JP2000225215A - Golf club - Google Patents

Abstract

(57) [Summary] An object of the present invention is to provide a golf club capable of further improving a meet rate by using a long shaft. A golf club according to the present invention has a total length of 47 inches or more and a moment of inertia around a grip end Q point of 2 inches.
It is not more than 90 g · m ² .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a golf club.

[0002]

2. Description of the Related Art Conventionally, golf clubs capable of flying farther away have been studied, and in recent years, long golf clubs having a longer shaft (47 inches or more) have been used. ing. Such a golf club enables a professional golf player or a golf player with physical strength to increase the head speed, and thus can hit a ball as intended to fly far.

[0003] However, for a general golf player, when the golfer swings, the club rotates with a delay while the body rotates, so-called swing delay occurs. The player hits the ball in an open state, and the number of missed shots tends to increase (the ball meet ratio decreases). On the other hand, if the ball is hit so that the rotation of the golf club is synchronized with the rotation of the body by changing the hitting method, the above-mentioned missed shots are reduced, but the head speed is reduced, and the advantage of the long club is not utilized. .

[0004] In addition, since a long golf club is longer than a conventional golf club, the shaft is in a pre-tuned state by giving tension to the hand side so that the shaft does not feel unreliable. In addition, in order to eliminate the uncomfortable feeling of having become longer, many of the shafts have been devised so that the hand side of the shaft is thicker so as not to feel the length in appearance. Is near the tip of the shaft). As a result, a sense of security can be obtained from the appearance at the time of addressing, but if the kick point is on the tip side, the change in head direction from the start of the swing to the hit ball becomes large, further deteriorating the ball meet rate. Let me do it. As described above, a long golf club is obtained by changing only the shaft of a golf club of a normal length.

The inventor of the present invention has found that in a long golf club conventionally used, the fact that the meet rate does not improve when actually swinging is due to the balance of the entire golf club,
In particular, they have found that the moment of inertia around the grip end, which greatly affects the swing, is high. In other words, such a moment of inertia determines how much force is required to rotate the club around the grip end,
Is considered to be an index expressing the degree numerically. However, if the moment of inertia is too large, it becomes difficult to rotate, and as a result, it becomes difficult to swing and to be late. Conventionally, a generally used golf club having a total length of about 48 inches has a moment of inertia around the grip end of about 300 g · m ² or more. No design has been made in consideration of the moment of inertia.

Further, the inventor of the present invention has focused on the point that the conventional long golf club simply lengthens the shaft and eliminates a sense of incongruity in the appearance. I found that it was a factor that hindered the improvement of the meeting rate. That is, when the kick point is on the tip side, the amount of change in the head direction from the start of the swing to the hit ball is large, and it is difficult to catch the ball at an accurate position.

[0007] It is an object of the present invention to provide a golf club that can further improve the meat ratio by using a long shaft.

[0008]

In order to solve the above-mentioned problems, a golf club of the present invention has a total length of 47 inches or more and a moment of inertia around a grip end of 290 g · m.
m ² or less.

As described above, in a golf club having a total length of 47 inches or more, by configuring the moment of inertia around the grip end to be 290 g · m ² or less, the club is easily rotated, and as a result, the golf club swings. It is easy to control the swing delay and the meet rate can be improved.

[0010]

FIG. 1 is a view showing the overall structure of a golf club, and FIG. 2 is a view for explaining kick points of a shaft. First, a method for measuring the moment of inertia around the grip end and a kick point of the shaft will be described with reference to these drawings. The golf club 1 is, for example, mounted on a shaft 2 made of fiber reinforced plastic (FRP), a grip 5 mounted on the proximal end side (hand side) of the shaft 2, and a distal end side of the shaft 2. Head 10
Composed of

Assuming that the central axis of the shaft 2 is X, the total length of the golf club is a point Q at which the axis X intersects the grip end face 5a and a point R at which the axis X intersects the lower edge 10a of the head.
Is defined by the distance L between That is, the total length is 47
The golf club of inches or more is a golf club in which L obtained as described above is 47 inches or more.

The moment of inertia Ie around the grip end of the golf club described above is defined by Ic + Cw · P ² . In this equation, Ic is the moment of inertia around the center of gravity (balance point BP) of the club, Cw
Is the total weight of the club, and P is the distance between the BP point and the Q point which is the grip end. In this case, the moment of inertia Ic around the center of gravity of the club is usually measured using an inertia moment measuring instrument (for example, manufactured by Inersia Dynamics) because the golf club is made of several types of constituent materials and has a complicated shape. The measurement method is obtained from the cycle of the swing by rotating the club by placing the club on the measuring device with the center of gravity of the club aligned (the club is laid down). As described above, the moment of inertia Ie around the grip end can be derived. However, if the golf club is supported at the grip end Q point and the pendulum is used to measure the moment of inertia around the grip end, a measuring device is used. It is possible to directly derive without using the above formula.

The above-mentioned kick point (KP) is a curved vertex of the shaft 2. This is achieved by holding the tip of the shaft 2 freely, as shown in FIG.
This is the most expanded position when the shaft is bent by pushing in by m. Therefore, the kick point 38 described later
% Means that the ratio of the length from the tip to the kick point position with respect to the entire length of the shaft when the shaft is straight is 38%. Therefore, as the ratio of the kick point increases, the position of the kick point approaches the grip side.

In the present invention, as described above, the measured moment of inertia Ie around the grip end is 290 g.
It is characterized by being less than or equal to m ^2, but such a configuration can be realized by variously adjusting the balance of the weight, dimensions, and the like of the head 10, the shaft 2, and the grip 5. Also, for example, club weight and balance point (B
The position P) can be adjusted by the material, thickness, shape, weight of the head 10, the shaft 2, and the grip 5, and the like. Therefore, for example, the grip 5
, The balance point (BP) can be made closer to the grip side, and the distance P can be reduced.

The following experiments were carried out to determine how the moments of inertia of the above-described long golf clubs differ when they are actually hit.

The moment of inertia around the grip end is
Four different golf clubs (280g
m ² , 290 g · m ² , 300 g · m ² , 310 g · m
² ) Prepare and make a total length of 4 for each golf club.
A total of eight types were prepared to be 7 inches and 48 inches. On the other hand, five average golfers having a handicap of 10 to 20 were selected as test hitters, and each test hitter performed a test hit of each of the prepared golf clubs at 10 balls × 3 cycles. And 20m left and right in the direction of aim
The percentage of those who came within the range was counted, and the average of five test hitters was obtained. The results in Table 1 below were obtained.

[0017]

[Table 1]

As is evident from the results, in both the 47-inch club and the 48-inch club, when the moment of inertia around the grip end is 290 g · m ² , the result is obtained that the directionality is most stable. Favorable results even 280 g · m ² is less was obtained. By the way, golf club (moment of inertia 290g · m ²⁾ the most desirable results were obtained in 47 inches Club,
Head weight 180g, shaft weight 50g, grip weight 37g, 48 inch club, head weight 1
The weight was 74 g, the shaft weight was 45 g, and the grip weight was 37 g.

Further, the two heads having the most desirable results were removed, and the two heads were mounted on shafts having different kick points, and an experiment was conducted on the meet ratio under the same conditions and the same striker. In this case, the moment of inertia around the grip end is set to 290 g · m ² , and the meet ratio is drawn as an ellipse of 10 mm up and down and 20 mm left and right around the face center. Was calculated according to the ratio of the number of pieces. And hitter 5
When the average of the people was taken, the following results in Table 2 were obtained.

[0020]

[Table 2]

As is clear from these results, in both the 47-inch club and the 48-inch club, if the kick point ratio increases (the position of the kick point is closer to the grip side), the result is that the meet rate can be improved. Was done. That is, as shown in FIG. 3, when the kick point is at the position of the point KP1, the amount of change in the direction of the head 10 from the start of the swing to the hit ball is smaller than that at the position of the point KP2. As shown by, the ball becomes easier to catch at the correct position.

When the shaft is formed by FRP, the position of the kick point can be adjusted to various positions by the configuration of the prepreg or by variously adjusting the diameter of the shaft.

As described above, by adopting a long golf club having a total length of 47 inches or more, the head speed during the swing can be increased to increase the flight distance, and the moment of inertia around the grip end can be reduced to 290 g · m. ^By setting the ratio to ² or less, even a general golf player can swing without delay and have a good meet rate, a ball is hard to bend, and a golf club having a long flight distance can be obtained. Further, by configuring the kick point of the shaft closer to the grip side, it is possible to reduce a change in the direction of the head at the time of a swing, thereby further improving the meet rate.

[0024]

According to the present invention, even if the golf club has a long length of 47 inches or more, the meeting rate can be improved, so that the flight distance can be improved and the directional property can be improved. Stabilization can be achieved.

[Brief description of the drawings]

FIG. 1 is a diagram showing an overall configuration of a golf club.

FIG. 2 is a view for explaining a kick point of a shaft.

FIG. 3 is a diagram showing a comparison between a golf club having a long kick point and a golf club having a short kick point when a golf club is swung.

[Explanation of symbols]

1 golf club, 2 shaft, 5 grip, 10
…head.

Claims (2)

[Claims] 1. A golf club having a total length of 47 inches or more and a moment of inertia around a grip end of 290 g · m ² or less. 2. The golf club according to claim 1, wherein the kick point of the shaft is at least 38% from the tip.