JP5785893B2 - Golf club head and golf club - Google Patents

Description

  The present invention relates to a golf club, and more particularly, to a hollow golf club head and a golf club having such a golf club head.

  Conventionally, it has been known that the face portion of a metal head having a hollow structure can be easily bent to prevent the ball from being crushed at the time of hitting, thereby reducing the energy loss due to the deformation of the ball and improving the flight distance. It has been. Therefore, in order to improve the flight distance, the central region of the face portion may be configured to be easily bent, but the deflection of the face portion is regulated by rules.

  In other words, as a measure of the deflection of the face portion, there is a method of measuring in accordance with the USGA (American Golf Association) pendulum test. It has been generalized to evaluate the deflection of the part. Specifically, the CT value specifies the center of the face portion (hereinafter also referred to as the center position of the face portion) according to the above-described Pendulum test procedure, and the contact time when a predetermined test piece collides with the center position. Is used to evaluate the elasticity of the face part. If the CT value increases (the contact time becomes longer), the face part is easily bent and the flight distance of the ball can be improved. When the CT value at the center position of the face part exceeds a predetermined value, it is determined that the value does not conform to the rule. Further, the CT value needs to be within a predetermined value even in a position other than the center position.

  By the way, when hitting with a golf club equipped with a metal head having a hollow structure, a normal golfer often has a swing path (upper blow system) like so-called hitting. This will be described with reference to FIGS. 1 and 3. When the ball is impacted by shifting from the top position of the swing to the downswing, the head 7 of the golf club 1 is in a direction along the horizontal plane from the top position. A swing trajectory is entered that enters from (see arrow D1), impacts the ball, and transitions directly to follow-through (slowly curved swing trajectory).

  In recent head structures, for example, as disclosed in Patent Document 1, the face portion is configured such that the maximum repulsion point is located on the crown side from the center position of the face portion, or disclosed in Patent Document 2, for example. As described above, the face portion is configured so that the crown side is relatively more repulsive than the sole side with respect to the center position of the face portion. For this reason, even if the ball impacts in the center position of the face or in the region close to the crown side from the center position, if the swing trajectory is as described above, the face portion is effective even if the hit points vary somewhat at the time of impact. And the flight distance can be improved.

JP 2004-267438 A JP2011-152275A

  As described in Patent Documents 1 and 2 described above, in the golf club head having a hollow structure, the rebound on the crown side is increased (the CT value is increased) with respect to the center position of the face portion. For golfers who swing with an upper blow system, the flying distance can be improved, but for golfers who swing with a down blow system, there is a possibility that the golf club does not have a flying distance. .

  This will be described with reference to FIG. 2 and FIG. 4. When a golfer who swings in a down blow system moves from the top position of the swing to the down swing, the head hits the ball from above (see arrow D2). And make an impact with the loft standing. Further, in the follow-through after impact, since the head does not collide with the ground, the head tends to be moved up as compared with the swing of the upper blow system.

  As mentioned above, a golfer who swings a downblow system inevitably impacts with a loft standing, so the trajectory is lower than when impacting with an upper blow using the head of the same loft angle. However, in a head in which the repulsion on the crown side as described above is set higher than that on the sole side, there is a possibility that inconvenience may occur in terms of flight distance. That is, as shown in the head travel directions D1 and D2 in FIGS. 3 and 4, when the impact occurs, the head (face surface) travel direction D2 is in a direction along the loft angle of the face in the downblow system swing. When approaching and comparing with the swing of the upper blow system (compared to the traveling direction D1), the face surface tends to impact like rubbing the ball. It becomes easy to take a movement behavior (arrow D3 direction).

  For this reason, as described above, if the CT value on the crown side is set to be relatively high, the ball tends to move to the crown side compared to the swing of the upper blow system, so that the ball separation is delayed. As a result, energy is lost and the flight distance is reduced (energy at the time of impact is absorbed and initial speed is also reduced). Also, if the ball is separated slowly, the ball tends to blow up with the down-blow type swing trajectory, that is, the follow-through trajectory that scoops up the head, and the flight distance may not be extended. is there.

  The present invention has been made paying attention to the above-mentioned problems, and a golf club head capable of improving and stabilizing a flight distance for a golfer who swings down blow, and a golf club having such a golf club head The purpose is to provide clubs.

In order to achieve the above object, a golf club head according to the present invention has a hollow metal head body having a face portion, a crown portion, a sole portion, and a side portion, face portion is configured to have a thick portion thicker than the peripheral portion on the back surface, top and bottom face thereof as the ball striking face is defined by the top edge and the sole edge, the thick portion, said face portion The CT value reduction rate on the crown side of the center position is larger than the CT value reduction rate on the sole side from the center position , and the thick part includes the center position and the toe heel A lateral rib extending in the direction, a crown side rib extending toward the crown side at each end of the lateral rib, and a sole side rib extending toward the sole side at each end of the lateral rib, The has the extending crown side ribs to said top edge, said sole-side rib is characterized in that terminating in the way to the sole edge.

According to the head structure described above, when the ball is impacted by a downblow swing, the head (face surface) travels along the loft angle so that the ball is rubbed and impacted so that the ball is on the crown side. Even if it behaves to move to the center, the CT value decrease rate on the crown side is larger than the center position of the face portion (the CT value decrease rate on the sole side from the center position is larger). Therefore, it becomes easy to move away from the face surface. Therefore, at the impact position, the tendency that the ball can be repelled without moving to the crown side is increased, and energy loss at the time of impact is reduced, thereby suppressing a decrease in initial speed and a flight distance. There is nothing. In particular, at the time of impact, since it is easy to move away from the ball, even if the head is changed after impact, the ball is prevented from blowing up, and the flight distance can be improved and stabilized. In addition, since the crown side rib extends to the top edge and terminates in the middle of the sole side rib reaching the sole edge, the top edge region is less likely to bend compared to the sole edge region. It becomes possible to make it difficult to bend.

  In the configuration described above, the reduction rate of the CT value on the crown side may be based on a predetermined range on the crown side from the center position of the face portion (for example, a range of 5 mm on the crown side). The center position of the face portion may be used as a reference. In the former configuration, the above-described action can be obtained when impacting at the center position, and the CT value does not decrease so much when impacting within a predetermined range on the crown side from the center position of the face (high CT value). Since the area is wide), the flying distance can be stabilized even if the hit point position fluctuates. In the latter configuration, if the hitting point varies on the crown side, the flight distance is reduced, so that it is easy for the golfer to detect a miss shot.

  Further, the present invention may be configured as a golf club having the golf club head having the above-described structure.

  ADVANTAGE OF THE INVENTION According to this invention, the golf club head and golf club which can aim at the improvement and stabilization of a flight distance are obtained for the golfer who swings a downblow type | system | group.

The figure which shows typically the swing state of an upper blow type | system | group in order from the left. The figure which shows typically the swing state of a down blow system in order from the left. The figure which shows the advancing direction of the head at the time of impacting a ball | bowl with the upper blow type | system | group swing shown in FIG. The figure which shows the advancing direction of the head at the time of impacting a ball by the swing of the down blow system shown in FIG. 1 is a front view showing an embodiment of a golf club according to the present invention. The front view of the head part shown in FIG. Sectional drawing along the AA line of FIG. 6 (longitudinal sectional drawing). FIG. 8 is a cross-sectional view taken along line B-B in FIG.

Hereinafter, embodiments of a golf club head and a golf club according to the present invention will be described.
5 to 8 are views showing one embodiment of a golf club according to the present invention, FIG. 5 is a front view of the golf club, FIG. 6 is a front view of the head portion shown in FIG. 5, and FIG. 6 is a cross-sectional view (longitudinal cross-sectional view) taken along the line AA in FIG. 6, and FIG. 8 is a cross-sectional view taken along the line BB in FIG. .

  The golf club 1 according to the present embodiment has a grip 5 attached to a base end of a shaft 3 made of metal or FRP, and has a lie angle and a loft angle defined with respect to a reference horizontal plane P at the tip. The set head 7 is fixed and configured. In this case, the head body 7A constituting the head 7 includes a face portion 7a having a hitting surface (face surface) 7B, a crown portion 7b extending rearward from the upper edge of the face portion 7a, and a lower edge of the face portion 7a. And a side portion 7d connecting the crown portion 7b and the edge portion of the sole portion 7c. The side portion 7d includes a back portion 7e that faces the face portion 7a, and a toe portion 7f and a heel portion 7g that pass from the face portion 7a to the back portion 7e.

  The head main body 7A is constituted by joining a plurality of outer shell members divided at various positions by welding, adhesion, etc., and each outer shell member is made of, for example, a titanium alloy, an aluminum alloy, magnesium, or the like. An alloy or the like can be integrally formed by casting and press forming, and the head main body 7A is created by welding each edge region (a weld bead provided at the time of welding is indicated by reference numeral 14). In this case, each member (outer shell member) constituting the head main body 7A includes a plurality of members or partial members of each member such as integrating the side portion and the sole portion, or integrating the crown portion and the side portion. The components may be integrally formed by casting or the like, and they may be fixed by welding, adhesion, or the like.

  Further, the face portion 7a is integrally formed by, for example, pressing, CNC processing, or forging of titanium, a titanium alloy, etc. In addition to the above-described welding, for example, laser welding, brazing It is possible to join to other outer shell members by bonding or the like. The face portion 7a of the present embodiment is configured by joining a face member 8 formed in a cup shape to another outer shell member, and the face member 8 constitutes the face portion 7a and a crown. Part, side part, and part of the sole part (see FIG. 7). In addition, about the face surface 7B which comprises the face part 7a, what was comprised in plate shape may be the structure fastened to the opening formed in the face part 7a.

  Further, a hosel portion 10 for fastening the tip of the shaft 3 is integrally formed in the head main body 7A. The hosel portion 10 protrudes upward from the crown portion 7b, and is fixed by fitting the tip end portion of the shaft 3 into the opening hole 10a.

  A hitting surface (face surface) 7B of the face portion 7a is a hitting portion, and is a region surrounded by a top edge 7P, a sole edge 7Q, and a side edge 7R that define the upper and lower sides. That is, as shown in FIG. 6, the face surface 7B has a ridge line between the crown portion 7b, the sole portion 7c and the side portion 7d so that it can be grasped when the head body 7A is viewed from the front. The edge 7P, the sole edge 7Q, and the side edge 7R) can be grasped (if the ridge is curved, it is defined by the curved top). In this case, a score line 7S may be separately formed on the face surface 7B, or the colors may be classified by colors or the like so that the face surface 7B becomes clear. The portions corresponding to the top edge 7P, the sole edge 7Q, and the side edge 7R for grasping the face surface 7B are indicated by dotted lines in FIG. 8, and when the face portion 7a is viewed from the back surface, the dotted lines are shown. The part surrounded by is the face.

  The face portion 7a is formed with, for example, a roll that curves along a crown / sole direction (hereinafter also referred to as an up / down direction) and a toe / heel direction (hereinafter referred to as a left / right direction). ), And a central position C of the face portion 7a specified in accordance with the above-described pendulum test procedure exists in the top region of both curved portions.

  In the present embodiment, when the face surface 7B is viewed from the front in a state where the golf club 1 is held at a specified lie angle with respect to the reference horizontal plane P, the length in the toe-heel direction on the crown side is the toe-heel on the sole side. It has a face part shape that is longer than the length of the direction, and both sides are formed in a shape that narrows toward the sole side (substantially triangular shape that narrows from the both sides on the crown side toward the center on the sole side). Has been.

  The face portion 7a described above is configured such that the CT value changes according to the position where the hit ball is made. Specifically, in the configuration of the present embodiment, the CT value at the center position C of the face portion is set to the maximum value (maximum value conforming to the rule), and the periphery thereof, in particular, to the range of 5 mm on the crown side of the center position C. Without greatly reducing the CT value (decreasing the resilience), further, when the CT value in the range of 5 mm from the center position C to the crown side is used as a reference, the decrease rate of the CT value on the crown side is more than that. The thickness of the face member 8 is changed so as to be larger than the decreasing rate of the CT value on the sole side from the center position C.

Hereinafter, a configuration example of the face portion 7a (face member 8) and a distribution example of CT values in the present embodiment will be specifically described.
First, the relationship between the CT value and the structure of the face portion will be described.
The CT value is a value obtained by installing the head itself in the measuring device, and is a contact time with the face portion when a so-called ball is hit. For this reason, the higher the CT value, the more easily the face portion bends, and the flight distance of the ball can be improved. Usually, the deflection characteristics of the face portion depend on the material, but greatly depend on the thickness and the distance from the edge region of the face portion. That is, by reducing the wall thickness, the face portion itself is easily bent, and the region farthest from the edge region (the central position C of the face portion) is easily bent greatly. Tend to be higher. In addition, for example, by changing the thickness partially, for example, by forming a thin-walled portion, the bending rigidity of the surrounding area is reduced and it becomes easy to bend, so the CT value can be partially improved. is there.

  On the other hand, the CT value is suppressed because the bending amount is small in areas with high rigidity, such as the edge area of the face part (the connection part between the crown part, side part, and sole part, which is the support area around the face part). Is possible. In addition to this, for example, by appropriately arranging ribs on the back surface of the face portion and appropriately forming a thick region, the bending rigidity around the periphery increases and it becomes difficult to bend. It is possible to lower.

  As is clear from the above description, the CT value at the center position is the area farthest from the edge area and can be easily improved, but the upper limit is determined by the rule, so the hitting position In order to obtain the same flight distance (stable flight distance) as when the ball is hit at the center position when the variation occurs, the CT values at the center position are efficiently regulated while the CT values around the center position are controlled. It is important to approximate the value by the CT value at the center position.

  In this case, in the present embodiment, the CT value is set to be higher (within the upper limit value of the rule) in the range of 5 mm from the center position C to the crown side. In order to make the rate of decrease in CT value greater than the rate of decrease in CT value on the sole side from the center position C, for the crown side region farther than 5 mm from the center position C on the crown side, It forms so that it may become difficult to bend rather than a side area | region. That is, it is relatively easy to bend in the center position C and in the range of 5 mm from the center position, but it is relatively difficult to bend from the center position to the sole side in the portion where the hit point is shifted to the crown side. It is formed. Further, in the toe-heel direction including the center position C, it is configured to have a bending characteristic close to that of the center position C so that the resilience does not decrease even if the hit points vary in the toe-heel direction.

  Specifically, while making the entire face portion flexible, a thick portion (rib) that is thicker than the peripheral portion is disposed in the central region, thereby suppressing the bending in the central region to some extent. It is possible not to reduce the bending state of the peripheral region so much. That is, if the structure has no ribs at the face part, the CT value in the central region can be increased, but in the region approaching the edge, the rigidity may increase rapidly and the CT value may decrease extremely. However, by increasing the thickness of the central region and making it somewhat difficult to bend, it is possible to adjust the CT value other than the central region to a state approximate to it or to a high state as the entire face portion.

  In this case, by forming the rib so that the toe-heel direction is longer than the crown-sole direction, the rigidity can be increased from the central region to the toe-heel direction, and the CT of the central region is effective. It is possible to enlarge the CT value close to the regulated CT value in the toe-heel direction while regulating the target. In addition, when the CT value of the center region is regulated by forming extension portions (ribs) extending on the crown side and the sole side on both sides of the ribs that expand in the toe-heel direction, It is possible to effectively regulate the rigidity of the portion where the CT value of the direction is relatively high. In the central region, the CT value close to the central region CT value (restricted CT value) is also applied to the crown side and the sole side. It becomes possible to enlarge.

  In the present embodiment, as described above, it is necessary to make it difficult to bend at a portion shifted from the center position C to the crown side with respect to the range of 5 mm in the crown direction. For example, it is possible to relatively increase the rigidity of the crown side by making the rib toward the crown side thicker, wider, or longer than the rib toward the sole side. is there.

  For this reason, as shown in FIG. 8, a lateral rib 20 including the central position C and extending in the toe-heel direction is formed in the central region of the face portion 7a (face member 8). A crown-side rib 21 and a sole-side rib 22 are formed from both sides (both sides only need to be formed at positions separated in the toe / heel direction) from the crown side and the sole side, respectively. The thick portion formed on the back surface of the face is formed as a substantially H-shaped rib as a whole.

  As described above, by forming the lateral rib 20 extending in the toe-heel direction, the CT value at the center position C is efficiently suppressed, while the suppressed CT value (close to the resilience at the center position). CT value), that is, the high repulsion region can be expanded from the center position of the face portion in the toe-heel direction, and the high repulsion region can be efficiently expanded. Accordingly, even if the hit point of the ball at the time of hitting is deviated from the center position, a flight distance approximate to that when the ball is hit at the center position is obtained, and the average flight distance can be improved and stabilized. In addition, the ribs 21 and 22 are formed on both sides of the lateral rib 20 extending in the toe-heel direction toward the crown side and the sole side, respectively, so that the CT value on the crown side and the sole side in the central region is also large. It is possible to maintain high resilience without lowering, and the high resilience region can be widened.

The ribs 20 to 22 described above do not form a step (perpendicular) with a thin region where the rib on the back surface of the face is not formed, but form an inclined portion 28 that gradually inclines toward the thin portion. It is preferable to keep it.
By forming such an inclined portion 28, it becomes possible to effectively prevent cracks and the like that are likely to occur due to stress concentration, and the resilience and durability can be improved and stabilized. It is possible to prevent a sudden change in value and a sudden change in feel (vibration). In addition, about the width | variety of the inclination part 28, it is preferable to set it as 1 mm or more so that the said effect can be obtained reliably, About the inclination rate of the inclination part 28, although it can set arbitrarily, it is inclined, so that it is near a thin part. By setting the inclination rate so that the angle becomes gentle, stress concentration can be relaxed and the strength of the face can be maintained.

  And, in the rib shape as described above, for example, by configuring as follows, the improvement in the flexibility (maintenance of the flexibility) in the vicinity of the central position is achieved, and the range from the central position to the crown direction 5 mm is achieved. In the region shifted to the crown side, it is more difficult to bend than the region on the sole side from the center position (the decrease rate of the CT value on the crown side is larger than the decrease rate of the CT value on the sole side from the center position). You can do it.

  The ribs 20, 21, and 22 of the present embodiment are formed in a substantially H shape as a whole. However, as shown in FIG. In particular, the area of the rib on the crown side (the area in plan view) may be increased.

  Specifically, the horizontal center line P2 of the lateral rib 20 is shaped so as to be located on the crown side of the horizontal line P1 (the substantially H-shaped rib is shifted to the crown side with respect to the horizontal line P1). Thus, it is possible to make the crown side region relatively difficult to bend. Alternatively, the width of the crown side rib 21 may be wider than the width of the sole side rib 22, and the positions of the toe side end portion PCt and the heel side end portion PCh of the crown side rib 21 are respectively set to the sole side rib 22. By forming the toe side and the heel side to be closer to the toe side and the heel side than the toe side end part PSt and the heel side end part PSh, the bending restriction effect by the crown side rib 21 is enhanced, and the area on the crown side is relatively difficult to bend. It becomes possible to do. Alternatively, by making the crown side rib 21 thicker than the sole side rib 22, the crown side region can be made difficult to bend.

  Further, as shown in FIG. 8, the crown side rib 21 may be extended to the face edge (top edge 7P), and the sole side rib 22 may be terminated on the way to the face edge (sole edge 7Q). If comprised in this way, since a top edge area | region will become difficult to bend compared with a sole edge area | region, it will become possible to make the area | region of a crown side relatively difficult to bend.

  The lateral ribs 20 formed in the central region only need to include the central position C of the face portion 7a. In this embodiment, two ribs toward the crown side at both ends in the toe-heel direction of the lateral ribs 20, A total of four ribs 21 and 22 are formed on the sole side. For this reason, four thin regions S1, S2, S3, and S4 are formed on the crown side, the sole side, the toe side, and the heel side by the ribs 20 to 22 in the face portion. When viewed on the crown side and the sole side, the rib side is formed so that the crown side region S1 <the sole side region S2, thereby making it difficult to bend the crown side region. Further, when the inclination angle θ1 of the crown-side rib 21 with respect to the lateral rib 20 and the inclination angle θ2 of the sole-side rib 22 with respect to the lateral rib 20 are formed, ribs 21 and 22 are formed so that θ1 <θ2, so that the crown side It becomes easy to achieve the region S1 <the region S2 on the sole side. Alternatively, the thickness T1 of the crown-side region S1 may be greater than or equal to the thickness T2 of the sole-side region S2 (T1 ≧ T2).

  In addition, regarding the thickness of the lateral rib 20, the crown side rib 21, and the sole side rib 22, the thin thickness regions S1 to S4 in the face member 8 can effectively suppress the CT value in the central region. The thickness of the thinnest portion may be set to 1.3 to 4 times, preferably 2 to 3 times. The thickness is 3 to 5 mm, preferably 3.5 to 4 times. It should be set within the range of 2 mm.

  In the above-described configuration, if the lateral rib 20 is formed too long in the toe-heel direction, the flexibility of the central region is hindered, and when the striking point varies from the central position C in the toe-heel direction, Since the drop in repulsive force becomes remarkable, when the face width (widest width) W is set, the length (the width w in the toe-heel direction at the center portion) is set to w ≦ (1/3) W. It is preferable to keep it. That is, by forming the lateral rib 20 extending in the toe-heel direction set to the above-described length in the central region including the central position C, it becomes possible to effectively regulate the bending in the central region, In addition, by forming ribs 21 and 22 that are substantially H-shaped on the crown side and the sole side with respect to both ends of such a lateral rib 20, while more effectively regulating the CT value of the central region, It is possible to enlarge the high repulsion region without greatly reducing the CT value in the toe-heel direction.

  The CT value in the central region can be effectively suppressed for the size, height, and thickness of the lateral rib 20, the crown side rib 21, and the sole side rib 22 and the formation positions of the ribs 21 and 22. And in the area | region which shifted | deviated largely from the range of 5 mm of crown directions from the center position, if it can bend more easily than the area | region of the sole side from a center position, it will not specifically limit. That is, the specific configuration of each rib described above can be appropriately modified based on the size of the head (the size of the face portion 7a), the material, the shape and configuration of the outer shell member, and the like.

  Actually, in the case of a golf club having the face portion 7a in which the lateral rib 20, the crown side rib 21, and the sole side rib 22 are formed as shown in FIG. 8, the face having the CT value distribution as shown in the following table is used. It is possible to obtain a structure. The face structure having the CT value distribution shown in the following table is based on the CT value measured at the center position C (the value is within the rule range, and this value is 100%). It shows the distribution of CT values in units of 5 mm in the U), sole (D) direction, and toe (T) and heel (H) directions.

  As described above, the characteristic part of the face structure of the present embodiment is based on the CT value in the range of 5 mm from the center position C to the crown side, and the distribution of CT values on the crown side and from the center position to the sole side. In this embodiment, the above-described rib structure is configured to obtain the maximum CT value (100%) in the range of 5 mm from the center position C to the crown side. Further, on the basis of such a range of 5 mm from the center position C to the crown side, the CT value is set to 98.4%, 90.6%, and 78.3% every 5 mm on the crown side. The distribution is changed, and on the sole side, the CT value is changed to be 99.6%, 97.5%, and 92.6% every 5 mm with reference to the center position C. That is, the reduction rate of the CT value on the crown side is formed so as to be larger than the reduction rate of the CT value on the sole side, and the structure is difficult to bend as it greatly shifts to the crown side.

  For this reason, when the ball is impacted by a downblow type swing, as shown in FIG. 4, the traveling direction of the head 7 (face surface) tends to follow the loft angle, and the ball moves to the crown side. Even if it behaves, since the decrease rate of the CT value on the crown side is large (relatively larger than the decrease rate of the CT value on the sole side from the center position), the rebound (CT value) The ball structure is faster compared to the face structure that maintains high), thereby reducing the energy loss at impact and preventing the initial speed from being lowered and the flight distance from being lowered. . Further, since it is easy to move away from the ball at the time of impact, even if the head changes after impact, the ball is prevented from blowing up, and the flight distance can be improved and stabilized.

  Furthermore, in the present embodiment, by setting the CT value in the range of 5 mm from the center position of the face portion to the crown side to be 100%, a region with a high CT value becomes wide, and even if the hit point position is slightly deviated, In addition to improving flight distance, flight distance can be stabilized. In this case, the CT value at the crown 5 mm position is not necessarily 100%, and the CT value at the center position is the maximum value (100%) and is 100% at the crown 5 mm position. If the values are close to each other, the flying distance can be stabilized even if the hit point position is slightly shifted.

  Alternatively, if the maximum CT value is within the range of the rule, the CT value at the position of 5 mm on the crown side may be set to the maximum value. According to such a rib structure, since a region having a high CT value becomes wide in the vicinity of the center position, it is possible to further stabilize the flight distance even if the hit points are slightly deviated.

  Further, the rib structure of the present embodiment has a crown side more than that when the CT value in the range from the center position of the face part to the toe / heel side is 5 mm and from that range to the crown side is 5 mm. The reduction rate of the CT value is formed to be larger than the reduction rate of the CT value on the sole side in the range of 5 mm from the center position to the toe / heel side.

  Specifically, with reference to the numerical values in the table, the CT values are 99.6% and 99.2% at the toe side and the heel side 5 mm from the center position of the face part. The CT values at the position 5 mm from the position on the crown side are 99.6% and 99.6%, respectively. When the CT value in this range is used as a reference, on the toe side, the CT value on the crown side is 95.9%, 91.4%, and 79.5% every 5 mm. The CT value on the sole side is changed in distribution so as to be 98.8%, 95.5%, and 91.8% every 5 mm. Similarly, on the heel side, the CT value on the crown side is changed in distribution to be 95.9%, 93.0%, 76.2% every 5 mm, and the CT value on the sole side is The distribution is changed so as to be 99.6%, 97.5%, and 91.0% every 5 mm. That is, even in the range of 5 mm from the center position to the toe / heel side, the reduction rate of the CT value on the crown side is larger than the reduction rate of the CT value on the sole side.

  For this reason, according to the configuration of the present embodiment, the same effect as the impact at the center position described above can be obtained even when the downblow swing is impacted at the position where the center position is shaken in the toe-heel direction. It becomes like this.

  In addition, in the rib structure of the present embodiment, a good CT value distribution is obtained from the central position C to the crown / sole direction in a range of 5 mm and a range of 20 mm on the toe side / heel side (90%). Therefore, even if the ball is slightly deviated in the toe / heel direction or crown / sole direction at the time of hitting, a flying distance approximate to that when the ball is hit at the center position is obtained, and the flying distance is stabilized. Can be planned.

  Further, in the structure of the face portion 7a (face member 8) shown in FIG. 8, the rib is formed in a substantially H shape, and the thin-walled regions S1 to S4 are formed on the crown side, the sole side, the toe side, and the heel side. Since it forms, the area | region of the horizontal rib 20, the crown side rib 21, and the sole side rib 22 becomes easy to bend, and it becomes possible to set to a high value, without reducing CT value as the whole face part. .

  Although the embodiment of the present invention has been described above, the present invention is not limited to the face structure as in the above-described embodiment, and various modifications can be made.

  The face structure shown in the above table was based on a range of 5 mm from the center position to the crown side, but with the center position as a reference, the decrease rate of the CT value from the center to the crown side, The configuration may be such that the rate of decrease is larger than that of the value, and a range larger than 5 mm or a smaller range may be used as a reference. Further, the face structure shown in the table measured the CT value every 5 mm to identify the reduction rate, but the measurement position (measurement position for specifying the CT value reduction rate) is, for example, the center position. Can be modified as appropriate, for example, every 4 mm or every 6 mm. Further, the shape of the thick part (rib) shown in the figure is merely an example, and if the CT value distribution as described above is obtained, the configuration and arrangement of the thick part formed in the face part The position can be appropriately changed. Further, the above CT value may be changed by integrally forming an additional structure such as a groove, a recess, or a protrusion on the back surface of the face portion.

DESCRIPTION OF SYMBOLS 1 Golf club 3 Shaft 7 Head 7A Head main body 7B Face surface 7a Face part 7b Crown part 8 Face member 20 Lateral rib 21 Crown side rib 22 Sole side rib C Center position

Claims (7)

A golf club head having a hollow metal head body having a face portion, a crown portion, a sole portion, and a side portion,
The face portion is configured to have a thick portion thicker than the peripheral portion on the back surface, top and bottom face thereof as the ball striking face is defined by the top edge and the sole edge,
The thick portion is formed such that the reduction rate of the CT value on the crown side relative to the central position of the face portion is larger than the reduction rate of the CT value on the sole side from the central position ,
The thick portion includes a lateral rib including the center position and extending in a toe-heel direction, a crown side rib extending to the crown side at each end side of the lateral rib, and a both end side of the lateral rib. Each having a sole side rib extending to the sole side,
The golf club head according to claim 1, wherein the crown side rib extends to the top edge, and the sole side rib terminates on the way to the sole edge . 2. The golf club head according to claim 1, wherein an area of the rib on the crown side is generally increased with respect to a horizontal line along a toe-heel direction including the center position. When the thick portion is based on the CT value in the range of 5 mm from the center position of the face portion to the crown side, the decrease rate of the CT value on the crown side from the center position is the CT value on the sole side from the center position. The golf club head according to claim 1 , wherein the golf club head is formed so as to be larger than a decreasing rate. The golf club head according to claim 3 , wherein the thick portion is formed so that a CT value becomes a maximum value at the center position. 4. The golf club head according to claim 3 , wherein the thick portion is formed so that a CT value becomes a maximum value at a position of 5 mm on the crown side from the center position. 5. The thick wall portion has a CT value on the crown side that is a range from the center position of the face portion to the toe / heel side of 5 mm and a CT value in the range of 5 mm from the range to the crown side. 6. The method according to claim 3 , wherein the reduction rate is formed to be larger than the reduction rate of the CT value on the sole side in a range of 5 mm from the center position to the toe / heel side. The described golf club head. A golf club in which a hollow metal head body having a face portion, a crown portion, a sole portion, and a side portion is fixed to the tip of a shaft,
The face portion is configured to have a thick portion thicker than the peripheral portion on the back surface, top and bottom face thereof as the ball striking face is defined by the top edge and the sole edge,
The thick portion is formed such that the reduction rate of the CT value on the crown side relative to the central position of the face portion is larger than the reduction rate of the CT value on the sole side from the central position ,
The thick portion includes a lateral rib including the center position and extending in a toe-heel direction, a crown side rib extending to the crown side at each end side of the lateral rib, and a both end side of the lateral rib. Each having a sole side rib extending to the sole side,
The golf club according to claim 1, wherein the crown side rib extends to the top edge, and the sole side rib terminates on the way to the sole edge .

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