JP2003210625A - Golf club head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a golf club head which can improve a distance. <P>SOLUTION: The golf club head has a high repulsion section 8 consisting of a metallic material with a Young's modulus E of 29 to 107 (GAa) in at least a portion of a face section 3 for hitting a ball. The moment of inertia around a horizontal axis parallel with the vertical plane of the head past its centroid in the measuring state of the head is specified to 1,600 to 4,000 (g/cm<SP>2</SP>). <P>COPYRIGHT: (C)2003,JPO

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 which can improve the flight distance of a hit ball.

[0002]

2. Description of the Related Art For example, International Publication WO98 / 4631
It is described in No. 2 that the use of a metal material having a small Young's modulus in the face portion for hitting a ball can improve the resilience of the head and increase the flight distance of the hit ball. this is,
It is based on the theory of increasing the initial velocity of the ball by making the impedance of the head closer to that of the ball and minimizing the loss of energy transmitted from the head to the ball when hitting the ball, which is also called impedance matching theory. .

[0003]

The inventors of the present invention have conducted extensive studies on this type of head in an attempt to further increase the flight distance. When such a head is hit at a sweet spot on the face surface, Although it was possible to obtain the maximum flight distance, it was found that when the ball is hit on the crown side (upper side) or the sole side (lower side) of the sweet spot, the loss of the flight distance is surprisingly large.

In view of such circumstances, the inventors further repeated various experiments. In FIG. 8, a plurality of types of heads having different Young's moduli of the face portion are used and hit at a sweet spot, a position 10 mm closer to the crown than the sweet spot, and a position 10 mm closer to the sole than the sweet spot. , Shows the result of measuring the change in the backspin amount of the hit ball.

As is clear from the figure, when the Young's modulus of the face portion becomes smaller, the backspin amount sharply increases when hit at a position 10 mm closer to the sole, and back when hit at a position 10 mm closer to the crown. It can be seen that the spin amount is rapidly decreasing. From this, it is understood that the head of low Young's modulus of this type has a stronger vertical gear effect than the head made of a general metal material of Young's modulus.

Here, the vertical gear effect means, as shown in FIG. 9, a sweet spot SS on the face surface f (an intersection of a normal line drawn from the center of gravity G of the head to the face surface f and the face f). When the ball is hit near the crown portion c or the sole portion s, a moment is generated in the head a which is approximately equal to the product of the impact force F and the orthogonal distance L1 or L2 to the head center of gravity G, and the head is moved to the center of gravity G of the head. This is a phenomenon in which the ball b is momentarily rotated about a horizontal axis through a small angle, and a force in the direction opposite to the rotation of the head a acts on the ball b. Therefore, when such a vertical gear effect appears strongly,
When the ball b is hit near the crown portion c of the face surface f as described above, the backspin amount of the ball b is significantly reduced, and conversely, when the ball b is hit near the sole portion s of the face surface f, This will significantly increase the backspin amount.

The reason why the vertical gear effect appears strongly in a head with a low Young's modulus has not yet been clarified theoretically, but since the face has a low Young's modulus, it is difficult to hit the ball. The deflection of the face is large,
It is inferred that one of the reasons is that the contact time with the ball becomes long and the influence of the frictional force becomes large.

On the other hand, in the golf club head, it is very important that the hit ball flies well, that is, the flight distance performance is very important. However, as described above, in the head in which the vertical gear effect is strongly exhibited, especially when hitting on the sole side rather than the sweet spot, the backspin amount of the hit ball becomes excessive and the loss of the flight distance is large, resulting in a large loss. is there. That is, there is still room for improvement in order to obtain stable flight distance performance.

The present invention has been devised in view of the above problems. At least a part of the face portion is provided with a high repulsion portion made of a metal material having a low Young's modulus, while a portion around the horizontal axis is provided. It is an object of the present invention to provide a golf club head that is effective in suppressing the vertical gear effect and stably improving the flight distance of a hit ball based on the restriction of the moment of inertia within a certain range.

[0010]

According to a first aspect of the present invention, a high repulsion made of a metal material having a Young's modulus E of 29 to 107 (GPa) is provided on at least a part of a face portion for hitting a ball. A golf club head having a portion, wherein a shaft center line of a shaft insertion hole into which a shaft is mounted is arranged in a vertical plane and is inclined at a specified lie angle, and a face surface is defined as a specified face with respect to the vertical surface. It is characterized in that, when the head is tilted at an angle and grounded on a horizontal plane, the moment of inertia about a horizontal axis passing through the center of gravity of the head and parallel to the vertical plane is set to 1600 to 4000 (g · cm ² ).

According to a second aspect of the present invention, the face portion has a thickness t (mm) of the high repulsion portion and the Young's modulus E.
The product (t · E) with (GPa) is 77 to 245 (GPa ·
mm) is the golf club head according to claim 1.

According to a third aspect of the present invention, in the head measurement state, the center-of-gravity distance which is the shortest distance between the center-of-gravity projection point obtained by projecting the center of gravity of the head at a right angle to the vertical plane and the axis center line is 26 to. The golf club head according to claim 1 or 2, wherein the golf club head has a diameter of 40 (mm).

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 illustrates a wood-type head (driver) as a golf club head (hereinafter, simply referred to as “head”) 1 of the present invention.
The head 1 has a face surface 2 which is a surface for hitting a ball.
A face portion 3 having a head portion, a crown portion 4 connected to the upper edge 2a of the face surface 2 to form the head upper surface, and a sole portion 5 connected to the lower edge 2b of the face surface 2 to form the head bottom surface (not visible in FIG. 1). A side portion 6 connecting the crown portion 4 and the sole portion 5 and extending from a toe side edge 2t of the face surface 2 to a heel side edge 2e of the face surface 2, a face portion 3 and a crown portion. A neck portion 7 provided in the vicinity of the heel side intersection where 4 and the side portion 6 intersect and to which one end of a shaft (not shown) is mounted
An example is one that includes and. A cylindrical shaft insertion hole 7a is formed in the neck portion 7, and the axis center line CL substantially coincides with the center line of the inserted shaft. Therefore, in this specification, when the head 1 is adjusted to the lie angle, the axial center line CL of the shaft insertion hole 7a is used as a reference.

The head 1 of this embodiment, as shown in exploded view in FIG. 2, has a head main body 1A having an opening O on the face side and forming a main part of the head, and the head main body 1
A face member 1B disposed in the opening O of A and integrally fixed thereto is illustrated.

The head main body portion 1A of this embodiment includes the crown portion 4, the sole portion 5, the side portion 6 and the neck portion 7 and surrounds the opening O on the face portion side. An example including the part 9 is illustrated. In this example, the head body 1A is made of titanium alloy (Ti
-6Al-4V) is used for the lost wax precision casting.

In the present embodiment, the face member 1B has a plate shape along the peripheral edge of the face surface 2, and the face portion 2
Of what constitutes a substantial impact area. The face member 1B is integrally fixed to the opening O of the head body 1A by various joining methods such as adhesion, welding, caulking, and press fitting.

In this embodiment, as shown in FIG.
An example is shown in which a supporting portion 9a that supports the back surface 11 of the face member 1B with a small width is formed on the face peripheral portion 9. The support portion 9a is formed continuously in a ring shape, for example. When the supporting portion 9 is provided, the contact area Sa between the supporting portion 9a and the back surface of the face member 1B is more preferably 2 to 20% of the total area S of the face surface 2, and more preferably 2
It is desirable to set the content to about 10%, preferably about 2 to 5%.

Such a supporting portion 9a is used for the face member 1
This is preferable in that the mounting strength of the face member 1B can be increased without deteriorating the bending characteristic of B. However, the present invention is not limited to such an aspect, and, for example, the supporting portion 9a may be omitted, and further, the supporting portion 9a may be formed on the entire rear surface 11 of the face member 1B. .

The face member 1B of this embodiment is made of a metal material having a Young's modulus E of 29 to 107 GPa. Thereby, in the present embodiment, the face member 1B forming a part of the face portion 3 forms the high repulsion portion 8. Such a high resilience portion 8 is useful for improving the flight distance of a hit ball based on the above-mentioned impedance matching theory.
When the Young's modulus E of the high repulsion portion 8 exceeds 107 GPa, the impedance of the head 1 tends to be significantly larger than that of the ball, and the effect of increasing the ball initial velocity is reduced. Particularly preferably, the Young's modulus E is 98 G
Pa or less, more preferably 88 GPa or less, and further preferably 78 GPa or less is desirable.

On the contrary, the Young's modulus E of the high resilience portion 8 is 2
When it is less than 9 GPa, durability is deteriorated, and there are problems such as an increase in manufacturing cost and productivity, which are not preferable. Particularly preferably, the Young's modulus E is 39 GPa or more in combination with any one of the upper limits, more preferably 49 or more.
It is desirable that the pressure is not less than GPa, more preferably not less than 58 GPa.

As the metal material satisfying the Young's modulus E, for example, an amorphous alloy or a titanium alloy is preferably used. As the amorphous alloy, for example, a Zr-based amorphous alloy can be relatively easily formed as the face member 1B, and if it is a crystalline metal, a Ti—Zr-based alloy is suitable.
However, in any case, it is needless to say that various alloys and the like can be adopted without being limited to these.

Further, the thickness t of the face member 1B (see FIG.
Is not particularly limited, but is preferably 1.0 to
It is desirable to set it to 3.5 mm. If it is less than 1.0 mm, the strength tends to be insufficient and the durability tends to be lowered, and conversely 3.5 mm.
When it exceeds, the rigidity of the face portion 2 becomes excessive, and the effect of increasing the flight distance based on the impedance matching theory tends to decrease. From this point of view, the lower limit of the thickness t is preferably 1.5 mm or more, more preferably 2.0 mm or more. The upper limit of the thickness t is preferably 3.0 mm or less, more preferably 2.8 mm or less, and particularly preferably 2.5 mm or less in combination with any of the lower limits.
In particular, it is preferable that the thickness of each part of the face portion 2 satisfies the above-mentioned regulation, and when the thickness of the face member 1B changes, the area average value (average value weighted by area ratio).
Is the thickness t.

Particularly preferably, the thickness t (mm) of the high repulsion portion 8 in the face portion 3 and the Young's modulus E (GP
The product (t · E) with a) is preferably 77 to 245 (GPa · mm). The product (t · E) is 77 (GPa
If it is less than 245 mm (GPa · mm), the rigidity of the face portion 3 will increase and the rigidity of the high repulsion portion 8 will decrease due to the impedance matching theory. The effect of improving the distance is reduced. Particularly preferably, the product (t · E) is 86 (G
Pa · mm) or more, more preferably 96 (GPa · mm)
It is desirable that the upper limit value is 231 (GPa · mm) or less, more preferably 221 (GPa · mm) or less in combination with any one of the lower limit values.

Regarding the material of the head body 1A,
In particular, the metal material is not limited to the above-mentioned regulation of Young's modulus, and various metal materials such as aluminum alloy, titanium, titanium alloy or stainless can be used. It can also be formed from fiber reinforced resin or the like. A titanium alloy having a high specific strength is preferable. The entire head may be made of the above-mentioned metallic material having a low Young's modulus.

Further, in the head 1 of the present invention, as shown in FIGS. 4 and 5, the shaft center line CL of the shaft insertion hole 7a of the head 1 is arranged in an arbitrary vertical plane VP1 and a prescribed lie angle is set. In the head measurement state in which the face surface 2 is tilted at β and the face surface 2 is tilted at a specified face angle δ with respect to the vertical surface VP1 and is grounded on the horizontal plane HP, a horizontal axis HL that passes through the center of gravity G of the head and is parallel to the vertical surface VP1. Is specified, and the inertia moment I about the horizontal axis HL is set to 1600 to 4000.
(G · cm ² ) is one of the features.
The face angle δ is an angle formed by a horizontal tangent line N in contact with the area center of gravity 2C of the face surface 2 and the vertical surface VP1.
Set to the specified angle.

The head 1 using a metal material having a small Young's modulus for the face portion 3 is likely to have a strong vertical gear effect as described above. Therefore, in the present invention, the inertial moment I of the head 1 about the horizontal axis HL is set to be larger than that of the conventional one to make it difficult for the head 1 to rotate about the horizontal axis HL, thereby suppressing the vertical gear effect. . This makes the ball
Even if the player strikes at a position displaced above or below the sweet spot SS (shown in FIG. 9) on the face surface 2,
Prevents a sudden decrease or increase in the backspin amount of the ball,
Get a stable trajectory. Therefore, the flight distance of a hit ball can be stably improved.

Preferably, the moment of inertia I is 180
0 (g · cm ² ) or more, more preferably 2000 (g · cm
cm ² ) or more, particularly preferably 2200 (g · cm ² ) or more. On the other hand, the moment of inertia I is 40
When it exceeds 00 (g · cm ² ), the head is likely to be remarkably increased in size, and handling and operability are poor, and swing balance is likely to be impaired. From such a viewpoint, the upper limit value of the inertia moment I is 3500 (g · cm ² ) or less, and more preferably 3100 (g · cm ² ) or less in combination with any one of the lower limit values. desirable. The moment of inertia I is measured by the head alone, and the cone-shaped ferrule and the like arranged at the connecting portion with the shaft is removed, but the moment of inertia I is measured including the coating. For measuring the moment of inertia I, for example, INERTIA DYNAMICS Inc.
A device such as MOMENT OF INERTIA MEASURING INSTRUMENT manufactured by the company can be used.

In order to set the inertia moment I of the head 1 to be large as described above, for example, a) increase the head volume, b) increase the thickness of the portion farther from the center of gravity of the head, and c). A method such as increasing the specific gravity of a portion farther from the center of gravity of the head, d) arranging a material with a higher specific gravity in a portion farther from the center of gravity of the head, and e) reducing the roll radius of the face surface is used alone. Alternatively, it can be realized by combining two or more kinds.

To increase the moment of inertia I
The head volume is, for example, 280-450 cm³Degree desired
Good Head volume is 280 cm³When it was less than,
The area of the face surface 2 seems to be small when doing so
This is because it is easy to invite a shot. Above all, shown in FIG.
So that the maximum width FW of the face surface 2 is 85 to 110 m
m, more preferably 90 to 106 mm, and
The maximum height FH of the surface (measured in the vertical direction) is 40 to 6
5 mm, more preferably 45-60 mm
Good Particularly preferably, the head volume is 290 cm³Since
Above, more preferably 300 cm³I would like to be more than
Yes. The head volume is 450 cm³The head exceeds
Remarkably large size, poor handling, and swing balun
It is easy to damage the fabric. More preferably, under any of the above
420 cm in combination with the limit value ³Below, especially
More preferably 400 cm³The following is preferable.

Further, in the head 1 in the head measurement state, the head 1 has a center of gravity projection point Ga obtained by projecting the center of gravity G of the head at right angles to the vertical plane VP1, as shown in FIG. 5 and FIG. It is desirable that the center-of-gravity distance C that is the shortest distance between the axis center line CL and the axis center line CL be 26 to 40 (mm).

As shown in FIG. 7 (A), the large head 1 of this embodiment does not return to the state in which the face surface 2 is held at the time of hitting the ball, and the so-called head 1 tends to return poorly. In the case of a right-handed golfer, the hit ball tends to shift to the right. Therefore, the center of gravity distance C is set to 26 to 4
It is desirable to reduce the moment of inertia of the head around the axis center line CL (in other words, around the shaft center line) by setting it to a relatively small value of 0 mm to improve the return of the head 1. As a result, as shown in FIG. 7B, the return of the head 1 is improved, and the hit ball can be prevented from being hit to the right of the target direction. Further, since the ball is better gripped, even an average golfer can easily hit a so-called draw-type ball line, which is also useful for increasing the flight distance.

If the center-of-gravity distance C is less than 26 mm, the moment of inertia of the head around the shaft center line becomes excessively small, resulting in a large variation in flight distance due to hitting, which is not preferable. More preferably, the center of gravity distance C is set to 2
8 mm or more, and more preferably 30 mm or more. On the contrary, if the center-of-gravity distance C exceeds 40 mm, the return of the head is apt to deteriorate. Particularly preferably, in combination with any of the above lower limits, it is desirable that the length is 38 mm or less, more preferably 36 mm or less, and particularly preferably 34 mm or less.

Further, as shown in FIG. 5, the bulge radius R1 of the face surface 2 is not particularly limited, but is preferably 2
54-304.8 mm, more preferably 279.4-29
2.1 mm is desirable, and as shown in FIG. 3, the roll radius R2 of the face surface 2 is preferably 22 mm.
8.6 to 330.2 mm, more preferably 254 to 30
It is desirable to set it to 4.8 mm. Roll radius R2
Is limited as described above, the moment of inertia I
Synergistic action with and help to more effectively reduce the vertical gear effect. The roll radius R2 is a second vertical plane VP2 that passes through the area center of gravity 2C of the face plane 2 and is orthogonal to the vertical plane VP1 in the measurement state of the head.
Is the radius of curvature of the face surface 2.

Although the embodiment of the present invention has been described above by taking the wood type golf club head as an example, the present invention is not limited to such a form, and any head having a hollow portion may be used. It is also applicable to iron type and utility type.

[0035]

EXAMPLE A plurality of types of golf club heads (# 1 driver) having the basic forms shown in FIGS. 1 to 3 were prototyped based on the specifications of Table 1, and a common carbon shaft (Flex R) was mounted on them. A wood type golf club having a total length of 45 inches was manufactured. Then, at each club, a hit test and an actual hit test were performed to compare the performance. The moment of inertia I and the distance of the center of gravity were adjusted by placing heavy objects on the rear side of the head body, the neck, the toe, and the sole. The following values are set as common specifications. Head volume: 270 cm ³ Maximum face width: 94 mm Maximum face height: 47 mm Bulge radius: 304.8 mm Roll radius: 304.8 mm The test method is as follows.

<Hit Test> Each of the test clubs was attached to a swing robot manufactured by Trutemper Co., and the head speed was adjusted to 40 m / s, and a commercially available 3-piece golf ball (manufactured by Sumitomo Rubber Industries, Ltd.) "HI-BRI
D "(registered trademark of the same company) was hit, and the backspin amount of the hit ball, the launch speed, and the flight distance (carry + run) were measured, and the performances were compared. In addition, each club hits five golf balls at a total of three places: a sweet spot hit by a sweet spot on the face surface, an upper hit and a lower hit 10 mm above and below the sweet spot. The average value is shown in.

<Actual hit test> Handicap 2-11
10 golfers hit each of the golf balls with 10 golfers, and measure the left-right deviation amount (measured as a + value on either left or right) of the ball drop point with respect to the target direction line, and average 10 players. Displayed by value. The smaller the value is, the smaller the deviation of the directionality is. The test results are shown in Table 1.

[0038]

[Table 1]

As a result of the test, focusing on the sweet spot hit, it is understood that the launch speed is improved and the flight distance is increased as the Young's modulus of the face portion is smaller. That is, the resilience of the head is improved. However, in the case where the moment of inertia about the horizontal axis is small as in the comparative example, the loss of the flight distance in the lower hit is larger than that in the sweet spot hit. It is considered that this is because the vertical gear effect appears strongly and the backspin amount of the hit ball greatly increases.

On the other hand, in Examples 1 and 2, the loss of the flight distance at the time of a lower hit is smaller than that of the sweet spot hit. This is because the heads of Examples 1 and 2 have a larger moment of inertia about the horizontal axis than Comparative Example 1, so that the vertical gear effect is suppressed and the increase in the backspin amount is suppressed even when hitting downward. It depends. For the driver, the appropriate backspin amount for the trajectory is 2000-310.
Although 0 rpm is considered to be good, it can be seen that in the examples, the backspin amount is included in the above range at any hit position of sweet spot hit, upper hit, and lower hit. As a result, it is considered that the trajectory of the hit ball is good and the flight distance is excellent.

Further, as in Examples 3 and 4, when the center-of-gravity distance is reduced, it is understood that the amount of displacement of the drop position is reduced and the directional stability is improved. It is considered that this is because the return of the head was improved because the distance of the center of gravity was reduced.

[0042]

As described above, according to the first aspect of the invention, at least a part of the face portion for hitting a ball is
Since the high repulsion portion made of a metal material having a small Young's modulus E is provided, the head can be made highly repulsive and the flight distance of a hit ball can be improved. Further, by limiting the inertia moment about the horizontal axis passing through the center of gravity of the head to a certain range, the head can suppress a large vertical gear effect even when the sweet spot is hit and hit. As a result, it is possible to suppress the change in the backspin amount of the hit ball and reduce the loss of flight distance.

In the face portion, when the product (t · E) of the thickness t of the high repulsion portion and the Young's modulus E is limited to a certain range, the durability is deteriorated. The above effect can be achieved while preventing the above.

When the center-of-gravity distance is limited to a certain range as in the third aspect of the present invention, the return of the head can be improved and the directionality of the hit ball can be stabilized.

[Brief description of drawings]

FIG. 1 is a perspective view showing a head of this embodiment.

FIG. 2 is an exploded perspective view thereof.

FIG. 3 is a sectional view of a head.

FIG. 4 is a front view showing a measurement state of a head.

FIG. 5 is a plan view showing a measurement state of the head.

6 is an end view taken along the line AA of FIG.

7 (A) and 7 (B) are schematic diagrams for explaining the return of the head during a swing.

FIG. 8 is a graph showing the relationship between the backspin amount of a hit ball and the Young's modulus of a face portion.

FIG. 9 is a cross-sectional view illustrating a vertical gear effect.

[Explanation of symbols]

1 golf club head 1A head body 1B face member 2 face 3 face part 4 Crown 5 sole part 6 side part 7 neck 7a Shaft insertion hole 8 High repulsion section CL Shaft insertion hole axis center line I moment of inertia

Claims (3)

[Claims] 1. A golf club head having a high repulsion portion made of a metal material having a Young's modulus E of 29 to 107 (GPa) on at least a part of a face portion for hitting a ball, wherein the shaft is mounted on the shaft. The center of gravity of the head is measured in a state in which the axial center line of the insertion hole is arranged in a vertical plane and is tilted at a specified lie angle, and the face surface is tilted at a specified face angle with respect to the vertical surface and grounded on a horizontal plane. A golf club head having a moment of inertia of 1600 to 4000 (g · cm ² ) about a horizontal axis that passes through and is parallel to the vertical plane. 2. The face portion has a thickness t of the high repulsion portion.
(Mm) and Young's modulus E (GPa) (tE)
Is 77 to 245 (GPa · mm), the golf club head according to claim 1. 3. The center of gravity distance, which is the shortest distance between the center of gravity projection point obtained by projecting the center of gravity of the head perpendicularly to the vertical plane and the axis center line in the head measurement state, is 26 to 40 (mm).
The golf club head according to claim 1 or 2, wherein