Patent Publication Number: US-2021187366-A1

Title: Golf club head

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application claims priority to and the benefit of Japanese Patent Application No. 2019-230580 filed on Dec. 20, 2019, the entire disclosure of which is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a golf club head. 
     Description of the Related Art 
     There has been proposed a technique of manufacturing a hollow golf club head by joining a plurality of parts. Japanese Patent Laid-Open No. 2003-205054 proposes a gold club head obtained by joining a part including a face portion, a hosel portion, and a crown portion, and a part including a sole portion and aside portion. Japanese Patent No. 4000797 proposes a golf club head obtained by joining a part including a face portion and a crown portion, and a part including a sole portion, a hosel portion, and a side portion. 
     Casting is widely used as a method of manufacturing parts of a golf club head. Casting has an advantage in that the degree of freedom in the shape of a part is high, but it is disadvantageous in homogenization and thinning. If the launch angle of a golf ball at the time of striking the ball is large, an increase in carry of a shot can be expected. If the upper portion of the face portion and the crown portion are easily bent at the time of striking the ball, this is advantageous in increasing the launch angle. In order to allow the upper portion of the face portion and the crown portion to be easily bent, homogenization and thinning are required. If the face portion and the crown portion are molded by casting, this is disadvantageous in terms of homogenization and thinning. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a golf club head that promotes an increase in launch angle at the time of striking a golf ball. 
     According to an aspect of the preset invention, there is provided a hollow golf club head that includes a face portion, a crown portion, a sole portion, a side portion, and a hosel portion, comprising: 
     a first metal member configured to form the face portion and at least a part of the crown portion; and 
     a second metal member configured to form the sole portion, the side portion, and the hosel portion, and to which the first metal member is joined, 
     wherein the first metal member is a forged member including at least one groove portion, and 
     the second metal member is a cast member including at least one reinforcing rib. 
     Further features of the present invention will become apparent from the following description of exemplary embodiments (with reference to the attached drawings). 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a golf club head according to an embodiment of the present invention; 
         FIG. 2  is a plan view of the golf club head shown in  FIG. 1   
         FIG. 3  is a bottom view of the golf club head shown in  FIG. 1 ; 
         FIG. 4  is an exploded perspective view of the golf club head shown in  FIG. 1 ; 
         FIG. 5  is another exploded perspective view of the golf club head shown in  FIG. 1 ; 
         FIG. 6A  is a sectional view taken along a line A-A in  FIG. 2 ; 
         FIG. 6B  is a view showing the relationship between the contour line and the joining line of the golf club head; 
         FIG. 7  is a view showing another arrangement example of reinforcing ribs; 
         FIG. 8  is a view showing still another arrangement example of the reinforcing ribs; 
         FIG. 9  is a view showing still another arrangement example of the reinforcing ribs; 
         FIG. 10  is a bottom view of a golf club head showing an example of a constraining structure of a face portion; and 
         FIG. 11  is a sectional view taken along a lineB-B in  FIG. 10 . 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     Hereinafter, embodiments will be described in detail with reference to the attached drawings. Note that the following embodiments are not intended to limit the scope of the claimed invention, and limitation is not made an invention that requires all combinations of features described in the embodiments. Two or more of the multiple features described in the embodiments may be combined as appropriate. Furthermore, the same reference numerals are given to the same or similar configurations, and redundant description thereof is omitted. 
     First Embodiment 
       FIG. 1  is a perspective view of a golf club head  1  according to an embodiment of the preset invention,  FIG. 2  is a plan view (a view when viewed from the side of a crown portion  12 ) of the golf club head  1 , and  FIG. 3  is a bottom view (a view when viewed from the side of a sole portion  13 ) of the golf club head  1 . 
     The golf club head  1  is a hollow member, and its peripheral walls forma face portion  11 , the crown portion  12 , the sole portion  13 , and a side portion  14 . The surface (front surface) of the face portion  11  forms a face surface (striking surface). A bulge and a roll can be formed on the face surface. The crown portion  12  forms the upper portion of the golf club head  1 . The sole portion  13  forms the bottom portion of the golf club head  1 . The side portion  14  forms the portion between the sole portion  13  and the crown portion  12 . The golf club head  1  also includes a hosel portion  15  to which a shaft is inserted. 
     In each drawing, an arrow D 1  indicates a face-back direction, and reference symbols F and B indicate the side of the face portion and the back side, respectively. An arrow D 2  indicates a toe-heel direction, and reference symbols T and H indicate the toe side and the heel side, respectively. The face-back direction is, for example, a target line direction (the target direction of a shot). The toe-heel direction is, for example, a direction in which the toe-side end and the heel-side end of the sole portion  14  are coupled, and has an approximately orthogonal relationship to the target line direction. 
     The golf club head  1  is a golf club head for a driver. However, the present invention is applicable to hollow golf club heads including those for fairway woods and the like other than those for drivers. 
     Referring to  FIGS. 2 and 6A ,  FIG. 6A  is a sectional view of the crown portion  12  taken along a line A-A in  FIG. 2 . A groove portion  21  and a groove portion  22  are formed in the crown portion  12  as thin-walled portions thinner than the surroundings. Both the groove portion  21  and the groove portion  22  are extended in a direction intersecting the D 1  direction, and particularly in this embodiment, extended in the D 2  direction. Since the groove portion  21  and the groove portion  22  are formed, the crown portion  12  is easily bent in the D 1  direction at the time of striking a ball. Accordingly, the upper portion of the face portion  11  is easily bent toward the back side at the time of striking a ball, so that the launch angle of a ball can be increased. The effect of increasing the launch angle can be obtained by forming one groove portion  21  or one groove portion  22 . However, by forming a plurality of groove portions  21  and  22  as in this embodiment, the further effect of increasing the launch angle can be obtained. 
     In this embodiment, the groove portion  21  is formed in the outer surface of the crown portion  12 , and the groove portion  22  is formed in the inner surface of the crown portion  12 . The groove portion  21  also contributes to improvement of the design of the golf club head  1 . The groove portion  22  cannot be visually recognized on the appearance of the golf club head  1 , and this can also appeal the existence of a hidden function to golfers. Note that both the groove portion  21  and the groove portion  22  may be formed in the outer surface of the crown portion  12 , or both may be formed in the inner surface of the crown portion  12 . 
     As for the groove portions  21  and  22 , the groove portion  22  is formed on the backside of the groove portion  21  when viewed in the D direction. By forming the groove portion  21  near the face portion  11 , the ease of bending near the boundary portion between the face portion  11  and the crown portion  12  can be improved. In addition, by forming the groove portion  21  near the face portion  11 , the groove portion  21  is readily included in the field of view of a golfer when the golfer is at the address position. This makes it easier for the golfer to expect the effect of bending caused by the groove portion  21 . Since the groove portion  22  is formed on the back side, the crown portion  12  can be easily bent as a whole. 
     The edge of the groove portion  21  on the face portion  11  side is a straight edge extending parallel to the face portion  11 . When a golfer is at the address position, the golfer can easily direct the face portion  11  to a target direction while using the groove portion  21  as an index. The groove portion  21  is wider in both end portions in the D 2  direction than in the central portion. Of the face portion  11 , the tow side and the heel side are more easily bent toward the back side than the center, so that it is possible to obtain the more uniform carry performance regardless of the ball striking position on the face portion  11 . 
     In the central portion of the crown portion  12  in the D 1  direction, the groove portion  22  extends in a belt shape with a constant width in the D 2  direction. At the time of striking a ball, the central portion of the crown portion  12  in the D 1  direction can be more uniformly bent in the D 1  direction. The groove portion  22  may be formed so as to cross the crown portion  12  in the D 2  direction. 
     The wall thickness of the crown portion  12  is, for example, in a range of 0.3 to 0.8 mm, and particularly in a range of 0.3 to 0.6 mm in terms of ease of bending. The depth of each of the groove portion  21  and the groove portion  22  is, for example, ½ to ⅙ of the wall thickness of the crown portion  12 . 
     The golf club head  1  of this embodiment is manufactured by joining a plurality of members. Each of  FIGS. 4 and 5  is an exploded perspective view of the golf club head  1 . The golf club head  1  is manufactured by joining a metal member  2  and a metal member  3 . The joining method is welding in this embodiment. Examples of the metal materials of the metal members  2  and  3  are a titanium-based metal (for example, titanium alloy 6Al-4V-Ti), a ferrous metal, stainless steel, an aluminum alloy, and a copper alloy such as beryllium copper. The metal member  2  and the metal member  3  may be the same metal material or different metal materials. 
     The metal member  2  is a member forming the face portion  11  and the crown portion  12 , and includes the groove portions  21  and  22  formed in the crown portion  12 . The groove portion  21  and the groove portion  22  may be formed during forming the metal member  2  by forging. Alternatively, the groove portion  21  and the groove portion  22  may be formed by machining or laser processing after a forged member without the groove portion  21  and the groove portion  22  is formed. 
     In this embodiment, the metal member  2  forms the entire crown portion  12  except the periphery of the hosel portion  15 . However, the metal member  2  may form a part of the crown portion  12 , and in this case, the metal member  2  may form a part of the crown portion  12  on the face portion  11  side. 
     The metal member  3  is a member forming the sole portion  13 , the side portion  14 , and the hosel portion  15 . In this embodiment, the metal member  3  includes a reinforcing rib  31  and a reinforcing rib  32  on its inner surface. The reinforcing rib  31  is formed in the sole portion  13 , and particularly, formed in the boundary portion between the sole portion  13  and the face portion  11  so as to cross them. The reinforcing rib  31  makes it easier to constrain the lower portion of the face portion  11 . As a result, it is possible to allow the upper portion of the face portion  11  to be easily bent at the time of striking a ball while ensuring the rigidity of the face portion  11 . 
     The reinforcing rib  32  is formed in the back-side side portion  14 , and particularly, formed in the boundary portion between the side portion  14  and the crown portion  12  so as to cross them. The reinforcing rib  32  makes it easier to constrain the back-side portion of the crown portion  12 . As a result, it is possible to allow the crown portion  12  to be easily bent toward the back side at the time of striking a ball. 
     The metal member  3  also includes, on its inner surface, a reinforcing rib  41  provided so as to bridge over the tow-side side portion  14  and the heel-side side portion  14 . The reinforcing rib  41  improves the rigidity of the golf club head  1  in the D 2  direction. A device  16  for replacing the shaft and adjusting the orientation of the golf club head  1  with respect to the shaft is attached to the hosel portion  15  of the metal member  3 . 
     In this embodiment, the metal member  2  is formed as a single part by forging it from a metal plate serving as a raw material, and the metal member  3  is integrally molded as a single part by casting. Forging is more advantageous than casting in terms of homogenization and thinning of members. On the other hand, casting has an advantage in that the degree of freedom in the shape of a part is higher than in forging. 
     By using a forged member as the metal member  2 , the crown portion  12  can be formed thinner and uniform. Further, since the metal member  2  includes the crown portion  12  and the face portion  11 , there is no welded joining portion at the boundary portion between them. If there is a joining portion, the rigidity is partially increased, and the bending performance at the time of striking a ball is decreased. In this embodiment, it is possible to give appropriate rigidity to the boundary portion between the crown portion  12  and the face portion  11 . By using a cast member as the metal member  3 , complicated molding is possible, and the reinforcing ribs  31 ,  32 , and  41  and the design shape of the outer surface of the sole portion  13  can be integrally molded. 
     Since the metal member  2  forms approximately the entire area of the crown portion  12 , when the metal member  2  and the metal member  3  are joined, the joining line extends in the boundary portion between the crown portion  12  and the side portion  14 . Since the rigidity is partially increased when there is a joining portion, the crown portion  12  has a property that the rigidity is high at its peripheral edge and low inside the peripheral edge. As a result, the crown portion  12  is more easily bent at the time of striking a ball. 
       FIG. 6B  is a view showing the relationship between a contour line L 1  in a planar view of the golf club head  1  and a joining line L 2  between the metal member  2  and the metal member  3 . The planar view of the golf club head  1  is a planar view when the golf club head  1  is set on a horizontal plane in accordance with a predetermined lie angle and a predetermined loft angle. The contour line L 1  is shown by a solid line, and the hosel portion  15  is omitted. The joining line L 2  is shown by a dashed line. In this embodiment, the joining line L 2  is one continuous joining line, and is along the contour line L 1  except in the periphery of the hosel portion  15 . The higher the proportion of the joining line L 2  along the contour line L 1 , the more the joining portion is located on the envelopes of the face portion  11  and the crown portion  12 , and the joining portion does not exist inside the envelopes. That is, the rigidity is improved by the joining portion on the envelopes of the face portion  11  and the crown portion  12 , and the rigidity is decreased inside the envelopes. As a result, the upper portion of the face portion  11  and the crown portion  12  are easily bent toward the back side at the time of striking a ball, so that the launch angle of the ball can be increased. The joining line L 2  is preferably along the range of 70% or more of the contour line, and more preferably along the range of 90% or more. 
     Second Embodiment 
     Another arrangement example can be adopted as the reinforcing ribs  31 ,  32 , and  41  of the metal member  3 .  FIG. 7  is a view showing another arrangement example of a sole portion  13  formed by a metal member  3  (a hosel portion  15  and the like are omitted), and shows an example in which a plurality of reinforcing ribs  33  are formed in a grid pattern on the inner surface of the sole portion  13 . The rigidity of the sole portion  13  can be improved. 
     The reinforcing rib may be formed on the outer surface of the metal member  3 .  FIG. 8  shows an example. In the illustrated example, a plurality of reinforcing ribs  34  are formed in a row in a D 2  direction in the end portion, on the side of a face portion  11 , of the sole portion  13  formed by the metal member  3 . The reinforcing ribs  34  can increase the degree of constraint of the lower portion of the face portion  11 , thereby allowing the upper portion of the face portion  11  to be easily bent at the time of striking a ball. 
       FIG. 9  shows an example in which reinforcing ribs  35  are formed on the outer surface of the metal member  3 . In the illustrated example, a plurality of the ribs  35  each extending in a D 1  direction are formed in the D 2  direction on the outer surface of the sole portion  13  formed by the metal member  3 . The reinforcing ribs  35  can improve the rigidity of the sole portion  13  in the D 1  direction and increase the degree of constraint of the lower portion of the face portion  11 , thereby allowing the upper portion of the face portion  11  to be easily bent at the time of striking a ball. 
     Third Embodiment 
     Another member that constrains the lower portion of the face portion  11  may be provided.  FIG. 10  is a bottom view of a golf club head  1  in this embodiment, and  FIG. 11  is a sectional view taken along a line B-B in  FIG. 10 . A concave portion  13   a  is provided in a sole portion  13 , and the wall portion of the concave portion  13   a  is a mounting portion of an abutment member  4 . 
     The abutment member  4  is a shaft-shaped member that abuts against a back surface (inner surface)  11   a  of a face portion  11 . The abutment member  4  abuts against the back surface  11   a  at the lower portion of the face portion  11 , and particularly below the face center. Since the abutment member  4  abuts against the lower portion (the side of a sole portion  14 ) of the face portion  11 , the deformation of the lower portion of the face portion  14  is constrained more than the upper portion. This contributes to an increase in launch angle of a ball at the time of striking the ball. Note that the face center can be specified by, for example, an impact point template used when measuring the CT value of the face portion. 
     The abutment member  4  includes a non-metal distal end portion  41  that abuts against the back surface  1   a  of the face portion  11 , a metal screw shaft  42  that is fixed to a screw hole  13   b  of the concave portion  13   a , and a metal head portion  40 . Examples of a non-metal material which forms the distal end portion  41  are, for example, a resin, rubber, and FRP. Examples of a metal material which forms the head portion  40  and the screw shaft  42  are, for example, aluminum, magnesium, titanium, iron, and tungsten. The abutment member  4  can adjust the degree of abutment (degree of pressing) with respect to the back surface  11   a  by adjusting the screwing amount of the screw shaft  42  into the screw hole  13   b . Note that the fixing structure of the abutment member  4  is not limited to the screw structure, and may be another fixing structure such as press fitting, adhesion, welding, caulking, or the like. 
     The invention is not limited to the foregoing embodiments, and various variations/changes are possible within the spirit of the invention.