JP2017000746A - Golf club head and golf club - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a golf club head having a more beautiful mirror surface capable of taking more light, and a golf club.SOLUTION: A golf club head 1 comprises a face part 2 having a ball hitting surface, and a back surface 3 located on the back side of the ball hitting surface in the face part 2 and connected to the face part 2. The back surface 3 includes one flat surface 4a and the other flat surface 4b arranged at an interval, and a mirror-finished concave surface 6 which is sandwiched between one flat surface 4a and the other flat surface 4b and extends from a toe side end part 1t to a heel side end part 1h. The concave surface 6 is a curved surface having different curvatures of a linear shape of which the concave surface 6 shows on a cut surface obtained by cutting the golf club head.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a golf club head and a golf club, and more particularly to a golf club head and a golf club having a mirror surface.

  The golf club head has a face portion having a hitting surface and a back surface facing the face portion. Of these, a recess is formed in a part of the back surface.

  From the viewpoint of making the back surface look more beautiful, the concave portion or the like of the back surface may be subjected to a mirror surface treatment. In view of this, for example, Japanese Patent Application Laid-Open No. 2012-170513 (Patent Document 1) discloses a golf club head in which a part of a concave portion of a back surface is subjected to a mirror surface treatment.

JP 2012-170513 A

  In the golf club head disclosed in Japanese Patent Application Laid-Open No. 2012-170513, a part of the recess on the back surface is mirror-finished, but the formed mirror surface has a planar shape. For this reason, the reflection of complex light on the mirror surface cannot be realized, and the appearance of the mirror surface may not be sufficiently beautiful.

  The present invention has been made in view of the above problems, and an object thereof is to provide a golf club head and a golf club having a mirror surface that can take in more light and look more beautiful.

  A golf club head according to one embodiment includes a face portion having a ball striking surface, and a back surface located on the back side of the ball striking surface of the face portion and connected to the face portion. The back surface is sandwiched between one flat surface and the other flat surface that are spaced apart from each other, and the one flat surface and the other flat surface, from the toe side end to the heel side end. And a concave curved surface that has been mirror-finished. The concave curved surface is a curved surface in which the curvature of the linear shape indicated by the concave curved surface is different on the cut surface obtained by cutting the golf club head.

  Another golf club head of the present embodiment includes a face portion having a ball striking surface, and a back surface located on the back side of the ball striking surface of the face portion and connected to the face portion. The back surface is sandwiched between one flat surface and the other flat surface that are spaced apart from each other, and the one flat surface and the other flat surface, from the toe side end to the heel side end. And a concave curved surface that has been mirror-finished. The line shapes indicated by the concave curved surfaces on the cut surface obtained by cutting the golf club head in an arbitrary toe heel direction and top sole direction are neither the same nor similar.

  According to the present invention, since a plurality of portions having the same curvature do not exist in a mirror-finished concave curved surface, more light can be taken in and reflected on the concave curved surface by irregular reflection of light incident on the concave curved surface. The indentation pattern can be complicated. For this reason, the concave curved surface can be shown more beautifully.

1 is a schematic view showing a golf club according to an embodiment of the present invention with a focus on a plate member provided in a golf club head. It is the schematic of the concave curved surface of the golf club head of FIG. It is a schematic sectional drawing of the part of the curve in alignment with the III-III line of FIG. It is a schematic perspective view which shows the center of the virtual circle which passes along each point on the curve extended on the surface of a concave curved surface in a toe heel direction. It is a schematic perspective view which shows the center of the virtual circle | round | yen which passes along each point on the curve extended on a concave surface on a top sole direction. It is a schematic perspective view which shows the aspect which looked at the center of the virtual circle | round | yen passing through each point on the curve extended on a concave surface on a concave curved surface from the direction different from FIG. Schematic (A) showing an aspect of the curved surface extending in the top sole direction on the concave curved surface viewed from the face side, and schematic diagram showing an aspect of the curved surface extending in the top sole direction on the concave curved surface viewed from the back surface side. B). It is a graph which shows the value which measured the curvature regarding the top sole direction on the curve extended on a concave surface on a top sole direction. It is a graph which shows the value which measured the difference of the curvature regarding the top sole direction on the curve extended on a concave surface on a top sole direction. It is the schematic which shows the aspect which looked at the curve extended in a toe heel direction on a concave curved surface from the face part side. It is a graph which shows the value which measured the curvature regarding the toe heel direction on the curve which extends on a concave curved surface in a toe heel direction. It is a graph which shows the value which measured the difference of the curvature regarding the toe heel direction on the curve which extends on a concave curved surface in a toe heel direction.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Referring to FIG. 1, golf club head 1 according to the present embodiment is fixed to the tip of shaft 20 to constitute a golf club. The golf club head 1 includes a face portion 2 and a back surface 3 that is located on the back side of the face portion 2 and connected to the face portion 2.

  The face portion 2 has a hitting surface. The back surface 3 is located particularly on the back side of the hitting surface in the face portion 2 and is connected to the face portion 2 via the top, side, and sole. The back surface 3 is provided from the heel portion 1h to the toe portion 1t.

  On the back surface 3, a back flat 4 is formed as a flat surface. The back flats 4 are arranged in pairs with a space therebetween, and specifically include one back flat 4a as one flat surface and the other back flat 4b as the other flat surface. Here, one back flat 4a is disposed on the upper side when the golf club is in use (when it is held). The other back flat 4b is arranged on the side of the sole portion 5 (that is, the lower side) located at the end of the side in contact with the ground when the golf club is used. The concave curved surface 6 is not formed so as to extend directly from one back flat 4a and the other back flat 4b, but may be formed via an inclined surface or another flat surface.

  When the sole portion 5 is viewed downward from the back surface 3 side as shown in FIG. 1, the concave curved surface 6 is sandwiched between one back flat 4 a and the other back flat 4 b on the back surface 3. Is formed. That is, the concave curved surface 6 is formed at a substantially central portion in the vertical direction when the golf club is used. In other words, the other back flat 4 b is the other flat surface formed on the opposite side to the back flat 4 a which is one flat surface with respect to the concave curved surface 6.

  One back flat 4a, the other back flat 4b, and the concave curved surface 6 all extend from the toe portion 1t (toe side end portion) to the heel portion 1h (heel side end portion). In other words, when the golf club head 1 is viewed from the toe side and the heel side, an edge on a curve constituted by the bottom surface of the concave curved surface 6 can be confirmed.

  Referring to FIGS. 2 and 3, the concave curved surface 6 has a shape recessed on the face portion 2 side with respect to one back flat 4 a and the other back flat 4 b on the back surface 3. That is, the surface of the concave curved surface 6 is a curved surface CVX that is concave toward the face portion 2 side (ball striking surface side). The surface of the concave curved surface 6 is mirror-finished to extend from the toe portion 1t to the heel portion 1h. As described above, while the back flat 4 is a flat surface, the surface of the concave curved surface 6 is curved.

  Here, in this embodiment, the curved surface means that the curvature (maximum value) in any one direction obtained at a certain point (measurement position) on the surface is 0.01 or more (more preferably 0.017). )). Further, when the curvature is measured as described above, a surface in which the average value of the curvature measured at a plurality of measurement positions at a predetermined interval (for example, 1 mm interval) is at least 0.01 in at least one direction. It is called a curved surface. That is, even if the average value of curvature in a certain direction on the surface is much smaller than 0.01, if the average value of curvature in another direction is 0.01 or more, the surface is a curved surface.

  Conversely, the flat surface herein refers to a surface that does not satisfy the above-mentioned curved surface condition, that is, a surface that has a curvature (maximum value) in any direction from the measurement position that is less than 0.01. However, in particular, the flat surface here means that, for example, when the curvature is measured on a curve extending in one arbitrary direction from a certain point, the curvature (maximum value) in any direction is approximately 0.003 or less (particularly 0.001 or less).

  In particular, referring to FIG. 3, in concave surface 6, the thickness as the distance between the surface and face portion 2 (for example, a hitting surface) gradually increases from the heel portion 1h side to the toe portion 1t side. . That is, the vertical direction in FIG. 3 is a direction from the back surface 3 toward the face portion 2 facing the back surface 3, and the thickness t1 on the toe portion 1t side in this direction is thicker than the thickness t2 on the heel portion 1h side. Yes. For example, the difference in thickness between the thickness t1 and the thickness t2 is 0.5 mm or more and 1.5 mm or less.

  Referring to FIG. 4, one concave curved surface boundary line 6a is formed at the boundary between the concave curved surface 6 and one back flat 4a, and the other concave curved surface boundary line is formed at the boundary between the concave curved surface 6 and the other back flat 4b. 6b is formed. One concave curved boundary line 6a and the other concave curved boundary line 6b are slightly curved but basically extend along the toe heel direction. That is, the concave curved surface 6 is a curved surface that extends in the toe heel direction along one concave curved boundary line 6a and the other concave curved boundary line 6b as edges.

  With reference to FIGS. 2 and 4, for example, a curved line TH <b> 1 extending in the toe heel direction at the center portion with respect to the top sole direction on the surface of the concave curved surface 6 is considered. At this time, a radius of curvature is obtained for each point adjacent to the curve TH1 at a predetermined interval, a virtual circle having a radius of each curvature radius is defined, and a center line P0 formed by connecting the centers of the virtual circles. Ask for. At this time, the center line P0 extends without any regularity with respect to the direction in which the curve TH1 extends. That is, the value of the radius of the virtual circle passing through each point on the curve TH1 and the direction of the tangent line are completely different for each point.

  With reference to FIGS. 5 and 6, next, consider curves C1, C3, and C5 that extend on the surface of the concave curved surface 6 from one concave curved boundary line 6a to the other concave curved boundary line 6b. Each of the curves C1, C3, and C5 is spaced from each other in the toe heel direction. At this time, for each of the curves C1, C3, and C5, a radius of curvature is obtained for each adjacent point at a predetermined interval, a virtual circle having each radius of curvature as a radius is defined, and the center of each virtual circle is defined. Center lines P1, P3, and P5 that are formed are obtained. Each of the center lines P1, P3, and P5 extends in a disorderly manner with respect to the extending directions of the curves C1, C3, and C5, similarly to the center line P0. That is, the value of the radius of the virtual circle passing through each point on the curves C1, C3, and C5 and the direction of the tangent line are completely different for each point. Further, even when the shapes of the center line P1, the center line P3, and the center line P5 are compared, there is no regularity between them, and they have completely different shapes.

  4 to 6, the concave curved surface 6 in the present embodiment is a linear shape indicated by the concave curved surface 6 on a cut surface obtained by cutting the golf club head 1 (hereinafter referred to as “cut surface curve”). However, even if it cut | disconnects in any direction of arbitrary toe heel directions and a top sole direction, it is comprised as a non-uniform curved surface which does not become the same curve and does not become a similar curve. In other words, the concave curved surface 6 is a curved surface having a different curvature in any cut surface curve.

  Here, in this embodiment, the curvature on the cut surface curve is different. In the top sole direction, there is no constant (that is, the same) curvature portion on the cut surface curve, and in the toe heel direction. This means that there is almost no constant curvature portion on the cut surface curve. Specifically, in the top sole direction, the standard deviation of the curvature of the surface of the concave curved surface 6 obtained at a predetermined interval (for example, 1 mm interval) on an arbitrary cut surface curve is 0.018 or more (more preferably 0). .022 or higher). Further, in the toe heel direction, the curvature of the surface of the concave curved surface 6 obtained at a predetermined interval (for example, 1 mm interval) on a part of the cut surface curve including at least the score line center region is not constant in at least adjacent portions. It shall be said.

  In the present embodiment, such a curved surface having a curvature state in the toe heel direction and the top sole direction is referred to as a curved surface having different curvatures on the cut surface curve. The toe heel direction is defined as a direction parallel to the score line, and the top sole direction is defined as a direction perpendicular to the score line.

  Next, it will be described with reference to FIGS. 7 to 12 that the concave curved surface 6 is a curved surface and the curvature is different on the cut surface curve of the concave curved surface 6.

  With reference to FIGS. 7A and 7B, first, consider each curve extending on the surface of the concave curved surface 6 in the top sole direction. Similar to FIGS. 5 and 6 above, curves C1, C2, C3, C4 extending from one back flat 4a to the other back flat 4b and spaced apart from each other in the toe heel direction, as in FIGS. , C5. Curve C1 is defined closest to the toe portion 1t, and curve C5 is defined closest to the heel portion 1h. Curves C1 to C5 in FIG. 7A overlap with the curves C1 to C5 in FIG. 7B when the sole portion 5 is viewed from the back surface 3 side as shown in FIG. 7B, for example. Is shown in That is, the curves C1 to C5 in FIG. 7A and the curves C1 to C5 in FIG. 7B are the same. Each of the curves C1 to C5 is substantially orthogonal to each of the plurality of score lines SL applied to the face portion 2 shown in FIG.

  As shown in FIG. 7A, the distance along the toe heel direction between the curve C1 closest to the toe part 1t and the curve C5 closest to the heel part 1h when viewed from the face part 2 side is 53 mm. By dividing this 53 mm region into four equal parts, the curves C1 to C5 are defined so that the distance between the adjacent curves, that is, the adjacent curves becomes 13.25 mm.

  For comparison, a straight line C6 having substantially the same length as the curve C1 is defined on the surface of the back flat 4a that is a flat surface.

  The length of each of the curves C1 to C5 and the straight line C6 is measured, and the curvature in the direction along the curve is obtained every 1 mm with respect to the direction along the direction in which each of the curves C1 to C5 and the straight line C6 extends. It is done. This curvature is measured based on CAD (Computer Aided Design) data.

  FIG. 8 shows the distribution of curvature values obtained in the above manner for each numbered point (measurement position) on each of the curves C1 to C5. FIG. 8 is a graph of the data in Table 1 below, in which the horizontal axis indicates each measurement position on each curve, and the vertical axis indicates the measured curvature value. The numbers of the respective measurement positions are numbered so that the points adjacent to each other on each curve are adjacent to each other (that is, in order of numbers in the direction along the curve).

  Referring to Table 1 and FIG. 8, the curves C1 to C5 indicated by the concave curved surface 6 on the cut surface obtained by cutting the golf club head 1 in an arbitrary top sole direction are all at each measurement position on each line. Since the curvature values in the extending direction of each line are almost all 0.01 or more (0.017 or more), it can be said that the concave curved surface 6 is a curved surface according to the above definition. In addition, the average value of curvature (indicated by “average” in Table 1) in the extending direction of each curve at each measurement position on each curve C1 to C5 is 0.01 or more (0.04 or more). Therefore, from this point of view, it can be said that the concave curved surface 6 is a curved surface according to the above definition.

  In particular, referring to Table 1, the curves C1 to C5 all have a standard deviation of curvature (indicated by “standard deviation” in Table 1) in the extending direction of each curve of 0.018 or more. For this reason, it can be said that the curvature of the concave curved surface 6 is completely different (varies greatly) on the cut surface curve. Further, the averages of the curvatures of the curves C1 to C5 obtained from the “average” in Table 1 are all different values. Also from this, it can be said that all of the line shapes indicated by the concave curved surface 6 on the cut surface when the concave curved surface 6 is cut along the curves C1 to C5 are different.

  On the other hand, as shown in Table 1, the value of curvature in the direction in which the straight line C6 extends at each measurement position on the straight line C6 on the back flat 4a is very small compared to the value of the same curvature of the curves C1 to C5. There is also a location that is less than 0.001. Also, the average value and standard deviation of the curvature are 0.00112 and 0.00080, respectively, which are very small compared to the curves C1 to C5.

  Further, even if the values on the vertical axis of the graph of FIG. 8 are on the same curve, the value of the curvature varies greatly depending on the measurement position (varies so as to vary greatly). From this, it can be said that the concave curved surface 6 has completely different curvatures (large variations) between different measurement positions on the curves C1 to C5 (within the same curve) on the surface.

  Further, for example, the shapes of the graphs (curves) of the curves C1 to C5 in FIG. 8 are completely different. From this, it can be seen that even when different curves C1 to C5 are compared, the curvatures on the respective curves are completely different. Also from this, it can be said that the concave curved surface 6 has a completely different curvature (large variation) on the cut surface curve.

  Next, Table 2 and FIG. 9 below show the difference in the absolute value of the curvature between the measurement positions adjacent to each other among the curvature values at the measurement positions on the curves C1 to C5 shown in Table 1 and FIG. It is displayed. That is, FIG. 9 is a graph of the data in Table 2 below, where the horizontal axis is a numbered region between a pair of adjacent measurement positions on each curve, and the vertical axis is the pair of measurements. The absolute value of the difference in curvature shown in Table 1 and FIG. 8 for each position is shown.

  Referring to Table 2 and FIG. 9, the number n of the region between the measurement positions indicates the difference in curvature between the measurement position n of Table 1 and FIG. 8 and the measurement position (n + 1) adjacent thereto. ing. That is, for example, the region 1 between the measurement positions indicates the difference in curvature between the measurement position 1 and the measurement position 2, and the region 2 between the measurement positions indicates the difference in curvature between the measurement position 2 and the measurement position 3. Yes.

  As shown in Table 2 and FIG. 9, even when the difference in curvature between adjacent measurement positions is examined, the variation in the difference in curvature between areas between different measurement positions on each curve is large, and The shape of the graph differs greatly between the curves. Accordingly, it can be said that the concave curved surface 6 has completely different curvatures (large variations) on the cut surface curve.

  Next, with reference to FIG. 10, each curve extending in the second direction in the concave curved surface 6 will be considered. Similar to FIG. 4 described above, curves TH2, TH3, TH4 are defined which extend on the surface of the concave curved surface 6 in the direction along the toe heel direction and are arranged at intervals. The curve TH2 is disposed on the side of the other back flat 4b, and the curve TH4 is disposed on the side of the back flat 4a.

  As shown in FIG. 10, when a virtual straight line L1 in contact with the sole portion 5 is considered, the curves TH2, TH3, TH4 viewed from the back surface 3 are substantially parallel to the straight line L1. For example, when the sole portion 5 is viewed from the back surface 3 side as shown in FIG. 10, the distance between the straight line L1 and the curve TH2 is 23 mm, the distance between the straight line L2 and the curve TH3 is 28 mm, and the straight line L3 The distance between the curve TH4 and the curve TH4 is 33 mm.

  For the flat surface, it can be considered that the result of the curvature C6 in Table 1 is almost the same as the curve C6 in Table 1, so the data in Table 1 can be used as comparison data here. is there.

  The length of each of the curves TH2 to TH4 is measured, and the curvature in the direction along the curve is obtained for each 1 mm in the direction along the direction in which each of the curves TH2 to TH4 extends on each curve. This curvature is measured based on CAD (Computer Aided Design) data.

  FIG. 11 shows the distribution of curvature values obtained in the above manner for each numbered point (measurement position) on each of the curves TH2 to TH4. FIG. 11 is a graph of the data in Table 3 below, in which the horizontal axis represents each measurement position on each curve, and the vertical axis represents the measured curvature value. The numbers of the respective measurement positions are numbered so that the points adjacent to each other on each curve are adjacent to each other (that is, in order of numbers in the direction along the curve).

  Referring to Table 3 and FIG. 11, the curves TH2 to TH4 all have a region where the value of the curvature in the extending direction of each line is partially less than 0.01 at each measurement position on each line. However, the area | region which is 0.01 or more has increased. In addition, although the curve TH4 has an average value of curvature with respect to the extending direction of each curve at each measurement position, it is less than 0.01. The value is 0.01 or more.

  The standard deviation of the curvature in the extending direction of each curve is less than 0.018, but is at least much larger than the standard deviation of the curvature in the back flat (see Table 1). Moreover, it turns out that the curvature in the same curve differs from FIG. In addition, as described above, if the curvature (or the average value of curvature) in at least one direction is 0.01 or more, the surface can be defined as a curved surface. For this reason, it can be said that the concave curved surface 6 has almost no constant curvature portion on the cut surface curve in the directions of the curves TH2 to TH4.

  Next, Table 4 and FIG. 12 below show the difference in the absolute value of the curvature between the measurement positions adjacent to each other among the curvature values at the measurement positions on the curves TH2 to TH4 shown in Table 3 and FIG. It is a plot. That is, FIG. 12 is a graph of the data in Table 4 below, where the horizontal axis is a numbered region between a pair of adjacent measurement positions on each curve, and the vertical axis is the pair of measurements. The absolute value of the difference in curvature shown in Table 3 and FIG. 11 for each position is shown.

  Even if the difference in curvature between adjacent measurement positions is examined with reference to Table 4 and FIG. 12, the variation is smaller than the direction along the curves C1 to C5, but at least on each curve compared to the back flat. The variation in the difference in curvature between regions between different measurement positions is large, and the shape of the graph is different between the curves. Therefore, it can be said that the concave curved surface 6 has a variation in curvature on the cut surface curve.

  As described above, the concave curved surface 6 has no constant curvature portion on the cut surface curve on the concave curved surface 6 in the top sole direction, and part of the cut including at least the score line center also in the toe heel direction. The curvature varies on the surface curve. That is, it can be said that the concave curved surface 6 is composed of a non-uniform curve in both the top sole direction and the toe heel direction. The concave curved surface 6 is a cut surface obtained by cutting the golf club head 1 in an arbitrary direction. The line shape indicated by the concave curved surface 6 does not become the same curve even if it is cut in any direction, and does not become a similar curve.

Next, the function and effect of this embodiment will be described.
First, in the present embodiment, the concave curved surface 6 formed on the back surface 3 is mirror-finished, so that light from various directions can be reflected on the surface of the concave curved surface 6.

  In addition, as shown in FIG. 8 and FIG. 11 and Tables 1 and 3 above, it is adjacent to any of the curves C1 to C5 shown in FIG. 7 and the curves TH2 to TH4 shown in FIG. There is almost no region with the same curvature between the matching measurement positions. That is, the concave curved surface 6 formed on the back surface 3 has almost all different curvatures on the cut surface curve. The concave curved surface 6 has a very large variation in surface curvature. This shows that the standard deviation of the curvature of the surface of the concave curved surface 6 is as large as 0.018 or more particularly in the direction along C1 to C5 (as shown in Table 1).

  In other words, the concave curved surface 6 is a curved surface shape whose surface shape changes with nonuniform curvature while having regularity of constant depth change in each of the toe heel direction and the top sole direction. Captures light from various directions. For this reason, the light is reflected unevenly in various directions, so that it looks neatly deep.

  As shown in FIG. 3, the concave curved surface 6 is a convex curved surface CVX toward the face portion 2 (ball striking surface). Also from this, the concave curved surface 6 can make the reflected state of light more beautiful.

  Further, the concave curved surface 6 has a thickness as a distance from the face portion 2 from the heel portion 1h to the toe portion 1t in the toe heel direction. Thereby, the value of the moment of inertia in the toe heel direction around the center of gravity of the golf club head 1 can be further increased. Therefore, for example, even when the hit point is shaken when the user hits the hit ball, the golf club head 1 can suppress the shake in the hit ball direction. Accordingly, it is possible to provide an iron golf club head capable of dealing with variations in hit points while having a muscle back type appearance that is considered difficult to use for an intermediate golfer.

  Although the embodiment of the present invention has been described above, the above-described embodiment can be variously modified. The scope of the present invention is not limited to the above-described embodiment. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The present invention is particularly advantageously applied to an iron golf club head and an iron golf club that can be mirror-finished on the entire back surface.

  1 golf club head, 1h heel portion, 1t toe portion, 2 face portion, 3 back surface, 4 back flat, 4a one back flat, 4b other back flat, 5 sole portion, 6a one concave curved surface boundary line, 6b The other concave curved boundary line, 20 shaft, C1, C2, C3, C4, C5, TH1, TH2, TH3, TH4 curve, P0, P1, P3, P5 center line.

Claims (5)

A golf club head,
A face portion having a ball striking surface;
A back surface located on the back side of the hitting surface in the face portion and connected to the face portion;
The back surface is sandwiched between one flat surface and the other flat surface, which are spaced apart from each other, and the one flat surface and the other flat surface, from the toe side end to the heel side. Including a concave curved surface that is mirror-finished to the end,
The concave curved surface is a golf club head that is a curved surface in which the linear curvature indicated by the concave curved surface is different on a cut surface obtained by cutting the golf club head. A golf club head,
A face portion having a ball striking surface;
A back surface located on the back side of the hitting surface in the face portion and connected to the face portion;
The back surface is sandwiched between one flat surface and the other flat surface, which are spaced apart from each other, and the one flat surface and the other flat surface, from the toe side end to the heel side. Including a concave curved surface that is mirror-finished to the end,
A golf club head in which neither of the linear shapes indicated by the concave curved surface is the same or similar on a cut surface obtained by cutting the golf club head in an arbitrary toe heel direction and a top sole direction.   The golf club head according to claim 1, wherein the concave curved surface has a thickness as a distance from the face portion that increases from a heel side toward a toe side.   The average of the curvature of the curve which the said concave curved surface shows on the cut surface obtained by cut | disconnecting the said golf club head to arbitrary top sole directions differs in any one of Claims 1-3. Golf club head.   A golf club comprising the golf club head according to claim 1.

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