JPH06210027A - Golf club designing method - Google Patents

Abstract

PURPOSE:To obtain club characteristics or shape which are most suitable for the swing of an individual golfer by a method wherein the physical properties or shape of a golf club are designed by performing a swing simulation by a finite element method using a model based on swing pattern data, and the physical properties or shape of the golf club as input data. CONSTITUTION:A video camera 1 is arranged at the directly opposite location to a straight line to connect the should and head of a golfer who addresses in the orthogonal direction so that the whole view of a swing may be included, and a coordinate measurement is performed by an image processing. Then, the swing of the golfer is measured, and a swing simulation is performed by a finite element method using the swing pattern data, a model base on the data, and the characteristics or shape of a golf club as input data, and the characteristics or shape of a golf club are designed so that a desired golf club behavior may be shown. By this method, basically, restrictions are not received in the design of a club, and club characteristics or the shape of a club which are most suitable for the swing of an individual golfer can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a golf club design system capable of providing an optimum golf club for individual golfers.

[0002]

2. Description of the Related Art It is most required for golf clubs (hereinafter referred to as clubs) that they do not fly and bend (hard to bend). It is important for clubs to have such characteristics, but finding a club that suits them is also a great concern for golfers. Traditionally, clubs have been manufactured in consideration of static characteristics such as the length, balance, club weight, and shaft hardness of the golf shaft (hereinafter referred to as the shaft). I had no choice but to judge, guess, or rely on my feelings at all.

On the other hand, since the golf swing is a dynamic behavior, attention has been paid to club selection in consideration of the dynamic characteristics of the club, that is, the natural frequency (indicating the first-order bending natural frequency). The natural frequency is an amount governed by the bending steel property of the shaft, the shaft weight, the shaft length, and the weight of the golf head (hereinafter referred to as the head), but it is roughly as follows. That is, it is considered that the shaft flexes and restores during the downswing, but the head speed becomes maximum when the shaft is restored and the shaft is in a straight state.
Therefore, if the ball is hit at this point, the maximum flight distance in the swing can be obtained. (However, it is said that the natural frequency of the golf club is related to such swinging behavior when the face of the head is correctly oriented). If a club with a lower natural frequency is used, the hit point is reached before the maximum head speed is reached, and if a club with a higher natural frequency is used, the maximum head is reached. It is thought that after hitting, the ball will be hit, and the flight distance will drop and the directionality will also deteriorate.

[0004]

In consideration of this, there are, for example, the frequency harmonization method of Console Co. and JP-A-1-285276. However, the drawback of these methods is that the method of selecting the optimum natural vibration may be unscientific or ambiguous. For example, the console's frequency harmonization method is a method of inferring other clubs of different counts from natural frequencies of two clubs of different counts that seem to suit one's own. There is no scientific basis for the golfer.
Further, in Japanese Patent Application Laid-Open No. 1-285276, the gender, age, golf calendar, number of rounds, practice count, sports calendar, extension, weight, grip strength, handicap, head speed, round stroke, flight distance of a driver, 5 It is assumed that the swing characteristics are analyzed based on at least one item of the flight distance and the ball stripe of the number iron, but it is unclear how each item has a causal relationship with the natural frequency, and also for statistical processing. Enormous data storage and processing was required.

In designing a club, the torsional steel of the shaft, the moment of inertia of the head, the position of the center of gravity, the shape (for example, loft angle, lie angle), etc. of the head speed, golf ball (hereinafter It is an important factor in the flight distance and direction, which is related to the launch angle of the ball, the amount of spin, and the ease of hitting.

The present invention has been made in view of the above problems, and there is basically no limitation in designing a club, and an optimum club characteristic or shape suitable for the swing of each golfer is obtained. The present invention aims to provide a golf club design method capable of achieving the following.

[0007]

The structure of the present invention for achieving the above object will be described with reference to FIGS. 1 to 6 corresponding to the embodiments. The present invention is to measure the swing of an arbitrary golfer. Using the swing pattern data, a model created based on that data, and the physical properties and shape of the golf club, which are design targets and can be changed, as input data, swing simulation is performed by the finite element method to obtain the desired golf club. It is characterized in that the physical properties and shape of the golf club are designed so as to show the behavior.

First, it was demonstrated that the head speed is maximized when the flexed shaft restores to a straight state during the downswing. FIG. 7 shows experimental results when a certain driver was hit with a swing robot in various swing patterns. The horizontal axis is the strain on the head face side in the middle of the shaft length (measured with a strain gauge)
The vertical axis represents the head speed / arm angular speed immediately before hitting, and the larger this ratio, the higher the head speed. From this result, it was found that the head angular velocity / arm angular velocity was the largest when the strain was near 0 (the shaft was not bent). Therefore, club design 1
As one index, when each golfer swings, the head speed becomes maximum if a golf club in which the shaft is deformed as described above at the striking point is used.

However, the way of swinging (hereinafter referred to as a swing pattern) is different for each golfer.
This needs to be measured. Although various methods are possible, one method is to take a video camera and process the image. Specifically, one video camera may be photographed from the direction perpendicular to the swing surface (it may be diagonally photographed and corrected later), or two or more cameras may be interlocked to photograph the swing. May be processed three-dimensionally. As the swing pattern data, the position and rotation angle of each part of the shoulder, elbow, wrist, waist, leg, etc., grip,
The position and rotation angle of each part of the club, such as the shaft and the head, are present and may be selected as necessary.

Next, using this swing pattern data, a swing simulation is performed by numerical calculation,
Select the optimal club physical properties and shape. Specifically,
First of all, there are a difference method, a finite element method, and a boundary element method as the numerical calculation method, but the finite element method is suitable in terms of technical perfection and ease of use. The objects to be designed in the golf club (hereinafter referred to as design variables) are the bending steel properties of the shaft, torsional steel properties, weight, length and head weight, center of gravity position, shape (including lie angle, loft angle, moment of inertia), etc. But there is
It is decided according to the purpose. Computational models are club models and human models (though they may not be necessary)
, But the model may be constructed according to the design variables. As a concrete example of modeling, in the case of a club model, the shaft can be constructed by one or a combination of beam element, shell element, cubic element, etc., and the head can be constructed by any one of concentrated mass element, shell element and cubic element. Or they can be constructed in combination. The human part may be constructed three-dimensionally, but it is more practical to use beam elements, truss elements, or the like.

This model is subjected to swing simulation, and swing pattern data is used for this. For example, shoulders, elbows, wrists (including wrist clasps)
Change the angle. Alternatively, the club may be directly forced (rotated) without using a human model.
Then, it is confirmed whether or not the club behaves in a predetermined manner by this swing simulation. The predetermined behavior means, for example, that the shaft becomes linear at the striking point and the head speed shows the maximum value during the swing. Other than this, the shaft twist state or the face angle may be taken into consideration. When the prescribed behavior is not exhibited, the physical properties and shape of the club are changed and the calculation is repeated to obtain the optimum physical properties.

[0012]

EXAMPLES Examples of the present invention will be described below. The present invention is not limited to this. Example 1 FIG. 1 shows an outline of a swing pattern measuring method. The video camera was installed so that the entire view of the swing could be entered at the position directly in front of the straight line connecting the shoulder and the head when the golfer addressed. Shooting speed is 1/60, shutter speed is 1 /
I made it 10000. Since coordinate measurement is performed by image processing,
An index of known length was set on the screen. As the ball, a pseudo ball (sponge ball) was used. this is,
When hitting an actual ball, the head speed changes before and after it, and the swing of the follow-through cannot be measured accurately, so a lightweight ball that was not easily affected by the hit was used. The clubs are Wood Nos. 1 and 3, Irons 2, 5, 7,
A No. 9 pitching wedge was used.

In the image processing, the coordinates of a predetermined point were measured for each screen as shown in FIG. Since we analyze how the golf club behaves,
All that is required is to know the trajectory of the club, but to measure the swing pattern of the golfer, the shoulders, elbows, and wrists are also measured at the same time.

Swing simulation was performed by the finite element method using this swing pattern data and arbitrary club physical properties. The finite element method program is a bit,
"ABAQUS" manufactured by Carlson & Solesen was used. The two-dimensional model used for the calculation is shown in FIG. This shows the time when the shaft is swung up (top swing). A beam element was used for the shaft and arm, and a lumped mass element was used for the head. The club expects to hold it with its left hand. The model's arms are rigid and do not represent the true position and size of the golfer's arms, which is quasi. This is because the purpose is to analyze the behavior of the club as described above, and the arm part is created for convenience because it is necessary for calculation. In addition, the swing was a backswing from the address state, and a downswing was performed until after the impact. The calculation results shown here are examples within the range studied. Figure 4 shows the shaft bending steel properties used in the calculation. The shaft weight was fixed at 80 g and the head weight was fixed at 200 g.

FIG. 5 shows the calculation results when the driver of the professional golfer is used. This shows the relationship between the natural frequency of the club and the head speed upon hitting. The natural frequency mentioned here is when the point 50 mm from the grip end of the club is completely restrained. The numbers in the symbols in the figure correspond to the numbers representing the type of bending steel in FIG.
From FIG. 5, it can be seen that the head speed is maximum at 53.5 m / s when the natural frequency is 3.75 Hz. The downswing state at this time is shown in FIG. It can be seen that the shaft has a linear shape when hit, and the natural frequency is optimum.

[0016]

According to the present invention, the swing of any golfer is measured, the swing pattern data, the model created based on the data, and the physical properties and shape of the golf club which are design targets and can be changed are input data. The swing simulation is performed by the finite element method and the physical properties and shape of the golf club are designed so as to show the desired golf club behavior. It is possible to provide a golf club design method that can obtain optimum club characteristics and shapes suitable for individual golfers' swings without having to do so.

[Brief description of drawings]

FIG. 1 is a side view of a swing pattern measuring method showing an embodiment of the present invention.

FIG. 2 is a front view of coordinate points to be measured by image processing according to an embodiment of the present invention.

FIG. 3 is a two-dimensional model diagram used in calculation by the finite element method of the present invention.

FIG. 4 is a steel characteristic diagram of shaft bending used in calculation by the finite element method of the present invention.

FIG. 5 is a diagram showing the relationship between the natural frequency of the club of the present invention and the head speed at the striking point.

FIG. 6 is a diagram showing a downswing state when the optimum club is used in FIG.

FIG. 7 is a hitting test result by a swing robot,
The figure which showed the relationship between the bending strain of the shaft and the head speed immediately before impact.

[Explanation of symbols]

1. Video camera 2. Golf club 3. Center point of both shoulders during top swing 4. Left shoulder 5. Elbow 6. Left hand back 7. 7. A point 300 mm from the grip end to the golf head side. Golf head 9. Golf ball 10. Arm 11. Golf shaft 12. Link join

Claims (5)

[Claims] 1. A swing of an arbitrary golfer is measured, and swing pattern data, a model created based on the data, and a golf club physical property or shape which is a design target and can be changed are used as input data. A golf club design method characterized by performing swing simulation by the finite element method and designing the physical properties and shape of the golf club so as to exhibit desired golf club behavior. 2. The golf club design method according to claim 1, wherein the method of measuring the swing comprises photographing with one or more video cameras and performing image processing. 3. The swing pattern data includes the position and rotation angle of each part of the body such as shoulder, elbow, wrist, head, waist, foot, etc., and the position and rotation of each part of the golf club such as grip, shaft and head. 3. The golf club design method according to claim 1, wherein the data is one or more of the angles. 4. The physical properties and shape of the golf club to be designed are
Any one of bending steel property, torsional steel property, weight, length of golf shaft, weight of golf head, center of gravity position and shape
The golf club design method according to claim 1, claim 2 or claim 3, wherein the data is one or more data. 5. The golf club according to claim 1, wherein the predetermined golf club behavior is such that the golf shaft is in a substantially straight state at the striking point and the head speed is maximized.
The golf club design method according to claim 3 or 4.