JP2001137397A - Wood golf club - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wood golf club that increases a backspin. SOLUTION: The longitudinal reference borderline L of a face 2a is curved outwardly. At acute angle side absolute value angles θcy and θsy formed by tangent lines Tcy and Tsy of the longitudinal reference borderline L at the crown portion side point cy and the sole portion side point sy separated by the distance of the vertical reference borderline L y in the direction of the tangent line To at the cardinal point O to the crown portion side and the sole portion side from the cardinal point O of the longitudinal reference borderline L and the tangent line To, if the distance y is 5 mm or more, θcy is larger than θsy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wood-type golf club capable of increasing the amount of back spin of a hit ball.

[0002]

2. Description of the Related Art A general wood type golf club head has a roll (sometimes referred to as a "vertical face roll") on a face on which a ball is hit. The “roll” is a vertical round or curved surface formed on the face f when the head a is viewed from the side as shown in FIG. 7A.

[0003] Such a roll has a function of weakening the vertical gear effect. First, the vertical gear effect is described as follows. When the ball is hit closer to the crown c or closer to the sole s than the center of the face f, the head a is a moment which is the product of the impact force F with the ball b and the orthogonal distance L1 or L2 to the center of gravity G. Instantaneously rotates about a horizontal axis passing through the center of gravity G. At this time, due to the frictional force between the two, a force in a direction opposite to the rotation of the head a, like a gear in which the ball b meshes with the face f. The phenomenon of receiving That is, when the ball b is hit near the crown c on the face f, the vertical gear effect reduces the backspin amount of the ball, and conversely, the sole s on the face f.
When the ball b is hit closer, the backspin amount of the ball b is increased.

[0004] As shown in FIG. 7B, the face f provided with the rolls is closer to the crown side or sole side than the center of the face face as compared with the face fn not provided with the rolls. When the ball b is hit at a position shifted by the same distance, the orthogonal distance L1 or L2 between the center of gravity G of the head and the impact force F becomes shorter, and the rotational moment of the head becomes smaller, so that the vertical gear effect is reduced. Weaken.

[0005]

By the way, the conventional roll has almost the same radius of curvature R from the upper edge to the lower edge of the face surface f, that is, the crown c from the center of the face surface f.
The side and the sole s side were each formed with the same roundness. However, when the head a having such a roll hits the ball near the sole portion s of the face f, the face b faces down as compared with the head without the roll, so that the ball b hits out. The angle is small, the vertical gear effect is weakened by the roll, the backspin amount can not be expected to increase sufficiently, causing insufficient carry, and the flying distance is easily lost due to the so-called drop ball that falls to the ground immediately after hitting the ball There was a disadvantage.
Especially for beginner golfers with a slow head speed, the above tendency is likely to appear remarkably, and the hitting angle of the head is often small. Tends to be in a low backspin state, and sufficient carry cannot be obtained.

The present invention has been devised in view of the above problems, and is based on changing the angle of the tangent of the roll between the sole portion and the crown portion. When hitting, the launch angle is reduced and more backspin is given to the ball, and when the ball is hit near the crown, the backspin amount of the ball is suppressed, so that the carry is sufficient even in the case of a miss shot. It is an object of the present invention to provide a wood-type golf club which can be secured to a golf club and minimize a decrease in flight distance.

[0007]

According to a first aspect of the present invention, there is provided a wood-type golf club having a head having a face roll, wherein a center line C of a shaft is positioned on a vertical plane VP. In a reference state where the center line C is placed at the lie angle of the club and the face surface is inclined at the loft angle and placed on the horizontal surface, a horizontal plane passing through a height position intermediate between the lowest position and the highest position of the face surface H
The intersection of P and the face surface is defined as a face horizontal reference contour line K, and a second line perpendicular to the vertical plane VP passing through a center point of a line connecting both ends of the face horizontal reference contour line K.
A vertical vertical contour line L where the vertical plane intersects the face surface is formed in a curved shape of an outward bulge, and a crown is formed from a base point O which is an intersection of the horizontal lateral reference contour line K and the vertical face reference line L. A crown side point cy that separates a distance y in a direction of a tangent line To at a base point O of the face vertical reference contour line L, and a face vertical reference contour line at a sole portion side point sy, on the part side and the sole part side. L tangent T
When the distance y is equal to or greater than 5 mm, θcy> θsy, where cy, Tsy and the absolute value angles θcy, θsy on the acute angle side formed by the tangent line To are characterized in that θcy> θsy.

[0008] In the invention described in claim 2, the face vertical reference contour line L is defined as θc when the distance y is 5 mm or more.
2. The wood type golf club according to claim 1, wherein y ≧ 1.1 × θsy.

According to a third aspect of the present invention, the face is provided.
The vertical reference contour line L is a terminal point cy on the crown side._n,
End point sy on sole side_nUp to the base point O
Cy₁, Cy_Two, ..., cy_n-1, C
y_n, And sy₁, Sy_Two, ..., sy_n-1, Sy_nIn
The absolute value angle θcy on the acute angle side of the tangent line₁, Θc
y _Two, ..., θcy_n-1, Θcy_n, And θsy₁, Θs
y_Two, ..., θsy_n-1, Θsy_nAt θcy₁≤θcy_Two≤ ... ≤θcy_n-1≤θcy_n θsy₁≤θsy_Two≤ ... ≤θsy_n-1≤θsy_n 3. The method according to claim 1, wherein the following relationship is satisfied.
It is a wood type golf club.

According to a fourth aspect of the present invention, the face
The vertical reference contour line L is a terminal point cy on the crown side._n,
End point sy on sole side_nUp to the base point O
Cy₁, Cy_Two, ..., cy_n-1, C
y_n, And sy₁, Sy_Two, ..., sy_n-1, Sy_nIn
The absolute value angle θcy on the acute angle side of the tangent line₁, Θc
y _Two, ..., θcy_n-1, Θcy_n, And θsy₁, Θs
y_Two, ..., θsy_n-1, Θsy_nAt θcy₁<Θcy_Two<… <Θcy_n-1<Θcy_n θsy₁<Θsy_Two<… <Θsy_n-1<Θsy_n 3. The method according to claim 1, wherein the following relationship is satisfied.
It is a wood type golf club.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a front view of a wood type golf club (hereinafter, may be simply referred to as “club”) 1 of the present embodiment, and FIG. 2 is a side view thereof. In the figure, a club 1 has a head 2 and one end of the head 2
And a shaft 4 having a grip (not shown) at the other end.

The head 2 has a face 2a which hits a ball and has a predetermined loft angle, a crown 2b which is connected to an upper edge of the face 2a and forms an upper surface of the head 2, and a face 2a. And a side portion 2d extending between the crown portion 2b and the sole portion 2c, and a shaft mounting portion 2e to which the shaft 4 is mounted. Further, the head 2 of the present example has a head volume of 22 for example.
It is exemplified that the metal is about 0 to 320 cm ³ and the depth of the center of gravity (the horizontal distance between the center of gravity of the head and the lower edge of the face surface 2 a) is about 21 to 46 mm. 1 and 2, the center line C of the shaft 4 is positioned on the vertical plane VP, and the center line C is set at a lie angle α preset for the club, and the face surface 2a is set at a loft angle β. A reference state in which the head 2 is mounted on a horizontal plane GP while being inclined is shown. The loft angle β is a state in which the hook angle is 0 ° as is well known.

In the present embodiment, the face surface 2a is formed to have a curved surface, that is, a roll that is smoothly convex outward in the vertical direction. And this roll 3
Is set as described below. First, a line segment in which the horizontal plane HP passing through the intermediate height position between the lowest position A and the highest position B of the face surface 2a intersects with the face surface 2a is defined as a face lateral reference contour line K. FIG. 3 illustrates a partial cross-sectional view of the club 1 cut along the horizontal plane HP. Then, both ends kt of the face horizontal reference contour line K,
A line segment that passes through the center point CP of a line segment (straight line) N connecting kh and intersects the second vertical surface VP2 perpendicular to the vertical surface VP and the face surface 2a is defined as a face vertical reference contour line L.

FIG. 4 is an enlarged diagram showing only the face vertical reference contour line L. As is clear from the drawing, the face vertical reference contour line L is formed as a curved shape of the outer bulge. The “outside” of the “outside bulge”
This is a concept that the inside i of the head 2 is “inside”. In this example, the face lateral reference contour line K is also an outwardly bulging curve, and the face surface 2a is formed with a bulge.

The face vertical reference contour L is defined as a base point O at the intersection of the face vertical reference contour L and the face horizontal reference contour K. Furthermore, the face vertical reference contour line L
Are a crown part side point cy and a sole part side point sy that separate a distance y in the direction of a tangent line To at the base point O of the face vertical reference contour line L from the base point O to the crown part side and the sole part side. Tangent T to the face vertical reference contour L
One of the features is that, when the distance y is 5 mm or more, θcy> θsy in the absolute value angles θcy and θsy on the acute angle side formed by cy, Tsy and the tangent line To.

In the head 2 having such a roll,
Since the absolute value angle θcy on the crown portion side is larger than the absolute value angle θsy on the sole portion side, as a result, the roll 3 is more rounded on the crown portion side than on the sole portion side. The gear effect on the crown portion side of 2a is relatively weakened. Therefore, when the ball is hit on the crown portion side from the base point O, the action of the force for applying the spin in the forward rotation to the ball is reduced, and the decrease in the backspin amount is suppressed. Further, in the head 2 of the present example, the absolute value angle θsy on the sole portion side of the face surface 2a is smaller than the absolute value angle θcy on the crown portion side, so that the sole portion side has a higher surface than the toe portion side. Is flattened, which in turn enhances the gear effect. Therefore, when the ball is hit on the sole portion side from the base point O, the launch angle is prevented from becoming small and the backspin amount of the hit ball is increased, which is useful for obtaining a carry as a so-called high spin state, as described above. Drop balls can be less likely to occur.

More preferably, it is desirable that the relationship of θcy ≧ 1.1 × θsy is satisfied when the distance y is 5 mm or more in the face vertical reference contour line L. If the absolute value angle ratio (θcy / θsy) is larger than 0 and smaller than 1.1, the effect of increasing the backspin amount on the ball launched on the sole side may be relatively reduced. In addition, the effect of suppressing a decrease in the backspin amount of the ball when the ball is hit on the crown side tends to relatively decrease. From this perspective,
The face vertical reference contour line L preferably satisfies θcy ≧ 1.2 × θsy when the distance y is 5 mm or more, and more preferably satisfies θcy ≧ 1.3 × θsy.

The angle ratio (θcy / θs) is opposite to the above.
If y) is too large, the shape of the face surface 2a becomes peculiar, giving the user a sense of incongruity. In addition, the gear effect on the sole side is too strong to give an excessive backspin to the ball, or the crown portion The roundness of the roll on the side becomes too strong, and the ball hit on the crown side tends to be hit straight up, which is not preferable. From such a viewpoint, the angle ratio (θcy / θsy) is 1.
1 to 2.0, more preferably 1.1 to 1.7, still more preferably 1.2 to 1.5, particularly preferably 1.3 to 1.
It is desirable to set it to 5.

[0019] As shown in FIG. 5, the face vertical reference contour line L, the termination point cy _n of the crown portion side, points to n divided respectively to the end point sy _n of the sole portion side from the base point O cy _{1 , cy 2, ..., cy n} -1, cy n, and _{sy 1, sy 2, ...,} sy n- 1, the absolute value angle Shitacy ₁ acute side of the tangent at _{sy n, θcy 2, ...,} θc
y _n-1, θcy _n, and _{θsy 1, θsy 2, ...,} θs
y _n-1, in _{θsy n, θcy 1 ≦ θcy 2} ≦ θcy 3 ≦ ... ≦ θcy n θsy 1 ≦ θsy 2 ≦ θsy 3 ≦ ... satisfy the relation of ≦ θsy _n, more preferably θcy ₁ <θcy ₂ < _{θcy 3 <... <θcy n θsy} 1 <θsy 2 <θsy 3 <... < desirably satisfies the relationship θsy _n.

In the present embodiment, the case where n is set to 4 is exemplified. In other words, the face reference contour line L has an end point cy ₄ on the crown side and an end point s on the sole side.
The points at which y ₄ is divided into four sections from the base point O are cy
_{1 to} cy ₄ and sy _{1 to} sy ₄ . In addition, the absolute value angle θcy ₁ to the acute angle side of the tangent line at each of the points
θcy _4, and in θsy ₁ ~θsy _4, while indicating preferred embodiments satisfies the relationship _{θcy 1 <θcy 2 <θcy 3} <θcy 4 θsy 1 <θsy 2 <θsy 3 <θsy 4.

In the club 1 having such a head 2, when the hitting position of the ball deviates from the base point O of the face vertical reference contour line L toward the crown portion or the sole portion, the tangential line increases as the amount of displacement increases. As a result, the effect of increasing the backspin amount toward the crown portion side can be suppressed, and the effect of increasing the backspin amount toward the sole portion side can be enhanced. Note as an example, the distance y point on the face reference contour line L of 5 mm cy _5, the absolute value of the acute angle side of the tangent sy ₅ angle θcy _5, θsy _5, for example Shitacy ₅ to 0.8 to 2 .
5 °, more preferably 1.0 to 2.0 °, more preferably 1.2 to 2.5 °, the Shitasy ₅ 0.1 to 2.0 °,
More preferably, it is 0.5 to 1.5 °, further preferably 0.8 to 1.1 °, and the distance y
Are cy ₁₀ , sy ₁₀ on the face reference contour L of 10 mm
Absolute angle Shitacy ₁₀ of the acute angle side of the tangent, θsy ₁₀
, For example Shitacy ₁₀ of 1.8 to 3.0 °, more preferably 2.0 to 2.7 °, more preferably 2.2 to 2.5
°, the θsy ₁₀ 1.0~2.5 °, more preferably 1.
It is desirable to be 5 to 2.1 °, more preferably 1.6 to 2.0 °.

Such a face vertical reference contour line L is
As long as satisfying the above-mentioned relationship it can be formed using a variety of curves such as, for example, the base point O termination point of the crown portion side from cy _n, wherein the sole portion from the base point O endpoint sy _n Each section may be formed by a single arc, or may be a composite curve formed by connecting two or more types of arcs or elliptic curves. When a single curve is used for each section, the face vertical reference contour L
Roll radius of curvature from the origin O of the sole portion side of the end point sy _n intervals of, for example, 300 to 500 mm, preferably 350～450Mm, more preferably to a 300~450mm desirable.

The face surface 2a of the head 2 has been described with reference to the face vertical reference contour line L because the actual hitting points are likely to fluctuate up and down on the contour line L. The surface of the face surface 2a on the toe portion side and the heel portion side with respect to the reference contour line L can be formed of a free-form surface or a flat surface that smoothly connects to the face reference contour line L.

The face vertical reference contour line L is, for example, a thin film or the like adhered to the face surface 2a so as not to wrinkle to cover the unevenness such as the score line of the face surface 2a. It can be obtained by measuring the surface. More specifically, the face surface 2 along the vertical plane VP is measured by a three-dimensional shape measuring device.
a is measured at, for example, minute intervals, and based on the obtained point cloud data, a three-dimensional Bezier curve or the like is created along the point cloud data using three-dimensional CAD or the like. And the angle of the tangent can be extracted from the curve.

[0025]

EXAMPLE A wood type golf club head having a roll having the specifications shown in Table 1 and having the same shaft mounted thereon (Ferject V513 carbon shaft hardness (R) manufactured by Sumitomo Rubber Industries, Ltd.) was mounted on each of the heads. A front view of the face is shown in FIG. 6A, and a cross-sectional view taken along the face vertical reference contour line L is shown in FIG.
(B). In Table 1, the angle of the tangent is measured at four points on the crown portion and the sole portion at intervals of 5 mm from the base point. In Examples 1 to 4, θcy ₁ <θcy ₂ <... < _{θcy n-1 <θcy n θsy} 1 <θsy 2 <... < satisfies the relationship θsy _n-1 <θsy _n.

Then, the club is set on a right-handed swing robot and the head speed is 33 m / s.
A test hit test was performed to measure the backspin amount of the hit ball and the carry, which is the distance to the first drop point of the ball. In the test hitting test, the following four positions on the face vertical reference contour line L were set as the positions of the face to hit the ball, and six balls were hit at each position, and the evaluation was made based on the average value at that time. went. RBI 1: Position 5 mm from the base point O to the crown side (c
y ₅ ) Hitting point 2: 10 mm from the base point O to the crown side (cy
₁₀ ) RBI 3: Position 5 mm from base O to sole part side (sy ₅ ) RBI 4: Position 10 mm from base O to sole part side (s)
y ₁₀₎

Each head was made of a 6Al-4V titanium alloy, the head volume was set to 270 cc, and the loft angle was set to 10 degrees. In addition, the backspin amount is measured using a measuring device to measure the number of rotations of the ball about the horizontal axis immediately after the launch, and the backspin amount and the carry are also relative values based on the value when the ball is hit at the base point O. Indicates (+
Indicates an increase, and-indicates a decrease). Table 1 shows head specifications and test results.

[0028]

[Table 1]

As apparent from the test results, in the golf club of Comparative Example 1, since the absolute value angle of the tangent to the sole portion side of the face reference contour L is large, the hit points 3 to 4 are obtained.
In the case of hitting, it can be confirmed that the backspin amount is not sufficiently increased and the carry is greatly reduced. In the golf club of Comparative Example 2, since the absolute value angle of the tangent to the crown portion side of the face reference contour L was small, the hit point 1
In the case of hitting with No. 1 to No. 2, the decrease in the backspin amount is large.

On the other hand, in the golf club according to the embodiment, the backspin amount is expected to increase in the hits at hit points 3 and 4 on the sole portion side as compared with the comparative example 1, and the decrease in carry is suppressed. ing. Further, in the hits with hit points 1 and 2, the decrease in the backspin amount is suppressed as compared with Comparative Example 2. From these results, the golf club of the present embodiment has a low head speed and a sufficient launch angle cannot be obtained for a hit ball.For example, in a beginner golfer, when the hit point is removed on either the crown side or the sole side. Even in this case, it is possible to increase the buoyancy by setting the hit ball in a high spin state and minimize the decrease in carry.

Next, four beginner golfers right-handed and slow in head speed (head speed 30 to 35 m / s)
Thus, the golf club (Examples 1, 2, Comparative Example 1,
An actual hit test was performed using 2). In this test, each golfer hit 10 balls at a time, measured the carry, and determined the average of each 10 balls. The results of the test are shown in Table 2. As a result of the test, in the golf clubs of the examples, the carry increased on average, and the superiority can be confirmed.

[0032]

[Table 2]

[0033]

As described above, in the wood type golf club of the present invention, when the ball is hit on the sole side of the face surface, the gear effect is relatively enhanced, and the ball effect is obtained on the crown side of the face surface. When the is hit, the gear effect can be relatively weakened. Thereby, in the golf club of the present invention, even when the hit point is removed on either the crown side or the sole portion side from the center of the face surface, a larger amount of backspin can be given to the ball, so that the drop ball And the like, and the carry distance, especially the loss of carry, can be minimized.

[Brief description of the drawings]

FIG. 1 is a front view of a head showing an embodiment of the present invention.

FIG. 2 is a side view as viewed from the toe portion side.

FIG. 3 is a plan view in which the head is partially sectioned on a horizontal plane HP.

FIG. 4 is an enlarged diagram showing a face reference contour line L;

FIG. 5 is an enlarged diagram showing a face reference contour line L;

FIG. 6A is a front view showing a face surface of the embodiment,
(B) is a sectional view along a face vertical reference contour line.

FIG. 7 is a sectional view of a head for explaining a vertical gear effect.

[Explanation of symbols]

 Reference Signs List 1 wood type golf club 2 head 2a face 3 bulge 4 shaft K face horizontal reference contour L face vertical reference contour S base point y distance

Claims (4)

[Claims] 1. A wood-type golf club having a head having a face roll, wherein a center line C of a shaft is located on a vertical plane VP, and the center line C is defined by a lie angle of the club and a loft angle is defined by a loft angle of the club. In a reference state where the face surfaces are inclined and placed on a horizontal surface, the intersection of the face surface with a horizontal surface HP passing through a height position between the lowest position and the highest position of the face surface is defined as a face lateral reference contour line K. And a face vertical reference contour line L passing through a center point of a line connecting both ends of the face horizontal reference contour line K and intersecting the face surface with a second vertical surface perpendicular to the vertical surface VP. And the face horizontal reference contour line K and the face vertical reference contour line L
A tangent line To of the face vertical reference contour line L at the base point O from the base point O which is the intersection with
A crown portion side point cy that separates the distance y in the direction of
And the face vertical reference contour L at the sole side point sy
A tangent line Tcy, Tsy and an absolute angle angle θcy, θsy on the acute angle side formed by the tangent line To, when the distance y is 5 mm or more, θcy> θsy. 2. The wood-type golf club according to claim 1, wherein the face vertical reference contour line L satisfies θcy ≧ 1.1 × θsy when the distance y is 5 mm or more. 3. The face vertical reference contour line L is
End point cy_n, The end point sy on the sole side_nMa
Is a point cy that divides n each from the base point O₁, Cy
_Two, ..., cy_n-1, Cy_n, And sy₁, Sy_Two,…,
sy_n-1, Sy_nAt the acute angle side of the tangent at
Value angle θcy₁, Θcy_Two, ..., θcy_n-1, Θc
y _n, And θsy₁, Θsy_Two, ..., θsy_n-1, Θs
y_nAt θcy₁≤θcy_Two≤ ... ≤θcy_n-1≤θcy_n θsy₁≤θsy_Two≤ ... ≤θsy_n-1≤θsy_n 3. The method according to claim 1, wherein the following relationship is satisfied.
Wood type golf club. 4. The face vertical reference contour line L is
End point cy_n, The end point sy on the sole side_nMa
Is a point cy that divides n each from the base point O₁, Cy
_Two, ..., cy_n-1, Cy_n, And sy₁, Sy_Two,…,
sy_n-1, Sy_nAt the acute angle side of the tangent at
Value angle θcy₁, Θcy_Two, ..., θcy_n-1, Θc
y _n, And θsy₁, Θsy_Two, ..., θsy_n-1, Θs
y_nAt θcy₁<Θcy_Two<… <Θcy_n-1<Θcy_n θsy₁<Θsy_Two<… <Θsy_n-1<Θsy_n 3. The method according to claim 1, wherein the following relationship is satisfied.
Wood type golf club.