JP2002210045A - Golf club head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a golf club head wherein both of the lowering the center of gravity and the increase in the gravity center depth are made possible while sufficiently ensuring an effective hitting point distance on the face surface. SOLUTION: This golf club head comprises a head main body 1 wherein the original loft angle is 8 deg. or lower, and an angle difference for which the original loft angle is subtracted from a real loft angle is 1 deg. or higher. Then, a retracting amount D from a shaft axis S for the gravity center G of the head main body 1 is set to be 18 to 40 mm. Also, the location of the gravity center of the head main body 1 which is projected on the face surface 3a is arranged at the center of the face surface 3a or an area lower than the center. The gravity center depth E comprising a distance between the gravity center G of the head main body 1 and a leading edge 6 is set to be 30 to 60 mm.

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 having a hollow structure, and more particularly to a golf club head capable of achieving both a low center of gravity and an increased depth of the center of gravity.

[0002]

2. Description of the Related Art Conventionally, the center of gravity of a golf club head has been reduced, and the distance between the point where the perpendicular line drawn from the center of gravity to the face surface intersects the face surface and the upper end of the face surface,
It is common practice to obtain a hit ball with a small back spin by increasing the effective hitting distance.

As described above, as a means of lowering the center of gravity of a golf club head, the mass of the head on the sole side is relatively increased. However, when the mass on the sole side is increased, there is a disadvantage that the degree of freedom for increasing the moment of inertia of the head is reduced. That is, if the weight distribution to the sole side required for lowering the center of gravity is excessively performed, the weight distribution to the peripheral portion of the head cannot be performed. Further, when the center of gravity of the golf club head is lowered, there is a disadvantage that the distance between the center of gravity of the head body and the leading edge (the depth of the center of gravity) is reduced. Therefore, it has been extremely difficult to simultaneously reduce the center of gravity of the head and increase the depth of the center of gravity and the moment of inertia. In addition, when the composite head is formed by using a high specific gravity metal or the like to satisfy these requirements, there is a disadvantage that the manufacturing cost of the golf club head is increased.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a golf club head capable of achieving both a low center of gravity and an increased depth of the center of gravity while sufficiently securing the effective hitting distance of the face surface. It is in.

[0005]

A golf club head according to the present invention for achieving the above object has an original loft angle of 8 degrees or less, and an angle difference obtained by subtracting the original loft angle from the real loft angle is 1 degree. The head body having the above structure, the amount of retreat of the center of gravity of the head body from the shaft axis is set to 18 to 40 mm, and the position of the center of gravity of the head body projected on the face surface is a central portion of the face surface or a portion thereof. It is characterized by being arranged in.

A golf club head according to the present invention for achieving the above object has a head having an original loft angle of 8 degrees or less and an angle difference obtained by subtracting the original loft angle from the real loft angle of 1 degree or more. The depth of the center of gravity consisting of the main body and the distance between the center of gravity of the head body and the leading edge is set to 30 to 60 mm, and the position of the center of gravity of the head main body projected on the face surface is set at the center of the face surface or a portion thereof. It is characterized by being arranged.

Thus, the original loft angle and the real loft angle of the head body are specified as described above,
By increasing the center-of-gravity receding amount or the center-of-gravity depth in the above range, the center of gravity of the head body can be lowered without concentrating the weight distribution on the sole side, and the effective hitting distance of the face surface can be sufficiently secured. However, both lowering the center of gravity of the head and increasing the depth of the center of gravity can be achieved.

In the present invention, the effective hitting point distance of the face surface is the distance between a point at which the perpendicular line drawn from the center of gravity of the head body to the face surface intersects the face surface and the upper end of the face surface. This effective hitting distance is preferably 23 to 35 mm. When setting the effective hitting distance to the above range, the vertical width of the face surface may be set to 40 to 70 mm.

Further, the center of gravity can be reduced without distributing the weight distribution of the head body to the sole side, so that the moment of inertia of the head body can be increased. In the present invention, the moment of inertia measured around an axis passing through the center of gravity of the head body and perpendicular to the sole surface is 3000 g ·
cm ² or more.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below in detail with reference to the accompanying drawings.

FIGS. 1 to 3 illustrate a golf club head according to an embodiment of the present invention. As shown in FIGS. 1 to 3, the golf club head according to the present embodiment has a cylindrical shape for mounting a shaft on the heel side of a head body 1 having a hollow structure including a face portion 3, a sole portion 4, and a crown portion 5. The hosel 2 is provided. When the shaft is mounted on the head body 1 and the address position is taken, the sole surface 4a is inclined so as to descend toward the rear of the head.

The address position means that the head main body 1 is set at the lie angle in the front view of the golf club head shown in FIG. 1, and the shaft axis S and the leading are shown in the plan view of the golf club head shown in FIG. This refers to the case where the edge 6 is set to be parallel to each other.
The leading edge 6 is where the head body 1 protrudes the most in the direction of the flying ball. The installation according to the lie angle is a state in which the gap between the round of the sole surface 4a and the installation surface is substantially equal on the toe side and the heel side. When the round of the sole surface 4a is unclear, the score line drawn on the face surface 3a and the installation surface are set in parallel. In the case where the roundness of the sole surface 4a is unclear and the score line is not linear, for example, when the parallel to the installation surface cannot be determined, the lie angle (degree) = (100-club length (inch)) is set. . For example, if the club length is 44 inches, the lie angle is 100-44 = 56 degrees. The club length is measured by a measuring method specified by the Japan Golf Equipment Association. As a measuring instrument, there is a club measure II manufactured by Kamoshita Seisensho Co., Ltd. That is, the distance between the heel end and the grip end is defined as the club length.

In the above golf club head, the original loft angle is 8 degrees or less, more preferably 5 degrees or less, and further preferably 3 degrees or less. When the original loft angle is large, the position of the center of gravity C projected on the face surface 3a increases, and the effective hitting distance B decreases. on the other hand,
When the original loft angle is small, the position of the center of gravity C projected on the face surface 3a becomes low, and the effective hit point distance B becomes large. By setting the original loft angle within the above range, the effective hitting distance B of the head can be increased.

The original loft angle refers to the head body 1
When viewed from the toe side, the face surface 3a and the sole surface 4a
And the angle between them. When the face surface 3a is a curved surface,
It is measured by the tangent to the midpoint of the face in the vertical direction. When the position of the midpoint in the face vertical direction changes depending on the position in the face horizontal direction, the face vertical direction is set at the center in the face horizontal direction. The center in the face left-right direction is set in the middle of the score line pattern. When the score line has an asymmetric pattern, the score line is set at the center of the face in the left-right direction at a position 21 mm above the leading edge along the face surface 3a. The upper, lower, left and right ends of the face 3a are defined by edges of the face 3a. When the sole surface 4a is a curved surface, the original loft angle is measured at a position where the head is stabilized without applying a restraining force. The procedure on the measuring instrument is to adjust the lie angle, fix the head at a stable position, and measure the original loft angle. By the way, in the head where the original loft angle is not the same as the real loft angle, a face angle of a hook or a slice occurs. become.

On the other hand, the angle difference obtained by subtracting the original loft angle from the real loft angle is 1 degree or more, more preferably 3 degrees or more, still more preferably 5 degrees or more, and most preferably 7 degrees or more.
Degrees or more. In the present invention, the effective hitting distance B of the head is increased by reducing the original loft angle. However, if the original loft angle and the real loft angle are the same or substantially the same as in a conventional golf club, the real The loft angle becomes too small, making it difficult to raise the hit ball to obtain a sufficient flight distance. Therefore, in the present invention, the real loft angle based on the shaft axis is made larger than the original loft angle based on the sole surface.

The real loft angle is an angle formed between the face surface 3a and the shaft axis S when the head main body 1 installed at the address position is viewed from the toe side. The golfer grasps the grip of the golf club, hits the ball on the face of the head along the shaft, and the loft angle for raising the hit is defined by the face 3a and the shaft axis S.
And the real loft angle. As a procedure on the measuring instrument, the lie angle is adjusted, the face angle is fixed at 0 degree, and the real loft angle is measured.

The above-described measurement of the original loft angle and the real loft angle is performed by using a golf ball measuring table manufactured by Shoho Kyokai, a golf club angle measuring device manufactured by Golf Galley, a golf club gauge manufactured by Golf Smith, and the like. It is possible with a measuring instrument. Such a measuring device may be any known device, and is not particularly limited in the present invention.

As shown in FIG. 3, the center of gravity G of the head body 1 is
The amount of retreat (the amount of retraction of the center of gravity) D from the shaft axis S is 18 to
It is set in the range of 40 mm. Even when the center-of-gravity receding amount D is set to a large value, the head body 1 having the above-described shape can sufficiently secure the effective hitting distance B.
When the center of gravity retreat amount D is less than 18 mm, the depth of the center of gravity is insufficient and the ball is difficult to lift. Conversely, when it exceeds 40 mm, the ball easily rises. I will.

The distance (depth of center of gravity) E between the center of gravity G of the head body 1 and the leading edge 6 is set in the range of 30 to 60 mm. Even if the depth E of the center of gravity is set to be large as described above, the head body 1 having the above shape can sufficiently secure the effective hitting distance B. If the depth E of the center of gravity is less than 30 mm, the depth of the center of gravity is insufficient and the ball is difficult to lift. Conversely, if the center of gravity E exceeds 60 mm, the ball easily rises. .

More specifically, the above-mentioned amount of retraction of the center of gravity means, more specifically, that the head main body 1 is installed on a horizontal plane at a lie angle and the face surface 3a is oriented in the direction F of the trajectory. Flying line direction F including the center of gravity G and the shaft axis S
Is the distance from the plane perpendicular to.

As shown in FIG. 4, the amount of retreat D of the center of gravity is
It is measured by a seesaw-type balance 10 which can swing in the direction of arrow U about the fulcrum 11. The balance meter 10 has a shaft pin 12 having a tight fit with the hosel hole of the head main body, and is balanced so that the arm 13 is horizontal when the head main body and the weight body are not mounted. . The measurement of the retreat amount D of the center of gravity G of the head main body 1 from the shaft axis is performed as shown in FIG.
The head main body 1 having the mass W is mounted on the arm and fixed so that the retreat amount D is measured in parallel to the longitudinal direction of the arm. In other words, the head main body 1 is fixed such that a plane P including the shaft axis S and perpendicular to the flight line direction F passes through the fulcrum 11 and is orthogonal to the arm longitudinal direction. Then, a weight body 14 having a mass W ′ such that the arm 13 is horizontally balanced and a length D ′ from the center of gravity G ′ of the weight body 14 to the fulcrum are selected.

As described above, the amount of retraction D of the center of gravity from the shaft axis is
Is given by D = (W ′) from the equation of balance W × D = W ′ × D ′.
× D ') / W. The balance 10 shown in FIG.
In the side view, since the head body 1 has the loft angle and the lie angle, the face surface 3a becomes slightly visible.

The above description is based on the principle of measurement of the amount of retraction of the center of gravity from the shaft axis, and examples of the measuring apparatus include a center of gravity measuring device manufactured by Kamoshita Seisensho Co., Ltd.

In the golf club head, the center of gravity C of the head main body 1 projected on the face surface 3a is disposed at the center of the face surface 3a or a portion thereof. More specifically, the vertical width A of the face surface 3a is 40 to 70 m.
When m, the effective hitting distance B is preferably 23 to 35 mm. When the effective hitting distance B is less than 23 mm, it is difficult to obtain a hit ball with a small backspin. On the other hand, when the effective hitting distance B exceeds 35 mm, the backspin is too small and the center of gravity and the hitting position are too far apart, resulting in poor initial velocity efficiency. Become.

Further, in the above golf club head, the moment of inertia may be increased by utilizing the fact that the lowering of the center of gravity of the head body 1 does not hinder the increase of the moment of inertia. That is, the moment of inertia of the head body 1 measured around an axis passing through the center of gravity G of the head body 1 and perpendicular to the sole surface 4a is:
It is preferably at least 3000 g · cm ² . By increasing the moment of inertia as described above, good directionality can be obtained. The head body 1 having such a moment of inertia preferably has a volume of 300 cc or more and a mass of 170 to 200 g.

The golf club head described above has the following effects.

(1) The position of the center of gravity C on the face surface can be arranged at the center portion between the sole and the crown or below, regardless of the amount of retreat D of the center of gravity and the depth of the center of gravity E. As a result, the effective hitting distance B can be increased.

(2) Regardless of the vertical width A of the face surface, the center of gravity position C on the face surface can be arranged at the central portion between the sole and the crown or less, and as a result, the effective hitting distance B can be reduced. Can be bigger. In other words, the center of gravity can be reduced even in a so-called deep face.

(3) Even when the head body has a low center of gravity, the thickness of the sole portion can be reduced, so that the head volume can be effectively increased with a limited mass and the moment of inertia is increased. be able to.

(4) Since the thickness of the sole portion and the crown portion can be designed to be equal, the head strength against impact upon hitting the ball can be improved.

[0031]

EXAMPLES The golf clubs of Comparative Examples 1-4 and Examples 1-2 in which the original loft angle, the real loft angle, the amount of retraction of the center of gravity, the depth of the center of gravity, the effective hitting distance, and the vertical width of the face surface of the head body were varied. Was produced respectively.

The launch angle, back spin, and flight distance of these test golf clubs were measured under the following measurement conditions, and the results are shown in Table 1.

Launch angle: Five golfers hit a ball in full swing, and the launch angle at that time was measured. The evaluation results were indicated by an index with Comparative Example 3 being 100, using the average value obtained from the measured values of five times for each person. A larger index value means a larger launch angle.

Back spin: The back spin amount of the ball at the time of hitting was measured. The evaluation result was calculated by using the reciprocal of the average value obtained from the measured values of five times for each person, and comparing Comparative Example 3 with 10
It was indicated by an index of 0. The larger the index value, the smaller the backspin.

Flying distance: The flying distance at the time of hitting the ball was measured. The evaluation results were indicated by an index with Comparative Example 3 being 100, using the average value obtained from the measured values of five times for each person. The greater the index value, the greater the flight distance.

[0036]

[Table 1] As can be seen from Table 1, the golf clubs of Examples 1 and 2 were able to obtain high launch angles and low-spin hit balls as compared with Comparative Examples 1 to 4.

[0037]

As described above, according to the present invention, the original loft angle and the real loft angle are specified, and the amount of retraction or the depth of the center of gravity is increased. The center of gravity can be lowered without concentration, and it is possible to achieve both the lowering of the center of gravity of the head and the increase in the depth of the center of gravity while sufficiently securing the effective hitting distance of the face surface.

Since the golf club head of the present invention can achieve a low center of gravity and a deep center of gravity that are not available in the conventional head, it is possible to obtain a high launch angle and a low spin ball to obtain a large flight distance. Can be. Moreover, according to the present invention, a high-strength head having a low center of gravity, a deep center of gravity, a large moment of inertia, and a high strength can be manufactured at low cost.

[Brief description of the drawings]

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

FIG. 2 is a sectional view taken along line XX of FIG.

FIG. 3 is a plan view showing a golf club head according to an embodiment of the present invention.

FIG. 4 is a side view showing an example of a center-of-gravity retreat amount measuring device.

FIG. 5 is a side view showing the measurement of the amount of retraction of the center of gravity by the measuring device of FIG. 4;

[Explanation of symbols]

 Reference Signs List 1 head body 2 hosel 3 face portion 3a face surface 4 sole portion 4a sole surface 5 crown portion 6 leading edge A vertical width of face surface B effective hitting distance C gravity center position on face surface D gravity center recession E gravity center depth G gravity center S Shaft axis

Claims (7)

[Claims] 1. A head body having an original loft angle of not more than 8 degrees and an angle difference obtained by subtracting the original loft angle from the real loft angle of not less than 1 degree, wherein the center of gravity of the head body is set back from the shaft axis. 18 to 4
A golf club head having 0 mm and a center of gravity of the head main body projected on the face surface located at a central portion or less of the face surface. 2. A head body having an original loft angle of 8 degrees or less and an angle difference obtained by subtracting the original loft angle from the real loft angle of 1 degree or more, and a distance between the center of gravity of the head body and the leading edge. A golf club head, wherein the center of gravity of the head body projected on the face surface is located at a central portion of the face surface or lower, the depth of the center of gravity being 30-60 mm. 3. The effective hit point distance of the face surface is 23 to
3. The golf club head according to claim 1, wherein the length is 35 mm. 4. 4. The vertical width of the face surface is 40 to 70 m.
The golf club head according to any one of claims 1 to 3, wherein m is m. 5. An inertia moment measured around an axis passing through the center of gravity of the head body and perpendicular to the sole surface is 3000 g.
· Cm ² or more at a golf club head according to any one of claims 1 to 4. 6. The golf club head according to claim 1, wherein the volume of the head body is 300 cc or more. 7. The mass of the head body is 170 to 200.
The golf club head according to any one of claims 1 to 6, wherein g is g.