JPH11290489A - Head of wood type golf club - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce duffing in a head of a wood type golf club capable of reducing generation of mis-shot such as duffing. SOLUTION: A head 1 of a wood type golf club comprises a face surface 2 to hit a ball, and a sole surface 3 as a bottom surface of the head 1. A sole length W between a sole forward end point P of the sole surface 3 on the face surface side, and a sole back end point Q where a sole reference line L2 formed by deducting a loft angle a from a line passing the sole forward end point P and perpendicular to a face surface 2 is set to be 35 mm or less.

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 head which can reduce the occurrence of miss shots such as so-called duffling.

[0002]

BACKGROUND OF THE INVENTION Wood-type golf clubs are often used mainly for two purposes. One is to use the tee on the first shot of each hole. In this case, a shot can be shot with the ball placed on a jig called tipeg having a height of several centimeters, that is, with the ball floating above the ground.

[0003] In such an application, a golfer can set the ball at a height suitable for his or her swing, and from the sense of security, even if the swing trajectory is slightly deviated in the first shot, When the club head hits the ground in front of the ball, the occurrence of so-called "duff" is relatively small.

On the other hand, another application of a wood-type golf club is to shot a ball directly placed on the turf or the ground after the second shot of each hole. In such a case, in order for the club head to make an accurate impact on the ball, it is necessary to make the golf club head FIG.
As shown in FIG. 1, the sole surface b of the head a needs to enter the ground slightly, and if the sole surface b is slightly displaced up and down, a large miss shot is caused.

If the swing trajectory of the head a shifts to the ground side even during such a missed shot, as shown in FIG. 12, a duffling occurs in which the head a hits the ground strongly before impacting the ball d. In addition to causing a great impact and discomfort to the golfer's hand, there is a problem that the head speed at the time of impact is greatly reduced due to collision with the ground or digging into the ground, and the flying distance is greatly reduced.

Such duffling is caused by various causes. For example, from the viewpoint of reducing the contact resistance between the sole surface of the head and the ground, as shown in FIG. .. Provided with rail-shaped projections c, c,...
As shown in (1), there has been proposed a head in which a sole surface b is formed by a curved surface e protruding toward the ground and the radius of curvature r of the curved surface e is reduced.

However, in such a head, when the projection c or the curved surface e is brought into contact with the ground, the face f is positioned above the ground due to the projection c and the curved surface e of the sole surface b. As a result, the ball d is impacted from below the face surface f, and a so-called “top” miss shot that causes a loss of flight distance is likely to be induced.

[0008] In view of such a problem, the present inventors have considered that
Various studies have been made on the difference in the swing trajectory of the head between a good shot and a duffling shot. In the case of a good shot, the sole surface b of the head is on the ground immediately before impact as shown in FIG. And the sole surface b is swung so as to pass under the ball d with the rear end point q of the sole rising above the ground rather than the front end point p (leading edge) of the sole surface b. On the other hand, in the case of a duffing shot, as shown in FIG.
Has been found that the rear end point q of the sole surface is swung so as to come into contact with the ground before the front end point p of the sole surface b.

The inventors of the present invention can effectively suppress the occurrence of duffling by making the rear end side of the sole surface of the head that causes duffling as hard as possible to be in contact with the ground as much as possible. This has led to the completion of the present invention. Thus, an object of the present invention is to provide a wood type golf club head that can reduce the occurrence of duffling.

[0010]

According to a first aspect of the present invention, there is provided a wood-type golf club head having a face surface for hitting a ball and a sole surface forming a bottom surface of the head. Between the sole front end point P on the face side of the surface and the sole rear end point Q at which the sole reference line obtained by reducing the loft angle with respect to a line passing through the sole front end point P and making a right angle with the face surface intersects the rear of the sole. Has a sole length W of 35 mm or less.

The invention according to claim 2 is the wood type golf club head according to claim 1, wherein the sole surface is connected to an upwardly inclined surface behind the sole rear end point Q.

According to a third aspect of the invention, in the sole surface, the sole length W is a center of gravity that is a distance between the sole front end point P and the center of gravity G of the head parallel to the sole reference line. 2. The structure according to claim 1, wherein the length is at least D.
Or a head of the wood type golf club according to 2.

According to a fourth aspect of the present invention, in the vertical section including the sole reference line, the sole surface has a convex or flat shape having a radius of curvature of 20 inches or more, and the center of gravity length D (mm). ) And the height H (mm) of the center of gravity which is a distance perpendicular to the sole reference line from the center of gravity G to the lowest point S of the sole surface closest to the ground on the sole surface, the following relationship is satisfied: D ≦ 2H-10 The wood-type golf club head according to claim 3, wherein the head is satisfied.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. As shown in FIGS. 1 and 2, a head 1 of a wood-type golf club according to the present embodiment has a face surface 2 which is inclined at a predetermined loft angle α with respect to a vertical surface and hits a ball, and a sole which forms a bottom surface of the head. And a sole 3 having a sole length W of 35 mm or less.

Here, as shown in FIG. 1, the sole length W is a sole front end point P on the face surface 2 side of the sole surface 3.
And a sole reference line L2 obtained by subtracting the loft angle α from a line L1 passing through the sole front end point P and forming a right angle with the face surface.
Is defined as a distance between the sole rear end point Q that intersects the rear of the sole. As shown in FIG. 2, when the head 1 is viewed from the sole surface side, for example, when a bulge is formed on the face, the sole front end point P is determined by the point at the front end of the sole.

In the head of the conventional wood type golf club, the sole length W of the sole surface 3 is set to be relatively long, about 50 to 70 mm. The end side was easy to contact the ground before impact of the ball,
In the head 1 of the present invention, by setting the sole length W to be as small as 35 mm or less, the rear end side of the sole surface 3 is less likely to touch the ground before impact of the ball, and the occurrence of duffling is effectively suppressed. be able to.

In the head 1, the effect of preventing the occurrence of duffling can be enhanced by reducing the sole length W.
On the other hand, if it is too small, the stability when the sole surface 3 of the head 1 is placed on the ground at the time of addressing may be reduced due to the balance with the center of gravity G of the head (a so-called "seat" is bad). In addition, if the stability at the time of addressing is to be ensured with a very small sole length W, it is necessary to set the center of gravity G of the head 1 to be shallower, and the design of the head 1 tends to be difficult. .

From such a viewpoint, it is desirable that the sole length W of the head 1 is preferably 20 to 35 mm, more preferably 20 to 34 mm, and further preferably 25 to 34 mm.

The sole surface 3 of the head 1 can be formed in various shapes from the rear end point Q of the sole surface 3 to the tail end of the head 1. In the present embodiment, the sole surface 3 of the head 1 is An example in which the rear is smoothly connected to the upward slope 4 is illustrated. Therefore, as shown in FIG. 3, the conventional club head a (indicated by a dashed line) further forms a head 4 by forming the slope 4 even on a swing path that is a completely duffed shot. The contact between the ball 1 and the ground before the ball impact can be effectively prevented, and the duffling can be further reduced.

The slope 4 can be formed in various forms such as a flat surface, a curved surface, or a combination thereof, and the angle β formed with the sole reference line L2 is 20 ° or more, more preferably 30 ° or more and 50 ° or less. Is preferred.

In the present embodiment, the sole surface 3 defines the sole length W as the sole front end point P and the center of gravity G of the head.
Are formed to be equal to or longer than the length D of the center of gravity, which is a distance parallel to the sole reference line L2. As described above, by setting the sole length W to be equal to or less than 35 mm and equal to or more than the length D of the center of gravity of the head, it is possible to prevent the occurrence of duffling and to secure the stability of the head at the time of addressing. Is preferred.

Incidentally, even when the sole length W is made small as described above, when a duffling shot occurs,
A device that does not lose the hitting distance of the hit ball is desired. In general, in the case of duffling, the club tends to dive into the ground and receive an impact, so that the ball can be easily impacted above the face surface 2. Therefore, in the present embodiment, by setting the position of the center of gravity G of the head 1 to be relatively high, the deviation from the center of gravity G can be reduced and the impact can be achieved even in the duffling shot, so that the flying distance is reduced. 2 illustrates a head that minimizes loss.

In the present embodiment, the sole surface 3 of the head 1 has a vertical section including the sole reference line L2.
Although a convex shape having a radius of curvature R of 20 inches or more is illustrated, it is preferable that the top surface is formed to be 100 inches or more, and more preferably flat, in order to suppress the above-mentioned misshot.

The head 1 has a length D (mm) of the center of gravity.
And a center-of-gravity height H (mm), which is a distance perpendicular to the sole reference line L2 from the center of gravity G to the lowest point S of the sole surface 3 closest to the ground, where D ≦ 2H-10. As a result of the trial production experiments by the present inventors, it was clarified that by satisfying the above condition, it is possible to determine an optimum position of the center of gravity that can reduce a miss shot in such a head 1 having a small sole length W. That is, in such a head 1 having a small sole length W, it has been found that the value obtained by subtracting 10 mm from twice the height H of the center of gravity is preferably equal to or more than the length D of the center of gravity.

It is particularly preferable that the head 1 satisfies the relationship of D <2H-10 in the length D of the center of gravity and the height H of the center of gravity, and more preferably D-0.5 <2H-10. It is desirable that

In this embodiment, the head 1 is made of what is called 6-4 titanium (Ti-6% Al-4% V alloy). However, the head 1 is made of other titanium alloys, pure titanium,
Stainless steel, aluminum, carbon and other various alloys, composite materials, and the face 2 may be formed of a material different from other parts. The total height Hf of the head 1 is about 25 to 45 mm, and the total length L of the head is 50.
It is preferable to set it to 80 mm. The volume of the head 1 is
For example, 130 to 250 cc, preferably 150 to 220
cc is desirable.

Such a head 1 can be manufactured by various molding methods such as casting and forging, and the inside of the head 1 may contain a synthetic resin material or a fluid, for example. Weight, balance, etc. can be adjusted as appropriate.

[0028]

EXAMPLES Wood type golf club heads (real loft 21 °, equivalent to No. 5 wood) were prototyped according to the specifications shown in Table 1, and each of these heads was fitted with a flex R standard hardness shast. A 41.5 inch long club was completed. A golfer with a handicap of 15 to 25 (head speed of 39 to 42 m / s) uses these clubs to hit 15 balls on the turf using each of these clubs. The ease of holding and hitting were evaluated. Table 1 shows the results of the test, and FIGS.

[0029]

[Table 1]

As a result of the test, it was confirmed that the club of the example had a reduced number of duffing miss shots and was easier to hit than the club of the comparative example. It can also be seen that the clubs of the examples have a small number of low-flying hits from the standpoint of flight distance.

In the first embodiment, since the length D of the center of gravity is larger than the length W of the sole, there are some difficulties in the ease of holding during addressing and the stability of the head. Was as easy to set up as the comparative example.

Further, in Examples 3 and 4 satisfying the relationship of D ≦ 2H-10, particularly, the number of hits at a flight distance of less than 180 yards is small, so that miss shots are particularly reduced, and the sole length is small. It can be confirmed that the position of the center of gravity in the head is optimized.

[0033]

As described above, in the head according to the first aspect, by setting the sole length as small as 35 mm or less, it becomes difficult for the rear end side of the sole surface to touch the ground before impact of the ball, The occurrence of duffling can be effectively suppressed.

According to the second aspect of the present invention, since the rear of the sole rear end point of the head is connected to an upward slope, even in a swing track which is a completely duffed shot in a conventional club, By forming the slope, contact between the head and the ground can be further effectively prevented before the ball impact, and duffling can be further reduced.

According to the third aspect of the present invention, the sole surface has a sole length W of 35 mm or less and a head center-of-gravity length D or more, thereby preventing occurrence of duffling and addressing of the head during addressing. Stability can be ensured.

According to the fourth aspect of the present invention, in a head having a small sole length, the center of gravity of the head can be set to an optimum position capable of reducing a miss shot.

[Brief description of the drawings]

FIG. 1 is a side view of a head according to an embodiment of the present invention as viewed from a toe side.

FIG. 2 is a view of the head according to the embodiment of the present invention as viewed from a sole surface side.

FIG. 3 is a diagram illustrating a head of the embodiment immediately before impact of a ball.

FIG. 4 is a graph of flight distance-number of hits showing test hitting results of a comparative example.

FIG. 5 is a graph showing the flight distance versus the number of hits showing the test hitting results of Example 1.

FIG. 6 is a graph showing the flight distance versus the number of hits showing the test hitting results of Example 2.

FIG. 7 is a graph of flight distance-number of hits showing test hitting results of Example 3.

FIG. 8 is a graph of flight distance versus number of hits showing test hitting results of Example 4.

FIG. 9 is a diagram illustrating a sole of a conventional head.

FIGS. 10A and 10B are side views of a conventional club.

FIG. 11 is a side view showing a conventional good shot immediately before impact.

FIG. 12 is a side view showing a duffling shot of a conventional club.

[Explanation of symbols]

 Reference Signs List 1 head 2 face surface 3 sole surface 4 slope P sole front end point Q sole rear end point L2 sole reference line α loft angle W sole length G head center of gravity H center of gravity height D center of gravity length

Claims (4)

[Claims] 1. A head of a wood-type golf club having a face surface for hitting a ball and a sole surface forming a bottom surface of the head, wherein a sole front end point P on the face surface side of the sole surface;
The sole length W between the sole reference line obtained by reducing the loft angle with respect to a line passing through the sole front end point P and making a right angle with the face surface and the sole rear end point Q crossing the sole rear is 35 mm or less. Wood type golf club head. 2. The wood-type golf club head according to claim 1, wherein the sole surface is connected to an upwardly sloped portion behind the sole rear end point Q. 3. The sole surface is formed such that the sole length W is equal to or longer than a center-of-gravity length D which is a distance parallel to the sole reference line between the sole front end point P and a center-of-gravity point G of the head. The wood-type golf club head according to claim 1 or 2, wherein: 4. The sole surface has a convex or flat shape having a radius of curvature of 20 inches or more in a vertical cross section including the sole reference line, the center of gravity length D (mm), and the center of gravity G The height of the center of gravity H (mm), which is a distance perpendicular to the sole reference line from the sole surface to the lowest point S of the sole surface closest to the ground, satisfies the relationship of D ≦ 2H-10. Item 4. A wood-type golf club head according to item 3.