JP2005304774A - Evaluation method for golf club - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To quantitatively predict and evaluate the hitting characteristics of a golf club such as a golf ball catching degree or the good quality of the return of a face surface conventionally sensed by a golfer in an evaluation method for evaluating the hitting characteristics of the golf club at the time of holding and swinging the golf club. <P>SOLUTION: The characteristic parameter of a golf club head for which the retreat amount R<SB>s</SB>of the golf club head and the mass W<SB>h</SB>of the golf club head are multiplied is calculated. By using a head speed H<SB>s</SB>at the time of a golf swing and a curvature radius R<SB>s</SB>in the trajectory of the golf club head immediately before hitting, the acceleration component of the golf club head in parallel with the ground surface is calculated. By multiplying the characteristic parameter with the acceleration component, the hitting characteristics of the golf club such as the golf ball catching degree or the good quality of the return of the face surface are predicted and evaluated. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a golf club evaluation method for evaluating the impact characteristics of a golf club when a golf swing is performed while holding the golf club.

  One hitting characteristic of a golf club when hitting a golf ball with a golf club is a so-called golf ball catching degree. The degree of catch means that when a golf ball is hit with a golf club in a certain golf swing, the face surface immediately before hitting does not open outward with respect to the track of the golf club head, and does not extremely close inward. The degree of touch that a golfer can feel from a hit feeling when a golf ball is hit with a face accurately. The better this feel is, the higher the golf player is highly evaluated as a golf club head that can hit a golf ball accurately as a golf club. This feeling can be explained by the orientation of the face surface. The impact of hitting a golf ball by performing back swing, top state, and further down swing from the address state in which the face surface of the golf club head is set in the hit direction. At this time, whether or not the orientation of the face surface is likely to return to the direction of the hitting direction set when the address is set corresponds to the sense sensed by the golfer, that is, the ease of returning the face surface.

  In general, when a golfer performs a golf swing using a golf club and hits a golf ball, when the golf ball is hit with a face face open, the golf ball is rotated in a slice (for a right-handed golfer, a right-turn spin). In the case of a right-handed golfer, the golf ball bends to the right and the flight distance does not increase. The hit feeling at this time is not good for the golfer, and it is not sensed that the golf ball was hit accurately. For this reason, it is possible to feel that the golf ball has been hit with a good hit feeling, that is, it is easy to return to the orientation of the face surface set when the face surface is addressed, and the face surface is hit in a square state. It is desirable for golfers to perform golf swing so that a straight golf ball trajectory can be obtained.

On the other hand, when hitting a golf ball, the golf club feels that it is easy to hit a golf ball with a straight trajectory, because the face surface does not open outward with respect to the track of the golf club and the golf ball can be caught accurately. Is also present. Such a golf club is generally said to have a good degree of catching a golf ball or a good return of a golf club head.
As described above, as the hitting characteristics of a golf club, the degree of catch and the return that the golf club has are important factors in the characteristics of the golf club.
Further, it is known that the degree of catch and the goodness of return change depending on the golf swing of each golfer. That is, even if a golf club has a good degree of catch for a certain golfer or a good return, it may be evaluated as a golf club with a bad degree of catch or a bad return for other golfers.

The degree of catch and return that golfers feel about such golf clubs are perceived sensuously by actually hitting the golf ball. Therefore, conventionally, the degree of catch and good return are characteristic of golf clubs. As a result, it has not been fully studied quantitatively.
In Patent Document 1 below, the center of gravity formed between the face surface and the vertical surface of the golf club head is held in a state where the golf club shaft can be rotated horizontally around the central axis and the rotation of the golf club shaft is stopped. A golf club having a corner set in a predetermined range is disclosed. It is described that when the barycentric angle is smaller than a predetermined angle, the golf ball is easily sliced and rotated. (Patent Document 1, column 5, lines 5-7)

  However, the barycentric angle referred to in Patent Document 1 is determined by the barycentric position that is the head configuration of the golf club, and is not an index to be evaluated based on the dynamic motion of the golf club head when the golf club is swung. . For this reason, it is a constant evaluation result that does not depend on the head speed at the time of golf swing that varies depending on each golfer. For this reason, the center-of-gravity angle is not necessarily an index that reflects the degree of golf club catching that the golfer feels and the good return of the face.

Japanese Patent No. 2645389

  Accordingly, the present invention provides an evaluation method for evaluating the hitting characteristics of a golf club when a golf club is held and a golf swing is performed, and the golf club catching degree or face surface that has been conventionally sensed by a golfer. An object of the present invention is to provide a golf club evaluation method capable of quantitatively evaluating the impact characteristics of a golf club expressed by the goodness of return.

  In order to achieve the above object, the present invention is an evaluation method for evaluating the hitting characteristics of a golf club when performing golf swing, and the golf club head from the center line of the golf club shaft or an extension of the center line. A calculation step of calculating a characteristic parameter of the golf club head obtained by multiplying the retraction amount of the gravity center position representing the distance along the striking direction to the gravity center position of the golf club and the mass of the golf club head, and using the calculated characteristic parameter, An evaluation method for evaluating a hit characteristic of a golf club is provided. A golf club evaluation method is provided.

Here, the evaluation step includes the head speed immediately before hitting the golf ball in golf swing and the golf club head immediately before hitting the golf ball in a projected trajectory projected on a plane parallel to the ground on which the golf swing is performed. By calculating the acceleration component parallel to the ground surface of the golf club head using the radius of curvature of the golf club, and multiplying the calculated result by the characteristic parameter, the hitting characteristic of the golf club during golf swing is evaluated. Is preferred.
Further, the evaluation step evaluates the hitting characteristic of the golf club by multiplying the result obtained by multiplying the characteristic parameter by the acceleration component by a torsion angle with respect to a torque having a predetermined magnitude around the central axis of the golf club shaft. It may be a thing.

  Furthermore, the present invention is a golf club evaluation method for evaluating the hit characteristics of a golf club characterized by the golf swing performed by the golfer, and performs golf swing out of the acceleration of the golf club head immediately before hitting the golf ball. An acquisition step of acquiring an acceleration component parallel to the ground, and a distance along the hitting direction from the center of the golf club head and the center line of the golf club shaft or an extension of the center line to the center of gravity of the golf club. A golf club evaluation method comprising: an evaluation step of evaluating a hit characteristic of a golf club by multiplying a product of a retraction amount of a center of gravity position representing

The present invention relates to a characteristic parameter obtained by multiplying a golf club head mass by a retraction amount of the center of gravity representing a distance along a striking direction from the center line of the golf club shaft or an extension of the center line to the center of gravity of the golf club head. Can be used to evaluate the return of the face surface of the golf club head immediately before hitting the golf ball, and thus the golf ball catching degree felt by the golfer can be predicted.
Furthermore, in a plurality of golf clubs made into a series or a plurality of golf clubs of an iron set, the predicted degree of catching of a golf ball can be changed intentionally depending on the series, or it can be changed in harmony according to the number. it can. Thereby, it is possible to provide a golf club or a golf club set that is most suitable for a golfer.

  Hereinafter, a golf club evaluation method of the present invention will be described in detail based on a preferred embodiment shown in the accompanying drawings.

FIG. 1 is a block diagram of an evaluation apparatus 10 that performs the golf club evaluation method of the present invention.
The evaluation apparatus 10 is supplied with the head speed of the golf club head immediately before hitting the golf ball and the trajectory of the golf club head immediately before hitting the golf ball measured by the swing measuring system 20. It is an apparatus that can quantitatively predict and evaluate the degree to which a golf ball is detected or the return of a face surface.

  The evaluation apparatus 10 includes an input unit 12, a calculation unit 14, a memory 16, a parameter calculation unit 18, and an evaluation unit 20.

The input unit 12 includes a golf club head mass W _h , which is a structural feature of the golf club, and a distance along the hitting direction from the center line of the golf club shaft or an extension of the center line to the center of gravity of the golf club head. when the data of the retraction amount G _r of the center-of-gravity position representing a is supplied, or, of a golf club head which is measured by the swing measurement system 20, (time series data of the position coordinate) data of the track just before the golf ball striking and golf When the head speed immediately before hitting the ball is supplied, the data is processed into a predetermined format, and the processed data is supplied to the calculation unit 14 and the parameter calculation unit 18.

When the data of the mass W _h and the retraction amount G _r is supplied from the input unit 12, the calculation unit 14 multiplies the mass W _h and the retraction amount G _r, and the multiplication result (W _h × G _r ) is golf club. This is a part acquired as a characteristic parameter of the golf club head that defines the structural characteristics of the golf club.
For each golf club designed and manufactured according to the same specifications, that is, for each golf club brand name and series, or for each iron golf club, the number of the brand name, series, or count. The information is stored in the memory 16 in association with the identification information of the specified golf club.
The retraction amount _Gr is measured as follows.

2 (a) is a plan view seen from above a golf club head in order to explain the retraction amount G _r of the center-of-gravity position, and FIG. 2 (b) is a side view from the toe side of the golf club head .
The retraction amount _Gr is defined as the center of gravity CG of the golf club head 40 and the plane P that includes the golf club shaft axis and is perpendicular to the flying ball direction F in the plan view of the golf club head shown in FIG. Is the distance between. Similarly in FIG. 2B, the reverse amount _Gr is represented. More specifically, the golf club head 40 includes a center of gravity CG of the golf club head 40 and a golf club shaft axis in a state where the golf club head 40 is installed on a horizontal plane according to the lie angle and the face surface is directed in the flying ball direction F. The distance from the plane P perpendicular to the flying ball direction F. Here, the installation along the lie angle is a state in which the gap between the round of the sole surface of the golf club head 40 and the installation surface formed of a horizontal surface is substantially equal on the toe side and the heel side. When the round of the sole surface is unclear, the score line and the installation surface are set in a parallel state. When the round of the sole surface is unclear and the score line is not linear, for example, when the parallel to the installation surface cannot be determined, the lie angle (degree) = (97−club length (inch)) is set. For example, if the club length is 44 inches, the lie angle is 97−44 = 53 degrees.
The club length is measured by a measurement method defined by the Japan Golf Equipment Association. An example of the measuring device is Club Major II manufactured by Kamoshita Seikosho Co., Ltd. That is, as shown in FIG. 3, the end portion of the heel side of the golf club as a starting point P _1, when the grip end and the end point P _2, the club length the distance C between these P ₁ and P ₂ .
As shown in FIG. 4A, the retraction amount _Gr is measured by a seesaw-type balance 41 that can swing in the direction of arrow U about the fulcrum 42. The balance 41 has a shaft pin 43 having a fit with no gap to the hosel hole of the golf club head 40 so that the arm 44 is horizontal when the golf club head 40 and the weight body are not attached. It is balanced. The distance of the center of gravity CG of the golf club head 40 from the golf club shaft axis is measured by mounting the golf club head 40 with a mass W _h on the shaft pin 43 as shown in FIG. 4 (b). 4 (a) shows the golf club head 40 shown in FIGS. 2 (a) and 2 (b) so that the retraction amount _Gr shown in FIGS. It fixes in the state rotated along the plane P so that it can mount | wear with the shaft pin 43 extended in a perpendicular direction. Then, a weight body 45 having a mass W ′ such that the arms 44 are horizontally balanced and a length L ′ from the center of gravity CG ′ to the fulcrum of the weight body 45 are selected.
From the above, the retraction amount G _r from the golf club shaft axis to the center of gravity position is G _r = (W ′ × L ′) / W _h from the balance formula W _h × G _r = W ′ × L ′. I want. In the side view of the balance 41 shown in FIG. 4B, the face surface 46 is slightly visible because the golf club head 40 has a loft angle and a lie angle.
The above description is the measurement principle of the retraction amount _Gr of the center of gravity position from the golf club shaft axis. Such measurement is performed using, for example, a center of gravity measuring device manufactured by Kamoshita Seikosho Co., Ltd.

  On the other hand, when the golf swing is made by the golfer, the head speed Hs and the time series data of the golf club head trajectory, which are measurement data measured by the swing measurement system 20 described later, are supplied to the input unit 12, and the parameter calculation unit 18 is supplied.

The parameter calculation unit 18 calculates a radius of curvature R of the projected trajectory of the golf club head projected onto a plane parallel to the ground on which the golf swing is performed, from the time-series data of the trajectory of the golf club head immediately before hitting the supplied golf ball. calculating a _s, a part for calculating a parallel acceleration component (H _{s 2} ^/ R s) further using the supplied head speed H _s on the ground to perform a golf swing.
Furthermore, the characteristic parameter (W _h × G _r ) of the golf club used for the golf swing stored in the memory 16 is called through the golf club identification information, and the calculated acceleration component is _expressed by the following equation: The moment M _t is calculated by multiplying as described above.
M _t = (H _s ² / R _s ) × (W _h × G _r )
Furthermore, if necessary, a value T obtained by multiplying the moment M _t by a twist angle X representing the characteristics of the golf club shaft is calculated.

Here, the torsion angle X is a torsion angle generated when a torque of 13.5 (kgf · cm) is applied around the central axis of the golf club shaft, and represents the torsional rigidity of the golf club shaft. It is used as a parameter. The twist angle X is stored in the memory 16 together with the golf club identification information, and is called by the parameter calculation unit 18 as necessary.
The obtained moment M _t or value T is supplied to the evaluation unit 20.

5A to 5C are explanatory diagrams of the moment M _t and the value T. FIG.
FIG. 5 (a) is an explanatory view schematically showing a golfer performing golf swing from the upper side perpendicular to the ground, and FIG. 5 (b) is schematically shown from the rear in the hitting direction of the golf ball. FIG. FIGS. 5A and 5B show a state immediately before hitting the golf ball 32 when the golfer G grips the golf club 30 and performs a golf swing.

Here, in FIG. 5A, the golf club head trajectory when the golf club head immediately before hitting is viewed from above in the direction perpendicular to the ground is indicated by a dotted line, and this trajectory is a radius of curvature R _s. It has become. The track of the golf club head is the track of the center of gravity position A of the golf club head.
In addition, the golf club head that moves at the radius of curvature R _s immediately before the golf ball hits has a centrifugal force component F _{x in} a direction parallel to the ground for golf swing as shown in FIGS. 5 (a) and 5 (b). Works. This centrifugal force component F _x is determined by the well-known formula for calculating the centrifugal force in a circular motion from the curvature radius R _s of the golf club head, the head speed H _s, and the mass W _h of the golf club head as follows: Can do.
F _x = W _h × (H _s ² / R _s )

Further, the moment M _t acting on the golf club shaft by the centrifugal force component F _x acting on the golf club head is expressed by the following equation. That is, by multiplying the centrifugal force component F _x by the retraction amount G _r shown in FIG. 5C, the moment M _t acting around the central axis of the golf club shaft can be calculated.
M _t = F _x × G _r

The moment M _t calculated by the above formula is a moment that causes torsional deformation around the central axis of the golf club shaft. Therefore, as this moment increases, the torsional deformation of the golf club shaft increases, and the orientation of the face surface immediately before hitting the golf ball is changed. Here, the orientation of the face surface refers to the orientation of the face surface in the toe-heel side direction (see FIG. 5C) of the golf club head. That is, it refers to the direction in which the face surface opens or closes when viewed from the golfer.

In the golf swing, the golf swing performs the golf swing so that the orientation of the face surface returns (returns) to the orientation of the face surface set in the address state during the impact from the top state. However, since the moment M _t acts on the golf club and the golf club shaft is twisted to change the orientation of the face surface, the face surface upon impact returns to the face surface orientation set in the address state. Thus, even if the golfer performs a golf swing, the orientation of the face surface does not necessarily return to the orientation of the face surface in the address state due to the torsional deformation. The evaluation device 10 performs such a face surface orientation prediction evaluation in the evaluation unit 20.

The evaluation unit 20 obtains a return value indicating the degree of ease of return of the face surface felt by the golfer based on the moment M _t or the value T calculated by the parameter calculation unit 18, and based on this value, the return of the face surface is further improved. This part predicts and evaluates the ease of catching a golf ball and outputs the evaluation result. This return value is associated with the moment M _t or the value T by a fixed expression, and the return value is calculated using this expression. Of course, the return value may be calculated using a reference table representing the relationship between the moment M _t or the value T and the return value instead of the equation.

FIGS. 6A and 6B are scatter diagrams showing an example of the correlation between the moment M _t or the value T and the return value actually sensed by the golfer. As can be seen from FIGS. 6A and 6B, the moment M _t or the value T shows a high correlation coefficient (0.834, 0.758) with the return value. Therefore, a relational expression for associating the return value with the moment M _t or the value T is determined, and using this relational expression, the return of the face surface felt by the golfer is quantitatively predicted and evaluated from the moment M _t or the value T. be able to.

On the other hand, swing measuring system 20 for measuring a golf swing is a system for measuring data of the trajectory representing the position coordinates of the head speed H _s and the golf club head of the golf club, for example, a magnetic sensor measurement system 22 and the head speed measuring device 24.
For example, as shown in FIG. 7, the magnetic sensor measurement system 22 arranges a transmitter 22a that forms a predetermined magnetic field behind a golfer performing golf swing, while applying a magnetic field to a grip end of a golf club held by the golfer. The receiver 22b, which is a three-dimensional magnetic sensor to be detected, is fixed, and the receiver 22b performs measurement using a magnetic field that detects the three-dimensional position and orientation of the grip end of the golf club.
On the other hand, the head speed measuring device 24 measures the passing speed of the golf club head by passing the golf club head and acquires the head speed.

Specifically, the transmitter 22a of the magnetic sensor measurement system 22 forms a magnetic field having a known distribution of strength and direction within the moving range of the grip end of the golf club during golf swing, and is a receiver fixed to the grip end. By detecting this magnetic field by 22b, a signal including information on the three-dimensional position and the Euler angle with respect to the reference position is output. Based on this signal, in the controller 22c, when the time-series data of the grip end three-dimensional position (x _m , y _m , z _m ) and the Euler angles (θ _y , θ _p , θ _r ) of the grip end are obtained. Generate series data.
Further, in the computer 22d connected to the controller 22c, the golf club shaft length of the golf club is determined from the data of the three-dimensional position (x _m , y _m , z _m ) and the Euler angles (θ _y , θ _p , θ _r ). As a known, a three-dimensional position (X, Y, Z) which is data of a trajectory representing the position coordinates of the golf club head is calculated. The calculated three-dimensional position (X, Y, Z) is displayed on the monitor 22e as necessary.
The time-series data of the three-dimensional position (X, Y, Z) of the golf club head calculated in this way is supplied to the evaluation device 10. Such a magnetic sensor measurement system 22 is disclosed in detail in Japanese Patent Application Laid-Open No. 2001-112903 by the present applicant.

In the present invention, in addition to measuring the position coordinates of the golf club head using the magnetic sensor measurement system described above, for example, a high-speed camera is installed vertically above the ground on which golf swing is performed to capture the trajectory of the golf club head. Then, the position coordinates of the golf club head may be obtained by image processing. As described above, in the present invention, the method for measuring the golf swing head speed H _s and the curvature radius R _s of the golf club head track is not particularly limited.
On the other hand, the head speed measuring device 24 is a head speed measuring device that calculates a head speed H _s by obtaining a time difference between golf club heads that cross two beams emitted from a light source. The distance between the two beams is preferably 100 mm. For this purpose, the head speed measuring device is arranged at the track position of the golf club head immediately before impact. Specifically, the beam is arranged at a position 40 mm away from the center of the golf ball 40 mm behind in the flying ball direction and a position 140 mm away 100 mm rearward in the flying ball direction starting from this position. Is preferred.

As described above, the evaluation apparatus 10 calculates the characteristic parameter of the golf club head by multiplying the retraction amount G _r that is a structural feature of the golf club head by the mass W _h of the golf club head, and the calculated characteristic parameter. Is used to evaluate the impact characteristics of the golf club. More specifically, the head speed H _s immediately before hitting the golf ball in the golf swing measured by the swing measuring system 20 and the curvature radius R _s immediately before hitting the golf ball calculated from the trajectory of the golf club head are used. By calculating an acceleration component (H _s ² / R _s ) parallel to the ground of the golf club head immediately before hitting the golf ball, and multiplying the calculation result by the characteristic parameter (W _h × G _r ), Predicting and evaluating the impact characteristics of a golf club when a golf swing is performed. Alternatively, the hitting characteristic of the golf club is predicted and evaluated by multiplying the product of the acceleration component of the golf club head and the characteristic parameter by the torsion angle X of the golf club shaft with respect to a certain torque indicating the golf club shaft characteristic.

As described above, the impact characteristics of the golf club evaluated by the evaluation device 10 are characterized by the golf swing characteristics (head speed H _s and curvature radius R _s ) of the golfer in addition to the structural characteristics of the golf club. Is. Therefore, in order to predict and evaluate the hitting characteristics of a golf club, it is assumed that the golf swing of the golfer is measured.
However, in the present invention, when the golf swing cannot be measured, a preset head speed and radius of curvature may be used. For example, the head speed can be used 3 minus value from the golf club shaft length value of the golf club (inch) as a substitute for head speed H _s. Moreover, 1300 (mm) may be substituted for the curvature radius R _s .

As shown in Table 1 below, the measurement results of the head speed H _s and the radius of curvature R _s of golf clubs 3 to 9 of five golfers (G _{a to} G _e ) using the swing measurement system 20 is there. FIG. 8 is a scatter diagram showing the relationship between the head speed H _s of the golfers G _{a to} G _e and the golf club shaft length.
Golfers G _{a to} G _e find that the value of golf club shaft length −3 expressed in inches substantially matches the head speed H _s . Thus, the head speed H _s is fast, slow, and graded the golfer of the intermediate or the like can be substituted at a head speed of these stages. For example, when the intermediate head speed, it is possible to make the value of the golf club shaft length -3 expressed in inches as a substitute value of head speed H _s. In the example shown in FIG. 8, in golfer golfer G _a has an intermediate head speed, it is possible to make the value of the golf club shaft length -3 and head speed.
Accordingly, if the head speed H _s can not be measured, it is possible to substitute the head speed obtained in association with the golf club shaft lengths depending on the type of golfer. For example, if the golfer intermediate head speed, it is possible to make the value of the golf club shaft length -3 expressed in inches as a substitute value of head speed H _s.
On the other hand, the curvature radius R _s is substantially constant regardless of whether the head speed is fast or slow, and further regardless of the count of the golf club, and 1300 mm can be used as a substitute value for the curvature radius R _s .

As described above, in the present invention, the golf club's hitting characteristics include the golf swing characteristics of the golfer (head speed H _s and the curvature radius R _s of the golf swing) and the structural characteristics of the golf club head (retraction amount R _s and mass). W _h ) can be used for predictive evaluation, as shown in FIGS. 6A and 6B, the return value obtained by quantifying the degree of return of the face surface sensed by the golfer is the moment M _t or value described above. This is because T has a high correlation.

Here, the moment M _t and the value T in FIGS. 6 (a) and 6 (b) are three kinds of a total of seven iron golf club sets from No. 3 to No. 9, that is, the moment of the golf club of 21 irons. the M _t and the value T, and is calculated on the basis of the golf swing the golfer G _a ~G _e shown in Table 1.

On the other hand, golf players G _{a to} G _e had golf balls hit with 21 golf clubs, and the degree of ease of returning the face surface felt by each golfer from the hit feeling was evaluated. The evaluation is based on the golf club of iron No. 6 in a certain golf club set, and the score is given in three types: easy to return (score 1), unchanged (score 0), difficult to return (score 1). The average of the scores of 5 people was used as the return value. Therefore, a golf club having a rating of 1 for all five players has a return value of 1, and can be said to be the golf club with the most easily returned face surface. On the other hand, a golf club having a score of −1 for all five players has a return value of −1 and can be said to be a golf club whose face surface is most difficult to return.

As can be seen from FIGS. 6A and 6B, the return value is associated with the moment M _t and the value T with high correlation (correlation coefficients 0.834, 0.758). As a result, the moment _Mt or the value T can be used to predict and evaluate the return of the face surface during golf swing, and thus the degree of catching of the golf ball.
Of course, golf swings have various characteristics depending on the golfer, and there are golfers who perform golf swings in which the face surface tends to open upon impact, and there are golfers who perform golf swings in which the face surface tends to close. For this reason, the degree of the favorable return of the face surface differs depending on the golf swing characteristics of each golfer. Therefore, in the present invention, by using the moment M _t or value T as a measure of the return of the good or of the golf ball caught the degree of the face for a golfer, golf club return of good and caught the degree of the face does not change or, Furthermore, it is possible to select a golf club having a relatively strong face surface and a relatively high degree of catch from a plurality of golf clubs.

  In addition, for multiple golf clubs in a series and multiple golf clubs in an iron set, the expected return of the face and the degree of catching of the golf ball can be changed intentionally depending on the series, or depending on the number Can be changed to harmonize with each other. Thereby, it is possible to provide a golf club or a golf club set that is most suitable for a golfer.

Furthermore, in the present invention, any method may be used as long as the moment M _t or the value T can be calculated. For example, an acceleration sensor that measures the acceleration in the direction of the central axis is attached to the golf club head on the extension line of the central axis of the golf shaft of the golf club head, and the acceleration during golf swing is measured. By calculating a parallel acceleration component and multiplying the acceleration component by the product of the mass W _h and the retraction amount R _s , a value T obtained by multiplying the moment M _t and the torsion angle X is calculated. It is also possible to evaluate the hitting characteristics.

  The hitting characteristics of the golf club of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiment, and various improvements and modifications may be made without departing from the spirit of the present invention. Of course.

It is a block block diagram of an example of the evaluation apparatus which performs the evaluation method of the golf club of this invention. FIG. 2A is a plan view of the golf club head as viewed from above in order to explain the retraction amount of the center of gravity position of the golf club head, and FIG. 2B is a side view of the golf club head as viewed from the toe side. . It is explanatory drawing explaining the club length of a golf club. (A) And (b) is a figure explaining the measuring method of the retraction amount of the gravity center position of a golf club head. (A)-(c) is explanatory drawing explaining the calculation result calculated with the golf club evaluation method of this invention. (A) And (b) is a scatter diagram which shows an example of the relationship between the value calculated by the evaluation method of the golf club of this invention, and the return value showing the return of the face surface which a golfer feels. It is a figure which shows an example of the swing measurement system used with the evaluation method of the golf club of this invention. It is a scatter diagram which shows an example of the relationship between head speed and golf club shaft length.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Evaluation apparatus 12 Input part 14 Calculation part 16 Memory 18 Parameter calculation part 20 Evaluation part 30 Golf club 32 Golf ball 40 Golf club head 41 Balance 42 Shaft pin 44 Arm 45 Weight body 46 Face surface

Claims (4)

An evaluation method for evaluating the impact characteristics of a golf club when performing a golf swing,
A golf club head characteristic parameter obtained by multiplying the golf club head mass by the retraction amount of the center of gravity representing the distance along the striking direction from the centerline of the golf club shaft or an extension of the centerline to the center of gravity of the golf club head. A calculating step for calculating
A golf club evaluation method comprising: an evaluation step of evaluating a hitting characteristic of the golf club using the calculated characteristic parameter.   The evaluation step includes a head speed immediately before hitting the golf ball in the golf swing and a radius of curvature immediately before hitting the golf ball in a projected trajectory projected on a plane parallel to the ground on which the golf swing is performed among the trajectories of the golf club head. And calculating an acceleration component parallel to the ground of the golf club head, and multiplying the calculated parameter by the calculated parameter, thereby evaluating a hit characteristic of the golf club when performing a golf swing. The evaluation method of the golf club of description.   The evaluation step evaluates a hitting characteristic of a golf club by multiplying the result obtained by multiplying the acceleration parameter by the characteristic parameter and a twist angle with respect to a torque having a predetermined magnitude around the center axis of the golf club shaft. Item 3. A golf club evaluation method according to Item 2. A golf club evaluation method for evaluating a hit characteristic of a golf club characterized according to a golf swing performed by a golfer,
An acquisition step of acquiring an acceleration component parallel to the ground for performing golf swing out of the acceleration of the golf club head immediately before hitting the golf ball;
Multiply the acquired acceleration component by the product of the mass of the golf club head and the centerline position of the golf club shaft or the extension of the centerline to the center of gravity position of the golf club and the retraction amount of the center of gravity position representing the distance along the hitting direction. An evaluation step for evaluating the hitting characteristics of the golf club.

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