JPH06190088A - Golf club head - Google Patents

Abstract

PURPOSE:To provide a golf club head which allows increase in flying distance by achieving a deformation thereof being harmonized with the ball along with excellent durability. CONSTITUTION:A plurality of slits 19 are arranged near a face surface 12 of a hollow head body 11 and formed in a plurality of rows and in zig zag toward the rear of the main body 11 extending spaced from one another along the periphery of the face surface. Thus, a two ends fixing beam section is formed between rows of the slits and is made to deflect when a ball is hit thereby enabling the deformation of the head body 11 being harmonized with the deformation of the ball.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a golf club head, and more particularly to a club head structure capable of extending a flight distance of a ball and having excellent durability.

[0002]

2. Description of the Related Art In order to increase the initial velocity of a golf ball at the time of hitting and increase the flight distance of the ball, it is important to make the coefficient of restitution between the ball and the club head as close to 1 as possible. It is desirable to synchronize the deformation cycle of the head with the deformation cycle of the ball. When the mass of the golf ball is m _b , the mass of the club head is m _c , the rigidity of the ball is K _b, and the effective rigidity of the head is K _c , the head synchronizes with the deformation cycle of the ball at the time of hitting the ball. In order to deform, it is necessary to satisfy the tuning condition of the following mathematical formula 1.

[0003]

## EQU1 ## K _c = (m _c / m _b ) K _b

Assuming that the mass m _b of the ball is about 46 g and the mass m _c of the head is about 200 g, the relationship between the rigidity of the ball and the head for satisfying the tuning condition can be calculated from the above formula 1.

[0005]

[Formula 2] K _c = 4.3 K _b

[0006] Further, when the head speed at the time of hitting the ball (that is, the initial velocity of the ball) is about 40 m / sec, the maximum load P applied to the ball at the time of hitting is about 14500 N, and the effective value is about 10,000 N. Therefore, as shown in FIG. 9, the compression deformation amount δ _b of the ball at this time is about 3.83.
mm, and the ball rigidity (secant rigidity) K _{b at} this time
It can be seen from the following equation 3 that it is about 2610 N / mm.

[0007]

(3) K _b = P / δ _b

Therefore, in order to deform the head in synchronism with the deformation cycle of the ball, the rigidity (secant rigidity) K _c of the head is about 11223 N / mm, that is, about 1145, from the formulas 2 and 3.
It turns out that it must be kg / mm. In addition, the head must be able to deform due to collision with the ball within its elastic range.

Various attempts have been made to achieve club heads that satisfy the tuning requirements described above. For example, a flexible face body is attached to the opening formed in the face portion of the club head body, and the flexible deformation of the face body is used to deform in synchronization with the ball, or the face portion of the club head body is attached. It has been considered that a spring means is interposed between the back surface of the face body and the support surface of the head body, and the spring means is deformed in synchronization with the ball when the face body collides with the ball. On the other hand, a composite face body consisting of a rubber-like elastic layer and a fiber reinforced resin layer covering the surface is fixed in a recess formed in the face portion of the head body, and this composite face body is deformed in synchronization with the ball when hitting. Have been proposed by the present inventors.

[0010]

However, in the case of the above-mentioned conventional head structure, since a separate member is incorporated into the head main body, the head structure becomes complicated and the manufacture thereof becomes difficult, and the weight of the head is heavy. There is a problem that the distribution is closer to the face surface, the depth of the center of gravity of the head from the face surface becomes shallow, and the directionality of the ball flight deteriorates. Further, since the face body, the spring means, and the like are fixed or engaged with each other, there is a drawback that impact resistance strength and durability are poor.

Accordingly, it is an object of the present invention to provide a golf club head which can extend the flight distance of the ball due to synchronous deformation with the ball and which is excellent in durability.

[0012]

In order to solve the above-mentioned problems, the present invention according to claim 1 provides a golf club head having a hollow head body, in the vicinity of the face surface of the head body and in the vicinity of the face surface. It is characterized in that a plurality of slits extending along each other are formed in a plurality of rows and arranged in a staggered pattern toward the rear of the head body.

According to a second aspect of the present invention, in the golf club head according to the first aspect, a plurality of slits in each row are provided around the face surface from the vicinity of the neck portion of the top surface of the head body to the vicinity of the neck portion of the sole surface. The head main body is formed with slits continuously extending from the vicinity of the neck portion of the face surface to the vicinity of the end portion of the rearmost slit row.

[0014]

According to the golf club head of the present invention, a plurality of slits are formed in a row near the face surface of the hollow head body and extend at intervals along the periphery of the face surface. Since the slits are arranged in a staggered pattern toward the rear, a plurality of both-end fixed beam portions formed of the head main body wall portion are arranged in a zigzag pattern between adjacent slit rows. Therefore, at the time of hitting the ball, the fixed beam portions at both ends of each row bend under the load distributed by the number of slits in the row at approximately the center of the row, and the beam portions at both ends fixed at the center of the beam portions at both ends of the next row from the ends. A bending load will be applied to. In this way, bending deformations in the elastic regions occur in the fixed beam portions at both ends between the slits arranged in a staggered manner. Therefore, since the head main body has the spring supporting structure in the slit row forming region by utilizing the bending of the both end fixed beam portions, the deformation cycle of the entire head main body at the time of hitting the ball can be almost synchronized with the deformation cycle of the ball. Moreover, since it is sufficient to form a plurality of slits in the head main body and it is not necessary to incorporate a separate member for the spring action, the head structure is simple and the manufacture is easy. Further, since no separate member needs to be engaged or fixed, the club head has excellent impact resistance and durability.

In the golf club head according to the present invention, a plurality of slits in each row are arranged along the periphery of the face surface from the vicinity of the neck portion of the top surface of the head body to the vicinity of the neck portion of the sole surface. Further, since the head body has slits continuously extending from the vicinity of the neck portion of the face surface to the vicinity of the end portion of the rearmost slit row, it is possible to compress and recover the slit row forming region substantially evenly when hitting a ball. The face surface can be moved in parallel. Therefore, the club head is capable of increasing the flight distance of the ball and stabilizing the directionality of the flight of the ball.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

1 to 5 show an embodiment in which the present invention is applied to a hollow club head of a wood club type. First, referring to FIGS. 1 to 4,
The club head has a hollow head body 11, which has a face surface 12 for hitting a ball, a top surface 13, and a sole surface 14, and further has a top surface 13 and a sole surface 14. A continuous heel side surface 15, a back side surface 16 and a toe side surface 17 are provided between them, and a neck portion 18 for connecting a club shaft (not shown) extends obliquely upward from the heel side surface 15.

The hollow head body 11 can be made of various materials such as metal and fiber reinforced resin. The head main body 11 may be formed by integrally molding the entire body, or may be formed by dividing the head main body 11 into a plurality of parts and then combining them to be integrated.

In the vicinity of the face surface 12 of the head body 11, a plurality of rows of slits 19 extending along the periphery of the face surface 12 at intervals are provided (in the illustrated embodiment, five slits 19 are provided).
The rows are arranged in a zigzag pattern in a row shape and toward the rear of the head body 11. The plurality of slits 19 in each row are arranged along the periphery of the face surface 12 from the vicinity of the neck portion 18 of the top surface 13 of the head body 11 to the vicinity of the neck portion of the sole surface 14, and the head body 11 further has a face surface. A slit 20 is continuously formed from the vicinity of the neck portion 12 to the vicinity of the end portion of the rearmost slit row. These slits 19 and 20 penetrate the wall of the head body 11. These slits 19 and 20 are O.1 to O.5m
m is preferable, but it can be easily formed by using, for example, the well-known laser method, carbon dioxide method, water jet method, or the like.

As described above, in the illustrated embodiment, the head body 11 is formed with the staggered slits 19 and the slits 20 continuously extending from the vicinity of the neck portion of the face surface 12 to the vicinity of the end portion of the rearmost slit row. Therefore, the slit row forming region can be compressed and deformed substantially evenly when the ball is hit, and the face surface 12 can be moved in parallel. Therefore, the club head is capable of increasing the flight distance of the ball and stabilizing the directionality of the flight of the ball.

FIG. 5 is a schematic enlarged view showing the staggered arrangement of the slits 19. As can be seen from the figure, a plurality of both-end fixed beam portions 21 formed of the wall portion of the head body 11 are formed in a staggered manner between the adjacent slit rows. Therefore, at the time of hitting the ball, the fixed beam portions 21 at both ends of each row have a concentrated load (actually, a distributed load over the width b between the slit end portions, which is distributed by the number of the slits 19 in the row, approximately at the center thereof. For the sake of simplification, it will be described as a concentrated load for the sake of convenience.) While being bent by receiving P, a bending load is applied from both ends thereof to substantially the center of both ends fixed beam portions 21 of the next row. In this way, bending deformations in the elastic regions occur in the fixed beam portions 21 at both ends between the slits 19 arranged in a staggered manner. Therefore, since the head main body 11 has the spring supporting structure in the slit row forming region by utilizing the bending of the both end fixing beam portions 21, the deformation cycle of the entire head main body at the time of hitting the ball can be substantially synchronized with the deformation cycle of the ball. .

In the club head having the above structure, the maximum moment of deflection δ (see FIG. 6) due to the second moment of inertia I and the load p of each of the fixed end beam portions 21 can be expressed by the following equations 4 and 5, respectively.

[0023]

[Equation 4]

[0024]

[Equation 5]

Here, t is the thickness of the both-end fixed beam portion 21 of the head body 1, h is the width of the both-end fixed beam portion 21, a is the length of the both-end fixed beam portion 21 corresponding to the length of the slit 19, and E Indicates the Young's modulus of the material of the beam portions 21 fixed at both ends. From the equations 4 and 5, the relationship between the load p applied to each of the fixed-end beam portions 21 and the maximum deflection δ can be expressed by the following equation 6.

[0026]

[Equation 6]

Further, the maximum moment M and the maximum bending stress σ of each end fixed beam portion 21 can be expressed by the following expression 7, and the bending limit strain ε _u can be expressed by the expression 8.

[0028]

[Equation 7]

[0029]

[Equation 8]

Therefore, by substituting the equation 6 into the equation 8, the limit deflection δ _lim of the fixed beam portions 21 at both ends can be expressed by the following equation 9.

[0031]

[Equation 9]

Next, let P be the total load at the time of ball impact, and Δ be the total deformation of the head body 11 at that time.
The total load P and the limit total deformation Δ _lim can each be expressed by _Expression 10, and the rigidity (secant rigidity) K _c of the head body 11 can be expressed by Expression 11.

[0033]

[Equation 10]

P = mp _Δlim = (n-1) _δlim

[0035]

[Equation 11]

Here, m represents the number of slits 19 in each row, and n represents the number of slit rows. From equations 6 and 10,
The total load P can be expressed by Equation 12, and Equation 9 and Equation 1
From 0, the limit total deformation Δ _lim can be expressed by _Equation 13.

[0037]

[Equation 12]

[0038]

[Equation 13]

As described above, in order for the club head to be deformed in synchronization with the ball, the rigidity (secant rigidity) of the club head head (head body 11) is calculated from Equations 2 and 3.
K _c is because should be about 1145kg / mm, the rigidity of the head main body 11 (secant stiffness) K _c can be represented by the number 14.

[0040]

[Equation 14]

Further, for the sake of simplification of explanation, if the total load P at impact is 1145 kg, the total deformation Δ of the head body 11 will be 1 mm, so that the deformation of the head body 11 is within the elastic range. In addition, the limit total deformation Δ _lim of the head main body 11 needs to satisfy the relationship of _Expression 15.

[0042]

[Equation 15]

That is, the relationship between the equations 14 and 15 is the tuning condition within the elastic range. Therefore, according to the material of the head body 11, the dimensions of each part of the head body 11, the number of slits m in each row, and the number of slit rows n may be set so as to satisfy the relations of the equations 14 and 15. .

Table 1 shows an example of setting when carbon fiber reinforced resin (CFRP) is used as the material of the head body 11. The Young's modulus E of CFRP depends on the mixing ratio of carbon fibers and is 3000 to 6000 kg / mm ² .
The limit strain ε _lim is about 2% in the case of CFRP.

[0045]

[Table 1]

FIG. 7 shows another embodiment of the present invention, in which each slit 19 is sealed with a flexible sealing material 22 that does not impede the elastic behavior of the slit row forming regions. Is characterized by. As such a sealing material 22, a soft resin, grease or the like can be used. Although not shown, the continuous slit 20 in the above embodiment can be provided with a similar sealing material. As described above, by sealing the slits 19 and 20 with the sealing material 22, it is possible to prevent the slits 19 and 20 from being clogged and foreign matter from entering the head body 11.

FIG. 8 shows still another embodiment of the present invention. In the figure, the same components as those in the above embodiment are designated by the same reference numerals. In this embodiment, the face surface 12 is provided near the face surface 12 of the head body 11.
A plurality of slits 19 are formed in a plurality of rows (five rows) extending along the periphery of the head body 11 in a zigzag pattern toward the rear of the head body 11. The plurality of slits 19 in each row are arranged along the periphery of the face surface 12 from the vicinity of the neck portion 18 of the top surface 13 of the head body 11 to the vicinity of the neck portion of the sole surface 14. However, unlike the above embodiment, the slit 20 of the above embodiment is omitted in this embodiment. Also in this embodiment, since it is possible to perform elastic deformation substantially in synchronization with the deformation cycle of the ball at the time of hitting in the slit row forming region, it is possible to extend the flight distance of the ball.

Although the embodiments shown in the drawings have been described above, the present invention is not limited to the embodiments described above,
Various changes can be made to the components within the scope of the invention described in the claims. For example, the inside of the head body 11 may be filled with a lightweight filler, such as urethane foam, which can be deformed in accordance with the elastic behavior of the slit forming region, or may be provided in a layered form on the inner surface of the head body. Further, the present invention is similarly applicable to an iron club type club head.

[0049]

As is apparent from the above description, according to the present invention, the face body behaves elastically within the range of compressive deformation that can be caused by the collision with the ball, and is substantially synchronized with the deformation of the ball. Since it has rigidity, it can extend the flight distance of the ball by effectively utilizing the collision energy with the ball, and does not require a separate member for obtaining the tuning condition, only forming the slit in the head body. As a result, tuning deformation can be generated, so that it is possible to provide a golf club head that has a simple structure, can be manufactured at low cost, and has excellent durability.

[Brief description of drawings]

FIG. 1 is a plan view of a golf club head showing an embodiment of the present invention.

FIG. 2 is a partial vertical cross-sectional side view of the head shown in FIG.

FIG. 3 is a bottom view of the head shown in FIG.

FIG. 4 is a front view of the head shown in FIG.

5 is a schematic enlarged view of a slit of the head shown in FIG.

FIG. 6 is an explanatory view showing a flexural deformation of a beam portion fixed at both ends between the slit rows of the head shown in FIG.

FIG. 7 is an enlarged sectional view of a slit portion of a golf club head showing another embodiment of the present invention.

8A and 8B are a plan view and a bottom view of a golf club head showing still another embodiment of the present invention.

FIG. 9 is a graph showing secant rigidity of a ball.

[Explanation of symbols]

 11 head body 12 face surface 13 top surface 14 sole surface 15 heel side surface 16 back side surface 17 toe side surface 18 neck portion 19 slit 20 continuous slit 21 both ends fixed beam portion 22 sealing material

Claims (2)

[Claims] 1. A plurality of slits extending in a row along the periphery of the face surface in the vicinity of the face surface of a hollow head body and arranged in a staggered pattern toward the rear of the head body. A golf club head characterized by being formed. 2. A plurality of slits in each row are arranged along the periphery of the face surface from the vicinity of the neck portion of the top surface of the head body to the vicinity of the neck portion of the sole surface, and the head body has a neck portion of the face surface. 2. The golf club head according to claim 1, wherein a slit continuously extending from the vicinity to the vicinity of the end of the rearmost slit row is formed.