JP2532650Y2 - Wood Golf Club Head - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention relates to a wood golf club head, and more particularly, to reduce the head speed by alleviating the turbulence of the airflow generated on the upper surface of the wood golf club when swinging. The present invention also relates to an improvement in a wood golf club head in which irregular vibration of a shaft is effectively prevented.

[Conventional technology]

In general, a wood golf club receives air resistance from the club head due to swinging at the time of hitting, which causes a reduction in head speed at hitting and an irregular vibration of a shaft, resulting in a decrease in a flight distance of a hitting ball, Has been adversely affected.

This tendency is particularly strong in wood clubs, and cannot be neglected due to the recent increase in the length of the club shaft for the purpose of increasing the flight distance and the use of a large head.

[Problems to be solved by the invention]

Meanwhile, a conventional wood golf club 1 is, for example, one shown in FIGS. 4 to 8, and as shown in FIGS. 4 and 5, the upper surface 2a of the club head 2 is formed in an arc shape. The airflow Q from the face surface 3 hits the face surface 3 as shown in FIG.
And separates and wraps around the sole portion 4 formed substantially horizontally with the upper surface 2a of the first member.

The air resistance to the club head 1 is due to the airflow Q generated around the club head 2 when the club is swung.

More specifically, it is divided into the air resistance of the airflow Q on the face surface 3 of the club head 1 and the resistance caused by the turbulence of the airflow Qa generated around the club head 1. These two airflows Q and Qa
Among them, the former has a large air resistance and is inevitable from the tendency of the hitting surface (face surface 3) to become large.

Although the size of the latter is small in size, the influence on the irregular vibration of the club shaft 6 is large, and the possibility of reducing the size by improving the shape of the club head 1 is possible.

FIG. 6 is a cross-sectional view of the center of the club head 2 (VI-V in FIG. 5).
FIG. 1 is a cross-sectional view taken along the arrow I) showing an ideal airflow during a swing. That is, the head upper surface 2a of the club head 2
The airflow Qa at is laminar and there is no turbulence in the airflow,
Actually, as shown in FIG. 7, the upper surface 2a of the club head 2
The airflow Qa is delaminated at the X position, and the airflow Qa is disturbed. This reduces the head speed while swinging,
It causes irregular vibration of the shaft.

When this is visualized by an oil film method known as one of the test methods, as shown in FIG. 8, an oil film adheres in the region of the Y portion, and the turbulence of the air flow Qa occurs on the head upper surface 2a. You can see that.

The oil film method based on the visualization experiment means that a mixture of oil and pigment (oil film) is applied to the surface of an object, and when the mixture is exposed to a flow, a fluid force (shear force) acts on the oil film, causing stripes and streaks on the oil film. A pattern appears. This pattern is used to check the flow direction, transition of boundary layer, separation, flow velocity, and secondary flow near the object surface.

The tendency of the turbulence of the airflow Qa becomes stronger as the head speed increases, and the shape of the club head 2 is as follows.
The greater the curvature of the upper surface, the stronger. It is difficult to reduce this curvature in order to reduce the turbulence at the head rear portion 2b.

[Purpose of the invention]

This invention was devised by focusing on such a conventional problem, and the turbulence of the airflow generated on the upper surface of the club head, in other words, the delamination of the airflow on the upper surface of the club head is reduced to reduce the head speed, It is an object of the present invention to provide a wood golf club head in which irregular vibration of a shaft is effectively prevented.

[Means for solving the problem]

In order to achieve the above object, the present invention provides a club head (2) with an arc-shaped head upper surface (S) separated by a distance (l) of 10 to 20 mm from the top of the upper surface (P) to the back side. ) Is set, and a circle having a contact point at the center of the position is defined as a minimum area of at least 0.5 mm to 1.5 mm over substantially the entire area of the upper surface of the club head from this position (S) toward the back side.
The gist is that a recess (7) having a depth (d) of mm is provided, and the bottom surface of the recess (7) is formed along an arcuate virtual line on the top surface of the head.

[Action of the invention]

This invention is configured as described above, and a moderate concave portion, that is, a step is provided slightly before the position where the layer separation of the airflow occurs on the upper surface of the club head, so that a small turbulent airflow on the upper surface of the club head, In other words, a vortex-like turbulent flow is generated, which greatly reduces the occurrence of delamination of the entire airflow to the rear portion of the head, reduces air resistance, and reduces delamination.

[Example of the invention]

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

The same components as those of the conventional example are denoted by the same reference numerals, and description thereof will be omitted.

FIG. 1 is a sectional view of a wood golf club head 1 embodying the present invention, in which an upper surface 2a of a club head 2 is formed in an arc shape, 3 is a face surface, and 4 is a sole portion.

In the wood golf club head 1 according to the present invention, as shown in FIG. 1, a position S is set at a predetermined distance l from the top P of the arc-shaped upper surface 2a of the club head 2 toward the back 2b. I do. And from the position S to the back side
2b, a circle having a contact point at the center of the position S (see FIG. 2 (d)) is defined as at least a minimum area, and the recess 7 having a predetermined depth is formed over substantially the entire upper surface 2a of the club head 2. That is, a step is formed.

Various shapes and widths of the concave portion 7 are conceivable as shown in FIGS. 2 (a) to 2 (d).

Further, when the above embodiment is specifically described, the club head 2 is placed on the upper surface 2a of the club head 2 from the top P of the curved surface.
From the position S separated by a distance l of 10 to 20 mm toward the back side 2b, the depth d is 0.5 to 1.5 mm toward the back side.
The concave portion 7 is formed.

The shape of the bottom surface 7a of the concave portion 7 is formed as a convex curved surface along the arcuate virtual line KK of the head upper surface 2a.

This is because a small turbulence, in other words, a vortex-like turbulence, is generated on the upper surface of the club head by providing an appropriate concave portion 7, that is, a step, slightly before the position where the layer separation of the air flow occurs on the head upper surface 2a. This greatly reduces the occurrence of delamination of the entire airflow to the rear of the head.

At this time, if the depth d of the step of the concave portion 7 is too small, no appropriate turbulence is generated, and if it is too large, the generated turbulence is large, which increases the turbulence of the air flow, which has an adverse effect. In addition, when the shape of the bottom surface 7a of the concave portion 7 is a concave curved surface, the turbulence is further increased, and the turbulence of the air flow is increased. As a result, the air resistance is increased.

At a head speed of 35 M / sec to 45 M / sec where the golfer's head speed is most distributed, the distance l from the top and the depth d of the concave portion 7 exhibiting the most effect are respectively
The values of 10 to 20 mm and 0.5 to 1.5 mm were confirmed by visualization experiments using the oil film method and the spark tracking method in the wind tunnel experiment.

The oil film method based on the visualization experiment is the method described above, and the spark tracking method is a method in which an electrode of an appropriate shape is arranged in an airflow, a high-voltage pulse is applied at a constant cycle, and air that is ionized by a discharge first is discharged. When the line flows downstream with the airflow, the flow is examined by utilizing the discharge on the ionized air line again.

FIGS. 3 (a) to 3 (c) show the depth d of the recess 7 formed on the upper surface 2a of the club head 2 as 0.5 in FIG. 3 (b).
The airflow Qa outside this range is shown on the basis of .about.1.5 mm.

That is, FIG. 3 (a) shows the flow of the airflow Qa when the depth d of the concave portion 7 is extremely shallow with less than 0.5 mm.
In this case, an appropriate turbulence does not occur as described above, and when the depth d of the recess 7 is set to 1.5 mm or more, the turbulence increases as shown in FIG. It can be seen that this increases the turbulence of the airflow Qa.

As described above, the depth d of the concave portion 7 in the visualization experiment is
By setting the thickness in the range of 0.5 to 1.5 mm as shown in FIG. 3 (b), the layer separation of the airflow Qa on the upper surface 2a of the club head 2 is alleviated, and the reduction of the head speed and the shifting vibration of the shaft are reduced. It can be prevented.

[Effects of the Invention] In the invention, a distance (l) of 10 to 20 mm from the top of the upper surface (P) to the back side is provided on the upper surface of the club head (2) formed in the arc shape as described above. A position (S) is set, and a circle having a contact point at the center of the position is formed in at least a minimum area of 0.5 mm to 1.5 mm over substantially the entire area of the upper surface of the club head facing the back side from the position (S). Since the concave portion (7) of (d) is provided, and the bottom shape of the concave portion (7) is formed along an arcuate virtual line on the upper surface of the head, appropriate rectification is generated to reduce the air flow on the upper surface of the club head. This has the effect of reducing delamination, effectively preventing head speed reduction and irregular vibration of the shaft, extending the flight distance of the hit ball, and improving the directionality of the ball.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a wood golf club head embodying the present invention, and FIGS. 2 (a) to 2 (d) are explanatory views of an embodiment showing recesses of various shapes formed on the upper surface of the head. FIGS. 3 (a) to 3 (c) are explanatory diagrams showing the state of air flow by changing the depth of a concave portion formed on the upper surface of a club head in a visualization experiment, and FIG. 4 is a conventional wood golf. FIG. 5 is a front view of the wood golf club head, FIG. 6 is a sectional view taken along the line VI-VI of FIG. 5, and FIG. 7 is an ideal air flow around the head at the time of hitting. VI-VI in Fig. 4
FIG. 8 is an explanatory diagram showing an actual air flow around the head when hitting the ball in a cross section taken along the arrow, and FIG. 8 is an explanatory diagram showing an attached state of an oil film in an oil film method at a flow velocity of 40 M / sec. 1 wood golf club head, 2 club head, 2a upper surface of club head, 3 face surface, 4
... Sole part, 7 ... Concave part, P ... Top part, S ... Position, l ... Distance.

Claims (1)

(57) [Scope of request for utility model registration] 1. An arc-shaped upper surface of a club head (2) is formed on the upper surface of the club head (10) from the top (P) to the back side by 10 to 20
A position (S) separated by a distance (l) of mm is set, and a circle having a contact point at the center of the position is formed in at least a minimum area over substantially the entire area of the upper surface of the club head going from this position (S) toward the back side. Recess (7) with a depth (d) of 0.5 mm to 1.5 mm as
Wherein the bottom shape of the recess (7) is formed along an arcuate virtual line on the top surface of the head.