JPH07236714A - Set of golf clubs - Google Patents

Abstract

PURPOSE:To make the direction of the club faces of golf clubs almost the same so that a player can hit a ball to a certain direction by fixing the rotation torque of each club head, which is expressed by a certain formula, around the shaft axis near the impact to a same value. CONSTITUTION:In a set of golf clubs 10 whose length and head weight are different each other, the rotation torque Nx of a club head 11, which is expressed by a formula, around its shaft axis near the impact is to be practically identical among the golf clubs 10. In the formula, Ix means the moment of inertia of the club head 11 around the 1st axis x which is along the shaft axis, Iz means the moment of inertia of the club head 11 around the 2nd axis z which crosses at right angle with the 1st axis x and extends to the direction of the club swing, and Iy means the moment of inertia of the club head 11 around the 3rd axis y which crosses at right angle with the 1st and the 2nd axes x and y. And Wx, Wz, and Wy mean the angular velocities of the club head around the 1st, 2nd, and the 3rd axes, x, y, and z respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a golf club set including a plurality of golf clubs, and more specifically, a golf club in which the rotational torques of the club heads about the shaft axis at the time of impact of each club are substantially the same. Regarding the set.

[0002]

2. Description of the Related Art Generally, a set of a plurality of golf clubs having different club lengths and club head weights, which are correlated with each other under a certain condition, is called a golf club set. For example, in the case of a wood club, the club number. 1
Drivers from club No. It is common to select some of the 5 wood clubs up to 5 creeks to form the set. In the case of an iron club,
Club No. 1 driving iron to club N
o. 9 up to 9 nibrick and pitching wedge,
It is common to select some from special clubs such as approach wedges and sand wedges to form a set. Further, in recent years, when head materials have been diversified and the degree of freedom in design has been increased, a golf club set functionally integrating both has also appeared.

A plurality of golf clubs constituting a set can swing with the same feeling, and the balls hit by the clubs fly a predetermined distance by drawing a preset trajectory. It is designed by correlating length, head shape and weight, lie, loft, etc.

[0004]

However, in the current golf club set, even if the golfer makes a certain swing, the longer the club length of the golf club is, the more the club head face is opened and the ball is hit. A golf club having a shorter club length tends to be sliced, and the face of the club head is closed at the time of impact and the hit ball tends to be hooked. As one of the causes, in the golf swing, the return of the club head near the impact of hitting the ball, that is, the rotation of the club head around the shaft axis of the club shaft is important. It is known to greatly affect the directionality.

[0005] Therefore, conventionally, attempts have been made to make the return degree of the club head of each golf club constituting the set the same, but conventionally, the shaft axis has been used as a factor for determining the returnability of the club head. Only the moment of inertia of the club head around was focused. For example, in the golf club set disclosed in Japanese Patent Laid-Open No. 1-166781, the return moment of the club head of each golf club is made equal by making the moment of inertia about the shaft axis of each golf club the same. .

However, it is not sufficient to make the moments of inertia about the shaft axes of the golf clubs the same. This is because the return of the club head is caused by the rotation torque of the club head around the shaft axis, and this rotation torque greatly affects the angular velocity of the club, which has the maximum size near the impact (usually immediately before the impact). Because it receives.

Now, as the inertial principal axis coordinate system of the golf club, the principal axis along the central axis (shaft axis) of the shaft of the golf club is the first axis (x), and the club is orthogonal to the first axis (x). If the main axis extending in the swing direction of the first axis is the second axis (z), and the main axis orthogonal to the first axis (x) and the second axis (z) is the third axis (y), the circumference of the first axis (x) The rotational torque N _x of the club head can be expressed by the following _equation 2.

[0008]

[Equation 2] Where I _x is the club head's moment of inertia about the first axis (x), I _z is the club head's moment of inertia about the second axis (z), and I _y is about the third axis (y). The club head moments of inertia, W _x , W _z , and W _y, are the angular velocities of the club head about the first, second, and third axes, respectively.

As is clear from the equation 2, the club head inertia moment I _x about the shaft axis, that is, the first axis (x) is the club head rotational torque N _x about the first axis (x).
However, even if the inertia moments I _x of the golf clubs are the same, the rotational torque N _x may change due to the relationship with other factors. According to the experiment, when a normal swing is performed with each of the general golf clubs forming the set, as shown in FIG. 3, each acceleration dW _x / dt of the club head around the first axis (x) is different. It is almost the same in golf clubs. Therefore, if the inertia moment I _x is the same, I _x · dW _x / dt will be the same.

On the other hand, as shown in the same figure, the angular velocities W _z and W _y around the second axis (z) and the third axis (y) of each golf club.
Regarding, the value (absolute value) of the product W _y · W _z of the angular accelerations W _y , W _z becomes maximum near the impact (just before the normal impact), and the maximum value (absolute value) of W _y · W _z Increases almost proportionally as the club length increases.

Therefore, in order to make the rotational torque N _x of the club head around the first axis (x) near the impact in each golf club the same, the vicinity of the impact is related to the moment of inertia I _x of each golf club. It was found that it is necessary to adjust the magnitude of (I _y −I _z ) W _y · W _z in.

Therefore, an object of the present invention is to make the direction of the club face (the degree of return of the club head) near the impact of each golf club constituting the set substantially the same and to make the direction of the hit ball constant. To provide a golf club set that can

[0013]

In order to solve the above-mentioned problems, the invention according to claim 1 provides a golf club set consisting of a plurality of golf clubs having different club lengths and club head weights, which is represented by the above formula 2. The rotational torque (N _x ) of the club head about the shaft axis near the impact of each golf club is substantially the same.

According to a second aspect of the present invention, in the golf club set according to the first aspect, the moment of inertia (I _x ) of the club head about the first axis in each golf club is substantially the same, and each golf club is the same. the difference in the moment of inertia of the club head about the second axis and third axis in the club (I _y -I _z) and the second axis and third near impact
The product value (absolute value) of the angular velocity (W _z , W _y ) around the axis is substantially the same.

A golf club set according to a third aspect is the golf club set according to the first aspect, wherein the moment of inertia (I _x ) of the club head about the first axis in each golf club substantially changes according to the change in the club length. It changes in proportion to the second axis and the third axis of each golf club.
The difference in the moment of inertia of the club head about the axis (I _y −
The product value (absolute value) of I _z ) and the angular velocities (W _z , W _y ) about the second axis and the third axis near the impact is equal to the moment of inertia (I _x ) of the club head about the first axis. The variation is substantially the same as the variation of the product value with the angular acceleration (dW _x / dt) around the first axis.

A golf club set according to a fourth aspect is the golf club set according to the second aspect, wherein the weight for adjusting the moment of inertia of the club head to the neck portion of each golf club or another golf club except one golf club. It is characterized by having a body.

A golf club set according to a fifth aspect is the golf club set according to the third aspect, wherein the weight for adjusting the moment of inertia of the club head to the club head of each golf club or another golf club other than one golf club. It is characterized by having a body.

[0018]

In the golf club set according to claim 1, the rotational torque N _x about the shaft axis of the club head in the vicinity of the impact of each golf club is the same, so that the orientation of the club face at the time of impact of each golf club. Therefore, the directions of the hit balls can be made the same.

In the golf club set according to the second aspect, at the time of impact of each golf club under the condition that the moment of inertia I _x of the club head around the first axis in each golf club is substantially the same. It is possible to provide a golf club set having the same club face orientation.

In the golf club set according to the third aspect, under the condition that the moment of inertia I _x of the club head around the first axis in each golf club changes substantially proportionally as the club length changes. Thus, it is possible to provide a golf club set in which the orientation of the club face at the time of impact of each golf club can be made the same.

In the golf club set according to claim 4, existing golf clubs are provided by providing a weight body for adjusting the moment of inertia of the club head at the neck portion of each golf club or another golf club except one golf club. The orientation of the club face at impact of each golf club is the same under the condition that the moment of inertia I _x of the club head about the first axis in each golf club is made substantially the same by a slight change of the club. The golf club set that can be realized can be easily realized.

In the golf club set according to claim 5, the existing golf clubs are provided by providing a weight body for adjusting the moment of inertia of the club heads on the club heads of each golf club or other golf clubs except one golf club. With a slight modification of the club, the moment of inertia I of the club head about the first axis in each golf club I
Under the condition that _x changes substantially proportionally, it is possible to easily realize a golf club set in which the orientations of the club faces at the time of impact of each golf club are the same.

[0023]

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

1 (a), 1 (b) and 1 (c) show the present invention as a club No. Club No. 3 to First when applied to a golf club set consisting of up to 9 iron clubs
1 is a view showing an example, and illustrates one of the iron clubs constituting the set. Referring to FIG. 1, an iron club 10 includes a club head 11, a neck portion 12 integral with the club head 11, and a club shaft 13 having a tip inserted and fixed to the neck portion 12.
And a grip (not shown) is attached to the base end side of the club shaft 13. As an inertial principal axis coordinate system of each iron club, a principal axis along the center axis (shaft axis) of the club shaft 13 is defined as a first axis (x), and extends in the club swing direction orthogonal to the first axis (x). Spindle (generally, this spin axis is orthogonal to the first axis, and at the sweet spot of the club head 11, the face (hit surface) 3a
It extends parallel to the vertical plane orthogonal to and is horizontal)
Is the second axis (z), and the main axis orthogonal to the first axis (x) and the second axis (z) is the third axis (y). The first embodiment of the present invention is, for example, a bar-shaped weight body 14 having a uniform mass distribution in the neck portion 12 of the iron club 10 of the existing form.
It is realized by fixing the through holes.

[0025]

[Table 1]

Table 1 shows club Nos. To which the first embodiment of the present invention is applied. Club No. 3 to The length of the iron club up to 9, the moments of inertia I _x , I _y , I _z about each main axis before the weight body 14 is attached, and the angular acceleration dW _x / of the club head 11 about the first axis (x) dt and the value (maximum value) of the product W _y · W _z of the angular velocities W _z and W _y of the club head 3 around the second axis (z) and the third axis (y) near the impact are shown. The moments of inertia I _x , I _y , and I _z around each main axis can be obtained by the following _equation 3.

[0027]

Equation 3] _{I (x, y, z)} = IG (x, y, z) · md 2 = mr 2 + md 2 where IG _{(x, y, z)} is the corresponding spindle (x, y,
z) is the moment of inertia about an axis parallel to and passing through the center of gravity of the club head, m is the mass of the club head, r is the radius of gyration, and d is the distance from the corresponding principal axis to the center of gravity of the club head.

FIG. 3 shows the club numbers of the golf club set. Angular acceleration dW _x during the swing from the top swing to the impact of each iron club 3, 6, 9
/ Dt and shows the temporal change in the value of the product W _y · W _z of the angular velocity. As can be seen from FIG. 3, the angular accelerations dW _x / dt around the first axis (x) at the time points from the top swing of each club to immediately before the impact have almost the same value, and the average value near the impact is about −. It is 125.0 rad ² / sec ² . Therefore, in Table 1, the first axis (x) of each iron club
The angular acceleration dW _x / dt around is set to -125.0 rad ² / sec ² . The product of the angular velocities W _y and W _z in Table 1 is the maximum value immediately before the impact (see FIG. 3),
When this is shown in a graph, as shown in FIG. 4A, the value of the product W _y · W _z of angular velocities (| W _y · W _z |) increases in club count (club number) (club number). The length will decrease)
It can be seen that it decreases almost proportionally according to.

Based on these data shown in Table 1, the rotational torque N _x of the club head 11 around the first axis (x) of each iron club is determined by the above-mentioned _equation 2, and Table 1 and FIG. As shown in c), it can be seen that the rotation torque N _x of each iron club near the impact is not constant.

[0030]

[Table 2]

Therefore, in this embodiment, as shown in FIG.
As shown in (a), (b), (c) and Table 2, the club No. Club No. 3 to The iron clubs up to 8 are provided with the bar-shaped weight bodies 14 having the same mass M (0.02 kg), and the inertia moment I _x of the club head 11 around the first axis (x) in each iron club is the same. The difference (I _y −I _z ) in the moment of inertia of the club head about the second axis and the third axis in each golf club and the angular velocities W _z and W _y around the second axis and the third axis near the impact. The product length (| (I _y −I _z ) W _y · W _z |) is substantially the same, and the length L and the mounting angle θ of each weight body 14 are changed. In addition, as shown in FIG. 1, the axis of the weight body 14 is located in the yz plane formed by the second axis (z) and the third axis (y), and the weight body 14 has the first axis (x ) Are arranged symmetrically by the length of L / 2. Then, the attachment angle θ of the weight body 14 is determined in the clockwise direction from the second axis (z) on the yz plane.

As described above, in the club set, the product value (| W _y · W _z |) of the angular velocities W _y and W _z increases almost linearly (proportionally) as the club length becomes longer. Therefore (see FIG. 4A), when the inertia moments I _x of the iron clubs are the same, the rotational torque N _x of the club head 11 around the first axis (x) near the impact in each iron club is the same. In order to achieve, the difference (I _y −I _z ) in the moment of inertia of the club head about the second axis and the third axis in each golf club and the angular velocity W about the second axis and the third axis near the impact The product of _z and W _y (| (I _y −I _z ) W _y · W _z |) must be the same. Therefore, in the first embodiment, as shown in FIG. 4B, the difference in moment of inertia (| I _y −I _z |) follows the hyperbola as the number of iron clubs (club No.) increases. Is changing.

Based on these data shown in Table 2, the rotational torque N _x of the club head 11 around the first axis (x) of each iron club is determined by the above-mentioned _equation 2, and the weight of the first embodiment is calculated. The rotational torque N _x of the club head 11 around the first axis (x) near the impact in each iron club after the body is attached has the same value (−0.260 Nm) as shown in Table 2 and FIG. 4C. I understand.

The vertical axis in FIGS. 4A to 4C indicates the club number. The ratio of the value of each of the other iron clubs to the value of the iron club of 9 is shown.

2 (a), (b) and (c) show the club No. 1 according to the present invention shown in Table 1. Club No. 3 to 9 shows a second embodiment when applied to a golf club set including iron clubs up to 9 and illustrates one of the iron clubs constituting the set. In the figure, the same components as those of the first embodiment are designated by the same reference numerals.

[0036]

[Table 3]

In the second embodiment, as shown in Table 3,
Club No. Club No. 3 to Weight bodies 15 having masses substantially only at both ends are fixed to the neck portion 12 of the iron club 10 up to 8 through. The mass M of each weight body 15 is the same (0.02 kg). Also in this second embodiment, the moment of inertia I _x of the club head 11 around the first axis (x) in each iron club is the same, and the second axis (z) and the third axis in each golf club are the same. The product of the difference (I _y −I _z ) in the moment of inertia of the club head about the axis (y) and the angular velocities W _z and W _y about the second and third axes near the impact (| (I _y -I _z )
Each weight 1 so that W _y · W _z |) is substantially the same.
The length L of 4 and the mounting angle θ are changed.

Based on these data shown in Table 3, the rotational torque N _x of the club head 11 around the first axis (x) of each iron club is determined by the above-mentioned _equation 2, and the weight of the second embodiment is calculated. As shown in Table 3, the rotational torque N _x of the club head 11 around the first axis (x) near the impact in each iron club after body attachment is the same value (−0.260 Nm).
It turns out that

In the above-mentioned first and second embodiments, the mounting position of the weight bodies 14 and 15 on the first axis (x) line is the rotational torque N of the club head 11 around the first axis (x). _Does not affect _x . Because the weight body 14,1
When the mounting position of No. 5 (position on the first axis) is changed by Δx, the amount of change in inertia moment around each main axis ΔI _x , ΔI _y ,
This is because ΔI _z is 0 as shown in the following formula 4.

[0040]

(4) ΔI _x = 0 ΔI _y = ΔI _z = M · Δx ² ∴ΔI _y −ΔI _z = 0

Therefore, the attachment positions of the weight bodies 14 and 15 can be set to arbitrary positions on the first axis (x).

Further, in the above-mentioned first and second embodiments,
Club No. By providing the weight bodies 14 and 15 on the iron clubs other than the iron club of No. 9, the value of the rotation torque N _x of these other iron clubs is set to the club number. Although the rotation torque N _x of the iron club No. 9 was made to match, the present invention is not limited to this mode, and the iron club omitting the weight bodies 14 and 15 is the club No. Any of the clubs other than 9 may be used, and the weight bodies 14 and 15 may be provided in all the iron clubs constituting the set.

5 (a), 5 (b) and 5 (c) show the club No. 1 according to the present invention shown in Table 1. Club No. 3 to It shows a third embodiment when applied to a golf club set composed of iron clubs up to 9, and illustrates one of the iron clubs forming the set. In the figure, the same components as those of the first embodiment are designated by the same reference numerals.

[0044]

[Table 4]

In the third embodiment, as shown in FIG. Club No. 3 to The weight body 16 is fixed to the back surface side of the club head 11 of the iron club 10 up to 9. Here, the mounting position of the weight body 16 is defined as a distance from the second axis (z) and b distance from the second axis (y) (see FIGS. 5A and 5B). In the third embodiment, the moment of inertia I _x of the club head 11 around the first axis (x) in each iron club is, as shown in FIG.
Number of clubs before and after installation (Club No.)
Increases almost proportionally with the increase of. The difference (I _y −I _z ) in the moment of inertia of the club head about the second axis (z) and the third axis (y) in each golf club and the angular velocity about the second axis and the third axis near the impact. The product value of W _z and W _y (| (I _y −I _z ) W _y · W _z |) is the moment of inertia I _x and the angular acceleration dW _x / d about the first axis (x).
The mass (M) of each weight body 16 and each main axis (x, y, so that the amount of change is substantially the same as the amount of change in the product value with t.
The mounting positions a and b with respect to z) are changed. At this time, as described above, under the condition that the values of W _y and W _z change in a substantially proportional manner, as shown in FIG. 6B, I _y − in each iron club before the weight body is attached. While the value of I _z changes substantially linearly, the value of I _y −I _z changes in a curve in each iron club after the weight body is attached.

Based on these data shown in Table 4, the rotational torque N _x of the club head 11 around the first axis (x) of each iron club is determined by the above-mentioned _equation 2, and each of the third embodiment is calculated. The rotational torque N _x of the club head 11 around the first axis (x) near the impact in the iron club is the same value (−0.257 Nm) as shown in Table 4 and FIG. 6C.
It turns out that

The vertical axis in FIGS. 6A and 6B represents the value of each iron club, and the vertical axis in FIG. 6C represents the club number. The ratio of the value of each of the other iron clubs to the value of the iron club of 9 is shown.

In the third embodiment, the weight bodies 16 are provided on the club heads 11 of all the iron clubs that make up the set. However, in any one iron club, the weight body 1 is used.
It is possible to omit 6.

The case where the present invention is applied to the set of iron clubs has been described above, but it will be apparent that the present invention can also be applied to the set of wood clubs. In addition, the number of golf clubs that make up the set (Club N
o. ) Can be arbitrarily selected.

[0050]

As is apparent from the above description, according to the present invention, the rotational torque of the club head around the shaft axis (first axis) near the impact in each golf club constituting the set is made the same. As a result, the direction of the club face (the degree of return of the club head) near the impact of each golf club forming the set can be made the same, so that the direction of the hit ball can be made constant under a constant swing. A golf club set capable of being provided can be provided.

[Brief description of drawings]

FIG. 1 shows a first embodiment in which the present invention is applied to an iron club set, (a) is a side view of a main part of the iron club as seen from the toe side of the club head, and (b) is a face of the club head. FIG. 3C is a front view of an essential part viewed from the side, and FIG. 3C is a plan view of the essential part viewed from above the shaft axis.

FIG. 2 shows a second embodiment in which the present invention is applied to an iron club set, (a) is a side view of a main part of the iron club as seen from the toe side of the club head, and (b) is a face of the club head. FIG. 3C is a front view of an essential part viewed from the side, and FIG. 3C is a plan view of the essential part viewed from above the shaft axis.

[Fig. 3] Club No. constituting the set. Weight swing of 3, 6, 9 iron club dW _x / dt and W _y · W _z during swing from top swing to impact
It is a graph which shows the change of.

FIG. 4A is a graph showing a ratio of maximum values (absolute values) of W _y and W _{z in} the vicinity of the impact of each iron club forming the set, and FIG. 4B is I _y −I _z of each iron club.
Is a graph showing the ratio (absolute value) of each of the iron clubs, (c) is (I _y −I _z ) W _y · W _z of each iron club before the weight body is attached and after the weight bodies of the first and second embodiments are attached. It is a graph which compares and shows the ratio of the value (absolute value) of.

FIG. 5 shows a third embodiment in which the present invention is applied to an iron club set, (a) is a plan view of a main part of the iron club seen from above the shaft axis, and (b) is a sole side of the club head. A bottom view of essential parts seen, and (c) is a schematic front view of the entire club viewed from the face side of the club head.

FIG. 6A is a graph showing the value of I _x of each iron club constituting the set before the weight body is attached and after the weight body of the third embodiment is attached, and FIG. 6B is the weight body attachment of each iron club. before a graph illustrating the value of I _y -I _z after weight body attached to the third embodiment, (c) the torque N _x after weight body attachment of the weight member before mounting the third embodiment of the iron clubs It is a graph which compares and shows the ratio of the value (absolute value) of.

[Explanation of symbols]

 10 Iron Club 11 Club Head 12 Neck 13 Club Shaft 14, 15, 16 Weight

Claims (5)

[Claims] 1. In a golf club set including a plurality of golf clubs having different club lengths and club head weights, the rotational torque of the club head around the shaft axis near the impact of each golf club represented by the following formula 1. Golf club set characterized in that (N _x ) is substantially the same: Where I _x is the moment of inertia of the club head about a first axis (x) along the shaft axis, and I _z is about a second axis (z) that is orthogonal to the first axis and extends in the club swing direction. Club head inertia moment, I _y is the club head inertia moment about a third axis (y) orthogonal to the first and second axes, and W _x , W _z , and W _y are the first axis and the second axis, respectively. And the angular velocity of the club head about the third axis. 2. The club head's moment of inertia (I _x ) about a first axis in each golf club is substantially the same, and the club head's inertia about a second axis and a third axis in each golf club. The product value (absolute value) of the difference between the moments (I _y −I _z ) and the angular velocities (W _z , W _y ) around the second axis and the third axis near the impact is substantially the same. The golf club set according to claim 1. 3. The moment of inertia (I _x ) of the club head about the first axis in each golf club changes approximately proportionally as the club length changes, and the second axis and the third axis of each golf club change. The product value (absolute value) of the difference (I _y −I _z ) in the moment of inertia of the club head about the axis and the angular velocity (W _z , W _y ) about the second axis and the third axis near the impact is Inertia moment (I _x ) of the club head about one axis and angular acceleration about the first axis (dW _x / dt)
2. The golf club set according to claim 1, wherein the golf club set is changed by a change amount substantially the same as a change amount of a product value of. 4. The golf club set according to claim 2, wherein each golf club or a golf club other than one golf club is provided with a weight body for adjusting a moment of inertia of the club head at a neck portion thereof. 5. The golf club set according to claim 3, wherein a weight body that adjusts the moment of inertia of the club head is provided on the club heads of each golf club or other golf clubs other than one golf club.