Source: https://patents.google.com/patent/JP2008022987A/en
Timestamp: 2020-01-27 22:18:44
Document Index: 216400926

Matched Legal Cases: ['art 7', 'art 7', 'art 7', 'art 7', 'art 7', 'art 8']

JP2008022987A - Golf club - Google Patents
JP2008022987A
JP2008022987A JP2006197222A JP2006197222A JP2008022987A JP 2008022987 A JP2008022987 A JP 2008022987A JP 2006197222 A JP2006197222 A JP 2006197222A JP 2006197222 A JP2006197222 A JP 2006197222A JP 2008022987 A JP2008022987 A JP 2008022987A
JP2006197222A
2006-07-19 Application filed by Daiwa Seiko Inc, ダイワ精工株式会社 filed Critical Daiwa Seiko Inc
2007-07-18 Priority claimed from US11/879,518 external-priority patent/US7775906B2/en
2008-02-07 Publication of JP2008022987A publication Critical patent/JP2008022987A/en
<P>PROBLEM TO BE SOLVED: To make it easy to match an image when hitting a ball and an actual carry of a hit ball and to improve the carry. <P>SOLUTION: The golf club has a head 7 in a hollow structure, which is provided with a face part 7a for hitting a ball, which has volume of ≥380 cc, whose inertia moment in a vertical direction is ≥2,200 g cm<SP>2</SP>and in which the height H of the face part 7a is ≥48 mm. Then, the head 7 has the face part provided with an area satisfying the condition of CTu/CTc≤0.75 in the range of the lower side 12 mm from the center position of the face part 7a when the CT value of the center position (FC) of the face part is defined as CTc and the CT value on the lower side of the center position of the face part is defined as CTu. <P>COPYRIGHT: (C)2008,JPO&INPIT
Conventionally, golf clubs equipped with a hollow head have been devised in various ways to improve the flight distance, and one of them is to improve the flight distance by flexing the face part when hitting a ball. It is known to do. That is, when the ball is hit, the face portion is bent, so that the ball is prevented from being crushed at the time of hitting. As a result, the energy loss due to the ball deformation can be reduced and the flight distance can be improved.
For this reason, recently, a new numerical value (hereinafter referred to as CT value) called characteristic time has been used as an index for measuring the characteristics of the face portion of the head. This CT value is a value measured in accordance with the USGA (American Golf Association) pendulum test, and the outline is obtained by using, for example, the center of the face portion using a measuring device as disclosed in Patent Document 1. The test piece is allowed to collide with and the contact time is measured to evaluate the flexibility of the face portion. As the CT value increases, the face portion is easily bent, and the flight distance can be improved for the reason described above.
As a golf club focused on such a CT value, for example, one disclosed in Patent Document 2 is known. This patent document 2 discloses that the maximum repulsion point (the point having the highest CT value) of the head is shifted from the center of the face portion which is the head striking surface in order to obtain a golf club suitable for a swing form for each golfer. Has been. In particular, for golfers who are “easy to top”, the head is designed so that the maximum repulsion point is below the center of the face portion, thereby improving the flight distance.
In addition, recent head structures are becoming larger in order to increase the moment of inertia in order to stabilize directionality, and deviate from the center of the face where the maximum flight distance can be obtained. Even if a ball is hit at a different position, it is designed so that a certain distance can be obtained.
Japanese Patent Application Laid-Open No. 2004-249086 JP 2004-267438 A
As described above, increasing the size of the head increases the tendency that the velocity component differs depending on the hit ball position. In other words, considering the swing fulcrum (grip position) as the center, the velocity component on the lower side (sole side), which is inevitably far from the swing fulcrum, becomes faster in the vertical direction (crown / sole direction) of the head. End up.
Considering the shape of the face surface of a recent large-sized head, a roll is formed in a cross-sectional side view, and the upper side (crown side) has an oblique collision with the ball, and the lower side (sole side). Since the head collides with the ball, the lower side becomes better considering the collision efficiency. Specifically, the loft angle of the head is defined by an angle between a tangent line at the center position of the face portion and a perpendicular line perpendicular to the reference horizontal plane, but is lower than the center position of the face portion by the roll described above. On the side, the loft angle decreases, and on the upper side, the loft angle increases. In other words, the sole side having a smaller loft angle has a higher tendency to collide frontward against the ball, and in terms of collision efficiency, the resilience is considered to be improved.
Therefore, it is considered that the initial velocity of the ball hit at the lower side of the face portion is increased in combination with the difference in the velocity component in the vertical direction of the head described above (the velocity component on the sole side becomes higher).
By the way, when hitting with a golf club, the golfer can sensuously grasp the distance of the ball by the ball speed immediately after hitting. For example, although it is difficult to determine an actual flight distance at a practice field, a golf course launch, or a downhill, it is possible to determine the flight distance to some extent based on the initial ball velocity at the time of hitting. For this reason, as described above, when the initial velocity of the ball hit at the lower side of the face portion increases, the golfer has an illusion that the ball is a hitting point as a hitting point at which the maximum flight distance by the club can be obtained. It becomes a trend.
However, as described above, in the recent large-sized head shape, the center portion of the face portion has a structure in which the maximum flight distance of the club can be easily obtained. The hitting ball slightly above the center of the part has a structure in which the maximum flight distance can be easily obtained. For this reason, for golfers who have the illusion that the ball hits as the optimum hitting point from the initial velocity of the ball, the club does not take full advantage of the club's performance, and the club does not fly away. And the flight distance cannot be improved.
Further, as disclosed in Patent Document 2 described above, it is considered possible to increase the speed at the time of hitting the ball by designing the head so that the maximum repulsion point is located below the center of the face portion. However, when the head shape is taken into consideration, there is a limit to the improvement of the flight distance with the hit ball below the center of the face portion. In other words, hitting the ball below the center of the face portion is caused by backspin due to a reduction in the launch angle due to the roll shape of the face surface and a gear effect caused by the vertical movement of the head around the center of gravity at the time of hitting. The amount becomes too large, and considering the total, there is a limit to the improvement of the flight distance.
The present invention has been made based on the above-described problems, and it is an object of the present invention to provide a golf club capable of improving the flight distance by making it easy to match the image when the ball is hit with the actual ball hit distance. To do.
The present inventor found that the head structure has a large size problem. That is, when the ball is hit below the center position of the face portion, the collision efficiency is improved by the roll shape of the face portion, and the inertia in the vertical direction is increased. Due to reasons such as improved moments, the initial velocity at the time of hitting is high, which led to the idea of the present invention focusing on the unique problem of giving the golfer the illusion that the ball was hit with a core. It is.
By the way, as introduced in the prior art described above, the CT value in the face portion can be changed for each part depending on the face structure based on, for example, the thickness, material, and the like. In general, increasing the CT value is considered to increase the speed of the ball because the contact time between the ball and the face becomes longer at the time of hitting and the collapse of the ball can be suppressed. There is a causal relationship between the two in which the higher the CT value, the higher the velocity of the ball.
However, conversely, if the CT value becomes too high, it takes a longer time for the face portion to bend and return to the original time than the time for the ball to collapse and return, and the ball speed is considered to decrease. Actually, although it depends on the material of the ball, the CT value is estimated to increase the ball speed by increasing the CT value up to about 400 × 10 −6 (seconds). Considering general materials used for the face portion, it is not realistic to increase the CT value to about 400 × 10 −6 (seconds). Therefore, if considering the material used for the conventional face portion, the CT value It is thought that the initial speed of the ball will be improved by increasing.
In the conventional large-sized head structure, not only is the face center position increased with respect to the CT value, but also the CT value around the face center position is increased as disclosed in Patent Document 2 described above. The ball speed was designed not to decrease even when the center position was removed. However, with such a head structure, the ball speed does not decrease even if the ball is hit on the sole side. It happens.
Accordingly, in order to achieve the above-described object, the golf club according to the present invention includes a face portion for hitting a ball, a volume of 380 cc or more, a vertical moment of inertia of 2200 g · cm 2 or more, and a height of the face portion. The head has a hollow structure with a diameter of 48 mm or more. When the CT value at the center position of the face portion is CTc and the CT value below the center position of the face portion is CTu, the head portion And a face portion having a region satisfying the condition of CTu / CTc ≦ 0.75 within a range of 12 mm below the center position.
According to the golf club having the head structure described above, the CT value (CTu) below the CT value (CTc) at the center position of the face portion is set to be lower at a predetermined ratio. Accordingly, the speed when hitting the ball below the center position of the face portion is suppressed, and the golfer is prevented from making the mistake that the core is located below the center position of the face portion. That is, the image when the ball is hit and the actual hitting distance tend to coincide with each other, and the golfer does not cause a misunderstanding that “the club does not fly”.
In the above-described head having a hollow structure, the “CT value” is a value measured in accordance with a pendulum test of USGA (American Golf Association). As for the size of the head, the above-mentioned specific problems caused by the increase in size tend to become conspicuous when the volume is 380 cc or more and the vertical moment of inertia is 2200 g · cm 2 or more. Therefore, the present invention is intended for such a head.
Further, the height of the face portion is based on the fact that when the ball hitting mark size at present is a head speed of 40 m / s, the soft system has a diameter of about 24 mm and the hard system has a diameter of about 21 mm. In other words, in the case of a normal golfer, considering that the hit ball mark is about 24 mm at the maximum, an illusion that “the ball was caught by the core” even if the ball is deviated by half the ball up and down from the center position of the face portion. Targeted for the head. Specifically, when the height of the face portion is less than 48 mm, if the ball is deviated from the center position of the face portion by half a ball, the spin amount becomes abnormal due to the influence of the boundary of the crown portion or the sole portion. Therefore, the height of the face portion is 48 mm or more. The loft angle corresponds to a range in which the problem of the collision efficiency due to the roll shape becomes apparent, specifically about 7 ° to 15 °.
In the above configuration, the condition of CTu / CTc ≦ 0.75 is that the volume is 380 cc or more, the vertical moment of inertia is 2200 g · cm 2 or more, and the height of the face part is 48 mm or more. In this head, when the ball speed when hit at the center position of the face portion is 100%, the ball speed when hit at the lower side is almost certainly less than 100%. .
In the head structure as described above, further, a region satisfying the condition of CTt / CTc ≧ 1.04 in the range of 12 mm on the upper side from the center position of the face portion when CT value on the upper center position of the face portion is CTt. It is preferable to provide.
That is, when a ball is hit on the upper side from the center position of the face portion, the loft angle is increased due to the influence of the roll, so the collision efficiency with the ball usually decreases, and the ball speed tends to decrease accordingly. . For this reason, by increasing the CT value of the area above the center position of the face portion above the CT value of the center position, it is possible to suppress the speed reduction of the upper hit ball and improve the flight distance.
According to the present invention, it becomes easy for the hitting image and the actual hitting distance of the hit ball to coincide with each other, so that the golfer hits at the portion where the best hitting image can be obtained, thereby improving the flying distance. The golf club which can plan can be obtained.
1 to 4 are views showing a golf club according to a first embodiment of the present invention. FIG. 1 is a front view of the golf club, FIG. 2 is a front view of the head, and FIG. FIG. 4 is a cross-sectional view taken along line A, and FIG. 4 is a cross-sectional view taken along line BB in FIG.
In the golf club 1 according to the present embodiment, a head 7 set to a specified lie angle α and loft angle β with respect to a reference horizontal plane P is fixed to the tip of a shaft 5 made of metal or FRP. It is configured. In this case, the head body 7A constituting the head 7 includes a face portion 7a having a hitting surface, a crown portion 7b extending rearward from the upper edge of the face portion 7a, and extending rearward from the lower edge of the face portion 7a. And a sole portion 7c that extends from the toe side edge of the face portion to the heel side edge of the face portion, and connects the edge portions of the crown portion 7b and the sole portion 7c. It is formed in the hollow structure provided with the side part 7d. In the drawings, the toe portion, the back portion, and the heel portion constituting such a side portion 7d are indicated by reference numerals 7e, 7f, and 7g, respectively.
As described above, in the present invention, when the CT value at the center position (FC) of the face portion 7a is CTc and the CT value below the center position (FC) of the face portion 7a is CTu, the center position of the face portion 7a. In the range of 12 mm below (FC), the region satisfying the condition of CTu / CTc ≦ 0.75 is provided. That is, such a condition can be realized, for example, by configuring the lower region of the center position of the face portion 7a to be less bent than the center position. In this embodiment, as will be described later. By providing a rib 10 having a predetermined shape on the sole side on the back side of the face portion 7a, the lower specific strength and specific rigidity of the face portion 7a are improved, the lower region is difficult to bend, and the upper region is partially It is configured to be deformable.
By such a structure of the face portion 7a, the entire face portion is not bent at the time of hitting the ball, and the lower region is difficult to be bent, and the lower CT value of the face portion 7a is compared with the center position (FC). Therefore, it is possible to satisfy the above condition of CTu / CTc ≦ 0.75.
Hereinafter, a specific configuration will be described.
A face member 8 on which a hit ball is actually formed is provided on the face portion 7a. The face member 8 is formed in a cup shape as will be described later, and constitutes a part of the front side of the crown portion 7b and the side portion 7d.
The head main body 7A is, for example, a titanium alloy (Ti-6Al-4V, Ti-15V-3Cr-3Sn-3Al), an aluminum alloy, a magnesium alloy, or the like other than the face member 8 provided on the face portion 7a. The face member 8 formed in a cup shape constituting the striking surface of the face portion 7a is preferably fixed to the front surface side by welding, brazing, bonding or the like. Is formed. 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 head main body 7A is integrally formed with a part of the face portion 7a, specifically, about 1/3 of the lower side of the face portion upward from the sole portion 7c. That is, the front end portion of the sole portion 7c of the head main body 7A is bent upward to form approximately one third of the lower side of the face portion, and the upper end thereof is further bent toward the center of the head main body. , Horizontal ribs (lateral ribs) 10a, which are part of the ribs 10 that constitute a means for lowering the CT value compared to the center position of the face portion, are formed.
At the tip of the inner extending portion of the horizontal rib 10a, a protrusion 10d serving as a joint is formed to protrude upward. The position where the protrusion 10d is formed is set so as to be flush with the front side opening of the crown portion 7b and the side portion 7d of the head main body 7A, whereby the face member 8 is attached. An opening 7B is formed. For this reason, the face member 8 is formed in a so-called cup shape, and is fixed so that the bent end surface is in contact with the opening 7B as a bonding surface.
The face member 8 provided on the face portion 7a is, for example, a titanium alloy (Ti-15V-3Cr-3Sn-3Al, Ti-6Al-4V, SP700, Ti-15V-6Cr-4Al, Ti-15Mo-5Zr-3Al). , Ti-30Nb-10Ta-5Zr, etc. are preferably integrally formed by pressing or forging so as to have a predetermined cup shape, and the face member 8 thus formed has an opening 7B. The face portion 7a is not fixed to the face member 8 which is a separate member, but is integrated with the head main body 7A. It may be formed, or a rib may be formed on the back surface of a separate face member 8 constituting the entire face portion.
A shaft fastening portion 12 for fastening the tip of the shaft 5 is integrally formed in the head main body 7A. In this case, the shaft 5 is fixed to the shaft fixing portion 12 by inserting the tip end portion of the shaft through an opening hole formed in the crown portion 7b.
In the lower region of the face portion described above, the rib 10 as a means for lowering the CT value further includes a plurality of vertical ribs (vertical ribs) 10b on the back surface of the face portion 7a below the horizontal rib 10a. Yes. The vertical ribs 10b are integrally formed with the head main body 7A constituting a part of the face portion, and are formed at three positions with a predetermined interval so as to be integrated with the horizontal rib 10a. Also, as shown in FIG. 4, by joining the shaft fastening portion 12 and the horizontal rib 10a (integral molding is preferable), the height, width and number of ribs can be reduced, and the weight can be reduced. It becomes possible.
Such ribs 10 (horizontal ribs 10a and vertical ribs 10b) are members that protrude from the inner surface of the face portion 7a toward the center of the head, and are in a specific region (lower region) of the face portion having a ball striking surface. It has a function of improving specific rigidity and specific strength. In this case, if the protrusion amount (rib height) with respect to the inner surface of the rib 10 becomes too large, the weight increase becomes too large and the degree of freedom of design decreases, and if the protrusion amount becomes too small, the specific rigidity, ratio Since the strength cannot be sufficiently improved, it is preferable that the protrusion amount (the height h1 of the rib 10a and the height h2 of the rib 10b) with respect to the inner surface is set in the range of 1.0 mm to 13.0 mm. . Further, the width (thickness) is preferably set in the range of 1.0 mm to 5.0 mm for the same reason. Further, as for the relationship between the rib cross-sectional areas of the horizontal rib 10a and the vertical rib 10b, it is more preferable to make the cross-sectional area of the horizontal rib larger than the cross-sectional area of the vertical rib in order to achieve the intended CT value relationship. That is, this makes it possible to efficiently adjust the CT value in the vertical direction.
Further, the thickness of the face member 8 described above is determined by the relationship with the CT value of the region where the rib 10 is formed. However, if the whole becomes too thick, the increase in weight becomes too large. Since the degree of freedom becomes small, it is preferable to set the distance in the range of 1.1 mm to 3.2 mm. In the present embodiment, the cup-type face member 8 has a relatively thick wall t1 in its center region so that the CT value at the center position (FC) of the face portion 7a is high, and its upper end region. The thickness t2 and the thickness t3 in the lower end region, and the thickness t4 of the region integrated with the crown portion are thinner than the thickness t1, so that the central region is easily bent. Particularly preferable ranges are t1 of 2.2 to 2.8 mm, t2 of 1.8 to 2.5 mm, t3 of 1.8 to 2.5 mm, and t4 of 1.1 to 2.0 mm, respectively.
The position where the rib 10 which is a means for lowering the CT value as described above is provided is set below the center position (FC) of the face portion 7a. In this case, it is preferable to provide the horizontal rib 10a in a range above the intermediate height between the center position (FC) of the face portion and the point P4. Thereby, it can reinforce widely under a face part, and can adjust CT value efficiently.
Here, the definition of the center position (FC) of the face part and the definition of the height H of the face part will be described.
The center position (FC) of the face portion 7a takes an intermediate perpendicular line of the maximum width L (heel side face boundary point P1, toe side face boundary point P2) in the toe-heel direction constituting the hitting surface, and on the intermediate normal line It is defined by the midpoint (center) between the crown side face boundary point P3 and the sole side face boundary point P4. The face boundary points P1 to P4 are usually defined by changes in the edge portion and finish (satin finish, mirror finish, blast finish, paint finish, etc.), but an R curved surface that cannot be determined by such criteria. In the state where the head is viewed from the front, a horizontal line is drawn to a part considered to be the widest among the parts constituting the ball striking face, and the heel side and the toe side on the horizontal line. The position smaller than R30 is determined and boundary points P1 and P2 are specified respectively. Then, the specified boundary points P1 and P2 are set to the maximum width L, and an intermediate perpendicular line of the boundary points P1 and P2 is drawn, and on the intermediate perpendicular line, a position smaller than R10 is determined on the crown side and the sole side. Points P3 and P4 are specified. The intermediate point between the boundary points P3 and P4 on the intermediate perpendicular is the center position (FC) of the face portion 7a.
The center position (FC) of the face portion 7a specified as described above is such that the intersection angle between the tangent line L1 at that position and the perpendicular to the reference horizontal plane P is the loft angle β, and the center position (FC) on the straight line parallel to the tangent line L1. The distance between the boundary points P3 and P4 is the height H of the face portion.
As described above, by forming the rib 10 on the sole side of the back surface of the face portion, the CT value on the lower side from the center position (FC) of the face portion 7a can be effectively reduced, and the center position of the face portion can be reduced. In the range of 12 mm on the lower side, the condition of CTu / CTc ≦ 0.75 can be satisfied. Specifically, the test results obtained by a golf club equipped with a head having the rib 10 as described above formed on the back surface of the face portion 7a will be described.
Table 1 below shows the thickness t1 to t4 of each face portion and the height of the rib 10 (the height h1 of the horizontal rib and the height of the vertical rib in the head structure shown in FIGS. By changing h2), the CT value in the vertical direction of the center position (FC) of the face portion 7a is set differently for each head. In Table 1, the CT value of each head was measured at the center position (FC) of the face portion 7a, and at the 6 mm and 12 mm positions in the vertical direction. Further, the hitting velocity was calculated as a ratio (percentage) with respect to the hitting velocity at the center position, where the hitting velocity at the center position (FC) was 100%.
Each head has a volume of 380 cc, a vertical moment of inertia of 2200 g · cm 2, and a face height H of 48 mm. The same structure is installed at the head speed of 40 m / s with the same structure. Ball was hit with a trial hitting robot.
The CT value at the center position (FC) of the face portion is CTc, the CT value at the lower position is CTu, and the CT value at the upper position is CTt, respectively, at positions 6 mm and 12 mm above and below the center position (FC). CTu / CTc and CTt / CTc were measured.
As seen in the trial hit test described above, the golf club of the conventional example has a speed of 100.8% when hit at a position 6 mm below the center position (FC), and 100.0 when hit at a position 12 mm below. %, And even when compared with hitting the ball at the center position, no speed reduction is observed. For this reason, when an actual golfer hits the ball, even if the ball is hit at such a position (a position where the core is removed), the speed equal to or higher than that hit at the center position is obtained. I hit the ball with the illusion.
However, in reality, hitting a ball at such a position results in a low launch angle and a large backspin amount due to the gear effect, and a flight distance as expected cannot be obtained.
On the other hand, in the structure of the face portion, the CT value on the lower side from the center position (FC) is lower than that of the conventional example, and as shown in Examples 1 to 4, a region where CTu / CTc ≦ 0.75 is satisfied. As a result, it is possible to make the speed when hitting the ball lower than the center position (FC) less than 100%. That is, when an actual golfer hits the ball, hitting the ball at such a position (a position where the core is removed) decreases compared with the hitting speed at the center position. Moreover, since the launch angle is low, the backspin amount is increased, and the flight distance is reduced as described above, the image when the ball is hit and the actual ball hit distance match. Thus, it is possible to clearly detect that the ball has been hit with the core removed.
By the way, as described above, it is possible to reduce the ball speed by setting the CT value low, but if it is set too low (the value of CTu / CTc is set too low). ) When the ball is hit with the core removed (the ball is hit on the lower side), the flight distance is excessively lowered, and the characteristics as a so-called large head are reduced, which is not preferable. That is, as one of the characteristics required by a general golfer for a large-sized head, it is possible to obtain a certain flight distance even if a ball is slightly removed and hit. Specifically, when the hitting speed becomes less than 95%, it is considered that such characteristics cannot be enjoyed (see Example 4 and Comparative Example 1), and the above-mentioned CTu / CTc value is 0. .48 ≦ CTu / CTc is preferably set.
On the other hand, when ball hitting from the center position (FC) is taken into consideration, ballistic efficiency (spin amount, launching distance efficiency of launch angle) is good, so the hitting speed is increased by increasing the CT value (increasing CTt / CTc). However, if the hitting speed is increased too much and exceeds 100% in comparison with the center position (see Comparative Example 1), conversely, the golfer tends to be unable to grasp the center position. turn into. For this reason, the hitting speed on the upper side from the center position (FC) is preferably set to be close to 100%, and more preferably set to a range not exceeding 100%. Specifically, an area satisfying the condition of CTt / CTc ≧ 1.04 is provided in a range of 12 mm on the upper side from the center position of the face portion, where CT value on the upper center position of the face portion is CTt. Is preferable (see Example 3), and it is further preferable that a region satisfying the condition of CTt / CTc ≦ 1.25 is provided (see Example 4).
According to the golf club having the above characteristics in the face portion of the head, when the ball is hit with the center position (FC) of the face portion removed, an image obtained from the ball speed at the time of hitting and the actual The golfer's hit distance will tend to match, so the golfer will try to hit the part where the best hitting image can be obtained (the center area of the face part, which is the part where the flying distance can be obtained most), As a result, the flight distance can be improved.
As described above, the present invention is characterized in that the CT value at the center position (FC) of the face portion of the head and the vertical position thereof is designed to have a predetermined ratio, and the CT value is increased. The specific means for lowering the height can be modified as appropriate. Specifically, for example, in a structure in which a rib is formed on the back surface of the face portion, the ratio condition regarding the CT value described above is satisfied by changing the shape, height, thickness, and formation position of the rib. In addition, it is possible to further improve the characteristics as a large head by changing the rib forming method.
For example, in the rib 20 shown in FIG. 5A, when the one horizontal rib 20a and the four vertical ribs 20b are provided, the horizontal rib 20a is moved from the toe side to the heel side so that the hitting surface on the toe side becomes wider. It is formed to rise toward According to the rib having such a shape, when a miss hit occurs on the toe side, the trajectory can be stabilized without increasing the launch angle. The lateral rib 20a may be formed so as to gradually rise while being bent, as shown in FIG. 5 (d).
Further, the rib 30 shown in FIG. 5 (b) has the lateral rib 30a in the central region so that the hitting surfaces on the toe side and the heel side are wide when providing one lateral rib 30a and three longitudinal ribs 30b. Is formed in a curved shape protruding. According to the rib of such a shape, when a miss-hit occurs on the toe / heel side, the trajectory can be stabilized without increasing the launch angle by utilizing the deflection of the face. Further, since the CT value on the toe / heel side can be kept high, there is a merit that the decrease in the flight distance at the time of a miss shot on the toe / heel side is small.
Moreover, about the structure which provides multiple vertical ribs, each vertical rib does not need to be formed in parallel. For example, as shown in FIG. 5C, a plurality of vertical ribs 40b are inclined to each other and connected to the horizontal rib 40a to form the rib 40, or as shown in FIG. The rib 50 may be configured such that the rib 50b is zigzag with respect to the lateral rib 50a. Alternatively, as in the rib 60 shown in FIG. 5 (f), a large number of horizontal ribs and vertical ribs are formed so as to form a lattice pattern below one horizontal rib 60a extending in the horizontal direction. May be formed. In this case, the shape of the recess formed by the lattice may be a circle, an ellipse or the like in addition to the polygonal shape shown in the figure.
As described above, by changing the shape of the rib, it is possible to appropriately change the specific strength and specific rigidity of the region below the face portion 7a. Then, it is possible to adjust the hit feeling when hit under the face.
Alternatively, in addition to forming the ribs described above, the thickness and material of the face portion may be changed, or the structure other than the face portion, for example, the configuration (thickness, material, etc.) of the crown portion and the sole portion may be changed. Therefore, it is possible to design so as to satisfy the above-described ratio condition.
BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows 1st Embodiment of the golf club which concerns on this invention, and is a front view of a golf club. The front view of a head. Sectional drawing along the AA line of FIG. Sectional drawing along the BB line of FIG. (A)-(f) is a figure which shows the modification of the shape of a rib.
DESCRIPTION OF SYMBOLS 1 Golf club 5 Shaft 7 Head 7A Head main body 7a Face part 7b Crown part 8 Face member 10, 20, 30, 40, 50, 60 Rib G Center of gravity P Reference horizontal plane
A golf club having a hollow head having a face portion for hitting a ball, having a volume of 380 cc or more, a vertical moment of inertia of 2200 g · cm 2 or more, and a face portion height of 48 mm or more,
When the CT value at the center position of the face portion is CTc and the CT value below the center position of the face portion is CTu, the head has CTu / CTc ≦≦ 12 mm from the center position of the face portion. A golf club having a face portion having a region satisfying a condition of 0.75.
When the CT value above the center position of the face portion is CTt, in the range of 12 mm above the center position of the face portion,
The golf club according to claim 1, further comprising a region that satisfies a condition of CTt / CTc ≧ 1.04.
JP2006197222A 2006-07-19 2006-07-19 Golf club Pending JP2008022987A (en)
US11/879,518 US7775906B2 (en) 2006-07-19 2007-07-18 Golf club
JP2008022987A true JP2008022987A (en) 2008-02-07
ID=39114252
JP2006197222A Pending JP2008022987A (en) 2006-07-19 2006-07-19 Golf club
JP (1) JP2008022987A (en)
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