JP4902871B2 - Golf club head - Google Patents

Description

  The present invention relates to a golf club head.

A golf club head with high resilience can improve the initial velocity of the hit ball and increase the flight distance. It is known that the resilience can be improved by increasing the elastic deflection of the face. Japanese Patent Laying-Open No. 2003-210627 discloses a golf club head in which a thin portion is provided in the vicinity of the face portion of the top portion and in the vicinity of the face portion of the sole portion.
JP 2003-210627 A

  A golf club head having a low center of gravity can increase the launch angle and increase the flight distance. From the viewpoint of increasing the flight distance, it is preferable that the head has a low center of gravity. Due to the synergistic effect of low center of gravity and high repulsion, further increase in flight distance can be achieved. Furthermore, the position of the sweet spot SS is related to the flight distance. The flight distance can be increased by optimizing the position of the sweet spot SS. The head of the above-mentioned patent document has a thin portion at the sole portion and has a high center of gravity.

  An object of the present invention is to provide a golf club head that can increase the flight distance by a synergistic effect of the position of the center of gravity and high resilience.

  The golf club head according to the present invention includes a face portion, a sole portion, and a crown portion. The sole part has a thick part having a thickness of 5 mm or more. In the cross section by the reference vertical plane, the length in the front-rear direction of the thick portion is 5 mm or more and 40 mm or less. In the cross section by the reference vertical plane, the shortest distance between the foremost point of the thick part and the inner face of the face is 10 mm or less. In the cross section by the reference vertical plane, a thin portion having a minimum thickness of 3 mm or less is formed between the thick portion and the face inner surface. This golf club head is hollow.

  Preferably, the toe-heel direction length of the thick part is 10 mm or more. Preferably, the toe-heel direction length of the thin portion is 10 mm or more.

  An increase in flight distance can be achieved by a synergistic effect of the position of the center of gravity and high resilience.

  Hereinafter, the present invention will be described in detail based on preferred embodiments with appropriate reference to the drawings.

  1 is a view of a golf club head 2 according to an embodiment of the present invention as seen from the crown side, FIG. 2 is a view of the head 2 as seen from the face side, and FIG. 3 is a view of the head 2 from the sole side. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG.

  The head 2 includes a face portion 4, a crown portion 6, a sole portion 8, a side portion 10, and a neck portion 12. The crown portion 6 extends from the upper edge of the face portion 4 toward the rear of the head. The sole portion 8 extends from the lower edge of the face portion 4 toward the rear of the head. The side portion 10 extends between the crown portion 6 and the sole portion 8. As shown in FIG. 4, the inside of the head 2 is hollow. The head 2 is a hollow golf club head. The head 2 is a so-called wood type golf club head.

  As shown in FIG. 2, a face line 11 is provided on the outer surface of the face portion 4. In FIG. 1 and FIG. 4, the description of the face line 11 is omitted.

  The head 2 is formed by welding a crown member 14 and a head main body 16. The crown member 14 constitutes a part of the crown portion 6. The crown member 14 constitutes a central portion of the crown portion 6. A wavy line indicated by reference numeral k <b> 1 in FIG. 1 is a boundary between the crown member 14 and the head main body 16. The boundary k1 coincides with the contour line of the crown member 14. The crown member 14 and the head body 16 are welded at the boundary k1. In FIG. 4, the welded part is painted black. The head body 16 constitutes a part other than the crown member 14. The head body 16 constitutes the entire face portion 4, a portion of the crown portion 6, the entire sole portion 8, the entire side portion 10, and the entire neck portion 12.

  In the present invention, a reference vertical plane, a front-rear direction, and a toe-heel direction are defined. In a reference state in which the head is placed on the horizontal plane H at a predetermined lie angle and real loft angle, a plane that passes through the head gravity center G and the sweet spot SS and is perpendicular to the horizontal plane H is a reference vertical plane. FIG. 4 is a cross-sectional view of the reference vertical plane.

  In the present application, the front-rear direction is a direction parallel to the reference vertical plane and parallel to the horizontal plane H.

  In the present application, the toe-heel direction is a direction perpendicular to the reference vertical plane. The toe-heel direction is parallel to the horizontal plane H and perpendicular to the front-rear direction.

  Note that the sweet spot SS is an intersection of a perpendicular drawn from the center of gravity of the head to the face surface and the face surface. In the cross section of the reference vertical plane, a straight line connecting the sweet spot SS and the head gravity center G is orthogonal to the tangent to the face surface at the sweet spot SS. The face surface is the outer surface of the face portion 4.

  As shown in FIG. 4, the sole portion 8 has a thick portion 18. The thick portion 18 is a portion having a thickness of 5 mm or more. The thick portion 18 is provided on the inner surface of the sole portion 8. The thick part 18 protrudes toward the inside of the head. The thick part 18 is not visually recognized from the outside of the head. Slope portions 19 exist in front of and behind the thick portion 18. In the embodiment of FIG. 4, the cross-sectional shape of the thick portion 18 is a substantially trapezoid. In addition, the cross-sectional shape of the thick part 18 is not limited. Examples of the cross-sectional shape of the thick portion 18 include a rectangle, a semicircular shape, and a hill shape. In the embodiment of FIG. 4, the flat portion is provided on the top of the thick portion 18, but the flat portion may not be provided.

  FIG. 5 is an enlarged cross-sectional view of the vicinity of the thick portion 18 in FIG. In FIG. 5, the frontmost point of the thick portion 18 is indicated by the reference symbol P <b> 1. The foremost point P <b> 1 is the foremost point in the thick portion 18. The foremost point P1 can be determined in any cross section parallel to the reference vertical plane. In FIG. 5, what is indicated by a symbol P <b> 2 is the last point of the thick portion 18. The rearmost point P2 is the rearmost point of the thick portion 18. The rearmost point P2 can be determined in any cross section parallel to the reference vertical plane.

  In FIG. 5, what is indicated by a double arrow W <b> 1 is the length of the thick portion 18 in the front-rear direction. The front-rear direction length W1 is a front-rear direction distance between the foremost point P1 and the rearmost point P2. The front-rear direction length W1 is measured in a cross section parallel to the reference vertical plane. The length W1 in the front-rear direction can be determined in any cross section parallel to the reference vertical plane. The foremost point P1 and the rearmost point P2 can be determined in any cross section parallel to the reference vertical plane.

  In FIG. 5, a point indicated by a symbol P <b> 3 is a point on the face inner surface 20 that has the shortest distance from the foremost point P <b> 1. The face inner surface 20 is the inner surface of the face portion 4. In FIG. 5, a double-headed arrow W <b> 2 indicates the shortest distance between the forefront point P <b> 1 and the face inner surface 20. The shortest distance W2 is measured in a cross section parallel to the reference vertical plane. The shortest distance W2 can be determined in any cross section parallel to the reference vertical plane.

  In the head 2, a thin portion 22 having a minimum thickness t 1 of 3 mm or less is formed between the thick portion 18 and the face inner surface 20. The minimum thickness t1 is measured in a cross section parallel to the reference vertical plane. The minimum thickness t1 can be determined in any cross section parallel to the reference vertical plane.

  In FIG. 3, a region A <b> 1 indicated by wavy hatching indicates a region where the thick portion 18 is provided. In FIG. 3, a region A <b> 2 indicated by solid line hatching indicates a region where the thin portion 22 is provided. The thin portion 22 extends in a groove shape substantially along the face inner surface 20. The thin portion 22 does not exist in the region A3 and the region A4 indicated by the one-dot chain line hatching. In the sole portion 8, the thickness of the portion excluding the regions A1 to A4 is 1.0 mm to 1.5 mm excluding the slope portion 19 described above.

  In FIG. 5, what is indicated by a double-headed arrow t2 is the maximum thickness of the thick portion 18 in a cross section parallel to the reference vertical plane. The maximum thickness t2 can be determined in each of all cross sections parallel to the reference vertical plane.

In the present embodiment, the thick portion 18 is located closer to the face portion 4. Thereby, the height h1 of the sweet spot SS can be lowered. This point will be described. As shown in FIG. 4, consider a virtual center of gravity Gk that is ahead of the head center of gravity G. In the head 2 in the reference state,
It is assumed that the height Hg of the head center of gravity G and the height Hgk of the virtual center of gravity Gk are the same. As shown in FIG. 4, the sweet spot height h1 due to the head gravity center G is higher than the sweet spot height hk due to the virtual gravity center Gk. Thus, the sweet spot height h1 tends to be lower as the center of gravity G of the head is closer to the face portion 4. This tendency becomes more prominent as the real loft angle of the head 2 is larger. The sweet spot height h1 is the height of the sweet spot SS from the horizontal plane H. The sweet spot height h1 is measured at the head 2 in the reference state.

  In FIG. 4, a double-headed arrow Fg indicates the depth of the center of gravity of the head 2. Since the thick portion 18 is positioned closer to the face portion 4, the center of gravity depth Fg is reduced. By reducing the center-of-gravity depth Fg, the so-called gear effect is reduced, the amount of side spin is suppressed, and the hitting directionality can be improved. The center-of-gravity depth Fg is the distance in the front-rear direction between the head front center G and the point at the forefront of the leading edge.

  In the cross section by the reference vertical plane, the longitudinal length W1 is preferably 5 mm or more, more preferably 10 mm or more, and further preferably 20 mm or more. By increasing the longitudinal length W1, the position of the head gravity center G and the position of the sweet spot SS can be lowered. In the cross section by the reference vertical plane, the length W1 in the front-rear direction is preferably 40 mm or less, and more preferably 30 mm or less. An excessive increase in the head weight is suppressed by reducing the length W1 in the front-rear direction.

  In the cross section by the reference vertical plane, the shortest distance W2 is preferably 10 mm or less, and more preferably 6 mm or less. By reducing the shortest distance W2, the thick portion 18 becomes closer to the face, so that the gravity center depth Fg tends to be small, and the sweet spot height h1 tends to be low. In the cross section by the reference vertical plane, the shortest distance W2 is preferably 1 mm or more, more preferably 2 mm or more, and further preferably 3 mm or more. At the time of hitting, an excessive stress acts on the face portion 4. This stress may concentrate on the thin portion 22. By increasing the shortest distance W2, stress concentration on the thin portion 22 can be relaxed, and the durability of the head can be improved.

  In the cross section taken along the reference vertical plane, the minimum thickness t1 of the thin portion 22 is preferably 3 mm or less, more preferably 2 mm or less, and even more preferably 1.5 mm or less. By reducing the minimum thickness t1, the displacement of the face portion 4 accompanying the elastic deformation of the head 2 increases, and the resilience can be improved. From the viewpoint of improving durability, the minimum thickness t1 is preferably 0.5 mm or more, and more preferably 1.0 mm or more.

  In the cross section by the reference vertical plane, the maximum thickness t2 of the thick portion 18 is preferably 10 mm or less, and more preferably 8 mm or less. By reducing the maximum thickness t2, an excessive increase in the head weight can be suppressed and the head speed can be improved.

  In FIG. 3, what is indicated by a double-headed arrow D <b> 1 is the length of the thick portion 18 in the toe-heel direction. From the viewpoint of lowering the sweet spot height h1 and the head center of gravity G, the length D1 is preferably 10 mm or more, more preferably 30 mm or more, and even more preferably 50 mm or more. From the viewpoint of suppressing an excessive increase in the head weight, the length D1 is preferably 80 mm or less, and more preferably 70 mm or less.

  In FIG. 3, what is indicated by a double-headed arrow D2 is the length of the thin portion 22 in the toe-heel direction. From the viewpoint of improving resilience, the length D2 is preferably 10 mm or more, more preferably 20 mm or more, and still more preferably 30 mm or more. From the viewpoint of enhancing the durability of the head, the length D2 is preferably 60 mm or less, and more preferably 50 mm or less.

  The thickness of the sole portion 8 behind the thick portion 18 is less than 5 mm. The average thickness Ta of the sole portion 8 behind the thick portion 18 is preferably 0.5 mm or more, more preferably 0.7 mm or more, and even more preferably 1.0 mm or more. The durability can be improved by increasing the average thickness Ta. From the viewpoint of reducing the sweet spot height h1, the average thickness Ta is preferably 3 mm or less, more preferably 2.5 mm or less, and even more preferably 2.0 mm or less.

  As shown in FIG. 1, a toe-heel direction reference position Fc, a toe side reference position Ft, and a heel side reference position Fh are defined. The toe-heel direction reference position Fc, the toe side reference position Ft, and the heel side reference position Fh are positions in the toe-heel direction. The toe-heel direction reference position Fc is the position of the reference vertical plane. In the toe-heel direction, the toe-heel direction reference position Fc bisects between the toe side reference position Ft and the heel side reference position Fh. The toe-heel direction distance between the toe-heel direction reference position Fc and the heel side reference position Fh is F1. The toe-heel direction distance between the toe-heel direction reference position Fc and the toe side reference position Ft is also F1. The vertical plane V is determined at every toe-heel direction position from the toe side reference position Ft to the toe-heel direction reference position Fc. This vertical plane V is a plane parallel to the reference vertical plane. A head cross section by the vertical plane V is defined as a cross section V1.

  As described above, it is preferable that at least one of the following requirement (A), requirement (B), requirement (C), and requirement (D) is satisfied in the cross section by the reference vertical plane.

  Requirement (A): The lower limit of the longitudinal length W1 is preferably 5 mm or more, more preferably 10 mm or more, still more preferably 20 mm or more, and the upper limit of the longitudinal length W1 is It is preferably 40 mm or less, and more preferably 30 mm or less.

  Requirement (B): The upper limit of the shortest distance W2 is preferably 10 mm or less, more preferably 6 mm or less, and the lower limit of the shortest distance W2 is preferably 1 mm or more, more preferably 2 mm or more, and further preferably 3 mm or more.

  Requirement (C): The upper limit of the minimum thickness t1 of the thin portion 22 is preferably 3 mm or less, more preferably 2 mm or less, still more preferably 1.5 mm or less, and the lower limit of the minimum thickness t1 is preferably 0.5 mm or more. 0.0 mm or more is more preferable.

  Requirement (D): The upper limit of the maximum thickness t2 of the thick portion 18 is preferably 10 mm or less, and more preferably 8 mm or less.

  From the viewpoint of further enhancing the effect of the requirement (A), the requirement (A) is preferably satisfied in the cross-section V1 at any toe-heel direction position from the toe side reference position Ft to the heel side reference position Fh. In this case, from the viewpoint of further enhancing the effect of the requirement (A), the distance F1 is preferably 10 mm or more, more preferably 15 mm or more, and further preferably 20 mm or more.

  From the viewpoint of further enhancing the effect of the requirement (B), the requirement (B) is preferably satisfied in the cross-section V1 at any toe-heel direction position from the toe side reference position Ft to the heel side reference position Fh. In this case, from the viewpoint of further enhancing the effect of the requirement (B), the distance F1 is preferably 10 mm or more, more preferably 15 mm or more, and further preferably 20 mm or more.

  From the viewpoint of further enhancing the effect of the requirement (C), the requirement (C) is preferably satisfied in the cross-section V1 at any toe-heel direction position from the toe side reference position Ft to the heel side reference position Fh. In this case, from the viewpoint of further enhancing the effect of the requirement (C), the distance F1 is preferably 10 mm or more, more preferably 15 mm or more, and further preferably 20 mm or more.

  From the viewpoint of further enhancing the effect of the requirement (D), the requirement (D) is preferably satisfied in the cross-section V1 at any toe-heel direction position from the toe side reference position Ft to the heel side reference position Fh. In this case, from the viewpoint of further enhancing the effect of the requirement (D), the distance F1 is preferably 10 mm or more, more preferably 15 mm or more, and further preferably 20 mm or more.

  From the viewpoint of improving the hitting direction by a large moment of inertia, the head volume is preferably 50 cc or more, more preferably 80 cc or more, and further preferably 100 cc or more. The head volume is preferably 300 cc or less, and more preferably 150 cc or less, from the viewpoint of suppressing an excessive weight increase and improving the degree of freedom in designing the center of gravity.

  From the viewpoint of improving the hitting direction by a large moment of inertia, the head weight is preferably 180 g or more, more preferably 190 g or more, and further preferably 200 g or more. The head weight is preferably 300 g or less, and more preferably 250 g or less from the viewpoint of obtaining a golf club that has an appropriate club balance and is easy to swing.

  As described above, the effect of lowering the sweet spot height h1 is achieved by arranging the thick portion closer to the face. As described above, the effect of reducing the sweet spot height h1 is more remarkable as the real loft angle is larger. From this viewpoint, the real loft angle of the head is preferably 12 degrees or more, more preferably 15 degrees or more, and further preferably 17 degrees or more. If the real loft angle is excessive, the sweet spot height h1 tends to increase. From this viewpoint, the real loft angle of the head is preferably 30 degrees or less, and more preferably 25 degrees or less.

  As described above, in order to reduce the sweet spot height h1, it is advantageous to reduce the gravity center depth Fg. On the other hand, as the gravity center depth Fg decreases, the inertia moment of the head tends to decrease. The sweet spot height h1 is preferably 17 mm or more, and preferably 17.5 mm or more from the viewpoint of suppressing the excessive decrease in the moment of inertia by suppressing the shallow center of gravity depth Fg from increasing excessively. More preferably, it is more preferably 18 mm or more. When the sweet spot height h1 is lowered, a high launch angle and a low backspin amount are achieved due to the so-called gear effect, and the flight distance tends to increase. In this respect, the sweet spot height h1 is preferably 25 mm or less, and more preferably 22 mm or less.

  In FIG. 4, what is indicated by a double arrow Hg is the height of the center of gravity G of the head. The center-of-gravity height Hg is the shortest distance between the horizontal plane H and the head center-of-gravity G in the head in the reference state. From the viewpoint of suppressing an excessive decrease in the backspin amount due to the gear effect, the center of gravity height Hg is preferably 10 mm or more, more preferably 10.5 mm or more, and even more preferably 11 mm or more. From the viewpoint of realizing a high launch angle and a low backspin amount, the center of gravity height Hg is preferably 18 mm or less, and more preferably 15 mm or less.

  From the viewpoint of lowering the sweet spot height h1, the center-of-gravity depth Fg is preferably 30 mm or less, and more preferably 25 mm or less. From the viewpoint of increasing the hitting ball directivity due to a large moment of inertia, the center of gravity depth Fg is preferably 20 mm or more, more preferably 22 mm or more, and further preferably 23 mm or more.

  The material of the head is not limited. Examples of the material of the head include metal, CFRP (carbon fiber reinforced plastic) and the like. Examples of the metal used for the head include one or more metals selected from pure titanium, titanium alloy, stainless steel, maraging steel, aluminum alloy, magnesium alloy, and tungsten-nickel alloy.

  The method for manufacturing the head is not limited. From the viewpoint of forming a hollow golf club head, the head is formed by joining two or more members. A preferred head is formed by joining a head body and another member. Preferably, the head main body constitutes part or all of the sole part and part or all of the face part. A preferred head is bonded to the head main body so as to close the concave portion or the opening, and a head main body having a concave portion or an opening provided over the crown portion, the side portion, the sole portion, the face portion or two or more thereof. And other members. The material of the other member is, for example, metal or CFRP (carbon fiber reinforced plastic). As the metal other member, a rolled titanium alloy, a forged titanium alloy, a cast magnesium alloy, a molded CFRP, or the like can be suitably used. From the viewpoint of enhancing the durability of the thin-walled portion, it is preferable that the joint portion (boundary portion) between the head main body and the other member is not located in the thinnest portion in the thin-walled portion, and more preferably not located in the thin-walled portion. As FIG.4 and FIG.5 shows, the thin part vicinity tends to become a complicated shape. Such a complicated shape is difficult to form by forging or pressing. From the viewpoint of facilitating molding even in a complicated shape, the head body includes at least a part of the sole part and at least a part of the face part, and at least a part of the sole part and at least a part of the face part. It is preferable that the thick part and the thin part are formed between a part and formed integrally by casting. Further, a weight member made of a tungsten alloy or the like may be disposed on the sole portion, the side portion, or the like. From the viewpoint of enhancing the durability of the thin portion and increasing the elastic displacement of the face surface at the time of impact, it is preferable that the weight member is disposed so as not to cover the thinnest portion of the thin portion.

  A double arrow L1 in FIG. 3 indicates a maximum length in the toe-heel direction of a portion of the head excluding the hosel (hosel excluded head). Here, the hosel means a portion protruding outward. This length L1 is measured in the head in the reference state. This length L1 is the distance between the most toe side point and the most heel side point in the hosel exclusion head. The length L1 is preferably equal to or greater than 80 mm, more preferably equal to or greater than 85 mm, and still more preferably equal to or greater than 88 mm, from the viewpoint of increasing the face area and achieving easy hitting even with an average golfer. From the viewpoint of reducing the ground resistance and improving the removal of the sole, the length L1 is preferably 110 mm or less, and more preferably 100 mm or less.

  In FIG. 3, what is indicated by a double-headed arrow L2 is the maximum length in the front-rear direction of the hosel exclusion head. This length L2 is measured in the head in the reference state. This length L2 is the distance between the frontmost point and the rearmost point in the hosel exclusion head. From the viewpoint of increasing the directionality of the hit ball with a large moment of inertia, the length L2 is preferably 50 mm or more, and more preferably 55 mm or more. The length L2 is preferably 95 mm or less, more preferably 85 mm or less, from the viewpoint of reducing the ground resistance and improving the removal of the sole.

  Hereinafter, the effects of the present invention will be clarified by examples. However, the present invention should not be construed in a limited manner based on the description of the examples.

[Example 1]
A head similar to the head 2 described above was produced. A head body having an opening in the crown portion and a crown member were produced. CUSTOM450 manufactured by Carpenter Co. was used for the head body and the crown member. CUSTOM450 is a precipitation hardening type stainless steel. The composition of this CUSTOM 450 is, by weight percentage, 0.05% carbon, 0.030% phosphorus, 1% silicon, 5-7% nickel, 1.25-1.75% copper, 1 manganese. %, Sulfur 0.03%, chromium 14-16%, molybdenum 0.5-1%, niobium 1.25-1.75%, the balance being iron.

  Both the crown member and the head main body were produced by lost wax precision casting. The crown member and the head main body were welded by TIG welding. The head surface was polished to obtain a head according to Example 1. The head weight was 215 g, the head volume was 112 cc, and the real loft angle of the head was 19 degrees. The thick portion was disposed in a region A1 indicated by wavy hatching in FIG. At every position in the toe-heel direction, the maximum thickness t2 of the thick portion was 6 mm. The thin portion was disposed in a region A2 indicated by solid line hatching in FIG. At every position in the toe-heel direction, the minimum thickness t1 was 1.5 mm. Further, in the region A3 indicated by the one-dot chain line in FIG. 3, the thickness of the sole portion is 5.3 mm, and in the region A4 indicated by the one-dot chain line in FIG. 3, the thickness of the sole portion is 3.0 mm. It was done. In a region other than the above A1 to A4, that is, a region Y not hatched in FIG. 3, the thickness of the sole portion was 1.0 mm to 1.5 mm. The average thickness Ta of the sole part at the rear of the thick part was 1.5 mm. The front-rear direction length W1 of the thick-walled portion was constant regardless of the position in the toe-heel direction. In all toe-heel direction positions, the length W1 in the front-rear direction was 20 mm. The shortest distance W2 was set to 3 mm at all positions in the toe-heel direction.

  A golf club according to Example 1 was obtained by attaching the shaft and grip of the head. The specifications and evaluation results of Example 1 are shown in Table 1 below. In addition, the meaning of the code | symbol shown in Table 1 is the same as the code | symbol mentioned above.

[Example 2]
Example 2 is the same as Example 1 except that the maximum thickness t2 of the thick portion is 8 mm at any toe-heel direction position and the front-rear direction length W1 is 30 mm at any toe-heel direction position. Got a golf club. The specifications and evaluation results of this example are shown in Table 1 below.

[Example 3]
A golf club of Example 3 was obtained in the same manner as in Example 1 except that the toe-heel direction length D2 of the thin portion was changed to 80 mm. Of the 80 mm thin portion, the heel side portion and the toe side portion have no thick portion behind them. The specifications and evaluation results of this example are shown in Table 1 below.

[Example 4]
A golf club of Example 4 was obtained in the same manner as in Example 1 except that the minimum distance W2 was set to 6 mm at all toe-heel direction positions. The specifications and evaluation results of this example are shown in Table 1 below.

[Comparative Example 1]
A golf club of Comparative Example 1 was obtained in the same manner as in Example 1 except that the thin part was not provided and there was no gap between the thick part and the face inner surface. In Comparative Example 1, the thickness of the region A2 where the thin portion was provided in Example 1 was 6 mm. The specifications and evaluation results of this example are shown in Table 1 below.

[Comparative Example 2]
A golf club of Comparative Example 2 was obtained in the same manner as in Example 1 except that the thickness of the sole part was constant at 2.5 mm. The specifications and evaluation results of this example are shown in Table 1 below.

[An endurance test]
The golf club of each example was attached to Shot Robot IV manufactured by Miyamae Co., Ltd., and a golf ball was hit at a head speed of 54 m / s. The hit point was the sweet spot position. The head was observed with the naked eye after every 500 hits to confirm damage to the head. The test was completed after 10,000 strikes. The results are shown in Table 1 below. In Example 3, cracks were confirmed in the thin portion at the time of impacting 9000 times. In other examples, no head damage was seen after 10,000 strikes.

[Measurement of flight distance and launch angle]
The golf club of each example was attached to a shot robot IV manufactured by Miyamae Co., Ltd., and a golf ball was hit at a head speed of 40 m / s. The hitting point was the face center. In each case, five balls were hit each other, and the flight distance and launch angle were measured. The average value of the flight distance and the average value of the launch angle are shown in Table 1 below.

[Restitution coefficient]
U. S. G. A. The restitution coefficient of each head was measured based on the procedure for Measureing the Velocity Ratio of a Club Head for Conformance to Rule 4-1e, Revision 2 (February 8, 1999). The larger the value, the better. The results are shown in Table 1 below.

  As shown in Table 1, the examples have higher evaluations than the comparative examples. From this evaluation result, the superiority of the present invention is clear.

  The present invention can be applied to all golf club heads such as a wood type golf club head and an iron type golf club head.

FIG. 1 is a view of a golf club head according to an embodiment of the present invention as seen from the crown side. FIG. 2 is a view of the head of FIG. 1 as viewed from the face side. FIG. 3 is a view of the head of FIG. 1 as viewed from the sole side. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. FIG. 5 is an enlarged cross-sectional view of a part of FIG.

Explanation of symbols

2 ... Head 4 ... Face part 6 ... Crown part 8 ... Sole part 10 ... Side part 12 ... Neck part 14 ... Crown member 16 ... Head body 18 ... -Thick part 20 ... Face inner surface 22 ... Thin part G ... Head center of gravity SS ... Sweet spot h1 ... Sweet spot height Hg ... Center of gravity height W1 ... Thick part Length in the front-rear direction W2 ... the shortest distance between the foremost point of the thick part and the inner surface of the face t1 ... the minimum thickness of the thin part

Claims (7)

With a face part, sole part and crown part,
The sole part has a thick part having a thickness of 5 mm or more,
In a reference state in which the head is placed on the horizontal plane H at a predetermined lie angle and real loft angle, a plane that passes through the center of gravity G of the head and the sweet spot SS and is perpendicular to the horizontal plane H is defined as a reference vertical plane. When the direction parallel to the surface and parallel to the horizontal plane H is the front-rear direction,
In the cross section by the reference vertical plane, the length in the front-rear direction of the thick portion is 5 mm or more and 40 mm or less,
In the cross section by the reference vertical plane, the shortest distance between the foremost point of the thick part and the face inner surface is 10 mm or less,
In the cross section by the reference vertical plane, a thin portion having a minimum thickness of 3 mm or less is formed between the thick portion and the face inner surface so as to extend along the face inner surface .
A hollow golf club head in which the thick portion exists over the entire region behind the thin portion . When the direction perpendicular to the reference vertical plane is the toe-heel direction,
The toe-heel direction length of the thick part is 10 mm or more,
The golf club head according to claim 1, wherein a length of the thin portion in a toe-heel direction is 10 mm or more. The toe-heel direction length of the thick part is 50 mm or more and 80 mm or less,
  The golf club head according to claim 2, wherein a length of the thin portion in a toe-heel direction is 10 mm or more and 50 mm or less. 4. The golf club head according to claim 1, wherein the thin portion extends in a groove shape substantially along the inner surface of the face. The golf club head according to any one of claims 1 to 4, wherein a real loft angle is 15 degrees or more. It has a head body and other members,
  The head main body includes at least a part of the sole part and at least a part of the face part, and the thick part formed between at least a part of the sole part and at least a part of the face part. And having the thin portion,
  The golf club head according to claim 1, wherein the head body is integrally formed by casting. The golf club head according to claim 6, wherein the other member is a crown member.

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