side of the club head by embodiment of this invention. FIG. 2 is a partial cross-sectional view of the club head of FIG. Sectional drawing which follows the XX line of FIG. FIG. 2 is an enlarged sectional view of a crown side and a sole side in a face portion of the club head of FIG. 1. FIG. 2 is an explanatory view showing a state in which the face portion of the club head of FIG. 1 is developed in a flat structure along a YY line. The figure similar to FIG. 1 of the club head by other embodiment.

  1 to 5 show a golf club 8 according to a preferred embodiment of the present invention. In the figure, similar parts are denoted by the same reference numerals.

  As shown in FIG. 1, the golf club 8 of the present embodiment has a tubular structure made of, for example, a fiber reinforced resin or a metal material, so that the club head 10 is placed at a lie angle α with respect to the reference horizontal plane B. The club head 10 is attached to the tip of 6 by setting the specified lie angle α and loft angle with respect to a reference horizontal plane B such as the ground on which the ball is placed, and the base end is made of a flexible material such as natural rubber or synthetic rubber. A grip formed of a soft material can be attached. Here, the lie angle α is a mounting angle of the shaft axis 6a with respect to a sole portion or a reference horizontal plane B, which will be described later, and the loft angle is an angle between a vertical plane orthogonal to the reference horizontal plane B and the front surface of the face portion 12. It is. Reference numerals X and Y denote center lines that pass through the center O of the face portion 12 and are virtual lines in the vertical and horizontal directions with respect to the reference horizontal plane B.

  As shown in FIGS. 1 to 3, in the metal club head 10 of the present embodiment, a face member 14 having a ball striking surface is disposed on the surface side of the face portion 12, and the head body 10a is the back surface of the face member 14. Support from the side. In the head body 10a, a crown portion 16 and a sole portion 18 extend from the top line 12a and the leading edge 12b of the face portion 12 to the back side, respectively. Between the crown portion 16 and the sole portion 18, the toe side side portion 20 and the heel side side portion 22 from the toe side side line 12 c and the heel side side line 12 d of the face portion 12 are the peripheral portions of the crown portion 16, respectively. And extending to the back side while being curved along the back portion 24.

  The top line 12a between the face portion 12 and the crown portion 16 can be specified by a ridge line between them, but is specified at a portion smaller than the curvature radius of the surface portion that forms most of the face portion 12. Also good. The same applies to the ridge line portions such as the leading edge 12b and the side lines 12c and 12d.

  The toe side part 20 and the heel side part 22 of the head body 12 have large dimensions in the vertical direction, that is, the crown / sole direction on the face part 12 side, and the dimensions gradually decrease to the back part 24. Accordingly, the club head 10 substantially forms an outer shell by the face portion 12, the crown portion 16, the sole portion 18, the toe side and heel side side portions 20 and 22, and the back portion 24 at the rear portion. Is formed in the outer shell.

  The head main body 10 a is integrally formed with a cylindrical shaft fastening portion (not shown) for fastening the tip of the shaft 6 and projects into the internal space N. The shaft 6 is fixed to the head main body 10a by inserting the tip end portion of the shaft 6 into the shaft fixing portion from the opening 26a of the hosel portion 26 formed to protrude from the crown portion 16.

  Further, the sole portion 18 is provided with a weight portion 28 integrally formed as a thick portion protruding toward the internal space N side. The weight portion 28 is formed in a triangular shape whose width gradually decreases from the front edge portion 28a wide in the toe-heel direction along the face portion 12 toward the back portion 24 side. The center of gravity is increased, and the sole portion 18 is reinforced on the face portion 12 side, and the force acting on the face portion 12 is received from the face member 14 and efficiently transmitted to the back side. A weight member may be further arranged on the back side of the head main body 10a, and a rib or a thick portion that efficiently transmits force to such a weight member may be formed.

  As shown in FIGS. 3 and 4, the face member 14 of the present embodiment has a front side opening of the head main body 10 a including a crown portion 16, a sole portion 18, toe side and heel side portions 20 and 22, and a back portion 24. 11 is formed of a shallow cup-shaped member that closes 11. The face member 14 surrounds the face portion 12 and bends the peripheral edge portion 30 on the back side along the top line 12a, the leading edge 12b, and the side lines 12c and 12d, and the crown side portion 30a, the sole side portion 30b, and Side side portions 30c and 30c (FIG. 2) are formed. The respective rear ends of the peripheral edge portions 30 are joined along the front side opening 11 of the head body 10a by, for example, TIG welding, plasma welding, laser welding, or the like. The front part which is a part of toe side and heel side side parts 20 and 22 is formed. When the weight portion 28 is formed by the thick portion of the sole portion 18, the front edge portion 28 a is preferably disposed along the front opening 11.

  The crown side portion 30a of the peripheral edge portion 30 is positioned behind the thin-walled portion 32a and has a groove-shaped or curved thin-walled portion 32a that opens into the internal space N along the top line 12a. 11 and a thick portion 34a welded to the steel plate. Similarly, the sole side portion 30b is also formed with a concave or curved thin portion 32b along the leading edge 12b and a thick portion 34b welded to the head body 10. By disposing the thin wall portions 32a and 32b in front of the thick wall portions 34a and 34b, it is possible to ensure the overall flexibility of the face portion 12 at the time of hitting.

  Further, instead of the above, a groove-shaped or curved thin portion 32b may be formed only on the sole side. Further, when the resilience is mainly the face part, the thickness of the thin part is preferably thicker than the peripheral part of the face part 12.

  The surface on the inner space N side of these thin-walled portions 32a and 32b forms a stepped portion where stress is easily concentrated from the back surface of the face portion 12 to the thick-walled portions 34a and 34b through the top line 12a and the leading edge 12b. Without forming, it is preferable to form with a smoothly curved surface. Further, since the face has an inverted triangular shape, the CT value tends to be lower in the lower part than in the upper part. Therefore, the thickness of the thin part 32b on the sole side is made thinner than the thin part 32a on the crown side. It is preferable to increase the amount of bending.

  Such thin portions 32c and 32d (FIG. 2) and thick portions are preferably formed also on the side portions 30c and 30d along the side lines 12c and 12d.

  Instead of forming the face member 14 with a cup-shaped member formed by bending the peripheral portion 30 of the face portion 12 and the integral member to the back side, the face member 14 is a plate that forms the entire area of the face portion 12. It is also possible to form the shape. Further, it is formed in a plate shape that fits into an opening of a predetermined size formed in the face portion 12 of the head body 10a, and a part of the face portion 12, such as a ball striking surface, together with the peripheral edge portion of the head body 10a surrounding the opening. May be formed only. In any case, the face member 14 is preferably formed of the same material as the head body 10a or a metal material that can be welded to the head body 10a.

  Further, in order to prevent variation in thickness due to welding, the head main body 10a and the face member 14 can be integrally formed of the same material by casting or the like.

  The head main body 10a is preferably integrally formed by casting, for example, a titanium-based alloy, an iron-based alloy, or the like, except for the face member 14, and the face member constituting the hitting surface of the face portion 12 on the front side thereof. An opening 11 is formed in which 14 is fixed by welding, adhesion or the like. Instead of such an integrated structure, each member constituting the head main body 10a (a member forming an outer shell such as a face portion, a crown portion, a sole portion, a side portion, etc.) is individually formed, and then assembled and welded. Or may be integrated by bonding or the like.

  Further, the crown portion 16 is formed of a fiber reinforced metal, fiber reinforced resin, magnesium alloy, a thin titanium alloy of 0.3 to 1.4 mm, a thin stainless alloy of the same thickness, etc., and is bonded to the main body or welded. Joining by brazing or the like is also possible. In this case, since the crown portion 16 of the head body is open, there is an effect that it is easy to insert a weight (not shown) or the like into the internal space N.

  The face member 14 coupled to the head body 10a is, for example, a titanium alloy, an iron alloy, or the like that is pressed or forged or cast so as to have a predetermined shape. By doing so, it is also possible to form a single body, or to integrate them by welding a plurality of members processed in this way. In order to ensure the flexibility of the face part 12, when a thin part is formed on the peripheral edge part 30, it is preferable that the rear part adjacent to the face part 12 is formed to have a thickness of about 0.6 to 2.5 mm, for example.

  Instead of welding and fixing the face member 14 to the end surface of the opening 11 formed in the head main body 10a, the entire head main body 10a is formed in an integral structure (for example, cast), and the head of this integral structure is formed. The face portion 12 may be formed on a part of the main body 10a.

  As shown in FIGS. 1 to 5, the face member 14 includes the thickest first region 36 that protrudes from the back surface of the face portion 12 toward the internal space N, and includes the center O of the face portion 12. It is formed at the center. Around the first region 36, a second region 38 formed thinner than the first region 36 and a peripheral region 40 formed thinner than the second region 38 are sequentially surrounded in a band shape. It is out. In the present embodiment, the outer edge portion of the peripheral region 40 is formed by a top line 12a, a leading edge 12b, and side lines 12c and 12d.

  The second region 38 is disposed so as to protrude to the crown-side top line 12a or the leading edge 12b on the sole side, but does not reach the top line 12a or the leading edge 12b. Alternatively, the thin portion of the peripheral region 40 is interposed on the sole side. As a result, the CT value can be effectively suppressed at the central portion of the face portion 12, and the thick first and second regions 36 and 38 can be formed so that the CT value does not partially drop. . For this reason, the CT value can be approximated over a wide range of the hitting surface of the face portion 12.

  In FIG. 5, the surface of the face portion 12, that is, the ball striking surface side is described in a straight line, but actually, as shown in FIGS. 2 and 3, the bulge is slightly bulged outward from the center portion. It is formed into a curved surface that is a combination of both curved surfaces (toe / heel direction) and roll (crown / sole direction). In addition, in a state where the peripheral bulges and rolls are formed, one or more of the first region 36, the second region 38, and the peripheral region 40 on the inner surface may be planar with a linear cross-sectional shape.

  In the figure, the inner surface of the first region 36 is formed in a flat shape, but the repulsion of the center position is suppressed by forming the portion corresponding to the center position O into a convex shape protruding toward the inner space N side. Can do. Further, the back surface of the second region 38 on the inner space N side may be formed in a plurality of steps.

  A number of score lines (not shown) extending in the toe / heel direction are formed on the surface of the face portion 12 by a suitable means such as a shallow groove in a substantially horizontal direction. A sweet spot that is a point extending through the center of gravity (not shown) of the club head 10 and extending perpendicularly to the striking surface of the face portion 12 is disposed in the first region 36 that is the central portion. The position of the sweet spot varies depending on the position of the center of gravity determined by the weight member 28 and the like described above.

  As shown in FIG. 1, the first region 36 located at the center of the face portion 12 is surrounded by an elliptical or oval edge that is longer in the toe / heel direction than in the crown / sole direction. 38 has an elliptical or oval outer edge that is longer in the toe-heel direction than in the crown-sole direction.

Then, at the intermediate position along the toe / heel direction of the second region 38, the second region 38 is recessed from the outer edge side on the crown side and the sole side to the first region 36 side. Also, thin-walled portions 42 and 44 are formed. These thin portions 42 and 44 are formed symmetrically in the left-right direction, that is, the toe-heel direction with respect to the longitudinal center line X, and the center O side, the toe side, and the heel side are formed in the second region. It is partitioned and continues to the peripheral region 40 on the crown side and the sole side. It is preferable that the thin portions 42 and 44 expand toward the outside near the peripheral region 40 rather than the inside near the first region 36, and the trapezoidal or rectangular shape shown in the figure is formed between the thin portions 42 and 44. Instead of the boundary portion, a boundary portion that curves in an arc shape may be defined.

  In the club head 10 having such a face portion 12, the first region 36 formed in the center portion of the face portion 12 is suppressed in resilience due to the thickness thereof, and the second region 38 surrounding the first region. In addition, the resilience of the peripheral region 40 is improved, so that it is possible to prevent the flight distance from decreasing even when the hit points vary and the ball is hit in the peripheral region 40. Further, by forming the thin portions 42 and 44 thinner than the second region 38 from the crown side or the sole side outer edge side of the second region 38 to the first region side, The resilience along the crown / sole direction of the second region 38 can be improved, and the flight distance can be stabilized even if the hit points vary.

  Such thin portions 42 and 44 have a CT value on the center line X having a CT value on the toe side or heel side of the center line X (for example, within a range of ± 25 mm from the center line X to the left and right). It is preferable to form so that it may become more than a value. In this case, it is possible to prevent the rebound of the position on the center line X where the CT value is usually low from being lowered, and thereby the rebound of the crown side or the sole side can be relatively improved. Even if the height of 12, ie, the dimension in the crown / sole direction, is not sufficiently large, the resilience on the crown side or the sole side is increased, thereby improving the flight distance and stabilizing it. Can do.

  In particular, the thin portion 42 is formed so as to be recessed on the crown side of the second region 38, whereby the projection 38 a protrudes on the crown side with the center line X of the second region 38 interposed therebetween. The protrusion 38a is configured such that a CT value of a portion disposed in the peripheral region 40 that passes through the protrusion 38a and parallel to the center line X, that is, a crown side portion of the protrusion 38a, is a thin portion 42 along the center line X and It acts to reduce the CT value of the region of the peripheral region 40. The same applies to the thin portion 44 on the sole side.

  Thus, when comparing the CT values in the left and right regions including the center line X, the left and right ranges vary depending on the size and shape of the thin portions 42 and 44 that are recessed in the second region 38. The center line X is sandwiched at a position 5 mm to 10 mm away from the line X on the left side or the right side, and measurements are made in the range from the inner part where the thin portions 42 and 44 are formed to the top line 12a or the leading edge 12b. It is preferable. The comparison of the CT values is performed using measured values at positions extending from the vertical center line X to the horizontal center line Y in parallel.

  In addition, it is preferable that the CT value is higher than the left and right at all positions on the center line X. However, since the shape is substantially limited, at least a part of the center line X is more than the left or right side. Increase the CT value above. The CT value is preferably in the range of 95% to 100% on the left or right side when the center line X is used as a reference.

  Of the thin portions 42, 44 formed on the crown side and the sole side of the second region 38, when the thin portion 42 on the crown side is formed longer in the toe-heel direction than the thin portion 44 on the sole side Even if the striking point is shifted to the crown side and the launch angle is large (high), high repulsion can be obtained in a relatively wide range, so that a decrease in flight distance can be prevented. Therefore, even a general player who does not have hit points at the time of hitting balls and the club head 10 does not have a high speed can improve the flight distance of the hit ball and achieve stabilization.

  The face portion 12 has a vertical dimension 36X of the first region 36 of 16 to 32% relative to the total height H of the club head 10 when the distance between the outer edge portions is measured on the center line X in the vertical direction. The vertical dimension 38X of the region 38 is preferably 33 to 55%, and the vertical dimension 40X of the peripheral region 40 is preferably about 55 to 75%. Moreover, it is preferable that the thin parts 42 and 44 recessed in the 2nd area | region 38 are 8-18% of the total height H, and 8-18% of each vertical dimension 42X, 44X.

  Regarding the toe-heel direction, when the distance between the outer edge portions is measured on the lateral center line Y, the lateral dimension 36Y of the first region is 15 to 25% relative to the maximum width W of the face portion 12, and the second It is preferable to form the lateral dimension 38Y of the region 38 to 40 to 65% and the lateral dimension 40Y of the peripheral region 40 to about 80 to 95%. In this case, the lateral dimensions 42Y and 44Y of the thin portions 42 and 44 are preferably about 10 to 25% and about 10 to 25% of the maximum width W, respectively.

  The vertical and horizontal dimensions 42X and 42Y of the thin portion 42 recessed on the crown side of the second region 38 are preferably larger than the vertical and horizontal dimensions 44X and 44Y of the thin portion 44 on the sole side. In particular, when the lateral dimension 42Y along the toe / heel direction of the thin-walled portion 42 on the crown side is longer or larger than the lateral dimension 44Y of the thin-walled portion 44 on the sole side, the striking point shifts to the crown side and launches. Even if the angle becomes large (high), the flying distance can be prevented from being lowered, and even a general player can improve the flying distance of the hit ball and stabilize it.

  The thicknesses of the respective regions formed in this way are as follows: the first region 36 provided at the center is 1.8 to 2.5 mm, the second region 38 is 1.6 to 2.3 mm, and the peripheral region 40 is 1. It is preferable to form the thin portions 42 and 44 with a thickness of 4 to 2.1 mm and a thickness of about 1.6 to 2.3 mm. The thickness of each region may be formed to be substantially constant, or may be slightly reduced toward the outside. For example, the first region 36 may be formed such that the thickness of the center O is the largest 2.3 mm and the thickness of the outer edge portion close to the second region 38 is about 2.2 mm.

  Between these adjacent regions, in order to suppress stress concentration due to a sudden change in thickness, a boundary portion in which the inner surface on the inner space N side is formed as an inclined surface is formed. For example, a band-shaped boundary portion 37 narrower than the second region is formed between the first region 36 and the second region 38, and a narrow band-shaped boundary portion is also formed between the second region 38 and the peripheral portion 40. 39 is provided. In addition, boundary portions 43 and 45 are formed between the second region 38 and the thin portions 42 and 44, respectively.

  The difference in thickness between the thin portions 42 and 44 and the peripheral region 40 is very small, for example, approximately the same as a range of ± 0.2 mm or a range of ± 0.4 mm, and is clearly specified in the figure. Absent. On the other hand, the boundary portion 37 formed between the first region 36 and the second region 38 is formed to be relatively large. Further, the boundary portions 43 and 45 formed between the thin portions 42 and 44 and the second region 38 are formed to be slightly smaller than the boundary portions 37 and 39. Thus, by making the thickness change rate of the boundary portion smaller than the thickness change rate of the boundary portion 37 between the first region 36 and the second region 38, the club head 10, particularly the face portion 12. Strength and durability can be improved, and the face portion 12 can be made thinner and lighter.

  The wall thickness change rate in the boundary portions 37, 38, 43, and 45 can be changed by increasing it in the crown / sole direction rather than in the toe / heel direction, but may be the same. In either case, the thickness difference between the first region 36 and the second region 38 is 0.6 mm or less, and the thickness difference between the second region 38 and the peripheral region 40 is 0.4 mm or less. Is preferred. In the case of providing a larger thickness difference, the thickness of the first region 36 and the second region 38 is formed so as to be gradually reduced toward the peripheral direction, and the thickness difference of the boundary portions 37 and 39 is set as described above. It is preferable to make it below the value.

  The CT value in each region formed in such various thicknesses is such that the first region 36 is the largest in the second region or more, the second region 38 is formed larger than the peripheral region 40, and the first region 36, When the values of the second region 38 and the peripheral region are 36M, 38M, and 40M, respectively, it is preferable that 40M <38M ≦ 36M. By setting it as such a magnitude | size, the improvement of resilience in a wide range and the improvement and stabilization of intensity | strength and durability are attained.

  FIG. 6 shows a club head 10A according to another embodiment. Since the club head 10A according to this embodiment is basically the same as the club head 10 according to the above-described embodiment, the same parts are denoted by the same reference numerals, and detailed description thereof is omitted.

  In this embodiment, the first region 36 is long in the toe-heel direction and is shortened to the crown / sole side so as to be elongated in the shape of an ellipse to the left and right as a whole. The portion is formed in a straight line shape along the reference horizontal plane B direction, and the thin wall portions 42 and 44 are formed in a state of being recessed from the straight outer edge portion toward the center side.

  The outer edge portion of the second region 38 has an appropriate shape as long as it can improve the resilience along the crown / sole direction of the face portion 12 by forming the thin portions 42 and 44 in this way. It can be. For example, the outer edge portion of the second region can be formed in a triangular shape or a trapezoidal shape instead of being formed in a curved shape protruding toward the toe side and the heel side.

The club head 10 of the present invention can be applied to any suitable club head 10 as long as it is a wood type, but the H / W is 45% or less, or the face height is 42% or less, For example, it is particularly suitable for fairway wood.
Hereinafter, the invention described in the scope of claims of the present application will be appended.
[1] The outer shell is formed by the face portion, the crown portion, the sole portion, the toe side and heel side side portions, and the back portion of the rear portion, each of which has a golf ball hitting surface formed on the front surface. A golf club comprising a hollow metal club head having an internal space formed therein,
A first region formed in the center of the face portion and surrounded by an elliptical edge that is longer in the toe-heel direction than in the crown-sole direction;
A second region that is thinner than the first region and surrounds the periphery of the first region and has an elliptical outer edge that is longer in the toe-heel direction than in the crown / sole direction;
A peripheral region that is formed thinner than the second region and surrounds the second region, forming a peripheral portion of the face portion;
At the intermediate position along the toe-heel direction of the second region, the second region is recessed from the outer edge side on the crown side or sole side to the first region side, and is formed to be thinner than the second region. And a thin-walled portion continuous to the peripheral region.
[2] The CT value of the thin portion is formed on the center line passing through the center position in the toe-heel direction, and is greater than or equal to the value of the toe side or heel side portion of the center line [1] ] The golf club as described in.
[3] The thin portion is formed on the crown side and the sole side of the second region, and the crown side is formed longer or wider in the toe-heel direction than the sole side [1] The golf club described in 1.
[4] The thickness change rate of the boundary portion between the thin portion and the peripheral region is smaller than the thickness change rate of the boundary portion between the first region and the second region [1] ] Or the golf club according to [2].

DESCRIPTION OF SYMBOLS 10 ... Club head 12 ... Face part 36 ... 1st area | region 38 ... 2nd area | region 40 ... Peripheral area | region 42,44 ... Thin part

Claims (3)

An outer shell is formed by the face portion, the crown portion, the sole portion, the toe side and heel side side portions, and the back portion of the rear portion, in which the hitting surface of the golf ball is formed on the front surface. A golf club comprising a hollow metal club head formed of
A first region formed in the center of the face portion and surrounded by an elliptical edge that is longer in the toe-heel direction than in the crown-sole direction;
A second region that is thinner than the first region and surrounds the periphery of the first region and has an elliptical outer edge that is longer in the toe-heel direction than in the crown / sole direction;
A peripheral region that is formed thinner than the second region and surrounds the second region, forming a peripheral portion of the face portion;
At the intermediate position along the toe-heel direction of the second region, the second region is recessed from the outer edge side on the crown side or sole side to the first region side, and is formed to be thinner than the second region. A thin-walled portion continuous to the peripheral region ,
The thin portion is formed on the crown side and the sole side of the second region, a golf club, wherein Rukoto crown side is wider and longer formed or area in the toe-heel direction than the sole side.   The CT value of the thin portion is formed on a center line passing through a center position in the toe-heel direction, and is formed to be equal to or greater than a value on a toe side or a heel side portion of the center line. Golf club.   The thickness change rate of the boundary portion between the thin wall portion and the peripheral region is made smaller than the thickness change rate of the boundary portion between the first region and the second region. The golf club described in 1.

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