JPH11319159A - Iron gold club set - Google Patents

Abstract

(57) Abstract: The present invention relates to an iron golf club set, in which an inertia moment important as a characteristic of an iron club head is represented by an inertia ellipsoid around a center of gravity, and a magnitude of an inertia moment around a main axis thereof. By setting the length within a certain range, the swing that varies for each club number is stabilized. SOLUTION: In an iron golf club set, when each iron club head 1 is set on a plane H such that a hosel end face 1C is horizontal, an axis passing through a center of gravity G of the iron club head 1 and perpendicular to the plane H is Z
The axis passes through the center of gravity G of the iron club head 1 parallel to the intersection line of the plane H and the face surface 1B, and passes through the center of gravity G of the iron club head 1; Assuming that the axis is the X axis, the maximum moment of inertia among the three inertia moments of the inertia ellipsoid passing through the center of gravity G of the iron club head 1 that are orthogonal to each other is between 2000 and 5000 gcm ² . An iron golf club set characterized by having a minimum moment of inertia of 100 to 1000 gcm ² .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an iron golf club set, in which an inertia moment important as a characteristic of an iron club head is represented by an inertia ellipsoid around a center of gravity, and the magnitude of the inertia moment around the principal axis is shown. By setting it within a certain range, the swing that varies for each club number is stabilized.

[0002]

2. Description of the Related Art In consideration of an inertia ellipsoid, Japanese Patent Laid-Open Publication No. 5-57034 discloses a method of reducing the weight distribution of the inertia ellipse in the main axis direction and increasing the weight of the iron club head by minimizing the reduction. However, in the case of an iron golf club set, variations in swing for each club number may hinder the intended shot.

In Japanese Patent Application Laid-Open No. 9-149954,
In some golf balls, the sweet area is set in accordance with the distribution of hit balls. However, in the case of an iron golf club set, variation in the swing of each club number may hinder the intended shot.

[0004] In the prior art, no proposal has been made in which the magnitude of the moment of inertia about the main axis of an inertial ellipsoid, which represents the moment of inertia using all axes around the center of gravity, is set within a certain range. . By representing the moment of inertia of an iron club head having a complicated shape with an equivalent ellipsoid and setting the magnitude of the moment of inertia around its principal axis within a certain range, the swing for each club number in the iron golf club set Can be suppressed.

[0005]

SUMMARY OF THE INVENTION An object of an iron golf club set is to reliably grasp the flight distance and direction of a ball aimed by a batter. For this reason, variation in the swing in the iron golf club set makes the flight distance of the ball unstable, which is not preferable in score making.

Generally, the moment of inertia I is given by I = Σmr
² (m: mass, r: distance from rotation axis to mass). However, in the iron golf club set generally used at present, the moment of inertia around one axis is considered, but the inertia ellipsoid is not considered. In fact,
The movement of the iron club head during the swing
It is not fixed around a certain axis, but makes complicated movements in three dimensions. Therefore, it is very important to consider the moment of inertia around the center of gravity. By setting the magnitude of the moment of inertia about the principal axis of the inertial ellipsoid within a certain range,
It is possible to minimize variations in the movement of the iron club head. An object of the present invention is to provide an iron golf club set in which the magnitude of the moment of inertia around the main axis of the inertial ellipsoid is kept constant, thereby stabilizing the swing between club numbers.

[0007]

In order to achieve the above object, according to the present invention, an inertial ellipsoid 5 is obtained by using a method having the following constitution. First, as shown in FIG. 2, X, Y and Z orthogonal three-dimensional coordinate axes are set around the center of gravity of the iron club head. Each iron club head is placed on a plane H such that the end face of the hosel is horizontal, an axis passing through the center of gravity G of the iron club head and perpendicular to the plane H is a Z axis
The axis passing through the center of gravity of the iron club head parallel to the intersection of the plane and the face surface is defined as the Y axis, and the axis passing through the center of gravity of the iron club head and perpendicular to the Y axis and perpendicular to the Z axis is defined as the X axis. Next, a moment of inertia around the X axis is IX, a moment of inertia around the Y axis is IY, a moment of inertia around the Z axis is IZ, and a new coordinate system when the Z axis is rotated by -α degrees as shown in FIG. Are defined as X ′, Y ′, and Z, and the moment of inertia about the X ′ axis at that time is defined as IX ′. Further, as shown in FIG. 5, the new coordinate system when the Y axis is rotated by -β degrees is X '', Y, Z '', and the moment of inertia about the X '' axis at that time is IX ''. . Further, as shown in FIG. 6, the new coordinate system when the X axis is rotated by −γ degrees is X, Y ″ ″, Z ″ ″, and the moment of inertia about the Z ′ ″ axis at that time is IZ '''. From the above value, 3
The two moments of inertia are calculated by Equations 1, 2, and 3.

[0008]

(Equation 1)

[0009]

(Equation 2)

[0010]

(Equation 3)

Using the above-mentioned six moments of inertia, the equation of the ellipsoid of inertia is obtained by Equation 4.

[0012]

(Equation 4)

Next, eigenvalues and eigenvectors are obtained from the moment of inertia matrix I. That is, eigenvalues and eigenvectors are obtained from the matrix I in Equation 5. The inclination angle and magnitude of the principal axis of inertia are determined from the eigenvalue and the eigenvalue vector.

[0014]

(Equation 5)

[0015]

Embodiments of the present invention will be described in detail below. That is, in the iron golf club set, when each iron club head 1 is set on the plane H such that the hosel end face 1C is horizontal,
The axis passing through the center of gravity G of the iron club head 1 and perpendicular to the plane H is the Z axis, and the axis passing through the center of gravity G of the iron club head 1 and parallel to the line of intersection between the plane H and the face surface 1B is Y.
When the X axis is perpendicular to the X axis and perpendicular to the Z axis through the center of gravity G of the iron club head 1, three mutually perpendicular inertia of the inertial ellipsoid passing through the center of gravity G of the iron club head 1 Among the moments of inertia around the main axis, the maximum moment of inertia is between 2000 and 5000 gcm ² , and the minimum moment of inertia is between 100 and 1000 g.
cm ² is an iron golf club set.

Further, in the iron golf club set, when each iron club head 1 is set on a plane H such that the hosel end face 1C is horizontal, the iron golf club set passes through the center of gravity of the iron club head 1. The axis perpendicular to the plane H is the Z axis, the axis passing through the center of gravity G of the iron club head 1 parallel to the intersection of the plane and the face surface is the Y axis, and the axis passing through the center of gravity G of the iron club head 1 is perpendicular to the X axis. When the axis perpendicular to the Z axis is set to the X axis, the maximum value of the inertia moment among the three inertia moments of the inertia ellipsoid passing through the center of gravity G of the iron club head 1 is 2,500. between ~5000gcm ^2, and the minimum moment of inertia is an iron golf club set, which is a 100~700gcm ^2. It should be noted that the principal axes of inertia I ₁ , I ₂ , and I ₃ of the present invention are defined as follows: principal axis of inertia: I ₁ has the largest moment of inertia around the principal axis among three orthogonal principal axes of inertia. Axis. The principal axis of inertia: I _2, of the three orthogonal principal axes of inertia, moment of inertia about principal axis is the axis nor a minimum at the maximum. Inertia principal axis: I3 is an axis of _three orthogonal principal axes of inertia in which the moment of inertia around the principal axis is minimized.

According to a third aspect of the present invention, in the iron golf club set, the value of the maximum moment of inertia among the three moments of inertia around the mutually orthogonal principal axes of inertia of the inertia ellipsoid passing through the center of gravity G of the iron club head 1 is set. Is 20
An iron golf club set characterized by having a minimum moment of inertia of between 300 and 700 gcm ² , between 0.00 and 4000 gcm ² .

According to a fourth aspect of the present invention, in the iron golf club set, the value of the maximum moment of inertia of the three inertial moments of the inertia ellipsoid passing through the center of gravity G of the iron club head 1 is provided. Is 25
Between 00~3500gcm ^2, and the minimum moment of inertia is an iron golf club set, which is a 400~600gcm ^2.

The invention according to claim 5 is an iron golf club set, wherein the iron golf club set is a long iron to short iron golf club set (2I to 9I).

The invention according to claim 6 is an iron golf club set, wherein the iron golf club set is a long iron golf club set (2I to 4I).

According to a seventh aspect of the present invention, the iron golf club set is a middle iron golf club set (4).
I-7I) is an iron golf club set.

An eighth aspect of the present invention is the iron golf club set, wherein the iron golf club set is a short iron golf club set (7I to 9I).

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be mainly described based on the second aspect of the present invention. In the embodiment of the present invention, an inertial ellipsoid 5 around the center of gravity G of the head body 1A of the iron club head 1 is shown. A weight rib member 7 is formed on the toe portion 2 and the heel portion 3 of the iron club head 1. Therefore, the size of the inertial ellipsoid 5 can be set to the size intended by the present invention. In FIG. 8, the weight rib members 7 are arranged on the toe portion 2 and the heel portion 3. However, in order to set the size of the inertial ellipsoid 5 in the major axis direction larger, the toe portion 2 shown in FIG. It is not necessary to limit the location of the heel portion 3 and the weight rib member 7
Can be variously changed.

In the present invention, the value of the maximum moment of inertia and the value of the minimum moment of inertia of the three inertia moments of the inertia ellipsoid passing through the center of gravity G of the iron club head 1 are considered. It is a design concept.

Table 1 shows examples.

[0026]

[Table 1] Maximum and minimum moments of inertia around three principal axes of inertia according to an embodiment of the present invention.
(Unit: gcm ² )

FIG. 9 is a graph showing the magnitude of the maximum moment of inertia about the principal axis of inertia in the iron club set according to the first embodiment of the present invention. FIG. 10 is a graph showing the magnitude of the minimum moment of inertia around the principal axis of inertia in the iron club set according to the first embodiment of the present invention. Table 2 shows the result of the amateur golfer swinging the club set of Example 1.

[0028]

[Table 2]

The iron golf club set of the present invention comprises:
It is designed so that the magnitude of the moment of inertia around the three principal axes of inertia around the center of gravity is within a certain range, and the magnitude of the moment of inertia greatly affects the rotational movement of the object. For example, when considering a toy like a top, it is considered that a thing that keeps rotating around a rotation axis for a long time is good. On the other hand, in the case of the iron club head, the golf club grips the grip portion to which the shaft is connected and gives the golf club a rotational motion by swinging, instead of the iron club head itself rotating. Movements are complex and very difficult to identify. However, by designing the magnitude of the moment of inertia around the principal axis of inertia to be within a certain range, the swing of the iron club head is stabilized for each count at the time of swing, so that the flight distance and the directionality are improved. is there.

The iron golf club set of the present invention comprises:
As described above, the magnitude of the moment of inertia around the principal axis of inertia of the inertial ellipsoid around the center of gravity of the iron club head is designed to be within a certain range, thereby stabilizing the swing and stabilizing the flight distance of the hit ball. The directionality of the hit ball is improved.

[0031]

According to the iron golf club set of the present invention, an iron club head representing the moment of inertia about all axes around the center of gravity of the iron club head, such as a long iron golf club set to a short iron golf club set. By designing the magnitude of the moment of inertia about three mutually perpendicular principal axes of inertia of the inertial ellipsoid passing through the center of gravity of the fixed range, the swing is stabilized, so that the flight distance of the hit ball is stabilized and the directionality is improved. This has an advantageous effect.

[Brief description of the drawings]

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

FIG. 2 is a perspective view showing coordinates in the iron club head of the present invention.

FIG. 3 is a perspective view showing an inertial ellipsoid in the iron club head of the present invention.

FIG. 4 is a perspective view showing coordinates in the iron club head of the present invention.

FIG. 5 is a perspective view showing coordinates in the iron club head of the present invention.

FIG. 6 is a perspective view showing coordinates in the iron club head of the present invention.

FIG. 7 is a perspective view showing Embodiment 1 of the iron club head of the present invention.

FIG. 8 is a perspective view showing Embodiment 2 of the iron club head of the present invention.

FIG. 9 is a graph showing the magnitude of the maximum moment of inertia around the principal axis of inertia according to the first embodiment of the present invention.

FIG. 10 is a graph showing the magnitude of the minimum moment of inertia around the principal axis of inertia according to the first embodiment of the present invention.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 iron club head 1A head main body 1B face surface 1C hosel end surface 2 toe portion 3 heel portion 4 back cavity portion 5 inertial ellipsoid 6 weight member 7 weight rib member 8 concave portion G center of gravity H plane I ₁ inertia main shaft I ₂ inertia main shaft I ₃ Main axis of inertia X X axis Y Y axis Z Z axis

[Procedure amendment]

[Submission date] March 16, 1999

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction contents]

[0007]

In order to achieve the above object, according to the present invention, an inertial ellipsoid 5 is obtained by using a method having the following constitution. First, as shown in FIG. 2, X, Y, and Z orthogonal three-dimensional coordinate axes are set around the center of gravity of the iron club head. Each iron club head is placed on a plane H such that the end face of the hosel is horizontal, an axis passing through the center of gravity G of the iron club head and perpendicular to the plane H is a Z axis, and is parallel to an intersection line between the plane and the face surface. The axis passing through the center of gravity of the iron club head is the Y axis, and the axis passing through the center of gravity of the iron club head and perpendicular to the Y axis and perpendicular to the Z axis is the X axis. Next, the moment of inertia around the X axis is I _X , the moment of inertia around the Y axis is I _Y , the moment of inertia around the Z axis is I _Z ,
As shown in FIG. 4, the new coordinate system when the Z axis is rotated by -α degrees is X ', Y', Z, and the moment of inertia about the X 'axis at that time is I _{X '} . Further, as shown in FIG. 5, the new coordinate system when the Y axis is rotated by -β degrees is X '',
Let Y, Z '' be the moment of inertia about the X '' axis at that time, I _{X ''} . Further, as shown in FIG.
X, Y '''', Z '''' new coordinate system when rotated by degrees
And the moment of inertia about the Z '''axis at that time is I
_{Z '''} . From the above values, three moments of inertia are calculated by Equations 1, 2, and 3.

Claims (8)

[Claims] In an iron golf club set, when each iron club head is installed on a plane such that an end surface of a hosel is horizontal, an axis passing through the center of gravity of the iron club head and perpendicular to the plane is a Z axis, and the plane is When the axis passing through the center of gravity of the iron club head parallel to the line of intersection with the club face is the Y axis, and the axis passing through the center of gravity of the iron club head and perpendicular to the Y axis and perpendicular to the Z axis is the X axis,
Of the three inertia moments of inertia around the principal axes of inertia of the inertia ellipsoid passing through the center of gravity of the iron club head,
The value of the maximum moment of inertia is 2000-5000 gcm
² and the minimum moment of inertia is 100-100
An iron golf club set having a weight of 0 gcm ² . 2. In the iron golf club set, when each iron club head is installed on a plane such that the end face of the hosel is horizontal, an axis passing through the center of gravity of the iron club head and perpendicular to the plane is the Z axis. When the axis passing through the center of gravity of the iron club head parallel to the intersection of the plane and the club face is the Y axis, and the axis passing through the center of gravity of the iron club head and perpendicular to the Y axis and perpendicular to the Z axis is the X axis, Of the inertia moments about three mutually orthogonal principal axes of inertia passing through the center of gravity of the iron club head, the maximum value of the inertia moment is 2500 to 5000.
gcm ² and the minimum moment of inertia is 100 to
The iron golf club set according to claim 1, wherein the iron golf club set is 700 gcm ² . 3. The iron golf club set, wherein the inertia ellipsoid 3 passing through the center of gravity of the iron club head.
Of the moments of inertia about the principal axes of inertia orthogonal to each other in the book, the maximum value of the moment of inertia is 2000 to 4000 g.
cm ² and a minimum moment of inertia of 300 to 7
3. The iron golf club set according to claim 2, wherein the iron golf club set is 00 gcm ² . 4. The iron golf club set, wherein the inertial ellipsoid 3 passing through the center of gravity of the iron club head.
Of the moments of inertia around the principal axes of inertia orthogonal to each other, the maximum value of the moment of inertia is 2500 to 3500 g.
cm ² and the minimum moment of inertia is 400-6
The iron golf club set according to claim 3, wherein the iron golf club set is 00 gcm ² . 5. The iron golf club set according to claim 1, wherein the iron golf club set is a long iron to short iron golf club set. 6. The iron golf club set according to claim 1, wherein the iron golf club set is a long iron golf club set. 7. The iron golf club set according to claim 1, wherein the iron golf club set is a middle iron golf club set. 8. The iron golf club set according to claim 1, wherein the iron golf club set is a short iron golf club set.