JP2000342721A - Wood club head - Google Patents

Abstract

(57) [Problem] To provide a wood club head that effectively corrects the tendency of a player who tends to bend a hit ball in a certain direction. SOLUTION: The center of gravity of the wood club head HG is defined by orthogonal coordinates having a point at which a shaft axis inclined at a predetermined lie angle (θ) intersects a ground line as an origin and a horizontal axis at a grind line passing through the origin. The relationship shown in the following equation (1) or (2) is set between and the center of gravity position XG from the toe end. Formula (1); HG ≧ A (XG-L) + B, Formula (2); HG ≦ C (XG-L) + D, where (L) is the face length, and items A to D are dry or fairway woods. In each case, the following values are selected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the relationship between the direction of a hit ball of a wood club head and the position of the center of gravity.

[0002]

2. Description of the Related Art The position of the center of gravity of the head of a conventional wood club is, as shown later, a ground line (horizontal ground) and a shaft axis, according to actual measurements of various commercially available clubs performed by the inventor. With the crossing point as the origin, it is distributed about 25 mm in horizontal distance from the origin.

If the player hits the ball with the center of gravity of the head, the hit ball will fly straight if the face surface is perpendicular to the target direction. However, it is very difficult for a player of ordinary skill to constantly hit the ball at the position of the center of gravity of the head, and the hit points are usually uneven on the left and right sides of the center of gravity of the head. As a result, there is a problem that the flight trajectory of the hit ball bends right and left and the ball flies in an unintended direction. Particularly, for a player called a hooker or a slicer, which has a habit of always hitting a ball in a certain direction, a weight of a lead plate is pasted to the head on the toe or hill as a correction method. In general, measures are taken to change the position of the center of gravity of the head.

[0004]

On the other hand, regarding the position of the center of gravity and the directionality of the hit ball, if the center of gravity of the head is arranged close to the toe side on the face surface, the hit point is generally on the heel side from the position of the center of gravity. Therefore, it is said that the face surface rotates leftward with the center of gravity as a fulcrum due to the impact at the time of hitting the ball (in the case of right-handed), and the ball is hit leftward and becomes a sliced ball. I have. Conversely, when the center of gravity of the head is moved to the toe side, it is said that when the club is swung, the face becomes difficult to return immediately before the ball is hit, and the hit ball is hit to the right and becomes a football. That is, conventionally, there is no established theory regarding the relationship between the position of the center of gravity on the face surface and the directionality of the hit ball.

[0005] Therefore, the measures against the bending of the hit ball must be made by trial and error, such as repeating the test hitting while changing the position where the weighted lead is applied in various ways. Furthermore, designing the club head itself in advance for the above-mentioned hooker or slicer can be a trial-and-error inefficient development under the current situation where there is no established theory regarding the center of gravity and the direction of the head. The sex is great. In view of such circumstances, an object of the present invention is to provide a club head that effectively corrects the tendency of a player who tends to bend a ball in a certain direction. .

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a wood club head according to the present invention is used for a player who has a tendency to hit the ball to the left (in the case of right-handed). As described in 1, in a wood club head having a normal lie angle (θ) and a loft angle and a normal address posture, a point at which a shaft axis and a ground line intersect is set as an origin, and a toe is set from this origin. The vertical distance from the ground line to the center of gravity of the head is assumed to be the height of the center of gravity H, assuming orthogonal coordinates with the ground line toward the side as the horizontal axis.
G, the horizontal distance from the toe end to the center of gravity of the head is a center of gravity position XG, and the horizontal distance from the toe end to the origin is a face length L, the height of the center of gravity HG and the position of the center of gravity XG Is characterized by the relationship shown in the following equation (1). Formula (1); HG ≧ A (XG−L) + B where A and B are the following values depending on the case of a driver or the case of a fairway wood.

In the above equation (1), as shown in FIGS. 4 and 5, a point at which a shaft axis inclined at a prescribed lie angle (θ) intersects a ground line is defined as an origin 0, and passes through the origin 0. In the orthogonal coordinates with the grind line as the horizontal axis and the vertical line to the ground line passing through the origin 0, the distance (XG-L) from the origin is taken in the horizontal axis direction, and the ground line is taken in the vertical axis direction. Height of the center of gravity from above (HG)
For each of the various existing wood clubs, plot the coordinates of the center of gravity separately for the driver and the fairway wood, and set the origin at the position closest to the point plotted closest to the toe side. When a line segment parallel to the passing shaft axis (that is, HG = A (XG-L) + B) is drawn, it indicates that the position of the center of gravity of the club head according to the present application exists above this line segment. . Hereinafter, the line segment parallel to the shaft axis is referred to as an (upper) limit line.

The term B in the equation (1) is the value of the ordinate at the point where the line segment parallel to the shaft axis crosses the vertical axis of the coordinate, as shown in each figure. The value of HG is
From the empirical restrictions on the shape and material of the head, it is preferable that the limit of shifting the position of the center of gravity to the toe side be within a range of 5 mm from the limit line of the formula (1) to the horizontal toe side.
In the equation (1), the value where B = B + 5 tan (θ) is set as the upper limit.

When swinging with the wood club head according to claim 1 of the present invention, since the center of gravity of the head is located closer to the toe than the region where the center of gravity of the conventional product exists, as shown in FIG. A so-called toe-down phenomenon in which the toe side of the head hangs down in the ground direction with respect to the shaft axis occurs largely, and the face is in a posture (i.e., open) that is largely open with respect to the target (target) direction of the hit ball. Become.
That is, the dynamic lie angle becomes flat and the face opens, and as a result, the hit ball tends to fly rightward (in the case of right hitting), and the hit ball has a habit of always bending to the left. The flight in the direction is corrected, and a straight hit ball can be obtained.

Further, in the wood club head according to the present invention, the hit ball has a tendency to bend right (in the case of right hit).
According to a second aspect of the present invention, in a wood club head having a normal lie angle (θ) and a loft angle and a normal address posture, a shaft axis and a ground line are provided. The point of intersection with is the origin,
The vertical distance from the ground line to the center of gravity of the head is defined as the height of the center of gravity HG, and the horizontal distance from the end of the toe to the center of gravity of the head is defined as the center of gravity position XG. When the horizontal distance from the toe end to the origin is the face length L, there is a relationship between the height HG of the center of gravity and the position XG of the center of gravity as shown in the following equation (2). I have. Formula (2); HG ≦ C (XG−L) + D Here, C and D are selected depending on the case of the driver or the case of the fairway wood, respectively, and the following values are selected.

In this case, in the existing product plotted in the coordinate axis described in the equation (1), a line segment parallel to the shaft axis passing through the origin at a position close to the point plotted on the heel side. (That is, HG = C (XG-L) +
When D) is subtracted, it indicates that the position of the center of gravity of the club head according to the present application exists below this line segment.
Hereinafter, the line segment parallel to the shaft axis is referred to as a (lower) limit line.

In the equation (2), the term D is the value of the ordinate at the point where the line parallel to the shaft axis crosses the vertical axis, as shown in FIGS. The value of HG is
From the empirical restrictions on the shape and material of the head, it is preferable that the limit of shifting the position of the center of gravity to the heel side is within a range of 5 mm from the (lower) limit line of the formula (2) to the heel side in the horizontal direction. , (2), the value where D = D−5 tan (θ) is set as the lower limit.

When swinging with the wood club head according to the present invention, the center of gravity of the head is changed closer to the heel than the region where the center of gravity of the conventional product is located.
The dynamic lie angle (the lie angle when the club is swung) is more upright than the conventional product, the degree of opening of the face is reduced, and the tendency of the hit ball to go to the left increases, so the existing club The ball muscle in the right direction of the so-called slicer, which is considered as a problem, is corrected.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described with reference to FIGS. FIG. 1 is a front view (a) and a side view (b) of a driver wood club head according to the present invention.
The solid line A is Example 1, the solid line B is Example 2,
Further, a broken line C indicates a head 1 of each club of a conventional product as a comparative example.
Is shown. Each club has a club length of 43 inches and a shaft to be mounted is R-flex.

First, in the club head 1 of the comparative example, which was used as a reference for comparison, the face length (L) was 89.2 mm and the maximum head height (M) was 47.4 mm.
The position of the head center of gravity 2 is located at a height of 22.8 mm from the origin 0 on the coordinate axis and at a distance of 32.5 mm from the origin to the horizontal toe 3 side.

In the wood club head of Embodiment 1, FIG.
As shown in the table, in order to move the position of the center of gravity of the head 2 to the toe 3 side, the face length (L) is smaller by 1.4 mm and the head maximum height (M) is smaller than the conventional product of the comparative example. Is set to be 2.1 mm larger. As a result ,
The position of the head center of gravity 2 is located at a height of 22.3 mm from the origin 0 and at a distance of 38.4 mm from the origin to the horizontal toe 3 side. Therefore, 5.9 m in the horizontal direction from the comparative example
The center of gravity has been moved closer to the m-toe.

In the second embodiment, in order to move the position of the center of gravity of the head 2 to the heel 4 side, the face length (L) is reduced by 8.4 mm and the maximum height of the head in comparison with the conventional product of the comparative example. (M) is set to be 1.4 mm larger. As a result, the position of the center of gravity of the head 2 is 23.7 m from the origin 0.
It is arranged at a distance of 26.1 mm on the horizontal toe 3 side from the origin at a height of m. Therefore, the center of gravity has been shifted in the horizontal direction toward the heel of 6.4 mm from the comparative example.

With respect to each club equipped with the above-mentioned heads, a hitting test was carried out with a hitting robot at a head speed of 45 m / s, and images of strobe photographs were taken from a position where the swing surface was viewed at a right angle. The amount of bending of the shaft 5 shown was confirmed. In the head of the first embodiment, the bending amount is 1
1.6 with respect to the head of the comparative example with 4.9 mm as a reference.
mm down head down. Therefore, the face 6 is opened to that extent, and the tendency to hit the ball in the right direction occurs. On the other hand, in the case of the second embodiment, the bending amount is 11.
It is 6 mm, which is 1.7 m from the head of the comparative example as a reference.
The head down becomes smaller as m. Therefore, the face 6 is closed as compared with the head of the reference club of the comparative example, and there is a tendency for the hit ball to fly to the left.

When the direction of the face 6 changed as a result of the toe-down is confirmed, the normal line set on the face 6 when the amount of deflection of the shaft is 13.3 mm in the club head of the comparative example. Based on the case where the direction matches the target direction of the impact, in the case of the first embodiment,
Observed that the normal direction set on the face 6 when the head of Example 1 had a deflection amount of 14.9 mm was inclined rightward by about 0.3 degrees with respect to the reference normal direction. Was done. That is, in this case, the face is turned rightward by about 0.3 degrees.
It was observed that it turned to the left about a degree. As a result,
In the club of the first embodiment, the hitting ball is extremely effective in correcting the hitting of a hooker having a habit of flying to the left. In the club of the second embodiment, the hitting of a slicer having a habit of hitting the ball to the right is corrected. It is found to be extremely effective for

[0020]

By setting the center of gravity of the head within the range defined by the present invention, it is possible to effectively change the dynamic lie angle as compared with the existing club, which is a problem with the conventional club. It is possible to effectively correct a hooker or slicer having a habit in the direction of the hit ball. Also, in changing the dynamic lie angle, there is no need to change the rigidity of the shaft or the weight of the head, so there is no adverse effect on the swing timing and swing feeling, and further, the change of the lie angle of the club itself Since the address is not required, the feeling at the time of addressing is not adversely affected.

[Brief description of the drawings]

FIG. 1 shows a front view (a) and a side view (b) of a wood club head according to an embodiment of the present invention.

FIG. 2 is a table showing head specifications and characteristic values of an example and a comparative example.

FIG. 3 is a diagram illustrating the deflection of a shaft during a club swing.

FIG. 4 is a diagram showing a position of a center of gravity of a head of a driver wood club.

FIG. 5 is a diagram showing the position of the center of gravity of the head of the fairway wood club.

[Explanation of symbols]

 1 Head 2 Head center of gravity 3 Toe 4 Heel 5 Shaft 6 Face

Claims (2)

[Claims] In an iron club head having a normal lie angle (θ) and a loft angle and a normal address posture, a point at which a shaft axis and a ground line intersect is defined as an origin, and the toe side is defined from the origin. The vertical distance from the ground line to the center of gravity of the head is assumed to be the height of the center of gravity HG, and the horizontal distance from the toe end to the center of gravity of the head is assumed to be the center of gravity position XG,
When the horizontal distance from the toe end to the origin is the face length L, there is a relationship expressed by the following equation (1) between the center of gravity height HG and the center of gravity position XG. Iron club head. Formula (1); HG ≧ A (XG−L) + B where A and B are the following values depending on the case of a driver or the case of a fairway wood. 2. In a wood club head having a normal lie angle (θ) and a loft angle and a normal address posture, a point at which a shaft axis intersects with a ground line is set as an origin, and from the origin to the toe side. Assuming orthogonal coordinates having the ground line as the horizontal axis, the vertical distance from the ground line to the center of gravity of the head is defined as the center of gravity height HG, the horizontal distance from the toe end to the center of gravity of the head is defined as the center of gravity position XG, and An iron club head characterized in that, when the horizontal distance to the origin is a face length L, the height of the center of gravity HG and the position of the center of gravity XG have a relationship represented by the following equation (2). Formula (2); HG ≦ C (XG−L) + D Here, C and D are selected depending on the case of the driver or the case of the fairway wood, respectively, and the following values are selected.