JP5046672B2 - Golf club head - Google Patents

Description

  The present invention relates to a golf club head having a face portion whose front surface is a ball striking surface and a head body provided on the rear side of the face portion.

  Golf clubs are required to have a long flight distance and a high directionality with respect to the direction in which the hit ball flies.

Among conventional golf clubs, there is known a golf club head having a lowered center of gravity by forming a recessed portion that is recessed toward the sole side rather than the outer peripheral portion in the vicinity of the center of the crown portion in order to extend the flight distance. (For example, refer to Patent Document 1). Such a golf club head is said to be capable of increasing the launch angle of the ball and extending the flight distance of the golf ball by a low center of gravity structure.
Japanese Patent Laid-Open No. 11-19253

  However, the flight distance of the ball is also affected by the direction of the hitting surface at the moment of impact. For this reason, it is desirable that the ball is hit with the ball hitting face in a predetermined direction at the moment of impact. By the way, since the golf club head speed is about 40 m / sec at the moment of impact, the hitting spherical surface may be unstable due to a large air resistance.

  Further, when the concave portion is provided near the center of the crown portion as in the conventional golf club head, the crown portion is less likely to be elastically deformed at the time of hitting the ball, and the repulsive force due to the elastic deformation of the crown portion is sufficient. There is a fear that it cannot be obtained and the flight distance cannot be extended.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a golf club head which can obtain a high repulsive force and whose ball striking surface is easy to stabilize at the time of hitting.

In order to achieve the above object, the present invention provides a golf club head having a face portion having a front face as a hitting surface and a head body provided on the rear side of the face portion, the direction intersecting the hitting surface. The contour of the upper surface of the head main body in the cross section is a contour curve in which the first curve that protrudes upward and the second curve that protrudes downward are connected in the state where the golf club head is solesed, In the contour curve, the top of the first curve is located in front of the center in the direction intersecting the hitting surface, and the first curve and the second curve are located behind the center in the direction intersecting with the hitting surface. A connecting inflection point is located, and the radius of curvature of the rearmost end of the second curve is larger than the radius of curvature of the frontmost end of the first curve.

Further, in the first curve, the curvature radius of the top portion is larger than the curvature radius of the front end portion, and the curvature radius at the intermediate position between the top portion and the inflection point is larger than the curvature radius of the top portion. It is good as well.

  According to the present invention, it is possible to provide a golf club head capable of obtaining a high repulsive force and having a ball hitting surface that is easily stabilized at the time of hitting.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a perspective view showing a golf club head according to the present embodiment. FIG. 2 is a plan view showing a state in which the golf club head according to the present embodiment is solesed. 3 is a cross-sectional view taken along line AA in FIG. FIG. 4 is a view for explaining the top shape of the golf club head.

  As shown in FIG. 1, the golf club head 1 of this embodiment is brought into contact with a horizontal ground G or the like with the face portion 10 having a front face 1a and the golf club head 1 being solesed. It has a sole portion 22 and a head main body 24 having a curved surface that is disposed above the sole portion 22 on the rear side of the face portion 10 and is curved substantially upward. The face portion 10, the sole portion 22, and the head main body 24 integrally form the outer shape of the golf club head 1, and the inside is formed to be hollow. Here, the sole state indicates a state where the sole portion 22 is in contact with the ground G or the like and stable when the golf club head 1 is placed in a horizontal place such as the ground G or the like.

  The face portion 10 is a plate-like member formed by casting or forging using a light metal, for example, a titanium alloy. The hitting surface 1a is formed in a curved surface that is curved so as to slightly protrude forward.

  The sole portion 22 is a stainless steel member that forms the lower surface of the golf club head 1. The sole portion 22 is a rear side of the golf club head 1 from the lower end 10 a of the face portion 10, that is, the face portion 10 of the golf club head 1. It is formed so as to reach a portion (hereinafter referred to as a rear portion) 1b opposite to the hitting surface 1a. The sole portion 22 of the present embodiment is provided with an inclination of a slight angle so as to be recessed upward from both end portions in the front-rear direction of the golf club head 1 toward the center. For this reason, when the golf club head 1 is in the sole state, the golf club head 1 comes into contact with the ground G at two places before and after the sole portion 22.

  The head main body 24 extends from the upper surface 1c of the golf club head 1 to the rear portion 1b side, to the toe side of the golf club head 1 in the width direction of the ball striking surface 1a and the side portion on the hosel side where the shaft is joined. Are integrally formed.

  The head main body 24 is almost entirely formed of a carbon fiber reinforcing material 25, and is provided with a titanium alloy fibrous material 24b having elasticity in a part thereof, and a cup stack type carbon nanotube 26 is contained in a predetermined region. A nanotube-containing region 24c is provided.

  Specifically, the head body 24 is configured by laminating three prepregs 25a, 25b, and 25c in which a carbon fiber 27 is impregnated with a thermosetting resin 28. The laminated intermediate prepreg 25b has a titanium alloy fibrous material 24b and a nanotube-containing region 24c positioned at the top of the head body 24, that is, in the vicinity of the portion that protrudes most upward in the sole state. Has been placed.

  The nanotube-containing regions 24c are provided at two locations, the most projecting top portion of the head body 24 and a position spaced from the top portion toward the hosel side. For example, the two nanotube-containing regions 24c each have a width of about 35 mm in the front-rear direction of the golf club head 1 and a width of about 5 mm in the width direction of the ball striking surface 1a, and a distance of about 25 mm in the width direction of the ball striking surface 1a. Are arranged apart from each other. Further, the titanium alloy fibrous material 24b is provided in a region sandwiched between the two nanotube-containing regions 24c, and the plurality of fibrous titanium alloys are arranged in a direction from the front to the rear of the golf club head 1. And are arranged in parallel at equal intervals in the width direction of the ball striking face 1a.

  Here, the titanium alloy fibrous material 24b is a fibrous material of a titanium alloy having superelastic properties with a Young's modulus of 60 Gpa or less and a tensile strength of 1000 Mpa or more, and the thickness per one is 0.1 mm. About 0.2 mm. The titanium alloy fibrous material 24b having superelastic properties is easily elastically deformed and has characteristics of quickly restoring from the deformed state.

  FIG. 5 is a conceptual diagram of a cup-stacked carbon nanotube. FIG. 6 is an enlarged cross-sectional view of a nanotube-containing resin containing cup-stacked carbon nanotubes.

  The cup-stacked carbon nanotube 26 is a nanocarbon material having a shape in which conical graphene sheets 26a as shown in FIG. 5 are connected in a state where the cups are stacked, and as shown in FIG. Innumerable cup-stacked carbon nanotubes 26 are contained in the thermosetting resin 28 impregnated in 27. An end portion exposed to the outside of the continuous graphene sheet 26 a functions effectively for load transmission between the cup-stacked carbon nanotube 26 and the thermosetting resin 28. For this reason, the prepreg 25b containing the cup-stacked carbon nanotubes 26 is higher in strength and elasticity than the prepreg in which the thermosetting resin 28 is impregnated with the normal resin and the carbon fibers 27, which are the characteristics of the cup-stacked carbon nanotubes 26. Have a rate.

  In the golf club head 1 of the present embodiment, the contour of the upper surface 1c of the head main body 24 in the cross section in the direction intersecting the ball striking face 1a is a first curve F1 that protrudes upward in a state where the golf club head 1 is solesed. And a contour curve F connected to a second curve F2 projecting downward is formed in a shape. The end portion on the rear portion 1b side of the upper surface 1c of the head body 24 is formed with a curved surface that descends toward the end edge 1e on the rear portion 1b side in a state where the golf club head 1 is solesed.

  Each of the first curve F1 and the second curve F2 is not a curve having a constant curvature radius R, but is formed by connecting curves in which the curvature radius gradually changes in a region from the front to the rear side of the golf club head 1. Has been. The position where the first curve F1 and the second curve F2 are connected is an inflection point P that changes from a curve that protrudes upward to a curve that protrudes downward.

  The contour curve F indicating the contour of the upper surface 1c of the head main body 24 is from the center in the direction intersecting with the ball striking surface 1a, with the apex T of the first curve F1 positioned in front of the center in the direction intersecting with the ball striking surface 1a. An inflection point P where the first curve F1 and the second curve F2 are connected is located behind.

  An example of the contour and shape of the upper surface 1c of the head body 24 according to the present invention will be described with reference to FIGS.

  2, the distance L0 from the edge 1d on the ball striking face 1a side to the edge 1e on the rear part 1b side of the upper surface 1c of the head body 24 is about 98 mm, as shown in FIG. The top T0 of the first curve F1 is located about 22 mm from the edge 1d on the ball striking face 1a side. Further, the inflection point P0 is about 79 mm from the edge 1d on the ball striking face 1a side, and the position U0 that protrudes downward on the second curve F2 is located about 90 mm from the edge 1d on the ball striking face 1a side. ing. At this time, the radius of curvature R1 on the top surface 1c of the head main body 24 on the ball striking face 1a side is about 60 mm, the radius of curvature R2 at the top T is about 70 mm, and the radius of curvature R3 at the intermediate position between the top T and the inflection point P is about 140 mm. The radius of curvature R4 at the position that protrudes downward most in the second curve F2 is about 90 mm. Thus, the curvature radius R of the contour curve F of the upper surface 1c of the head body 24 changes gently over the entire region including the region from the top T of the first curve F1 toward the inflection point P. Further, the AA cross section, that is, the cross section of the head main body 24 in the cross section in the direction intersecting with the ball striking face 1a at positions X1 to X4 separated from the position X0 in FIG. Table 1 shows data indicating the contour of the upper surface 1c. Here, in Table 1, the distance from the edge 1d on the ball striking face 1a side to the edge 1e on the rear part 1b side in each cross section is L1 to L4, the top is T1 to T4, the inflection points are P1 to P4, The positions of the two curves that protrude downward in F2 are U1 to U4, and all indicate the distance from the edge 1d on the striking surface 1a side.

  According to the golf club head 1 of the present embodiment, since the inflection point P is located on the rear side of the head body 24, the upper surface 1c in the region of the inflection point P from the top T of the golf club head 1 at the time of hitting the ball. The direction of the airflow flowing slightly downward along the line is changed so that the inclination angle becomes gentler than the airflow ahead of the inflection point P on the rear side of the inflection point. Such a change in the airflow acts to suppress the blur of the golf club head 1 and stabilize the track.

  FIG. 7A shows the fluid analysis data of the golf club head of the present embodiment, and FIG. 7B shows the fluid analysis data of the conventional golf club head.

  As shown in the figure, according to the golf club head 1 of the present embodiment, there is no separation of air in the head main body 24, and the Karman vortex row generated behind the rear portion 1b can be made smaller than that of the conventional golf club head 2. Is possible. For this reason, when a golf club using the golf club head 1 of the present embodiment is swung, there are few Karman vortices generated at the time of hitting and the air flow around the golf club head 1 becomes smooth. In particular, the curvature radius R (for example, R4) on the rearmost end side represented by the second curve F2 from the curvature radius R (for example, R1) on the foremost end side of the head body 24 represented by the first curve F1. Therefore, the air resistance can be reduced by reducing the turbulence of the airflow due to the smooth airflow caused by the curved surface having a small curvature. For this reason, it is possible to reduce the blur of the golf club head 1 at the time of hitting and to stabilize the track.

  Further, a down force is generated on the rear side of the golf club head 1 so as to be pulled to the ground G side at the time of hitting, and a centrifugal force is increased by the generated down force, whereby the golf club head 1 is stabilized and the hitting surface is stabilized. It is possible to stabilize 1a.

  Particularly, in the golf club head 1 of the present embodiment, the contour curve F of the upper surface 1c of the head body 24 has a curvature radius R that gradually changes from the top T of the first curve F1 toward the inflection point P. The airflow flowing along the upper surface 1c of the golf club head 1 is less likely to be disturbed. For this reason, it is possible to provide the golf club head 1 in which the golf club head is more stable and the hitting surface 1a is easily stabilized.

 Furthermore, in the sole state, the rear end in the direction intersecting with the ball striking face 1a is formed by a curved surface descending toward the rear edge 1e, so that the air resistance is further reduced. Thus, it is possible to increase the head speed.

  Further, in the golf club head of the present embodiment, the outline of the upper surface 1c of the head body 24 in the cross section in the direction intersecting with the ball striking face 1a in the state where the golf club head 1 is sole is in the direction intersecting with the ball striking face 1a. The apex T of the first curve F1 is located ahead of the center, and the inflection point P where the first curve F1 and the second curve F2 are connected is located behind the center in the direction intersecting with the ball striking face 1a. For this reason, the top portion T of the first curve F1 and the inflection point P are located apart from each other, and a region that is raised upward including the top portion T of the first curve F1, that is, a so-called crown portion region is secured widely. The In other words, since the golf club head 1 has a crown portion that protrudes upward in a wide region, the crown portion can be more elastically deformed at the time of hitting, and at the time of hitting by the large elastic deformation of the crown portion. It is possible to realize the golf club head 1 that can obtain a high repulsive force.

  Further, the golf club head 1 of the present embodiment has a titanium alloy fibrous material 24b near the top of the head body 24 that is most elastically deformed at the time of hitting, that is, in the vicinity of the portion that protrudes most upward in the sole state. And a nanotube-containing region 24c containing cup-stacked carbon nanotubes. Both the titanium alloy fibrous material 24b and the nanotube-containing region 24c are more easily elastically deformed than ordinary carbon materials, and have characteristics of quickly restoring from the deformed state. For this reason, it is possible to increase the amount of deformation of the golf club head 1 at the time of hitting, and it is possible to quickly restore from a larger deformation state. For this reason, it is possible to generate a higher repulsive force and extend the flight distance.

  In addition, since the titanium alloy fibrous material 24b and the nanotube-containing region 24c have high strength, for example, the head body 24 that is thinner than a golf club head formed of a normal carbon material has sufficient strength that is not easily damaged. Can be provided. Furthermore, since the thinned head body 24 is more easily elastically deformed, it is possible to further increase the flight distance. Further, it is possible to reduce the center of gravity of the golf club head 1 by reducing the weight of the head main body 24 and to increase the size of the golf club head.

  FIG. 8 is a view showing a modified example of the golf club head according to the present invention. In the following description, the same members as those in the above embodiment are denoted by the same reference numerals and the description thereof is omitted.

  In the above embodiment, in the state where the golf club head 1 is solesed, the rear side end in the direction intersecting with the ball striking face 1a is formed by a curved surface descending toward the rear side edge 1e. However, the present invention is not limited to this. For example, as shown in FIG. 8, in the sole state, the rear end portion 29 in the direction intersecting with the ball striking face 1a may be formed as a curved surface that rises toward the rear edge 1e. Good. In this case, the down force generated in the golf club head 3 becomes larger and the centrifugal force increases. For this reason, when the golf club head 3 becomes more stable, the hitting surface 1a can be made more stable.

  In addition, this invention is not restricted to said embodiment, For example, glass fiber, an aramid fiber, etc. other than carbon can be used as a reinforcing fiber.

  Moreover, the said embodiment is for making an understanding of this invention easy, and is not for limiting and interpreting this invention. The present invention can be changed and improved without departing from the gist thereof, and it is needless to say that the present invention includes equivalents thereof.

1 is a perspective view showing a golf club head according to an embodiment. It is a top view in the state where the golf club head concerning this embodiment was solesed. It is AA sectional drawing in FIG. FIG. 4 is a view for explaining the top shape of the golf club head. It is a conceptual diagram of a cup stack type carbon nanotube. It is an expanded sectional view of nanotube content resin containing a cup stack type carbon nanotube. FIG. 7A shows the fluid analysis data of the golf club head of the present embodiment, and FIG. 7B shows the fluid analysis data of the conventional golf club head. It is a figure which shows the modification of a golf club head.

Explanation of symbols

1 golf club head, 1a hitting surface, 1b rear part, 1c upper surface,
1d edge on the ball striking surface side, 1e edge on the rear side, 2 conventional golf club head,
3 golf club head, 10 face portion, 10a lower end, 22 sole portion,
24 head body, 24b titanium alloy fiber, 24c nanotube-containing region,
25 carbon fiber strong material, 25a-25c prepreg,
26 cup stack type carbon nanotube, 26a graphene sheet,
27 carbon fiber, 28 thermosetting resin, 29 end,
F contour curve, F1 first curve, F2 second curve, G ground,
L, L0 to L4 Distances from the end on the ball striking face 1a side to the end on the rear portion 1b side,
P, P0-P4 inflection point, R, R0-R4 radius of curvature, T, T0-T4 top,
T, T0 to T4 Top, U, U0 to U4 Positions that protrude most downward in the second curve

Claims (2)

A golf club head having a face portion having a front face as a ball striking surface and a head body provided on the rear side of the face portion,
The contour of the upper surface of the head main body in the cross section in the direction intersecting the hitting surface has a first curve that protrudes upward and a second curve that protrudes downward when the golf club head is solesed. It is a connected contour curve,
In the contour curve, the top of the first curve is located in front of the center in the direction intersecting the hitting surface, and the first curve and the second curve are located behind the center in the direction intersecting with the hitting surface. The connected inflection points are located ,
The golf club head according to claim 1, wherein a radius of curvature of a rearmost end portion in the second curve is larger than a radius of curvature of a frontmost end portion of the first curve. The golf club head according to claim 1,
In the first curve, the curvature radius of the top portion is larger than the curvature radius of the front end portion, and the curvature radius at the intermediate position between the top portion and the inflection point is larger than the curvature radius of the top portion. A characteristic golf head.