JPH0970453A - Golf club - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to increase the carry of a golf ball by controlling the deformation of a shaft at the time of the impact of a golf club, thereby forming the deformation approximated to the initial hit angle at the hitting point of a sweet spot. SOLUTION: The golf shaft 3 is a shaft composed of carbon fiber reinforced plastics, etc., which are generally used from heretofore and have no problems in strength. The golf shaft 3 is constituted by providing the shaft with a bending rigidity body 5 for enhancing bending rigidity near its hosel part 2. The region of the part of the golf shaft 3 enhancing the bending rigidity of the golf shaft 3 is preferably between the slight spacing L (preferably 5mm) parted from the hosel part 2 of the golf club head 1 and the prescribed length La (about 50mm) toward the grip part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a golf club, and more particularly to a golf club having a shaft mounted on a hosel portion of the golf club and having a structure in which bending rigidity is increased in a predetermined region near the hosel portion. Is.

[0002]

2. Description of the Related Art A conventional golf club using a golf shaft made of carbon fiber reinforced plastic has, for example, a golf shaft 3 mounted on a hosel portion 2 of a club head 1 as shown in FIG. There is. In order to increase the breaking strength, such a golf shaft 3 has a structure in which the number of plies is continuously increased from the tip of the golf shaft 3 to about 100 mm to continuously increase the strength.

[0003]

However, in the case of the conventional golf shaft 3, since the reinforcing structure is focused only on the point of increasing the breaking strength as described above, a golf club using such a golf shaft 3 is used. When the ball is hit with, there is a large variation in the launch angle of the ball depending on the hitting position, and as a result, there is a problem that the flight distance on a miss shot is reduced.

That is, the shaft is deformed into an S shape within a range of about 75 mm from the hosel portion when the shot position is displaced up and down from the sweet spot (see FIG. 8 (a)). The variation in the launch angle of the ball became large, and as a result, the flight distance on a miss shot was reduced. Next, the results of measuring the deformation (curvature) of the golf club at the time of impact of the golf club with a conventional non-reinforced golf shaft are shown in Table 1 (spot position: face center) and Table 2 below.
(Spotting position: 14 mm above the face center), Table 3
(Spotting position: 14 mm below the face center).

The symbols in Tables 1 to 3 are respectively shown in FIG.
FIG. 6A shows a modification as shown in FIG. Tables 1-3
The experimental condition of No. 2 is the club head speed: 40 m / s, and the numbers in the table indicate the measurement points of the strain gauges attached to the shafts, and the measurement points are shown in FIG. The curvature was obtained from the strain at the strain gauge measurement points.

Tables 1 to 3 show head speeds of 40 m / s,
It shows the curvature of the shaft at each measurement point (see Fig. 7) for 500 µs from immediately before the impact with the club driver used (Loft: 12 °). Tables 1, 2 and 3 show conditions that the hitting point position is the face center, 14 mm above the face center and 14 mm below the face center, respectively.

The measuring conditions are as follows. Shaft: Mass: 53.7g Head: Mass: 214.6g Loft: 12 ° Ball: 2-piece ball Club: Mass: 340.5g Length: 44 inches Swing balance: D3.0 Club frequency: 217 (CPM) Swing Conditions: Swing robot head speed: 40 (m / s) The deformation of the shaft in FIGS. 6A and 6B is at 3/10000 seconds after impact. Also, the curvature is shown magnified ten times. All the trial hits in Tables 1 to 3 were performed by a swing robot.

[0008]

[Table 1]

[0009]

[Table 2]

[0010]

[Table 3]

As is clear from Tables 1 to 3, (25
In Tables 1 and 2, it can be seen that the curvature at the mm measurement point) and the curvature at the (50 mm measurement point) are reversed within 3 / 10,000 seconds after impact. It is apparently within the time period during which the face portion of the golf head and the golf ball are in contact with each other for 3 / 10,000 seconds after the impact. That is,
Schematically, as shown in FIG. 8 (a) in Table 1 (striking position: face center) and in Table 2 (striking position: 14 mm above the face center) as shown in FIG. 8 (a) (hole is the club face). The shaft is deformed (while it is in contact with).

It was found that the bending node of the S-shaped shaft (the position where the sign of the curvature is reversed) is at least within 50 mm from the end of the head hosel toward the grip side. Further, the change in curvature becomes larger as it approaches the head side, and the sign of the curvature is "+" at the upper hit point and "-" at the lower hit point. In general, when the ball is hit at the upper hit point of the face, the launch angle becomes extremely high, and when it is hit at the lower hit point, the launch angle becomes extremely lower than that at the face center hit point.
This leads to not getting the desired distance when dropped above or below the hitting point, or to drastically reduce the flight distance. From the above results, it can be said that the deformation of the shaft from the end of the head hosel to the grip portion is the main cause of the large change in the launch angle depending on the hitting position. This is schematically shown in FIGS. 8 (b) and 8 (c).

The present invention has been devised in view of the above-mentioned conventional problems. By controlling the deformation of the shaft at the time of impact of a golf club, the launch angle on a miss shot is stabilized, that is, the sweet spot. It is an object of the present invention to provide a golf club capable of increasing the flight distance of a ball by making it approach the launch angle at a hit point.

[0014]

SUMMARY OF THE INVENTION In order to achieve the above object, the gist of the present invention is to provide a structure in the vicinity of a hosel portion of a shaft with a high bending rigidity. The area of the portion for enhancing the bending rigidity of the shaft is preferably between 5 mm and 50 mm from the hosel portion of the club head. As means for enhancing the bending rigidity of the shaft, when the shaft is carbon fiber reinforced plastic, The number of plies in the region where the bending rigidity is increased is increased, a material having a high elastic modulus is used, or a cylindrical rigid tube is fitted.

The present invention is constructed as described above, and a slight distance (preferably 5 mm) is provided from the head hosel portion to the conventional shaft having no problem in strength, and the distance from the head hosel portion to the grip portion is reduced. For bending rigidity between 50 mm, there are some cases where the number of plies in the carbon shaft is increased only in the part where the rigidity is desired to be increased, or a material having a high elastic modulus is used, and a cylindrical rigid tube is simply used in the above part. By being fitted, the bending rigidity is increased. With such a configuration, the launch angle at the time of a miss shot is stable, that is, the launch angle at the sweet spot striking point is made to be close, whereby the flight distance of the ball can be increased.

Moreover, the portion for increasing the bending rigidity is a part of the shaft, and the weight and the feel (hardness, balance) of the hitter do not change much as compared with the conventional shaft.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. The same components as those in the conventional example are denoted by the same reference numerals, and description thereof will be omitted. FIG. 1 is a front view of a golf club 1 embodying the present invention. 1 is a wood golf club head, 2 is a hosel portion of the golf club head 1, 3 is a golf shaft, 4 is a grip, and 5 is a bending of the shaft. The bending rigidity body provided in the area | region of the part which raises rigidity is shown.

The golf shaft 3 is a shaft made of carbon fiber reinforced plastic or the like which has been generally used conventionally and has no problem in strength. The golf shaft 3 has a bending rigidity near the hosel portion. This is configured by providing a bending rigidity body 5 to be enhanced. The region X of the golf shaft 3 where the bending rigidity is increased has a slight distance L (preferably 5 mm) from the hosel portion 2 of the golf club head 1 and a predetermined length La (about 5 mm) from the hosel portion 2 toward the grip portion. It is preferably between 50 mm).

As a means for increasing the bending rigidity of the golf shaft 3, when the golf shaft 3 is made of carbon fiber reinforced plastic as shown in FIG. 1, the number of plies in the region X where the bending rigidity is increased is increased. A material having a high elastic modulus is used, and as shown in FIG. 2, a cylindrical rigid tube 6 is fitted and configured. As described above, the bending rigidity body 5 is provided near the hosel portion 2 of the golf shaft 3.
By making the structure with improved bending rigidity, it is possible to increase the flight distance of the ball by bringing it closer to the launch angle at the sweet spot.

Moreover, the portion that increases the bending rigidity is a part of the shaft, and the weight and the feel (hardness, balance) of the hitter do not change much as compared with the conventional shaft. Next, Table 4 below shows the measurement results of the ball initial trajectory of the golf club in the example of the present invention and the conventional golf club by using a high-speed camera.

The measurement conditions are as follows. Shaft: Mass: 53.7g Head: Mass: 214.6g Loft: 12 ° Ball: 2-piece ball Club: Mass: 340.5g Length: 44 inches Swing balance: D3.0 Club frequency: 217 (CPM) Swing Conditions: Swing robot head speed: 40 (m / s) The deformation of the shaft in FIGS. 6A and 6B is at 3/10000 seconds after impact. Also, the curvature is shown magnified ten times.

[0022]

[Table 4]

As is apparent from Table 4, in the golf club of the embodiment of the present invention, the launch angle at the vertical hitting point is close to the launch angle at the face center. Regarding the initial velocity of the ball, the initial velocity of the ball is increased due to the decrease in strain energy. This is due to the reduced distortion of the shaft during contact between the ball and the club face.

[0024]

As described above, according to the present invention, the vicinity of the hosel portion of the shaft has a structure in which the bending rigidity is increased. Therefore, the partial bending rigidity of the shaft is increased so that the hitting position is above and below the sweet spot. In the case of a missed shot such as when the player misses the ball, it is possible to suppress the extreme rise and fall of the launch angle, and it is possible to prevent the flight distance of the trial hitter from greatly deviating, and launching at a sweet spot By bringing the ball closer to the corner, it is possible to increase the flight distance of the ball.

[Brief description of drawings]

FIG. 1 is an overall view of a golf club embodying the present invention.

FIG. 2 is a partially enlarged front view of a golf club showing another embodiment of the present invention.

FIG. 3 is a graph explanatory view showing a relationship between a hitting point position and a launch angle when a test hit is performed using the golf club in the embodiment of the present invention.

FIG. 4 is a graph explanatory view showing a relationship between a hitting point position and a ball initial velocity when a trial hit is performed using the golf club in the example of the present invention.

FIG. 5 is a partially enlarged front view of a conventional golf club, in which a portion where strength is increased is indicated by diagonal lines.

6 (a) and 6 (b) are explanatory views showing the deformation of the golf shaft when the golf club is hit with a conventional golf club, in which the signs of curvature "+" and "-" and bending deformation of the shaft are shown. It shows the correspondence with.

FIG. 7: When performing a trial hit using a conventional golf club,
It is explanatory drawing which shows the strain gauge attachment position (-) at the time of strain measurement.

FIG. 8 (a) is an explanatory view schematically showing the golf shaft in an S-shape, and FIG. 8 (b) shows the bending of the shaft when the hitting point is above the face center (head). (Area) and a ball trajectory of the ball are schematically illustrated, and (c) is an explanatory diagram schematically illustrating a shaft bend (near the head) and a ball trajectory when the hitting point is below the face center. is there.

[Explanation of symbols]

1 Wood Golf Club Head 2 Hosel Part 3 Golf Shaft 4 Grip 5 Bending Rigid Body 6 Cylindrical Rigid Tube

Claims (3)

[Claims] 1. A golf club having a shaft attached to a hosel portion of a club head, wherein the shaft has a structure in which a bending rigidity is increased in the vicinity of the hosel portion. 2. The golf club according to claim 1, wherein a region of a portion of the shaft which enhances bending rigidity is between 5 mm and 50 mm from a hosel portion of the club head. 3. As a means for increasing the bending rigidity of the shaft, when the shaft is made of carbon fiber reinforced plastic, the number of plies in the area where the bending rigidity is increased is increased, or a material having a high elastic modulus is used, Alternatively, the golf club according to claim 1 or 2, wherein a cylindrical rigid tube is fitted.