JP2014113268A - Golf club head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce weight of a golf club head while securing impact resistance strength.SOLUTION: A hollow golf club head includes a face part in which a score line is formed, a crown part, a sole part, and a side part. The wall thickness of the face part is less than 2.0 mm. The face part is made of a material with a tension strength of 1,800 MPa or more.

Description

  The present invention relates to a hollow golf club head.

  In hollow golf club heads represented by drivers and fairway woods, it is known that the position of the center of gravity affects the flight distance and height of the hit ball. The position of the center of gravity can be adjusted by weight distribution of the golf club head, such as by providing a weight. However, if the weight of the basic structure other than the weight that is originally necessary is heavy, the adjustment allowance becomes narrow. Therefore, Patent Document 1 discloses a golf club head in which the thickness of the face portion is reduced to reduce the weight. Further, Patent Document 2 discloses a golf club head in which a score line formed on the face portion is processed to be extremely fine so as to suppress a decrease in impact strength even when the thickness of the thinned face portion is large. Has been.

Japanese Patent Laid-Open No. 10-225539 JP 2005-153575 A

  The volume of the golf club head tends to increase, and the area of the face portion also increases. Therefore, the weight of the face portion is also increased. Regarding the adjustment of the position of the center of gravity, the influence of the weight of the face portion is particularly large for the deep center of gravity. On the other hand, the face portion is a portion where an impact load is applied by hitting a golf ball, and it is necessary to consider the impact resistance strength.

  An object of the present invention is to reduce the weight of a golf club head while ensuring impact strength.

  According to the present invention, a hollow golf club head including a face portion on which score lines are formed, a crown portion, a sole portion, and a side portion, wherein the thickness of the face portion is less than 2.0 mm. There is provided a golf club head characterized in that the face portion is made of a material having a tensile strength of 1800 MPa or more.

  According to the present invention, it is possible to reduce the weight of a golf club head while ensuring impact resistance strength.

1 is a perspective view of a golf club head according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of the golf club head of FIG. 1. Sectional drawing of a score line.

  FIG. 1 is a perspective view of a golf club head 10 according to an embodiment of the present invention, and FIG. 2 is an exploded perspective view of the golf club head 10. In FIG. 2, a part of the shell member 2 is a cutaway view. In each figure, the arrow d1 indicates the face-back direction, and the arrow d2 indicates the toe heel direction.

  In the present embodiment, the golf club head 10 forms a hollow body formed by joining a plurality of shell members 1 to 3 as shown in FIG. 2, and the peripheral wall forms a face surface (striking surface). And a crown part 12, a sole part 13 and a side part 14 forming the top part, bottom part and side part of the golf club head 10, respectively. The side portion 14 has respective portions on the toe side, the back side, and the heel side. The golf club head 10 includes a hosel portion 15 to which a shaft is attached.

  The golf club head 10 is a golf club head for a driver, but the present invention is a wood type golf club head including a fairway wood other than a driver, a utility type (hybrid type) golf club head, and other hollow golf clubs. Applicable to club head.

  Examples of a method for joining the shell members 1 to 3 include welding, adhesion, and the like, but welding is preferable in terms of joining strength. In the case of the present embodiment, the shell member 1 constitutes a main body portion of the golf club head 10, and includes a part of the crown portion 12, most of the sole portion 13, most of the side portion 14, and the hosel portion 15. It is. The shell member 3 is a crown member that includes most of the crown portion 12.

  The shell member 2 is a face member including the face portion 11. In the case of this embodiment, the shell member 2 is a cup-shaped member provided with extending portions 2 a to 2 c extending from the edge of the face portion 11 to the back side. The extending portions 2 a to 2 c form part of the crown portion 12, the sole portion 13, and the side portion 14 on the face portion 11 side. That is, the extended portion 2 a forms part of the crown portion 12, and the extended portion 2 b forms part of the sole portion 13. The extending portion 2 c forms a part of the side portion 14.

  The face portion 11 is formed with a plurality of score lines 11a extending in the toe-heel direction. In the present embodiment, the score line 11 a is formed at the center of the face portion 11, but may be formed over the entire area of the face portion 11.

  The wall thickness t of the face portion 11 is less than 2.0 mm. When the wall thickness t varies depending on the part of the face portion 11, the maximum wall thickness is set to less than 2.0 mm. By making the wall thickness t less than 2.0 mm, the face portion 11 can be reduced in weight. From the viewpoint of weight reduction, it is preferable that the wall thickness t is thin. However, if the wall thickness t is too thin, it is difficult to ensure the impact strength. Therefore, the wall thickness t is preferably 1.6 mm or more and 1.9 mm or less.

  The golf club head 10 can be made of a metal material, but the face portion 11 is particularly made of a material having a tensile strength of 1800 MPa or more. If the material has a tensile strength of 1800 MPa or more, the impact resistance strength can be ensured even if the thickness t of the face portion 11 is less than 2.0 mm. Examples of materials that can achieve such tensile strength include steels having a tensile strength of 1800 MPa or more among steels such as high-tensile steel, austenitic stainless steel, and maraging steel. The tensile strength of the material of the face portion 11 is preferably higher, and preferably 2000 MPa or more. When the face portion 11 is a part of the shell member 2 as in the present embodiment, the other portions (extension portions 2a to 2c) can be integrally formed of the same material.

  Examples of the metal material of the other part of the golf club head 10 include titanium alloys (for example, 6Al-4V-Ti titanium alloy), copper alloys such as stainless steel and beryllium copper. Although the thickness of the crown portion 12, the sole portion 13, and the side portion 14 depends on the material, in the case of a metal material, for example, the crown portion 12 is 0.5 mm to 1.0 mm, and the sole portion 13 is 0 The side part 14 can be 0.6 mm or more and 2.5 mm or less. In terms of improving the launch angle of the hit ball, it is preferable that the thickness of the crown portion 12 is relatively thin and the thickness of the sole portion 13 is relatively thick.

  If the thickness of the face portion 11 is reduced, it may be difficult to ensure impact resistance strength in the score line 11a. Therefore, it is preferable that the score line 11a is formed so as not to extremely reduce the impact strength while giving spin to the golf ball. FIG. 3A is a cross-sectional view of the score line 11a, and is a cross-sectional view of the score line 11a in the short direction (vertical direction perpendicular to the toe-heel direction).

  In the case of this embodiment, the score line 11a has a trapezoidal cross-sectional shape. The depth D of the score line 11a (the distance from the surface of the face portion 11 to the deepest portion) is preferably 0.1 mm in terms of spin amount and impact strength. The width W is preferably 0.5 to 0.9 mm.

  In this embodiment, although the case where the cross-sectional shape of the score line 11a was made into the trapezoid was illustrated, the cross-sectional shape without a corner | angular part is preferable at the point which suppresses stress concentration. For example, a partial circular shape as shown in FIG. 3B, a partial ellipse shape as shown in FIG. 3C, or a partial oval shape as shown in FIG. ) Is preferable.

  In the present embodiment, the golf club head 10 is composed of the three shell members 1 to 3, but the number of divisions is not limited to this, and may be two or four or more. At this time, the shell member forming the face portion 11 is preferably formed in a cup shape having the extending portions 2a to 2c like the shell member 2 of the present embodiment. This is advantageous in that, for example, when welding is employed for joining with other shell members, it is possible to prevent the material characteristics of the face portion 11 from being deteriorated by welding and the formation of a shape portion where stress concentration occurs. . The extending portions 2 a to 2 c may be thicker than the face portion 11.

  In the present embodiment, the extending portions 2 a to 2 c are provided on the edge of the face portion 11 on the crown portion 12 side, the edge on the sole portion 13 side, and the edge on the side portion 14 side. You may provide an extension part only about the edge of a part. For example, as described above, it is preferable that the crown portion 12 is thinner than other portions. Therefore, an extending portion is provided on the end edge on the crown portion 12 side to facilitate welding, and the other end edge is extended. It is also possible to adopt a configuration in which no installation part is provided.

<Example>
A plurality of golf club heads were prototyped, and an endurance test was performed in which 1000 golf balls collided continuously with the face portions. The face portion was made of maraging steel (containing 18% nickel) having a tensile strength of about 1800 MPa, and the maximum wall thickness was 1.5 mm. The prototype golf club head was a golf club head for No. 3 to No. 5 fairway wood, having a volume of 147 to 154 cc and an area of the face portion of 1900 to 2000 mm ² . A plurality of score lines having a depth of 0.2 mm were formed in the center of the face portion.

  As a result of the test, no conspicuous depression or crack occurred in the face portion of any golf club head. Therefore, even if the wall thickness of the face portion is less than 2.0 mm, it is considered that if the tensile strength is 1800 MPa or more, the impact strength can be ensured with a margin. Further, if the thickness of the face portion is 1.6 mm or more with a margin, it is considered that the impact strength can be secured.

Claims (4)

A hollow golf club head including a face portion on which a score line is formed, a crown portion, a sole portion, and a side portion,
The thickness of the face portion is less than 2.0 mm;
The face portion is made of a material having a tensile strength of 1800 MPa or more.
A golf club head characterized by that. The depth of the score line is 0.1 mm,
The golf club head according to claim 1. The thickness of the face part is 1.6 mm or more and 1.9 mm or less,
The golf club head according to claim 1, wherein the golf club head is provided. The golf club head is formed by welding a plurality of members including a face member including the face part,
The face member is
Including an extending portion extending from the edge of the face portion to the back side,
The golf club head according to claim 1, wherein the golf club head is provided.

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