JP2010148703A - Golf club - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a golf club easy to swing and excellent in operability by controlling air resistance for the motion of a head up to hitting from a top position, considering the overall swing of a player. <P>SOLUTION: The golf club includes: a metallic head 7 of a hollow structure in which an outer shell is formed by a face part, a crown part, a sole part, side parts on a toe side 11a and a heel side 11b, and a rear back part so as to have an internal space within the outer shell. The sole part includes a heel-side recessed part 20 and a toe-side recessed part 21. A ridge line 20a forming the heel-side recessed part is curved to be directed to the heel side in the course of extending from the face side to the back side, and a ridge line 21a forming the toe-side recessed part is curved to be directed to the toe side in the course of extending from the face side to the back side. The ridge line 21a of the toe-side recessed part 21 is extended closer to the back side over the ridge line 21a of the heel-side recessed part 20. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a golf club, and more particularly to a golf club that reduces the adverse effects of air resistance during a swing, is easy to swing, and has excellent operability.

  Conventionally, for example, a technique disclosed in Patent Document 1 is known as a technique related to air resistance during swing in a golf club. This technique has a central rib at the rear of the head and a cavity above and below it, and forms a curved concave shape in the cavity to prevent vibration of the head due to air resistance.

Further, in Patent Document 2, an air flow guide groove is formed on the sole surface so as to extend from the ball striking surface side toward the rear end portion and penetrate rearward from the head rear end portion. A technique is disclosed in which the rear end side is made smaller. In this technique, the movement of the high pressure portion of the air by reducing the groove width and the action of the rectified air flow act synergistically to prevent the head from side to side blurring.
Japanese Patent No. 3697270 JP-A-5-337220

  However, the golf club disclosed in the above-mentioned patent document only captures the movement of the head in the direction orthogonal to the face surface, that is, the movement of the head after the direction of hitting the ball. In other words, during the series of swings of the player, only measures are taken by capturing only the movement of the head immediately before the ball is hit. Considering the air resistance acting on the head as seen from the entire swing, It is difficult to achieve a sufficient effect. In other words, since the golf swing moves from the top state to the downswing position and from the time when the golfer hits the ball to hit the ball, the direction of the head changes. Even if only the moving direction of the head is taken into consideration, the effect cannot be expected or it is extremely limited.

  The present invention has been made on the basis of the above-mentioned problems. In consideration of the player's entire swing, the air resistance is controlled for the movement of the head from the top position until the hitting ball is made, and the swing is easy to operate. An object of the present invention is to provide an excellent golf club.

  In order to achieve the above object, a golf club according to the present invention forms an outer shell with a face portion, a crown portion, a sole portion, a side portion on a toe side and a heel side, and a back portion on the rear side. And a hollow metal head having an inner space formed in the outer shell, and a heel side recess is formed on the heel side of the sole portion, and a toe side recess is formed on the toe side. The ridge line forming the side recess is curved so as to go from the face side to the back side and toward the heel partway, and the ridge line forming the toe side recess is The ridge line of the toe side recess is curved toward the toe side in the middle, and the ridge line of the toe side recess extends to the back side than the ridge line of the heel side recess.

  In general, when a golfer swings, the face is facing the front until the golfer swings from the top position to the downswing position, and the air flow due to the swing moves from the heel side of the head to the toe side. To come. Further, from the downswing position to the impact, the head gradually moves by rotating the wrist so that the face faces the ball, so that the air flow caused by the swing also rotates accordingly. That is, when the sole side is viewed in plan, the air flow along the toe / heel direction is such that the toe side turns toward the back side as the downswing is shifted.

  According to the golf club having the head having the structure as described above, the air resistance can be reduced by forming the heel side concave portion in the sole portion. Also, by forming the toe side recess, a passage through which air flows from the heel side to the toe side direction is formed, and when the golfer swings, the swing before the transition from the top position to the downswing position During this, air easily flows from the heel side to the toe side, air resistance acting on the head can be reduced, and a reduction in head speed is suppressed.

  Further, the ridge line forming the heel side recess is curved so as to go from the face side to the back side and toward the heel side in the middle, and the ridge line forming the toe side recess is from the face side to the back side. The ridge line of the toe side recess extends toward the back side of the heel side recess, and the toe side recess has a heel side recess. It is in the state extended to the back side compared with. As a result, when the head turns in the downswing position, the air flow in the toe / heel direction so far is easy to turn naturally toward the toe / back side. It is possible to further reduce the air resistance when turning toward the golf ball.

  Therefore, according to the golf club having the sole structure as described above, the golfer can suppress the air resistance over the entire swing from the top position to hit the ball, and is easy to swing and excellent in operability. Is obtained.

  According to the present invention, when a golfer swings, the air resistance is controlled with respect to the movement of the head from the top position until a hit ball is made, and a golf club that is easy to swing and has excellent operability can be obtained. It becomes like this.

Hereinafter, embodiments of a golf club according to the present invention will be described.
FIG. 1 is a front view showing an embodiment of a golf club according to the present invention. The golf club 1 has a specified lie angle α with respect to a reference horizontal plane P at the tip of a shaft 5 made of metal or FRP. The head 7 set to be fixed. In this case, the head main body 7A constituting the head 7 is made of a hollow metal, and includes a face portion 8, a crown portion 9, a sole portion 10, a toe side 11a and a heel side 11b as will be described later. An outer shell is formed by the side portion 11 and the back portion 12 on the rear side, and an internal space is formed in the outer shell.

  When the golfer swings as described above, the golf club 1 addresses and holds the head 7 with respect to the ball (impact position P1) as shown in FIG. 2 and then backswings to the top position P2. Shake up. Then, the shaft 5 is swung down along a predetermined circular orbit until it shifts from this state to the downswing position P3 (position immediately before the head return operation is performed). Until the transition from the top position P2 to the downswing position P3, the face portion 8 of the head 7 is substantially facing the front (as shown in FIG. 2, the face portion 8 is always visible when the golfer is viewed from the front. During the swing, air flows on the surface of the sole portion 10 of the head 7 from the heel side toward the toe side.

  Then, while the golf club moves from the downswing position P3 to the impact position P1, the face portion 8 faces the front with respect to the ball while the head rotates approximately 90 ° by the wrist turning operation. The position where the face portion 8 faces the front with respect to the ball is an impact position P1, and after impacting the ball, the golf club is finally swung up to the position P4 by a follow-through operation.

  As described above, in the swing operation when impacting the ball, the air moves from the heel side to the toe side along the surface of the sole portion 10 of the head 7 until the top position P2 shifts to the downswing position P3. In the present invention, the sole portion is shaped so as to be easily controlled without lowering the swing speed of the head 7 by paying attention to the air flow.

  Further, in this embodiment, even in such a sole portion shape, even if the head 7 is rotated and rotated by the wrist returning operation during the transition from the downswing position P3 to the impact position P1, the influence of the air resistance during that time. And the head 7 is easily controlled.

  Hereinafter, a specific configuration of the head 7 will be described with reference to FIGS. 3 is a plan view of the head viewed from the crown side, FIG. 4 is a front view of the head viewed from the face side, and FIG. 5 is a bottom view of the head viewed from the sole side. 6 is a cross-sectional view taken along line VI-VI in FIG. 5, FIG. 7 is a side view of the head viewed from the heel side, FIG. 8 is a side view of the head viewed from the toe side, and FIG. It is the rear view which looked at the head from the back side.

  The head main body 7A constituting the head 7 is made of metal having a hollow structure, and includes a face portion 8 having a hitting surface, a crown portion 9 extending rearward from an upper edge (top edge TE) of the face portion 8, and a face And a sole portion 10 extending rearward from the lower edge (leading edge LE) of the portion 8 and further extending from the toe side edge of the face portion 8 to the heel side edge of the face portion. It is formed in a hollow structure provided with a side portion 11 that connects the crown portion 9 and the edge portion of the sole portion 10. In the drawings, the toe side and the heel side constituting such a side portion 11 are denoted by reference numerals 11a and 11b, respectively. Moreover, the toe side 11a and the heel side 11b are connected by the back part 12 as it moves rearward.

  The face portion 8 is provided with a face member 8a on which a hit ball is actually formed. In this case, the face member 8a may be formed of a plate-like member that closes the front opening of the crown portion 9, the sole portion 10, and the side portion 11 (the entire face portion is constituted by a face member). ), May be formed in a so-called cup shape, and may constitute part of the crown portion 9, the sole portion 10, and the side portion 11. Alternatively, a configuration in which an opening having a predetermined size is formed in the face portion 8 and a plate-like face member is fitted in the opening portion may be employed.

  The head main body 7A is preferably integrally formed by casting, for example, a titanium-based alloy, an iron-based alloy, or the like, except for the face member 8a provided on the face portion 8, and on the front surface side of the face portion 8A. An opening is formed in which the face member 8a formed in the cup shape constituting the hitting surface is fixed by welding, adhesion or the like. Of course, in the head main body 7A, each member (face portion, crown portion, sole portion, side portion; outer shell member) constituting the head main body 7A is individually formed and fixed by welding, bonding or the like. good.

  The face member 8a provided in the face portion 8 is preferably integrally formed by, for example, pressing or forging a titanium alloy, an iron alloy, or the like so as to have a predetermined cup shape, The face member 8a thus formed is fixed to the end face of the opening by adhesion, welding, brazing or the like. Of course, the face portion 8 may be integrally formed with the head main body 7A instead of fixing the face member 8a as a separate member.

  Further, a shaft fastening portion (not shown) for fastening the tip of the shaft 5 is integrally formed in the head main body 7A. In this case, the shaft is fixed to the shaft fixing portion by inserting the tip end portion of the shaft through the opening 9a of the hosel portion 9b formed to protrude from the crown portion 9.

  As shown in FIGS. 3 and 4, the crown portion 9 constituting the head body 7 </ b> A defines a ridge line 14 between the side portion 11 and the back portion 12. This ridge line 14 is a portion (boundary) that divides the air flow into the direction of the sole portion and the direction of the crown portion at the time of swing, and as shown in the figure, it may have some width, You may comprise linearly, without having. As shown in FIG. 4, the front end side of the crown portion 9 and the front end side of the sole portion 10 define a top edge TE and a leading edge LE between the face portion 8. Note that these top edge TE and leading edge LE may also have a predetermined width as shown in the figure.

  As shown in FIG. 5, the sole portion 10 has a plurality of recesses. The plurality of concave portions have a heel side concave portion, a toe side concave portion, and a central concave portion so that a passage through which air flows as indicated by an arrow X from the heel side toward the toe side is formed. In this embodiment, the heel side recess is formed at one location (indicated by reference numeral 20) so as to extend from the face side to the back side of the sole portion, and the toe side recess is formed on the face side of the sole portion. One point (indicated by reference numeral 21) is formed so as to extend from the back toward the back side. In addition, as will be described later, the central concave portion is formed at two locations (indicated by reference numerals 22 and 23, respectively) between the heel side concave portion 20 and the toe side concave portion 21 formed one by one.

  As described above, by forming a plurality of recesses in the sole portion 10, the air flowing through the sole portion via the ridge line 14 easily flows to the toe side until the transition from the top position P2 to the downswing position P3. is doing. That is, by forming the heel side recess 20 on the heel side, the resistance of the air flowing along the sole portion is reduced.

  In this case, as shown in FIG. 7, the heel side recess 20 is formed not only on the sole portion but also on the side portion (the length L1 is formed from the face side to the back side of the side portion), thereby increasing the amount. The air resistance is reduced by facilitating the flow of air along the sole surface.

  Further, as with the heel side, the toe side recess 21 is formed not only on the sole portion but also on the side portion as shown in FIG. 8 (length L2 is formed from the face side to the back side of the side portion). By doing so, the air flowing along the sole surface can pass more smoothly.

  In this way, the heel side recess 20 and the toe side recess 21 are formed in a wide range from the face side to the back side over the sole portion and the side portion, so that the path of air flowing from the heel side to the toe side of the sole portion. When a downswing is performed, a path through which air can flow effectively in the direction of the arrow X is secured, and a golf club that is easy to swing and has excellent operability can be obtained.

  The ridge line 20a of the sole portion 10 forming the heel side concave portion 20 is curved so as to go from the face side to the back side and to the heel side in the middle. Further, the ridge line 21a of the sole portion 10 forming the toe side concave portion 21 is curved so as to go to the toe side in the middle while going from the face side to the back side. The ridge line 21a of the toe side recess extends to the back side than the ridge line 20a of the heel side recess, and the toe side recess 21 extends to the back side as compared with the heel side recess 20. Yes.

  Thereby, in addition to the above-mentioned arrow X direction, air can easily flow in the arrow A direction shown in FIG. 5, and the head 7 is rotated by the wrist returning operation during the transition from the downswing position P3 to the impact position P1. It becomes possible to reduce the influence of air resistance when traveling. Further, since the influence of the air resistance is reduced, a decrease in the head speed is suppressed and the head 7 can be easily controlled during the turn.

  In the configuration described above, the length of the head in the face / back direction is defined as L, the length of the heel side recess 20 defined by the ridge line 20a in the face / back direction is defined as L1, and the ridge line 21a. When the length of the toe side recess 21 in the face-back direction is L2, L1 / L is 50 to 68%, preferably 55 to 65%, and L2 / L is 60 to 75%, preferably 65. By setting it to ˜75%, the air efficiently flows in the direction of the arrow X until it shifts from the top position P2 to the downswing position P3, and the air resistance acting on the head can be reduced. Further, by setting L1 / L2 to 75 to 90%, preferably 80 to 90%, air efficiently flows in the direction of arrow A with the turn of the head, and impact from the downswing position P3. It is possible to reduce the air resistance when the head 7 moves while rotating by the wrist returning operation while moving to the position P1.

  Further, the cross-sectional shape (recessed shape) of the heel side recess 20 is not particularly limited. For example, by forming the cross section into a curved shape, the direction of the arrow X or the arrow A as a whole. Air becomes easier to flow in the direction. In such a shape, the extension direction A1 of the maximum depression (the deepest position in the curved cross section) is the heel with respect to the toe-heel direction (same as or substantially the same as the arrow X direction). It is preferable to incline in the direction toward the back side on the toe side from the face side position (indicated by reference symbol Pa) on the side.

  In this way, by extending the extending direction A1 of the maximum depression portion with respect to the toe / heel direction substantially coincident with the arrow X direction, air can easily flow in the arrow A direction, and the downswing position P3. It is possible to more effectively reduce the air resistance acting on the head 7 during the transition from 1 to the impact position P1.

  Further, the toe-side recess 21 is not particularly limited with respect to the cross-sectional shape (the shape of the recess), but as with the heel-side recess 20, the cross section is formed into a curved shape, so that the arrow X as a whole is formed. Air easily flows in the direction or the direction of arrow A. Even in such a shape, the extending direction A2 of the maximum recess (the deepest position in the curved cross section) is formed so as to extend along the extending direction of the maximum recess A1 of the heel side recess 20. It is preferable to keep it. That is, it is preferable that the extending direction A2 is also inclined with respect to the toe / heel direction substantially coincident with the arrow X direction.

  Thus, by forming the extension direction A2 of the maximum depression part along the extension direction A1 of the maximum depression part of the heel side recess 20, the air can easily flow in the direction of the arrow A as a whole. During the transition from the downswing position P3 to the impact position P1, the air resistance acting on the head 7 can be further effectively reduced. In the extending direction A2, as shown in the drawing, the inclination angle is made larger than that in the extending direction A1, so that air can easily flow in the B ′ direction described later.

  Further, in the configuration described above, the heel-side recess 20 is further provided so that the head 7 can be easily rotated during the transition from the downswing position P3 to the impact position P1 (so that it can be easily rotated in the direction of arrow B in FIG. 5). It is preferable to form an inclined guide surface 20e that curves from the center toward the heel side on the back side. The heel side recess 20 of the present embodiment has a configuration including a plurality of surfaces (a bottom surface 20d and an inclined guide surface 20e), and such an inclined guide surface 20e is formed in the heel side recess 20. This makes it easier for air to flow in the direction in which the head turns (the direction of arrow B). As a result, air can flow smoothly when the head 7 turns, and air resistance acting on the head can be reduced. That is, the air that has flowed from the heel side to the toe side during the transition from the downswing position P3 to the impact position P1 is smoothly guided along the turn direction as the head turns, and the air flow. Can be guided in a focused manner, and a reduction in head speed during head turn can be suppressed. In addition, about the width W1 of the inclination guide surface 20e, it is preferable to set it as 10-20 mm in maximum width. With such a width, air can be easily received and rotated.

  Furthermore, it is preferable that an inclined guide surface 21e that curves from the center toward the heel side is also formed on the back side of the toe side recess 21. The toe side recess 21 of the present embodiment has a configuration including a plurality of surfaces (a bottom surface 21d and an inclined guide surface 21e), and such an inclined guide surface 21e is formed in the heel side recess 21. As a result, air easily flows in the direction in which the head turns. And about such an inclination guide surface 21e, if curvature is made smaller than the inclination guide surface 20e of the said heel side recessed part 20 (the curvature of the ridgeline 21a is made smaller than the curvature of the ridgeline 20a, and it is curving gently). When the head is turned, the air flowing in the direction of the arrow A naturally easily flows in the direction of the arrow B ′ (the direction along the turn direction B). In combination with the inclined guide surface 20e, the air smoothly flows along the sole surface, and the air resistance acting on the head can be reduced. The width W2 of the inclined guide surface 21e is preferably 5 to 20 mm at the maximum width. Moreover, it is preferable to make the width narrower than the heel side.

  Then, the action of the inclined guide surfaces 20e and 21e formed on the back side described above makes it possible to stabilize the behavior of the head at the time of head turn, and to suppress the head shake when impacting the ball. It becomes possible.

  The inclined guide surfaces 20e and 21e may be formed on the back side of each recess. However, as shown in FIG. 5, the inclined guide surfaces 20e and 21e are formed so as to be curved in a substantially arc shape continuously from the face side. You can keep it. By forming in this way, the air flow in the A direction naturally changes to the B direction and the B ′ direction, and it becomes possible to further reduce the air resistance when the head 7 turns.

  In the present embodiment, central recesses 22 and 23 extending in the face-back direction are formed between the heel side recess 20 and the toe side recess 21 of the sole portion 10. In this case, the central recesses 22 and 23 are formed at two locations so as to be substantially symmetric with respect to the center line Y in the face / back direction (defined in a direction perpendicular to the face portion 8 through the center of gravity G). By forming the central recesses 22 and 23, air can easily flow in the direction along the center line Y, and after the head 7 is turned, before the transition to the impact position P1, the face The air resistance acting on the head in the back direction is reduced, and the head speed can be prevented from decreasing until just before the impact. In addition, as shown in FIG. 6, the top part between the center recessed parts 22 and 23 is comprised so that it may become substantially horizontal.

  The central recesses 22 and 23 are preferably curved in cross section and formed so that the substantially central portion is most depressed so that air can flow more easily from the face side to the back side.

  Furthermore, in the present embodiment, a back-side recess 25 is formed on the back side of the sole portion 10. By forming such a back-side concave portion 25, after the head 7 turns, turbulence occurs in the air flow until the head 7 moves to the impact position P1, and the head turns and faces the front. The behavior of the head is stabilized before impact, and it is possible to hit the ball at an accurate position. The shape of the back-side recess 25 is not particularly limited. However, as shown in FIG. 5, the back-side recess 25 has a width that covers the center recesses 22 and 23 in the toe-heel direction. Is preferred. Also, as shown in the figure, by forming it so as to gradually become wider as it moves from the center to the back side, air can be easily removed and air resistance can be reduced.

  Further, as described above, by forming the plurality of recesses 20, 21, 22, 23, 25 in the sole portion 10, when air flows, the ridge line portion between the recesses and the depth of each recess Causes turbulence. Such a turbulent flow is generated in each of the recesses, and such a turbulent flow is caused when the air flow on the surface of the crown portion 9 and the air flow on the surface of the sole portion 10 are taken into consideration. It acts to reduce the difference (suppressing the sole side from becoming low pressure). This makes it possible to reduce the force pulled in the centrifugal direction while the head moves from the top position to the downswing position, and prevents strong tension from acting on the hand where the player grips the golf club. It becomes easy to control the head.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to above-described embodiment, It can change variously.

  The recesses 20, 21, 22, 23, and 25 described above improve the flow of air flowing along the sole side until the head 7 moves from the top position P2 to the impact position P1 through the downswing position P3. It is only necessary to have an arrangement mode and shape that reduce the air resistance and does not decrease the head speed. For this reason, the recesses 20, 21, 22, 23, 25, when viewed as the sole part, air easily flows from the heel side toward the toe side, and the air flows smoothly even when the head turns. And may be shifted to the face side or to the back side.

  In addition, the depth of each recess, the slope shape that defines the recess, and the shape of the ridge line can be appropriately modified in consideration of the air flow, such as the inclination angle and curvature due to curvature. Each recess may be formed in the sole portion, but preferably is formed from the sole portion to the side portion as shown in FIGS. In this way, the recesses (particularly, the heel side recess 20 and the toe side recess 21) are continuously formed from the side part toward the sole part, so that the air flow becomes better and the air resistance is more effectively improved. It becomes possible to reduce. Moreover, about each recessed part, when the sole part is cross-sectional-viewed, it should just be the shape depressed from the sole surface, and the inner surface which comprises the recessed part may be comprised by the several surface.

  Further, as shown in FIG. 10, the central concave portion formed between the heel side concave portion 20 and the toe side concave portion 21 may be omitted, and a ridge line extending in the face-back direction therebetween. May be formed. The central recess may be formed at one location along the center line Y.

  Further, the maximum recesses (positions indicated by A1 and A2) formed in the heel side recess 20 and the toe side recess 21 are ± in the front-rear direction with respect to the center of gravity position G of the head when the head is viewed from the sole side. The range is set to 20 mm, preferably ± 15 mm, and more preferably ± 10 mm.

  By setting in this way, the air flow path (air flow) flowing from the heel side to the toe side in the sole portion passes through the gravity center G of the head 7 or near the gravity center G, so that a stable air flow is generated. It becomes like this. For this reason, it is possible to prevent the head 7 from being shaken during the swing, to make the swing easy and to make the golf club excellent in operability.

  In the above-described configuration, the depth (maximum depth) of each of the recesses 20, 21, 22, 23, and 25 is less likely to cause turbulence of air if too shallow, and a large number of recesses are formed. On the contrary, if the depth is too deep, the air resistance becomes large and the shape discomfort and the low center of gravity are hindered. However, by arranging the weight member, etc., it is possible to make it 10 mm or more, and it is possible to make it an arbitrary depth.

  Furthermore, since the above-described sole portion 10 may not have a shape in which an intermediate portion is depressed in consideration of contact with the ground or lawn and guideability, all of the above from the heel side to the toe side is as described above. Thus, it is not necessary that the recesses are continuous, and a shape having no recesses in part may be used. Specifically, the concave portion can be arbitrarily set, but may be formed at least on the heel side and the toe side. Furthermore, it is preferable to form it on the heel side and the toe side, and form 2 to 4 places in the center so that the total is 6 places or less.

  Further, as shown in FIG. 7, it is preferable to form an inclined portion 10c at the rear portion of the sole portion 10 so as to be gradually inclined upward as it moves to the back side.

  By forming the inclined portion 10c in this way, in addition to the action of the back-side recessed portion 30 described above, air can be easily flowed to the rear of the sole portion. In addition, about the shape which inclines upwards, it may be a shape that rises flush, or may be a shape that rises in a multifaceted (stepwise) manner.

It is a figure showing one embodiment of a golf club concerning the present invention, and a front view of a golf club. The figure which showed the swing of the golf club typically. The top view which looked at the head from the crown side. The top view which looked at the head from the crown side. The front view which looked at the head from the face side. The bottom view which looked at the head from the sole side. Sectional drawing along the VI-VI line of FIG. The side view which looked at the head from the heel side. The side view which looked at the head from the toe side. The rear view which looked at the head from the back side. It is a figure which shows another embodiment, and is the bottom view which looked at the head from the sole side.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Golf club 5 Shaft 7 Head 8 Face part 9 Crown part 10 Sole part 11 Side part 11a Toe side 11b Heel side 12 Back part 20 Heel side recessed part 21 Toe side recessed part 22, 23 Central recessed part 25 Back side recessed part

Claims (8)

A metal made of a hollow structure in which an outer shell is formed by a face portion, a crown portion, a sole portion, a side portion on the toe side and a heel side, and a back portion on the rear side, and an inner space is formed in the outer shell. A golf club comprising a head,
Forming a heel side recess on the heel side of the sole portion and forming a toe side recess on the toe side;
The ridge line forming the heel side recess is curved so as to go to the heel side in the middle while going from the face side to the back side,
The ridge line forming the toe side concave portion is curved so as to go to the toe side in the middle while going from the face side to the back side,
The golf club according to claim 1, wherein a ridge line of the toe side recess extends further toward a back side than a ridge line of the heel side recess.   The extending direction of the maximum depression formed in the heel side recess is inclined from the face side position on the heel side to the back side direction on the toe side with respect to the toe / heel direction. The golf club according to claim 1.   The extension direction of the maximum depression formed in the toe side recess is formed along the extension direction of the maximum depression formed in the heel side depression. Golf club.   4. The golf club according to claim 1, wherein the heel side concave portion has an inclined guide surface that curves from the center toward the heel side on the back side. 5.   The toe-side concave portion has an inclined guide surface that curves toward the heel side from the center on the back side, has a smaller curvature than the inclined guide surface of the heel-side concave portion, and extends toward the back side. Item 5. A golf club according to item 4.   The golf club according to claim 1, wherein the heel side recess and the toe side recess are formed over the side part.   The center portion that extends in the face-back direction is formed between the heel side recess and the toe side recess in the sole portion, according to any one of claims 1 to 6. The listed golf club.   The golf club according to claim 1, wherein a back-side recess is formed on the back side of the sole portion.

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