JP4340177B2 - Golf club head - Google Patents

Description

The present invention relates to a golf club head that is useful for increasing a ball launch angle and decreasing a backspin amount to increase a flight distance.

  Conventionally, various developments of golf club heads aimed at improving the flight distance of the hit ball have been made. Currently, in order to fly a hit ball further, it is considered effective to first increase the initial velocity of the ball launched from the face surface, and secondly to increase the ball launch angle and reduce the backspin amount. ing. In the latter case, it is assumed that the backspin amount of the hit ball is large as a cause of the flight distance not being extended, and as a result, the ball is raised too high.

  In order to increase the initial velocity of the ball launched from the face surface (in other words, increase the coefficient of restitution of the head), it is effective to reduce the vertical rigidity, which is the rigidity in the direction perpendicular to the face surface of the face portion. When the vertical rigidity of the face portion decreases, the frequency indicating the first-order minimum value in the frequency transfer function of the head approximates that of the ball, and as a result, the kinetic energy of the head is efficiently transmitted to the ball. This is known as impedance matching theory, and is described in detail, for example, in Patent Document 1 below.

  In order to reduce the vertical rigidity of the face portion, attempts have been made to reduce the thickness of the face portion within a range that does not impair the strength, and to use a material having a low elastic modulus for the face portion. However, these improvement methods are almost reaching their limits at the current technical level.

  In order to increase the ball launch angle and reduce the backspin amount, it is generally considered effective to lower the center of gravity of the head. In the head having a low center of gravity, the sweet spot is located below the face surface. In other words, the area above the sweet spot on the face surface becomes wider. For this reason, the golfer can easily hit the ball on the upper side of the sweet spot on the face surface. As a result, the vertical gear effect acts on the ball to increase the launch angle and reduce the backspin amount.

JP-A-4-56630

However, golfers' demands for improving flight distance are never exhausted, and further improvements are desired. The present invention has been devised in view of such circumstances, and at least a part of the face surface is parallel to the face surface and has a rigidity in the crown-sole direction rather than a vertical rigidity that is a rigidity in the direction perpendicular to the face surface. An object of the present invention is to provide a golf club head capable of improving the flight distance of a hit ball by a method different from the conventional one, on the basis of providing a hit portion having a reduced shear stiffness with a low vertical shear stiffness.

The invention according to claim 1 of the present invention is a golf club head comprising a face portion formed only of a metal material that hits a ball, wherein at least a part of the face portion is perpendicular to the face surface. It is characterized in that there is provided a shear rigidity lowering portion which is smaller in vertical shear rigidity, which is parallel to the face surface and in the crown-sole direction, than the vertical rigidity which is rigidity.

The invention according to claim 2 is a golf club head having a face portion for hitting a ball, wherein the face portion is provided with a striking plate whose front surface constitutes at least a part of the face surface, and The striking plate includes a crown portion, a sole portion, a side portion that connects between the crown portion and the sole portion, and a face base portion that is integral with the front edges of the crown portion, the sole portion, and the side portion. The face base of the main body is supported so as to be displaceable in the crown-sole direction via a joint member , and the joint member extends between the striking plate and the face base in the toe-heel direction and the crown-sole. It includes a plurality of rib-like bodies made of a metal material and spaced apart in the direction .

  According to a third aspect of the present invention, in the golf club head according to the second aspect, the striking plate is supported in a non-contact manner with the face base portion.

  According to a fourth aspect of the present invention, the face base includes a recess recessed inward of the head and an edge provided around the recess, and the striking plate has its front face on the front of the edge. The golf club head according to claim 2, wherein the golf club head is arranged in the concave portion.

According to a fifth aspect of the present invention, in the golf club head according to any one of the second to fourth aspects, the striking surface substantially forms the entire area of the face surface .

The invention according to claim 6 is a golf club head having a face portion for hitting a ball, wherein the face portion is provided with a striking plate whose front surface constitutes at least a part of the face surface, and The striking plate includes a crown portion, a sole portion, a side portion that connects between the crown portion and the sole portion, and a face base portion that is integral with the front edges of the crown portion, the sole portion, and the side portion. A plurality of joint members are supported on the face base portion of the main body so as to be displaceable in a crown-sole direction via a joint member, and the joint member has an outer diameter substantially equal to a gap between the striking plate and the face base portion. And a holding body made of an elastic material that fills the gap and connects the plurality of spheres .

  In the present invention, at least a part of the face surface has a lower vertical shear stiffness that is parallel to the face surface and that is in the crown-sole direction than the vertical stiffness that is perpendicular to the face surface. A lowering portion is provided. Such a reduced shear rigidity portion can be greatly bent in the vertical shear direction as compared with the vertical deflection at the time of hitting the ball. Such an action reduces the backspin amount of the ball. Therefore, the hitting of the hit ball is prevented and the flight distance is extended.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is an overall perspective view of a reference state in which a golf club head 1 of the present embodiment is held on a horizontal plane while maintaining a specified lie angle and loft angle (real loft angle), FIG. 2 is a longitudinal sectional view thereof, and FIG. FIG. 2 is a partially enlarged view of FIG.

  A golf club head (hereinafter sometimes simply referred to as “head”) 1 of the present embodiment has a face portion 3 having a face surface 2 that is a surface for hitting a ball, and an upper surface of the head connected to the face portion 3. The crown portion 4, the sole portion 5 connected to the face portion 3 to form the bottom of the head, and the crown portion 4 and the sole portion 5 are connected to each other and from the toe 3a of the face portion 3 to the heel 3b through the back face. A driver made of a metal material having a extending side portion 6 and a neck portion 7 provided on the heel side of the crown portion 4 and fitted with one end of a shaft (not shown) and having a hollow portion i provided therein ( A wood type such as # 1) or a fairway wood is illustrated. In the head 1 of the present invention, at least a part of the face portion 3 has a vertical shear rigidity parallel to the face surface 2 and a rigidity in the crown-sole direction, rather than a vertical rigidity that is a rigidity in the direction perpendicular to the face surface 2. Is characterized in that a low shear stiffness reduction portion 9 is provided.

  First, the reason why the flight distance is increased by providing the face portion 3 with the shear rigidity reduction portion 9 will be described. As shown in FIG. 6, when the ball B is hit with a head 1 such as a driver having a loft angle, the force F with which the face surface 2 hits the ball B is a vertical force Fa perpendicular to the face surface 2; Parallel to the face surface 2 (more precisely, the tangential direction of the face surface 2 at the contact point between the ball and the face surface) and a vertical shearing force Fb along the crown-sole direction, the vertical force Fa is , And the shearing force Fb acts as a force that gives back spin around the horizontal axis of the ball.

  FIG. 7 shows a time calendar of the vertical force Fa and the shear force Fb when the ball 1 is hit with the head 1. A broken line indicates the vertical force Fa, and three solid lines indicate the shear force Fb. Regarding the shearing force, the results are obtained for three types of heads having the same loft angle but the friction coefficient of the face surface 2 being large, medium, and small, and are indicated by symbols Fb1, Fb2, and Fb3, respectively. Further, a positive (+) shear force acts in a direction in which a backspin is applied to the ball, and a negative (−) shear force acts in the opposite direction (top spin direction).

  First, the vertical force Fa rises smoothly in a parabolic shape after hitting, reaches a peak, and then smoothly decreases to zero. When the normal force becomes zero, the ball moves away from the face surface 2. Accordingly, the shearing force is also zero. Even if the surface state of the face surface 2 is different, the vertical force Fa hardly changes. This is because the vertical force Fa and the contact time depend on the vertical rigidity between the ball and the head.

  However, the action of the shearing force Fb varies significantly depending on the friction coefficient of the face surface 2. When the loft angle of the head is, for example, 5 ° or more and smaller than 35 °, when the ball B is hit with the face surface 2 having a general friction coefficient, the shearing forces Fb1 and Fb2 acting on the ball B are temporarily reduced. After working in the positive direction to apply backspin, the direction changes to the negative direction in which reverse spin is stopped. As a result of simulations and experiments, it was confirmed that the backspin amount of the launched ball is almost proportional to the difference between the time integral of positive shear force (equivalent to impulse) and the time integral of negative shear force. It has been.

  Further, when the friction coefficient of the face surface 2 is increased, the slip in the initial contact between the ball B and the face surface 2 is decreased. As indicated by the shearing force Fb1 in FIG. 7, this can reduce the time T until the peak value of the positive shearing force that tries to apply the back spin to the ball B becomes large and becomes zero at the same time. Then, a negative shearing force acts to stop the backspin until the end of contact. For this reason, the impulse of the negative shearing force is increased, thereby reducing the backspin amount of the ball to be launched.

  On the other hand, when the friction coefficient of the face surface 2 is reduced, slip at the initial contact between the ball B and the face surface 2 is increased. When the slip increases, as shown by the shear force Fb3 in FIG. 7, the force to apply the back spin to the ball B is hardly increased and the time T until the positive shear force becomes zero is increased. And As a result, although the impulse of the negative shear force hardly occurs, the peak value of the positive shear force itself is small, and as a result, the backspin amount of the ball is also reduced.

  Therefore, in order to reduce the backspin amount of the ball, the friction coefficient of the face surface 2 may be increased as compared with the conventional case, or on the contrary, it may be decreased. However, it is difficult to obtain practical effects. In view of these, in the present invention, as described above, by providing the shear stiffness reducing portion 9 having a vertical shear stiffness smaller than the vertical stiffness on at least a part of the face portion 3, the shear force is as if the friction coefficient is lowered. Can be obtained.

  That is, as shown in an enlarged view in FIG. 8, the face surface 2 receives an upward shearing force Fb ′ as a reaction to the impact of the ball B. Since the shear stiffness reduction portion 9 has a small vertical shear stiffness, it can be displaced more in the direction of the shear force than in the conventional case. Such a displacement in the shearing direction matches the direction in which the ball B tries to move on the face surface, so that the ball B moves with the face surface, and the shearing force Fb acting on the ball B eventually rises. Shows a behavior similar to that when the friction coefficient of the face surface 2 is reduced. In other words, the backspin amount of the ball B can be reduced by displacing the shear stiffness reduction portion 9 in synchronization with the sliding direction of the ball B and following the ball B at the time of hitting.

  The contact time between the ball B and the face surface 2 at the time of hitting is governed by the vertical rigidity of the face surface 2 when the balls are the same. Therefore, if not only the vertical shear stiffness but also the vertical stiffness of the face surface 2 is lowered at the same time, the sign reverses like the shear forces Fb1 and Fb2, and the effect of reducing the backspin amount is sufficiently obtained. Absent.

  In the face portion 3, the vertical rigidity of a specific portion is obtained as a displacement amount per unit vertical force obtained by applying a normal force of a specified magnitude to the specific portion and dividing the vertical maximum displacement by the vertical force. Can do. Similarly, with respect to the vertical shear rigidity of a specific portion of the face portion, a displacement amount per unit shear force obtained by applying a shear force of the specified magnitude to the specific portion and dividing the displacement amount in the shear direction by the shear force. Can be obtained as

  The above-described action by the shear rigidity reduction portion 9 of the present invention can be obtained without changing the friction coefficient of the face surface 2 from the conventional value, and the above-described action can be obtained regardless of the friction coefficient. Therefore, it goes without saying that means for reducing the friction coefficient of the face surface 2 may be used in combination. Hereinafter, some examples of specific configurations of the shear stiffness reduction portion 9 that obtains such an action will be described.

  As shown in FIGS. 1 to 3, the shear rigidity reduced portion 9 of the present embodiment is configured such that the front surface is constituted by a rectangular striking plate 10 that forms the central portion 2 </ b> A of the face surface 2. The striking plate 10 is supported by the face base 12 of the head body 11 via a joint member 13 so as to be displaceable in the crown-sole direction.

  In the head main body 11, the crown portion 4, the sole portion 5, the side portion 6, and the face base portion 12 are integrally formed. The face base portion 12 includes a front edge 4a of the crown portion 4, a front edge 5a of the sole portion 5, a front edge 6b of the side portion 6 (a front edge 6b1 on the toe side, and a front edge 6b3 on the heel side) 1 is also schematically shown in FIG. 1), and is formed of a wall-like body that closes the hollow portion i on the face surface side.

  Further, the face base portion 12 of the present embodiment has a concave portion 12A that is recessed with a step inside the head on the hollow portion i side, and an edge portion 12B that is provided around the concave portion 12A. What is comprised including is illustrated. The concave portion 12A is formed in a substantially rectangular shape, and as shown in FIG. 3, a bottom surface 12A1 forming the most concave surface, and a four-side wall surface 12A2 connecting between the bottom surface 12A1 and the edge portion 12B, Is included. Further, the front surface of the edge portion 12B of the face base portion 12 constitutes the peripheral edge portion 2B of the face surface 2.

  The striking plate 10 is disposed in the recess 12 </ b> A of the face base 12 via a joint member 13. It is desirable that the front surface of the striking plate 10 be arranged substantially in line with the front surface of the edge portion 12B of the face base portion 12. Thereby, it is possible to prevent a large step from being formed on the face surface 2. Further, the striking plate 10 of this embodiment is supported in a non-contact state with the bottom surface 12A1 and the side wall surface 12A2 of the recess 12A of the face base portion 12. Thereby, the striking plate 10 is allowed to be displaced at least in the vertical shear direction with respect to the head body 11. Moreover, although the front surface of the striking surface 10 is exemplified as a convex curved surface that forms a roll and a bulge in this embodiment, it may be formed as a flat surface.

  The joint member 13 of the present embodiment includes a plurality of rib-like bodies 14 extending between the striking plate 10 and the face base portion 12 in the toe-heel direction and spaced in the crown-sole direction. Things are shown. In the cross section shown in FIG. 3, each rib-like body 14 is exemplified by a material extending substantially vertically from the front surface of the striking plate 10 (the central portion 2 </ b> A of the swath surface 2). The rib-like body 14 is configured such that the rib thickness t in the direction perpendicular to the joint length L is smaller than the joint length L joining between the back surface of the striking plate 10 and the bottom surface 12A1 of the recess 12A. Is exemplified.

  As shown in FIG. 4, such a rib-like body 14 exhibits a strong rigidity that is difficult to be deformed in the direction of the force Fa in the vertical direction when the ball B is hit. Deforms in the shearing direction and follows the sliding direction of the ball B. Therefore, such a splicing member 13 can cause the striking plate 10 to function as the shear stiffness reducing portion 9 having a vertical shear stiffness smaller than the vertical stiffness. For this reason, when the ball B is hit, the hitting plate 10 is greatly deformed in the shearing direction toward the crown portion rather than the vertical direction with respect to the face base portion 12. As described above, the shearing force acting on the ball B can be reduced as if the frictional force of the face surface 2 is reduced as described above. As a result, the ball B is hit highly and the amount of backspin is reduced, so that it is possible to suppress a blow-up and increase the flight distance.

  The joint member 13 of this embodiment is exemplified by a plurality of rib-like bodies 14 extending in the toe and heel directions, but instead of this, the face surface 2 from the back surface of the striking plate 10 can be replaced with this. However, it is also possible to use a columnar body such as a rectangular columnar body or a cylindrical body extending substantially perpendicular to the above.

  9 and 10 show an overall perspective view of the head 1 and a longitudinal sectional view of the face portion 3 as other embodiments of the present invention. In this embodiment, the front surface of the face base 12 is formed smoothly without having a recess. Further, the striking plate 10 is exemplified by a front surface that substantially forms the entire area of the face surface 2. The joint member 13 is formed of a plurality of rib-like bodies 14 extending in the toe and heel directions as in the above embodiment. The head 1 of such an embodiment can be provided with the shear rigidity reduced portion 9 in a wider range. In the present embodiment and the embodiment of FIG. 1, an elastic material (not shown) such as rubber or resin that does not hinder the vertical shear displacement of the striking plate 10 in the gap j between the striking plate 10 and the face base 12. It is also preferable to fill the gap by arranging. As a result, if the head 1 is painted or the like, it can have an appearance comparable to that of the conventional one.

  Furthermore, FIG. 11 shows another embodiment of the joint member 13. The joint member 13 of the present embodiment is exemplified by a member including a plurality of spheres 16 and a holding body 17 made of an elastic material connecting the plurality of spheres 16.

  The sphere 16 is made of a hard material, and is preferably made of a metal material or ceramics. In this embodiment, steel balls for ball bearings are used. The outer diameter R of the steel ball is set to be substantially equal to the gap between the striking plate 10 and the face base portion 12 (the bottom surface 12A1 in this example) located on the back side thereof. Although not shown, it is desirable that the spheres 16 are arranged in a grid pattern with intervals of, for example, about 5 mm on the top, bottom, left and right. In the present embodiment, the holding member 17 is made of a rubber material, and is filled in a gap between the striking plate 10 and the face base 12 and holds a plurality of spheres 16 connected to each other.

  In such a splicing member 13, the sphere 16 exhibits a large compression resistance against the vertical force at the time of hitting. Thereby, the vertical rigidity of the striking plate 10 can be maintained high. On the other hand, the striking plate 10 is merely point-contacted with the sphere 16 and is bonded to the holding body 16 made of a substantially rubber material. Dominated by low shear stiffness. That is, the vertical shear rigidity can be made smaller than the vertical rigidity of the striking plate 10. For such a splicing member 13, for example, unvulcanized liquid rubber is first poured into the recess 12 </ b> A of the face base 12, and then a plurality of spheres 16 are embedded therein at appropriate intervals so as to hit the striking plate from the outside. 10 and can be easily formed by vulcanizing the liquid rubber.

  Although several embodiments of the present invention have been described in detail above, the present invention is not limited to the case where the face portion 2 is provided with a shear stiffness reduction portion 9 having a vertical shear stiffness smaller than the vertical stiffness. Needless to say, the present invention can be realized in various shapes without being limited to the above embodiment. For example, a structure of a seismic isolation bearing made of laminated rubber used in a building, that is, a structure in which a thin rubber sheet and a steel plate are laminated can be used. This structure also exhibits high rigidity for vertical loads, but low rigidity for shear loads.

(Example 1)
A wood-type golf club head shown in FIG. Using a titanium alloy of Ti-6Al-4V, a head base 11a forming the main part of the head body 11 was integrally cast as shown in FIG. The head base 11a is provided with an opening O1 in the sole portion 5, and a sole plate (not shown) made of the same material, which is separately formed, is fixed thereto by welding. Further, the head base 1a is provided with a rectangular recess 12A in the face portion 3, and an opening O2 is provided in the bottom surface thereof. The opening O2 has a square shape of 30 mm in length and width. A hitting unit U separately formed in advance was fixed to the opening O2 by welding.

  The striking unit U includes a striking plate 10 that constitutes the shear rigidity reduction portion 9, a splicing member 13 composed of a rib-shaped body 14 having one end connected to the back surface of the striking plate 10, and the rib-shaped body 14. The substrate 18 is formed integrally with the end 18. The striking unit U was manufactured by welding parts machined from a Ti-6Al-4V plate. Further, the striking plate 10 was formed in a 30 mm square shape with a thickness of 2.0 mm, and the substrate 18 was formed with a 30 mm square shape with a thickness of 3.0 mm. Further, six rib-like bodies 14 were provided at a pitch of 5 mm in the crown-sole direction. The rib thickness t of the rib-like body 14 was 0.5 mm, and the joint length L was 2 mm. The gaps t1, t2, t3, and t4 shown in FIG. 1 were all 2 mm, and the substrate 18 and the opening O2 of the striking unit U were welded from the opening O1. Thereafter, the sole plate was welded to the opening O1 to obtain the head shown in FIG.

(Example 2)
A wood-type golf club head shown in FIG. 11 was prototyped. First, the head body 11 having the recess 12A shown in FIG. 11 was integrally cast using a titanium alloy of Ti-6Al-4V. The recesses were 34 mm both vertically and horizontally. Then, an unvulcanized liquid rubber in which 20 parts by weight of zinc acrylate and 1 part by weight of dicumyl peroxide are added to 100 parts by weight of liquid butadiene rubber “POLYOIL130” manufactured by Nippon Zeon Co., Ltd. is poured into the recess 12A. At the same time, 36 chrome balls (ball balls for ball bearings) having an outer diameter of 2 mm were positioned and arranged in a lattice shape at a pitch of approximately 5 mm vertically and horizontally. After that, a striking plate 10 made of Ti-6Al-4V having a thickness of 2.0 mm and a 30 mm square was pressed from the outside and temporarily bonded. At this time, the striking plate 10 was arranged so that a gap of 2 mm was formed between the striking plate 10 and the side surface of the recess 12A. And the head 1 could be manufactured by vulcanizing | curing liquid rubber for 30 minutes in 150 degreeC oven.

It is a perspective view of the standard state of the head which shows one embodiment of the present invention. It is the longitudinal cross-sectional view. FIG. 3 is an enlarged view of a main part of FIG. 2. It is an enlarged view explaining the effect | action at the time of a hit ball of a shear rigidity fall part. It is a perspective view of the standard state of the head which shows one embodiment of the present invention. It is the schematic explaining the force at the time of hitting with a ball and a head. It is a graph which shows the relationship between the force which acts on a ball | bowl, and time. It is the schematic explaining the effect | action. It is a perspective view of the standard state of the head which shows other embodiments of the present invention. It is a fragmentary sectional view of the face part. It is a fragmentary sectional view of the face part showing other embodiments of the present invention. It is an exploded perspective view explaining the concrete design thru / or manufacturing method of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Golf club head 2 Face surface 3 Face part 4 Crown part 5 Sole part 6 Side part 7 Neck part 9 Shear rigidity reduction part 10 Strike board 11 Head main body 12 Face base part 12A Face base part recessed part 12B Face base edge part 13 Joint member 14 Ribs

Claims (6)

A golf club head having a face portion formed only of a metal material for hitting a ball,
At least a part of the face portion is provided with a shear stiffness reduction portion that is parallel to the face surface and has a lower vertical shear stiffness that is a stiffness in the crown-sole direction than a vertical stiffness that is perpendicular to the face surface. A golf club head characterized by. A golf club head having a face portion for hitting a ball,
The face portion is provided with a striking plate whose front surface constitutes at least part of the face surface,
The striking plate has a crown portion, a sole portion, a side portion that connects between the crown portion and the sole portion, and a face base portion that is integral with the front edges of the crown portion, the sole portion, and the side portion. on the face the base of the head body, through a joint member crown - is displaceably supported in the sole direction, moreover
The joint member includes a plurality of rib-like bodies made of a metal material extending in a toe-heel direction between the striking plate and the face base and spaced in a crown-sole direction. Club head.   The golf club head according to claim 2, wherein the striking plate is supported in a non-contact manner with the face base. The face base, a recess recessed toward the head inwardly, with and an edge provided around the recess, wherein the striking plate that has been placed in the recess by aligning the front in front of the edge The golf club head according to claim 2, wherein: The golf club head according to claim 2 , wherein the hitting surface substantially forms the entire area of the face surface . A golf club head having a face portion for hitting a ball,
The face portion is provided with a striking plate whose front surface constitutes at least part of the face surface,
The striking plate has a crown portion, a sole portion, a side portion that connects between the crown portion and the sole portion, and a face base portion that is integral with the front edges of the crown portion, the sole portion, and the side portion. Supported by the face base of the head body so as to be displaceable in the crown-sole direction via a joint member,
In addition, the joint member includes a plurality of spheres having an outer diameter substantially equal to a gap between the striking plate and the face base, and a holding body that is filled with the gap and connects the plurality of spheres. A golf club head comprising:

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