JP2010088805A - Golf club - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a golf club capable of preventing the decline of carry even when a hitting point is shifted from the center part of a face part, stabilizing the carry and improving the carry totally. <P>SOLUTION: The golf club includes a metallic club head 10 in a hollow structure, in which an arch-like rib 32 whose center part in a toe-heel direction is projecting upwards and respective end parts are extended to a sole part, is formed on the inner surface of the face part 12 and at the lower part of the sole side, and a plurality of center areas 42a, 44a and 46a formed to be thinner in the order toward the crown side, a plurality of toe side inclined areas 42b, 44b and 46b formed to be thinner in the order toward the toe side and the crown side, and a plurality of heel side inclined areas 42c, 44c and 46a formed to be thinner in the order toward the heel side and the crown side are formed on the outer side of the arch-like rib 32. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a golf club having a hollow metal club head.

  In general, when a golf ball is hit with a sweet spot of a club head, the longest flight distance is obtained, but the area of the sweet spot is extremely small. For this reason, golf clubs have been developed that maintain a small difference in flight distance with respect to the maximum flight distance when a ball hits the sweet spot even if the hit point deviates from the sweet spot.

In such a golf club, a rib protrudes from the inner surface of the face portion toward the center of the club head, and a thick portion is formed in the central portion of the upper region above the rib, so that the energy at the time of hitting the ball is increased. There are some which improve the resilience by reducing the loss and increase the launch angle to improve the flight distance (see, for example, Patent Document 1).
JP2007-185502

  Although this conventional golf club is beneficial in improving the resilience to the golf ball, the range in which the hitting point is shifted is generally over a wide range on the toe side and the heel side. It is desired to further improve the range in which the resilience is improved to adjust the toe side and the heel side.

  The present invention has been made based on such circumstances, and even when the hit point is shifted from the center part of the face part to the toe side or the heel side, the flight distance is prevented from decreasing and the flight distance is stabilized. It is an object of the present invention to provide a golf club that can improve the overall flight distance.

  In order to achieve the above object, according to the present invention, a golf ball is formed with a face portion formed with a ball hitting surface on the front surface, a crown portion, a sole portion, a toe side and heel side portion, and a back portion at the rear. A golf club comprising a hollow metal club head having a shell and an internal space formed in the outer shell, wherein the golf club has a central portion in the toe-heel direction at an inner surface of the face portion and a lower portion on the sole side. Projecting upward, and each end portion forms an arched rib extending to the sole portion, on the outside of the arched rib, a plurality of central areas formed in order of decreasing thickness toward the crown side, and a toe side and Golf that has a plurality of toe-side inclined areas that are formed to be thinner in the direction toward the crown, and a plurality of heel-side inclined areas that are formed to be thinner in the order toward the heel side and the crown. Love is provided.

  In the face portion, a thin area thinner than an adjacent inclined area may be formed outside the toe side inclined area and the heel side inclined area.

  The upper end portion of the arch-shaped rib is in a range of 60% to 25% of the height of the face portion in a plane perpendicular to the reference surface and including the sweet spot when the sole portion is placed on the reference surface. Preferably, it is disposed within.

  The arch-shaped rib has a toe side at the upper end extending in the toe-heel direction and a leg portion extending from the heel side to the sole side, and these leg portions are provided when the sole portion is placed on a reference plane. Each may have an inclination angle in the range of 0 to 70 degrees with respect to a perpendicular perpendicular to the reference plane, and the distance between these legs may increase downward.

  The arch-shaped rib is preferably formed to have a dimension in the width direction larger than the height protruding from the inner surface of the face portion, and may have a side surface inclined with respect to the inner surface of the face portion. .

  The inner area surrounded by the arch-shaped rib can be formed with a thickness smaller than the thickness of the area adjacent to the outside of the arch-shaped rib.

  According to the golf club of the present invention, on the outside of the arch-shaped rib, a plurality of central areas formed with a thin thickness in order toward the crown side, and a plurality of thicknesses formed with a thin thickness in order toward the toe side and the crown side. By forming the toe-side inclined area and the plurality of heel-side inclined areas that are formed in order of decreasing thickness toward the heel side and the crown side, the coefficient of restitution in the center area of the face portion can be efficiently suppressed. In addition, the toe side and heel side restitution coefficients can be approximated to the restitution coefficients of the central region, and restitution coefficients that are approximated over a wide range of the face portion can be obtained. As a result, even when the hit point is shifted from the center area of the face portion to the toe side or the heel side, it is possible to prevent a decrease in the flight distance, stabilize the flight distance, and improve the overall flight distance. A golf club is provided.

  When forming a thin area thinner than the adjacent inclined area outside the toe side inclined area and heel side inclined area, the approximate range of the coefficient of restitution can be further expanded to the toe side and heel side. it can.

  When the upper end portion of the arch-shaped rib is placed on the reference plane, the height of the face portion in the plane perpendicular to the reference plane and including the sweet spot is in the range of 60% to 25%. In the case where the sweet spot is arranged, the coefficient of restitution in the central region where the sweet spot is arranged can be reliably suppressed.

  The arch-shaped rib has a toe side at the upper end portion extending in the toe-heel direction and a leg portion extending from the heel side to the sole side, and these leg portions are referred to when the sole portion is placed on the reference plane. If the spacing between these legs increases downward with an inclination angle in the range of 0 to 70 degrees with respect to the normal perpendicular to the surface, on the toe side and heel side of the arched rib An inclined area having a small thickness can be formed over a wide range, and a coefficient of restitution approximate to the central region can be secured over a wide range in the toe-heel direction.

  When the arch-shaped rib is formed with a dimension in the width direction larger than the height protruding from the inner surface of the face part, or has a side surface inclined with respect to the inner surface of the face part, the coefficient of restitution due to the difference in the hit point position The variation in the rebound coefficient can be reduced, and the coefficient of restitution can be effectively adjusted.

  When the inner area surrounded by the arched rib is formed to be thinner than the thickness of the area adjacent to the outside of the arched rib, the coefficient of restitution of the lower part of the face part can be adjusted, and the arched rib By adjusting the width and height, it is possible to more effectively adjust the restitution coefficient of the central region.

  1 to 5 show a golf club 8 according to a preferred embodiment of the present invention. In the figure, similar parts are denoted by the same reference numerals.

  As shown in FIG. 1, the golf club 8 of the present embodiment is defined with respect to a reference horizontal plane B such as the ground on which a ball is placed at the tip of a shaft 6 formed into a tubular structure with, for example, a fiber reinforced resin or a metal material. The club head 10 is attached with the lie angle α and the loft angle set, and a grip formed of a flexible or soft material such as natural rubber or synthetic rubber is attached to the base end. Here, the lie angle α is a mounting angle of the shaft axis 6a with respect to a sole portion or a reference horizontal plane B, which will be described later, and the loft angle is between the vertical plane R perpendicular to the reference horizontal plane B and the front surface of the face portion 12. Angle β (FIG. 4).

  As shown in FIGS. 1 to 3, in the metal club head 10 of the present embodiment, a face member 14 having a ball striking surface is disposed on a face portion 12, and the head body 10a supports the face member 14 from the back side. In the head body 10a, a crown portion 16 and a sole portion 18 extend from the top line 12a and the leading edge 12b of the face portion 12 to the back side, respectively. Between the crown portion 16 and the sole portion 18, the toe side side portion 20 and the heel side side portion 22 from the toe side side line 12 c and the heel side side line 12 d of the face portion 12 are the peripheral portions of the crown portion 16, respectively. And extending to the back side while being curved along the back portion 24.

  The top line 12a between the face portion 12 and the crown portion 16 can be specified by a ridge line between them, but is specified at a portion smaller than the curvature radius of the surface portion that forms most of the face portion 12. Also good. The same applies to the ridge line portions such as the leading edge 12b and the side lines 12c and 12d.

  The toe side part 20 and the heel side part 22 of the head body 12 have large dimensions in the vertical direction, that is, the crown / sole direction on the face part 12 side, and the dimensions gradually decrease to the back part 24. Accordingly, the club head 10 substantially forms an outer shell by the face portion 12, the crown portion 16, the sole portion 18, the toe side and heel side side portions 20 and 22, and the back portion 24 at the rear portion. Is formed in the outer shell.

  The head main body 10 a is integrally formed with a cylindrical shaft fixing portion 26 (FIG. 3) for fixing the tip of the shaft 6 and protrudes into the internal space N. The shaft 6 is inserted into the shaft fixing portion 26 by, for example, inserting the tip end portion of the shaft 6 into the shaft fixing portion 26 through the sleeve 26a from the opening 28a of the hosel portion 28 formed to protrude from the crown portion 16. It is fixed.

  Such a head main body 10a may be integrally molded, and a plurality of members can be assembled and integrated by welding or the like.

  As shown in FIGS. 4 and 5, the face member 14 of the present embodiment has a front side opening of the head main body 10 a including a crown portion 16, a sole portion 18, toe side and heel side portions 20 and 22, and a back portion 24. 11 is formed of a shallow cup-shaped member that closes the face 11, and a peripheral edge 30 that is bent to the back side so as to surround the face 12 is welded to the head body 10a along the front opening 11. This weld is indicated by the symbol W. The peripheral edge portion 30 has a crown side portion 30a, a sole side portion 30b, a toe side portion 30c, and a heel side portion 30d, and is welded to the head main body 10a. The front part which is a part of toe side and heel side side parts 20 and 22 is formed. Therefore, unless necessary, the crown side portion 30a, the sole side portion 30b, the toe side portion 30c and the heel side portion 30d of the peripheral edge portion 30 are connected to the crown portion 16, the sole portion 18, the toe side and the heel side side portion. 20 and 22 will be described.

  In this embodiment, the hosel portion 28 is formed on the head main body 10a. However, the hosel portion 28 can also be provided on the face member 14. Further, the hosel portion 28 is prepared in advance as a single unit, and both the club head 10 It is also possible to integrate it with the other members which comprise by welding. Further, instead of forming the face member 14 with a cup-shaped member formed by bending the peripheral portion 30 of the face portion 12 and the integral member to the back side, the face member 14 is a plate that forms the entire area of the face portion 12. It is also possible to form the shape. Further, it is formed in a plate shape that fits into an opening of a predetermined size formed in the face portion 12 of the head body 10a, and a part of the face portion 12, such as a ball striking surface, together with the peripheral edge portion of the head body 10a surrounding the opening. May be formed only. In either case, the face member 14 is preferably formed of the same material as the head body 10a or a metal material that can be welded to the head body 10a.

  The head main body 10a is preferably integrally formed by casting, for example, a titanium-based alloy, an iron-based alloy, or the like, except for the face member 14, and the face member constituting the hitting surface of the face portion 12 on the front side thereof. An opening 11 is formed in which 14 is fixed by welding, adhesion or the like. Instead of such an integrated structure, each member constituting the head main body 10a (a member forming an outer shell such as a face portion, a crown portion, a sole portion, a side portion, etc.) is individually formed, and then assembled and welded. Or may be integrated by bonding or the like.

  Further, the crown portion 16 is formed of a fiber reinforced metal, a fiber reinforced resin, a magnesium alloy, a thin titanium alloy having a thickness of 0.3 to 0.7 mm, a thin stainless steel alloy having the same thickness, or the like. It is also possible to join by brazing or the like. In this case, since the crown portion 16 of the head body is open, it becomes easy to insert a weight (not shown), a rib described later, and the like into the internal space N. effective.

  The face member 14 coupled to the head body 10a is, for example, a titanium alloy, an iron alloy, or the like that is pressed or forged or cast so as to have a predetermined shape. By doing so, it is also possible to form a single body, or to integrate them by welding a plurality of members processed in this way.

  Instead of welding and fixing the face member 14 to the end surface of the opening 11 formed in the head main body 10a, the entire head main body 10a is formed in an integral structure (for example, cast), and the head of this integral structure is formed. The face portion 12 may be formed on a part of the main body 10a.

  The face member 14 of the present embodiment forms a bulge in which the central portion of the face portion 12 is slightly bulged outward, and the front surface on which the bulge is formed forms a ball striking surface for hitting a golf ball. A large number of score lines (not shown) extending in the toe-heel direction are formed on the hitting surface by a suitable means such as a shallow groove in a substantially horizontal direction. A sweet spot S, which is a point extending through the center of gravity G of the club head 10 (see FIG. 4) and extending perpendicularly to the ball striking surface of the face portion 12, is located at a substantially central position of the face portion 12.

  As shown in FIG. 3 and FIG. 4, the club head 10 of the present embodiment has a center portion in the toe-heel direction projecting upward toward the crown side on the inner surface of the face portion 12 and the lower portion on the sole side. Each of the end portions on the side and the heel side is formed with an arched rib 32 extending to a portion corresponding to the inner surface of the sole portion 18 or the leading edge 12b. In FIG. 3, for the sake of simplicity, the top line 12a, the leading edge 12b, and the side lines 12c and 12d are formed so as to overlap the folding line of the peripheral portion 30, and the same reference numerals are used as the folding lines. However, it is obvious that the top line 12a, the leading edge 12b, and the side lines 12c and 12d may be formed at separate positions that do not overlap the folding line.

  The arch-shaped rib 32 has an upper end portion 34 extending linearly in the toe-heel direction along the sole side edge or leading edge 12b on the inner surface of the face portion 12 in the center of the toe-heel direction. Legs 36 and 38 extend from the toe side and heel side ends of the upper end 34 toward the sole side.

  The upper end 34 of the arch-shaped rib 32 has a face height H (between the top line 12a and the leading edge 12b) in a plane perpendicular to the reference horizontal plane B and including the sweet spot S (the plane in FIG. 4). The distance is set within a range of 60% to 25% (preferably 50% to 33%). The length of the upper end portion 34 along the toe-heel direction is the total length L (maximum distance between the side lines 12c and 12d) of the face portion along the toe-heel direction over the toe side and the heel side of the sweet spot S. Thus, it is preferable that the length is 15% to 50% or about 15 mm to 52 mm. The legs 36 and 38 form an inclination angle θ1 in the range of 0 to 70 degrees (preferably 15 to 60 degrees) with respect to the perpendicular P perpendicular to the reference horizontal plane B. It is preferable that the space | interval between 38 increases gradually toward the sole side. Note that the inclination angles of the legs 36 and 38 with respect to the perpendicular P are preferably opposite to each other and formed in substantially the same size, but one inclination angle may be formed larger than the other.

  Such an arch-shaped rib 32 includes a sweet spot S and is a central region extending to the toe side and the heel side of the sweet spot S, and in particular, the upper end portion 34 is 60% to 25% of the height H of the face portion 12. By forming within this range, the rigidity of the lower part of the face portion 12 is increased in the central region in the toe-heel direction, whereby the restitution coefficient of the central region including the sweet spot S can be suppressed. Further, as the interval between the leg portions 36 and 38 increases downward, a region where the thickness is formed thin is secured over a wide range on the toe side and the heel side of the arched rib 32 as described later, and the central region The coefficient of restitution approximated to If such an area where the thickness can be reduced can be formed over a wide range, the legs 36 and 38 are formed in a straight line, or in a curved shape that curves outward or inward. You can also.

  The arch-shaped rib 32 has a protrusion height t from the inner surface of the face portion 12 of 1 mm to 6 mm, and a width d between the side surfaces 35 and 37 extending from the inner surface of the face portion 12 to the upper surface (width on the inner surface side of the face portion 12). ) Is preferably formed to be 1 mm to 10 mm, and the width dimension is preferably larger than the height. The arch-shaped rib 32 is formed in a trapezoidal shape in a plane perpendicular to the inner surface of the face portion, and the side surfaces 35 and 37 are, for example, 1 to 60 degrees with respect to the inner surface of the face portion 12. It is preferable to form with an inclined surface inclined at an angle of degrees. The inclined surfaces 35 and 37 preferably transition smoothly between the inner surface of the face portion 12 via the curved surface portions 35a and 37a. If necessary, the entire surface may be formed of a curved surface.

  By forming the cross-sectional shape of the arch-shaped rib 32 in this way, as will be described later, the rebound characteristics are effectively controlled together with the area where the wall thickness on the outer side of the arch-shaped rib 32 is formed thinly. It is possible to reduce the variation in the coefficient of restitution due to the difference and to effectively adjust the coefficient of restitution. The cross-sectional shape of the arch-shaped rib 32 is preferably formed the same along its entire length, but can be changed according to the arrangement position of the upper end portion 34 and the leg portions 36 and 38, for example. In addition, it is possible to form not only a single continuous rib but also a plurality of ribs arranged in the extending direction.

  The lower end of the arch-shaped rib 32, that is, the lower end side of the leg portions 36, 38 can be connected to the inner surface of the sole portion 18 directly to the rib extending in the face-back direction or via the front portion of the sole portion 18. . In this case, the force acting on the face portion 12 at the time of hitting the ball can be efficiently applied to the back side of the club head 10 via the rib of the sole portion 18.

  The inner area 40 surrounded by the arch-shaped rib 32 is formed to have a thickness that is thinner than the thickness of the arch-shaped area 42 adjacent to the outside of the arch-shaped rib 32. Thereby, the restitution coefficient of the lower part of the face portion 12 can be adjusted, and the restitution coefficient of the central region can be adjusted more effectively by adjusting the width and height of the arch-shaped rib 32.

  On the outer side of the arch-shaped rib 32 formed in this way, a plurality of central areas 42a, 44a, 46a formed in order with decreasing thickness toward the crown side, and thickness in order toward the toe side and the crown side. A plurality of thinly formed toe side inclined areas 42b, 44b, 46b, and a plurality of heel side inclined areas 42c, 44c, 46c formed in order of decreasing thickness toward the heel side and the crown side, In the embodiment, the thickness of each central area and the inclined area adjacent to the toe side and the heel side of the central area are formed to be substantially equal, and the toe side and the heel side are respectively formed along the arched rib 32. First to third areas 42, 44, 46 extending in an arch shape are formed. Note that “substantially equal” means that the wall thickness difference is smaller than the wall thickness difference between adjacent areas in the direction from the arch-shaped rib 32 to the outside.

  The first area 42 adjacent to the arched rib 32 is formed such that the width of the central area 42a is 5 mm to 20 mm, and the width of the inclined areas 42b and 42c forming the inclination angle θ2 of 15 degrees to 60 degrees is 2 mm to 10 mm. It is formed. These inclined areas 42b and 42c extend to the toe side and the heel side of the arch-shaped rib 32 and extend to the leading edge 12b which is a bent portion.

  The second area 44 arranged outside the first area 42 is formed such that the width of the central area 44a is 10 mm to 20 mm, and the inclined areas 44b and 44c forming the inclination angle θ3 of 15 degrees to 60 degrees. It is formed to 2 mm to 10 mm. These inclined areas 44b and 44c extend to the toe side and the heel side of the first area 42, and do not reach the leading edge 12b.

  The third area 46 arranged outside the second area 44 has an upper end 46a extending to the top edge 12a and a width of 5 mm to 20 mm. The inclined areas 46b and 46c forming the inclination angle θ4 of 15 to 60 degrees extend to the leading edge 12b. Further, the lower ends of the inclined areas 46 b and 46 c extend between the inclined areas 44 b and 44 c of the second area 44 and the leading edge 12 b and are disposed adjacent to the inclined areas 42 b and 42 c of the first area 42.

  The central areas 42a, 44a, 46a of the first to third areas 42, 44, 46 are arranged in the central area in the toe-heel direction including the sweet spot S, and the length in the toe-heel direction on the crown side is The central area 42a is preferably formed to 15 mm to 30 mm, the central area 44a to 15 mm to 30 mm, and the central area 46a to 30 mm to 50 mm.

  The area in which the wall thickness changes is not limited to the first to third areas. For example, two to five areas may be formed between the arched rib 32 and the crown portion 46. It is also possible to divide into 6-10 areas. The width of each area is preferably at least 2 mm. Although it is possible to smoothly transition between these areas without forming a step, when providing a stepped boundary such as an inclined surface described later, the thickness is adjusted in each area. It is easy to adjust each coefficient of restitution.

  Further, the face portion 12 is formed on the toe side and the heel side of the upper portion, that is, on the toe side of the inclined area 46b of the third area 46 and the heel side of the inclined area 46c. 48a and 48b are arranged so that the approximate range of the center region and the coefficient of restitution can be further expanded to the toe side and the heel side.

  In the present embodiment, the thickness is 2.0 mm to 2.8 mm in the inner area 40, 2.8 mm to 4.0 mm in the first area 42, 2.4 mm to 3.4 mm in the second area 44, and the third area. 46 is 2.0 mm to 2.8 mm, and the thin areas 48 a and 48 b are 1.7 mm to 2.8 mm thick. Each area has a constant thickness. It is also possible to change the wall thickness between the area and the inclined area, or to change the wall thickness between the respective inclined areas in the first, second and third areas. . The thin areas 48a and 48b formed in the upper part of the face portion 12 are formed so that the thin area 48b on the heel side is thinner than the thin area 48a on the toe side, and the thickness in the face portion 12 is reduced to the heel side. It is preferable to form the thinnest area in the thin-walled area 48b to improve the repulsive force at this portion.

  In the present embodiment, an arched inclined surface 43 is formed between the first and second areas 42 and 44, and an arched inclined surface 45 is formed between the second and third areas 44 and 46. An inclined surface 47 is formed between the inclined area 44b in the third area and the thin area 48a on the toe side, and an inclined surface 47b is formed between the inclined area 44c and the thin area 48b on the heel side. By arranging such inclined surfaces 43, 45, 47a, 47b between adjacent areas, it is possible to suppress the occurrence of stress concentration between areas having different thicknesses. Further, when stress concentration is difficult to occur, a stepped shape may be formed without forming such inclined surfaces 43, 45, 47a, 47b. In any case, the thickness may be changed smoothly instead of forming the inclined surface or the step. Further, it is possible to continuously change the thickness without dividing each area from the first arched area 42 to the third arched area 46.

  According to the club head 10 formed in this way, a plurality of central areas 42a, 44a, 46a, which are formed so as to decrease in thickness sequentially toward the crown side, on the outer side of the arch-shaped rib 32, and toward the toe side and the crown side. A plurality of toe side inclined areas 42b, 44b, and 46b that are formed to be thin in order, and a plurality of heel side inclined areas 42c, 44c, and 46c that are formed to be thin in order toward the heel side and the crown side are formed. As a result, the coefficient of restitution in the central area of the face portion 12 can be efficiently suppressed, and the coefficient of restitution on the toe side and the heel side can be approximated to the coefficient of restitution in the central area. The coefficient of restitution approximated by is obtained. As a result, even when the hit point is shifted from the center region of the face portion 12 to the toe side or the heel side, the flight distance is prevented from decreasing and the flight distance is stabilized, and the overall flight distance is improved. A golf club 8 is provided.

  In the club head 10 described above, the upper end 34 of the arch-shaped rib 32 extends linearly in the toe-heel direction, and the first, second, third area 42, 44, 46 central areas 42a, 44a, 46a. 6 is formed in a straight line along this, but if the coefficient of restitution in the central region can be suppressed and the coefficient of restitution approximate to the central region can be formed over a wide range of the face portion 12, FIG. It is also possible to form an arc shape as shown.

  Furthermore, the inclination angle θ1 of the leg portions 36 and 38 of the arch-shaped rib 32 may be formed at 0 degree, and the upper end portion 34 may be formed in a straight line shape, or may be formed so as to protrude downward as opposed to FIG. If necessary, the upper end portion 34 may be omitted, and the leg portions 36 and 38 may be formed in a triangular shape. In this case, the first, second, and third areas 42, 44, 46 may also be formed in a shape corresponding to the arched rib 32, and the arched rib 32 as shown in FIG. 3 or FIG. You may form in the shape different from. The first, second, and third areas 42, 44, and 46 may be formed in different shapes. Further, the arched rib 32 may be formed separately and integrated by welding or the like instead of being formed as an integral member with the face member 14.

  FIG. 7 shows an embodiment in which a plurality of inclined areas are formed outside a plurality of central areas.

  This embodiment is also basically the same as the above-described embodiment, but the central areas 50, 52, and 54 are formed so as to be thinner in order toward the crown side outside the upper end portion 34 of the arched rib 32. The inclined surface 51 along the toe-heel direction is formed between the central areas 50 and 52, and the inclined surface 53 is formed between the central areas 52 and 54.

  Also, a plurality of toe-side inclined areas 56a, 58a, 60a are formed on the outer side of the leg portion 36 and the central area 50-54 of the arch-shaped rib 32, and the thicknesses are gradually reduced toward the toe side and the crown side, A plurality of heel-side inclined areas 56b, 58b, 60b are formed on the outer side of the leg portion 38 and the central area 50-54, and the heel-side inclined areas 56b, 58b, 60b are formed so as to decrease in thickness toward the heel side and crown side. Reference numerals 57a, 57b, 59a, and 59b denote inclined surfaces between adjacent inclined areas. The inclined areas 56a and 56b adjacent to the arch-shaped rib 32 on the innermost side are thinner than the central area 50 adjacent to the arch-shaped rib 32 at the upper side, and may be formed to have the same thickness as the central area 52 at the intermediate position. preferable.

  Thus, even when the central area and the inclined area are individually formed, the coefficient of restitution of the central area of the face portion 12 can be efficiently suppressed and the repulsion on the toe side and the heel side can be suppressed as in the above-described embodiment. The coefficient can be approximated to the coefficient of restitution of the central region, and the coefficient of restitution approximated over a wide range of the face portion 12 can be obtained, whereby the hit point is shifted from the center region of the face portion 12 to the toe side or the heel side. Even in this case, it is possible to prevent a decrease in the flight distance, stabilize the flight distance, and improve the overall flight distance. In particular, when the restitution coefficient is largely adjusted in the vertical direction, or when the restitution coefficient in the center region is efficiently reduced, it can be adjusted extremely effectively.

  In this embodiment as well, as in the above-described embodiment, the thickness is reduced in order from the arched rib 32 toward the outside, but the area at the intermediate position may be formed the thinnest. Specifically, the central area 52 can be formed thinner than the thickness of the central area 54 on the crown side, that is, on the outer side. Further, the inclined areas 58a and 58b at the intermediate positions can be formed thinner than the thickness of the outer inclined areas 60a and 60b, respectively. In this case, in particular, a high repulsion region can be formed widely on the slightly crown side of the central portion, and advantages such as prevention of a decrease in initial speed when the hitting point is removed can be obtained.

  The thickness of the face portion 12 formed in this way is such that the central area 50 is 2.8 to 4.8 mm, the central area 52 is 2.6 to 4.0 mm, and the central area 54 is 2.0 to 3 mm. The inclined areas 56a and 56b are 2.4 to 3.4 mm, the inclined areas 58a and 58b are 2.0 to 2.8 mm, and the inclined areas 60a and 60b are 1.8 to 2.mm. It is preferable to form in about 4 mm. In addition, the inclination angles θ5 and θ6 with respect to the above-described normal line P are preferably formed to be about 20 to 60 degrees outside the inclination areas 56a and 58a.

  Also in this embodiment, the number of sections of the central area and the inclined area is not limited to three as in the above-described embodiment, and it is possible to continuously change the wall thickness at the boundary between adjacent areas. It is. Further, as shown in FIG. 6, the arch-shaped rib 32 may have a curved shape at the upper end.

  In any case, as long as it is formed in a hollow structure, a normal wood club that hits a tee-up ball, a fairway wood that can be used in a fairway that hits a ball placed directly on the ground, or a utility club head It can be formed as various types of club heads, such as a hollow iron commonly called.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory view of a club head of a golf club according to a preferred embodiment of the present invention. The top view of the club head of the golf club of FIG. Sectional drawing which follows the III-III line | wire of FIG. Sectional drawing which follows the IV-IV line of FIG. Explanatory drawing of a face member. Explanatory drawing similar to FIG. 3 of the club head by a modification. FIG. 4 is a view similar to FIG. 3 of a club head according to another embodiment.

Explanation of symbols

  8 ... Golf club, 10 ... Club head, 12 ... Face part, 32 ... Arched rib, 42, 44, 46 ... Arched area.

Claims (7)

An outer shell is formed by the face portion, the crown portion, the sole portion, the toe side and heel side side portions, and the back portion of the rear portion, in which the hitting surface of the golf ball is formed on the front surface. A golf club comprising a hollow metal club head formed of
On the inner surface of the face portion and the lower portion on the sole side, a central portion in the toe-heel direction protrudes upward, and each end portion forms an arched rib extending to the sole portion. A plurality of central areas formed with thinner thicknesses toward the side, a plurality of toe side inclined areas formed with thinner thicknesses toward the toe side and the crown side, and a thickness sequentially toward the heel side and the crown side. A golf club comprising a plurality of heel-side inclined areas having a reduced thickness.   2. The golf club according to claim 1, wherein the face portion is formed with a thin area thinner than an adjacent inclined area outside the toe side inclined area and the heel side inclined area.   The upper end portion of the arch-shaped rib is in a range of 60% to 25% of the height of the face portion in a plane perpendicular to the reference surface and including the sweet spot when the sole portion is placed on the reference surface. The golf club according to claim 1, wherein the golf club is disposed within the golf club.   The arch-shaped rib has a toe side at the upper end extending in the toe-heel direction and a leg portion extending from the heel side to the sole side, and these leg portions are provided when the sole portion is placed on a reference plane. 4. An angle of inclination in the range of 0 to 70 degrees with respect to a perpendicular perpendicular to the reference plane, respectively, and the distance between the legs increases downward. The golf club as described in any one.   6. The golf club according to claim 1, wherein the arch-shaped rib is formed so that a dimension in a width direction is larger than a height protruding from an inner surface of the face portion.   6. The golf club according to claim 1, wherein the arched rib has a side surface that is inclined with respect to the inner surface of the face portion.   The inner area surrounded by the arched rib is formed to have a thickness that is thinner than the thickness of the area adjacent to the outside of the arched rib. Golf club.

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