JP2006115936A - Evaluation method of golf club, golf club and golf club set - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an evaluation method of the golf clubs which enables the accurate evaluation of the performance of hitting with the golf clubs, golf clubs evaluated using the evaluation method and a golf club set which achieves the harmonization between the sizes in the height and directivity of the golf balls hit. <P>SOLUTION: In the golf club, at least one of the angle of deflection and the degree thereof at the tip of the golf club shift is determined by measurement based on the kinematic information of the golf club head immediately before the hitting of the golf ball involved and at least one of the effective loft and the effective lie is determined for the golf club immediately before the hitting of the golf ball from the result of the measurement. The golf club has a display medium which displays at least one of the angle of deflection and the degree thereof obtained by the measurement and the effective loft and the effective lie. In the golf club set, at least one of the angle of deflection and the degree thereof is shifted almost linearly in the decreasing order of the sizes of the golf clubs to harmonize. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a golf club evaluation method, a golf club, and a golf club set for evaluating the hit performance of a golf club, and more particularly to a golf club that informs a golfer of a deformation state at the tip of a golf club shaft immediately before hitting a golf ball, The present invention also relates to a golf club set in which this deformed state is harmonized between the golf club counts.

Golfers seek to improve their skills to play better golf, while seeking better performance golf clubs to get better scores. Therefore, golf clubs are always required to have better performance. Better performance means that, for example, the flight distance is increased, it is easy to hit, or the flight distance is easily adjusted.

By the way, golf is performed by aligning a plurality of golf clubs up to 14 golf clubs having different club lengths or loft angles.
For example, wood golf clubs such as No. 1, No. 3, No. 5 wood, irons of No. 3 to No. 9, and pitching wedges, sand wedges, putters, etc. are arranged, and golf clubs are appropriately selected according to the distance to the pins. Select and hit the ball.
In particular, in the case of an iron, in order to accurately shot a golf ball around a pin, it is desired that the flight distance be accurately determined by the iron count.
Conventionally, with respect to irons, it is known to measure the frequency of a golf club shaft of an iron by a method described later, and to provide a golf club set in which the iron number is harmonized by this frequency (for example, patents) Reference 1).

The measurement of the vibration frequency of a conventional iron golf club shaft is performed as follows.
First, the grip portion of the golf club is fixed and gripped, and the tip end portion on which the golf club head is mounted is vibrated as a free end, and the number of times the tip portion of the golf club shaft crosses the phototube by the vibration is counted. Find the frequency from the number of crossings. Also, the rear end portion of the golf club shaft alone to which the grip is attached is fixed and gripped, and a weight of several hundred grams is attached to the front end portion to which the golf club head is attached, and is vibrated as a free end. The number of times that the tip crosses the phototube can be measured, and the frequency can be obtained from the number of times the tip crosses per minute.

In general, in order to obtain a high golf ball hitting ball by increasing the launch angle of the golf ball, the golf club shaft is flexed by lowering the rigidity of the golf club shaft to increase the effective loft angle immediately before the golf ball hitting. It is known to increase the value. Therefore, the vibration frequency obtained by the above-described measurement method representing the rigidity of the golf club shaft is also an index representing the height of the hit ball of the golf ball hit by the golf club.
Further, Patent Document 1 below proposes a golf club set composed of golf clubs in which the frequency measured in this way is changed at regular intervals corresponding to the golf club number.

JP 52-126321 A

  However, even if a golf club set in which the frequency measured by the above method is harmonized with the golf ball count is used, the hit ball height of the launched golf ball may not necessarily match the count. For example, the difference in the hit height of the golf ball between the No. 5 iron and the No. 6 iron and the difference in the hit ball height between the No. 4 iron and the No. 5 iron are not constant, and the hit ball height In some cases, golf balls could not be struck by adjusting according to the number. In addition, not only the height of the hit ball but also the bending state (flying direction) of the golf ball does not harmonize, for example, only a golf ball hit with a 5-iron despite having substantially the same swing. In some cases, it was easy to bend in the slice direction. For this reason, the golfer cannot select an appropriate iron of the golf club set from the golf club set and accurately shot the golf ball around the pin.

  Accordingly, the present invention has been made to solve the above-described problem, and is a golf club evaluation method capable of accurately evaluating the hit performance (the height of the hit ball and the flight direction) of the golf club. It is an object of the present invention to provide a golf club set evaluated using the evaluation method, and a golf club set in which the height and directionality of the hit golf ball are harmonized among the counts.

  In order to achieve the above object, the present invention provides a golf club evaluation method for evaluating the hit performance of a golf club in which a golf club head is mounted on the tip of a golf club shaft, immediately before hitting a golf ball by the golf club. Obtaining a motion information of the golf club head, obtaining a deformation state at the tip of the golf club shaft based on the motion information, an effective loft angle of the golf club immediately before the golf ball is hit from the deformation state, and There is provided a golf club evaluation method comprising: obtaining at least one of an effective lie angle and evaluating a hitting performance of the golf club from the effective loft angle and the effective lie angle.

  Here, the step of obtaining the deformation state of the golf club shaft obtains the force acting on the golf club head from the motion information, and from the moment acting on the golf club shaft generated by this force, the tip of the golf club shaft It is preferable to determine at least one of the deflection angle and the deflection amount as the deformation state of the golf club shaft. In this case, for example, in the step of determining the deformation state of the golf club shaft, the moment is applied to the tip of the golf club shaft to measure and determine at least one of the bending angle and the bending amount. At this time, the action of the moment on the tip of the golf club shaft includes an insertion hole for inserting and gripping and fixing the tip portion of the golf club shaft, and the action point for applying an external force is the insertion hole for inserting the golf club. Preferably, the measurement is performed using a measuring jig offset by a predetermined distance from the central axis.

  Further, the moment acting on the golf club shaft is defined by the distance between the center of gravity in each of two different directions between the center of gravity of the golf club head and the center axis of the golf club shaft or an extension line of the center axis. A step of obtaining a deformation state of the golf club shaft by multiplying a force acting on the golf club head, and using the moment component in the two directions to determine the deformation state of the golf club shaft. It is preferable to obtain the deformation state.

  Further, the present invention is a golf club having a golf club head attached to the tip of the golf club shaft, the tip of the golf club shaft determined based on the motion information of the golf club head immediately before hitting the golf ball, Provided is a golf club comprising display means for displaying at least one information of a deflection angle and a deflection amount immediately before hitting a golf ball.

  Furthermore, the present invention provides a golf club having a golf club head mounted on the tip of a golf club shaft, wherein the golf ball of the golf club head is obtained based on motion information of the golf club head immediately before the golf ball is hit. There is provided a golf club comprising display means for displaying at least one information of an effective loft angle and an effective lie angle immediately before hitting the ball.

  In addition, the present invention is a golf club set comprising a plurality of golf clubs having different numbers with a golf club head attached to the tip of the golf club shaft, wherein the golf club shaft is bent at the tip of the golf club shaft just before hitting a golf ball. There is provided a golf club set comprising a group of at least three golf clubs, wherein at least one of an angle and a deflection amount changes substantially linearly in ascending order or descending order of the count.

In the golf club evaluation method of the present invention, the deformation state at the tip of the golf club shaft is obtained based on the motion information of the golf club head immediately before the golf ball is hit by the golf club, and the golf club immediately before the golf ball is hit from this deformation state. Since at least one of the effective loft angle and the effective lie angle is obtained, the hitting performance of the golf club can be accurately evaluated as compared with the conventional one.
Further, since the golf club has a display means such as a display medium that displays the evaluation result evaluated using the golf club evaluation method, the evaluation result is effective when the golfer selects the golf club. Can be used as
Further, in the golf club of the golf club set, at least one of the deflection amount and the deflection angle at the tip of the golf club shaft immediately before the impact changes substantially linearly between the counts. The height and direction of flight are harmonized without fluctuation between counts. Therefore, it can be said that the golf ball can be launched with the trajectory expected by the golfer.

  Hereinafter, embodiments of a golf club evaluation method, a golf club, and a golf club set according to the present invention will be described in detail with reference to the drawings as appropriate.

The golf club evaluation method of the present invention uses the centrifugal force generated at the center of gravity of the golf club head generated when the golf club is gripped to swing, and the deflection angle and the deflection of the golf club shaft at the tip of the golf club shaft. And determining the effective loft angle and effective lie angle immediately before hitting the golf ball by the golf club (immediately before impact) by using at least one of the amounts and determining the effective hitting performance of the golf club, for example, the golf ball This is a method for evaluating the height of the hit ball and the flight direction (slice direction, hook direction) of the golf ball.
Such evaluation can be performed by the evaluation apparatus 10 and the measurement system 20.

The evaluation device 10 includes an exercise information acquisition unit 12, an external force calculation unit 14, a deformation information acquisition unit 16, and an evaluation unit 18.
The exercise information acquisition unit 12 is a portion that acquires exercise information (head speed and swing radius) of the golf club head by inputting input data. Examples of the input data include a golf club head speed and a golf club shaft length. By inputting the length of the golf club shaft, the swing radius is automatically calculated and acquired by the relational expression described later. Further, as shown in Japanese Patent Laid-Open No. 2001-112903, the input data includes time-series data of three-dimensional position coordinates representing the behavior of the grip portion when the golf club is gripped and swings, and the grip portion orientation. It may be series data. In this case, the motion information evaluation unit 12 calculates the head speed immediately before the impact and the swing radius of the golf club head from these time series data, assuming that the length of the golf club shaft is known.

  The external force calculation unit 14 determines the center of gravity G of the golf club head immediately before the impact from the head speed and swing radius obtained by the motion information acquisition unit 12 and the mass of the golf club head given as input data (FIG. 4A). To (c)), a moment acting on the tip of the golf club shaft is obtained from the centrifugal force, and this moment is divided by a distance W (see FIG. 2) of a measuring jig to be described later. This is the part that supplies the measured value to the measurement system 12 as the magnitude of the external force F applied to the measurement system 12.

  The deformation information acquisition unit 16 is a part that acquires at least one measurement result of the deflection angle and the deflection amount at the tip of the golf club shaft obtained by the measurement system 12 described later as the deformation information of the golf club shaft.

  The evaluation unit 18 obtains a change amount of the loft angle and the lie angle of the golf club head from at least one of the obtained deflection angle and deflection amount of the golf club shaft, and the obtained change amount is obtained as a loft in a static state. The effective loft angle and the effective lie angle immediately before impact are obtained by adding the angle and the lie angle, and the height of the hit golf ball and the flight direction of the golf ball are evaluated based on the effective loft angle and the effective lie angle. This is the part that is output as the evaluation result.

FIG. 2 is a schematic configuration diagram showing a schematic configuration of a measurement system 20 that measures a deflection angle and a deflection amount in the golf club shaft 2. In the present invention, at least one of the bending angle and the bending amount may be obtained.
The measurement system 20 includes a fixing jig 21 for fixing a portion of the golf club shaft 2 on the grip portion side, and a tip portion of the golf club shaft not attached with the golf club head (end portion on the mounting side of the golf club head). From a measuring jig 22 having a substantially L-shape having an insertion hole 24 to be inserted and held and fixed, and a central axis of the insertion hole 24 (this central axis coincides with the central axis of the golf club shaft 2) An acting portion 26 provided on the measuring jig 22, to which an external force F is applied using an actuator (not shown) in a direction parallel to the central axis of the golf club shaft 2, and the acting portion 26. A load cell 28 for measuring an acting external force F; laser displacement sensors 30 and 32 for measuring a deflection angle β and a deflection amount b at the tip of the golf club shaft 2; A control unit 34 for controlling the magnitude of the external force F while feeding back the measurement result of the load cell 28 to an actuator (not shown), obtaining sensor signals of the laser displacement sensors 30 and 32, and calculating a deflection angle and a deflection amount; It is comprised.

For example, according to the information of the external force F calculated by the external force calculation unit 14 and supplied to the control unit 34, an actuator (not shown) is operated, and the external force F is applied to the action unit 26 offset by a distance W from the central axis of the insertion hole 24. The golf club shaft 2 is deformed as shown by a dotted line in FIG. As the deformed state at the tip portion of the deformed golf club shaft 2, the bend angle β and the bend amount b are measured using the laser displacement sensors 30 and 32, and the measured bend angle and bend amount are obtained from the control unit 34 as deformation information. It is configured to be supplied to the acquisition unit 16.
The insertion hole 24 of the measuring jig 22 is preferably a hole having a length substantially equal to the shaft insertion hole of the hosel part in the golf club head.

  As will be described later, the external force F has different external forces F so that moment components in the toe down direction for changing the lie angle of the golf club and the kickback direction for changing the loft angle act on the golf club shaft 2 separately. It is given to the action part 26. If the golf club shaft 2 has an isotropic rigidity distribution around the central axis of the golf club shaft, the action portion is released without releasing the grip and fixing of the golf club shaft 2 by the measuring jig 22. It is possible to continuously apply different external forces F corresponding to the moment components in the toe down direction and the kickback direction to 26, and measure the deflection angle and the deflection amount.

In such an evaluation apparatus 10 and measurement system 20, the golf club evaluation method of the present invention is performed as follows.
FIG. 3 is a flowchart showing a flow of an example of the golf club evaluation method of the present invention.
First, the motion information acquisition unit 12 acquires the motion information of the golf club head immediately before hitting the golf ball (immediately before impact) caused by the swing performed while holding the golf club (step S10).
For example, when the length L (inch) of the golf club shaft is input as input data, the swing radius r (mm) is set according to the following formula (1).
r = 450 + L · 25.4 (1)
Further, the head speed V (m / second) is input.
The length L (inch) of the golf club shaft is the length from the contact point between the sole surface of the golf club head and the back of the neck portion to the grip end (not including the roundness of the cap). It is measured by the traditional standard measurement method which is standard by the Japan Golf Equipment Association using a measuring instrument such as the club measure II manufactured by our company. For example, if L = 36 inches, the swing radius r is 1364.4 (mm). Thus, the swing radius can be determined by the above equation (1) by calculating the swing orbit circle using the swing measurement method disclosed by the applicant of the present application in Japanese Patent Laid-Open No. 2001-112903, This is because it has been found that it is possible to set as in the above formula (1).

  In the present invention, the swing measurement method disclosed in the above publication, that is, the time series data of the three-dimensional position coordinates and the time series data of the orientation of the grip part representing the behavior of the grip part when the golf club is gripped and swung are used. As input data, using this input data, the length of the golf club shaft may be known, and the head speed immediately before impact and the swing radius of the golf club head may be obtained and acquired simultaneously.

Next, the external force F applied to the action unit 26 in the measurement system 20 is calculated in the external force calculation unit 14 (step S12).
Specifically, the centrifugal force acting on the center of gravity of the golf club head from the head speed and the swing radius is obtained with the mass of the golf club head known, and the moment acting on the tip of the golf club shaft 2 caused by this centrifugal force is calculated. The external force F is obtained by dividing this moment by the distance W of the measuring jig 22. At that time, as shown in FIGS. 4 (a) and 4 (b), the golf club head acts on the golf club head and the center-of-gravity distances GR and GLt in two different directions with respect to G. The two-direction moment components obtained by multiplying the force are obtained, and the two-direction moment components are divided by the distance W to obtain two external forces F corresponding to the two-direction moment components. 4A to 4C are views for explaining the position of the center of gravity G in the golf club head 3, and FIGS. 4A, 4B, and 4C are front views of the golf club head. It is a figure, a top view, and a side view.

Next, the measurement of the deflection angle and the deflection amount at the tip of the golf club shaft 2 is performed in the measurement system 20 (step S14).
In the measurement system 20, an actuator (not shown) is operated via the control unit 34, and the external force F is controlled while constantly feeding back the output signal of the load cell 28, and the tip of the golf club shaft 2 on which the external force F is acting. Are measured using the laser displacement sensors 30 and 32.
In this case, as described above, the external force F corresponding to the two moment components is separately applied, and the deflection angle and the deflection amount are measured. In this case, the amount of deflection angle and deflection due to the external force F which is calculated by using the distance between the centers of gravity GR becomes a parameter for determining the amount of change in the kickback direction to change the loft angle (R ₁ direction shown in FIG. 4 (a)), the amount of deflection angle and deflection due to the external force F which is calculated by using the distance between the centers of gravity GL _T is a parameter for determining the amount of change in toe down direction to change the lie angle (R ₂ direction shown in FIG. 4 (c)).
In this way, a moment acting on the tip of the golf club shaft immediately before the impact of the golf ball is simulated, and a moment equivalent to this moment is applied to the tip of the golf club shaft 2 by the measurement system 20.

Next, the effective loft angle and effective lie angle of the golf club immediately before the impact of the golf ball are calculated using the measured deflection angle and deflection amount at the tip of the golf club shaft 2 (step S16).
Specifically, the amount of change in the loft angle and lie angle of the golf club head is obtained from the angle and amount of deflection of the golf club shaft, and the obtained amount of change is added to the loft angle and lie angle in the static state. Thus, the effective loft angle and the effective lie angle immediately before the impact are obtained.

Finally, the evaluation unit 18 evaluates the golf club (step S18).
Specifically, the height of the hit ball and the tendency of the flight direction of the golf ball are evaluated by the obtained effective loft angle and effective lie angle, and the evaluation result is output. For example, a golf club having a small effective loft angle is evaluated as a golf club having a strong tendency to fly while keeping the hitting height of the golf ball low, even if it is the same number golf club, and a golf club having a large effective loft angle Is evaluated as a golf club having a strong tendency to fly by increasing the height of the hit ball of the golf ball. A golf club having a small effective lie angle is evaluated as a golf club having a strong tendency to fly the golf ball in the hook direction, and a golf club having a large effective lie angle has a strong tendency to fly the golf ball in the slicing direction. It is evaluated.

  Thus, since the effective loft angle and effective lie angle of the golf club immediately before the impact of the golf ball can be calculated using the position of the center of gravity of the golf club head and the individual characteristics of the golf club shaft, In comparison, the trajectory (the hit ball height and flight direction) of the golf ball to be launched can be expressed more accurately.

  In the present embodiment, an external force F calculated based on the centrifugal force acting on the golf club head is applied to the golf club shaft, and the deflection angle and the deflection amount are obtained by measurement. Is stored in advance in the evaluation apparatus 20 as a single characteristic of the golf club shaft as a single characteristic of the golf club shaft, using the single characteristic of the golf club shaft. Then, the deflection angle and the deflection amount immediately before the impact at the tip of the golf club shaft may be calculated by calculation.

The deflection angle and the deflection amount representing the deformation state of such a golf club, and the effective loft angle immediately before the impact of the golf ball, the effective lie angle, and the like are as follows in a golf club in which a golf club shaft and a golf club head are combined: Since the head speed is uniquely determined, at least one numerical value of the deflection angle, the deflection amount, the effective loft angle, and the effective lie angle is calculated according to the head speed or the predetermined head speed as a representative value. It is preferably displayed on a display medium such as a club head, a golf club shaft, a seal attached to these parts, and a product tag secured to a golf club as a product. Moreover, you may display on a goods brochure.
Information displayed on such a display medium is effective as a judgment material when a golfer intends to purchase a golf club. Based on the displayed information, the golfer can select a golf club suitable for the golfer himself.

Also, such a golf club evaluation method can be used when the golf club brought in by the golfer is evaluated for hitting performance and adjusted to fit the golfer's swing. For example, the golfer holds the golf club and swings, and the head speed at this time is measured with a known head speed measuring device, and the deflection angle and the deflection amount at the tip of the golf club shaft immediately before the impact are measured by the method described above. The effective loft angle and the effective lie angle are obtained from the measurement result, and the loft angle or lie angle of the golf club is corrected based on the effective loft angle or the effective lie angle, or the golf club head By attaching a weight for adjusting the center of gravity of the golf club, the golf club can be adjusted to fit the golfer's swing.
Further, in the design stage of the golf club, the above-described golf club shaft and golf club head are changed in various ways, or from the individual characteristics of the golf club shaft and the position information of the center of gravity of the golf club head. By calculating the effective loft angle and the effective lie angle by the method, it is possible to design a golf club having an optimum hitting performance.

The bend angle and the bend amount obtained by the above method may be applied to a golf club set including a golf club such as a plurality of irons.
That is, the present invention relates to a golf club set comprising a plurality of golf clubs having different numbers and having a golf club head mounted at the tip of the golf club shaft, and the deflection angle at the tip of the golf club shaft immediately before hitting the golf ball. In addition, a golf club set having a group of at least three golf clubs, in which at least one of the deflection amounts changes substantially linearly in ascending or descending order of the golf club counts. FIG. 5 shows a set of 10 irons in which the golf clubs are number 3 (# 3) to number 9 (# 9) and a pitching wedge (PW), an approach wedge (AW) and a sand wedge (SW). ing.
As shown in FIG. 5, the count is mainly a golf club having a different loft angle θ formed by the center axis S of the golf club shaft and the face surface of the golf club head in the order of the loft angle θ. It is the contents of the identification information regarding the order of the loft angles represented by numbers (natural numbers), letters, symbols, etc. given to each golf club, and the loft angles of each count are constant or almost constant The interval is appropriately set by those skilled in the art. Also, the large count means a count with a large loft angle.

Thus, by changing at least one of the deflection angle and the deflection amount at the tip of the golf club shaft immediately before the impact of the golf ball approximately linearly in ascending or descending order of the count, the effective loft angle of the golf club immediately before the impact and It is possible to provide a golf club set including at least three golf clubs in which the effective lie angle is uniformly changed and the height of the golf ball hit and the flight direction of the golf ball are harmonized.
Such adjustment can be performed by adjusting the shape and structure of the golf club head that affects the single-piece characteristics of the golf club shaft and the position of the center of gravity of the golf club head. In addition, this adjustment can be performed independently while maintaining the frequency of the conventional golf club set that changes substantially linearly corresponding to the number of golf clubs.

FIG. 6 is a graph showing the relationship between the golf club number and the frequency in the golf club set S ₁ according to the present invention and the conventional golf club set S ₂ . Loft angle and lie angle of the golf club of each count in the golf club set S ₁ and the golf club set S ₂ is one that is set at the same angle.
In FIG. 6, from the 3rd iron (count 3: # 3) to the 9th iron (count 9: # 9), pitching wedge (PW), approach wedge (AW), and sand wedge (SW) in descending order on the horizontal axis. The frequency (cpm) is taken on the count and the vertical axis.
Further, □ is a plot of the frequency of an example of the golf club set of the present invention for each count. The black circles plot the frequency of the conventional golf club set for each count. According to FIG. 6, the golf club set of the present invention has substantially the same frequency as the conventional golf club set.

FIG. 7 is a graph showing the relationship between the deflection angle measured in the present invention and the golf club count.
The horizontal axis indicates the same count as in FIG. 6, and the vertical axis indicates the deflection angle (°). ◯ is the deflection angle in the kickback direction of each golf club of the golf club set S ₁ (present invention) shown in FIG. 6, and ● is each golf club of the golf club set S ₂ (conventional product) shown in FIG. The deflection angle in the kickback direction, Δ is a plot of the deflection angle in the toe down direction of each golf club of the golf club set S ₁ , and the triangle is a plot of the deflection angle in the toe down direction of each golf club of the golf club set S _2. .

According to the graph shown in FIG. 7, the deflection angles in the kickback direction and the toe down direction change (decrease) in a substantially linear manner in the case of the golf club S ₁ according to the present invention, whereas in the case of the golf club set S ₂ is variation of the angular deflection between adjacent count greatly fluctuates. In addition, that a bending angle changes substantially linear means that the fluctuation | variation for the change of the bending angle between adjacent counts is 0.3 degrees or less. Accordingly, the substantially linear range includes a range in which the change in the deflection angle between adjacent counts varies by 0.3 ° or less.

For example, in the case of No. 9 iron (# 9), the deflection angle in the golf club set S ₂ (conventional product) is the same in the golf club set S ₁ (invention product) as the deflection angle in the kickback direction and the deflection angle in the toe down direction. It is larger than the deflection angle. This is because the 9th iron of the golf club set S ₂ has a larger effective loft angle and a smaller effective lie angle than the 9th iron of the golf club set S ₁ having the same loft angle and lie angle. Means. Therefore, it is shown that the height of the hit ball of the golf ball is increased, the golf ball is easily bent in the slicing direction, and the flight distance is hardly generated. On the other hand, the 8-iron of the golf club set S ₂ means that the effective loft angle is smaller and the effective lie angle becomes larger than the 8-iron of the golf club set S ₁ having the same loft angle and lie angle. . Therefore, the height of the hit ball of the golf ball is reduced, and it is easy to bend in the hook direction. On the other hand, since the deflection angles of the 7 irons of the golf club sets S ₁ and S ₂ are equal in the kickback direction and the toe down direction, the effective loft angle and the effective lie angle are considered to be substantially equal. .

Therefore, in the case of the golf play with a golf club set S _2, taking into account the change in the height of the high and low, and changes in the flight direction of the ball of the ball between the 7-iron and 8-iron, 9-iron Even if a golf ball is selected and hit, the hitting height and flight direction expected by the golfer cannot be obtained. On the other hand, in the golf club set S ₁ , the deflection angle in the kickback direction and the toe-down direction changes approximately linearly between the counts, so that the golfer has a hit ball height between the 7th iron and the 8th iron. Considering the change in height and the flying direction of the hit ball, if the 9th iron is selected, the hit ball height and flight direction can be obtained as expected. Therefore, it is possible to adjust the hitting ball height between the counts in the golf club set, or to adjust the flight direction, and to easily adjust the flight distance.
Thus, it can be said that the golf club set of the present invention can launch a golf ball with the trajectory expected by the golfer.

FIG. 8 is a graph showing the relationship between the count of the golf club sets S ₁ and S ₂ shown in FIG. 6 and the amount of deflection. The horizontal axis represents the same count as in FIG. 6, and the vertical axis represents the amount of deflection (mm). ○, the amount of deflection of the kickback direction in each of the golf club of the golf club set S _1, ●, the amount of deflection of the kickback direction in each of the golf club of the golf club set S _2, △, each of the golf club set S ₁ the amount of deflection of the toe down direction in a golf club, ▲ is a plot of the amount of deflection of the toe down direction at each golf club of the golf club set S _2. The graph shown in FIG. 8 shows the same tendency as the deflection angle shown in FIG. That is, in the case of the golf club set S ₁ (product of the present invention), the deflection amount in the kickback direction and the toe down direction changes (decreases) substantially linearly, whereas the golf club S ₂ (conventional) Product), the amount of change in the amount of deflection between adjacent counts varies greatly. In addition, that the amount of bending changes substantially linear means that the fluctuation | variation of the amount of change of the amount of bending between adjacent counts is 2.0 mm or less. Accordingly, the substantially linear range includes a range in which the amount of change in the amount of deflection between adjacent counts varies by 2.0 mm or less.
In the above example, the bending angle and the bending amount decrease in a substantially linear order in descending order of the count, but in the present invention, the bending angle and the bending amount increase in a substantially linear order in the descending order of the count. May be.

  The golf club evaluation method, golf club, and golf club set of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various improvements and modifications can be made without departing from the spirit of the present invention. Of course, changes may be made.

It is a block diagram which shows the outline of an example of the evaluation apparatus and measuring system which perform the evaluation method of the golf club of this invention. It is a figure explaining an example of the measurement system which performs a part of evaluation method of the golf club of this invention. It is a flowchart which shows the flow of an example of the evaluation method of the golf club of this invention. (A)-(c) is a figure explaining the position of the gravity center of a golf club head. It is a figure which shows an example of the golf club set of this invention. It is a graph which shows an example of the relationship between the count of each golf club in a golf club set, and a vibration frequency. It is a graph which shows an example of the relationship between the count of each golf club in a golf club set, and the deflection angle obtained by the golf club evaluation method of the present invention. It is a graph which shows an example of the relationship between the count of each golf club in a golf club set, and the amount of bending obtained by the golf club evaluation method of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 Golf club shaft 3 Golf club head 10 Evaluation apparatus 12 Motion information acquisition part 14 External force calculation part 16 Deformation information calculation part 18 Evaluation part 20 Measurement system 22 Measuring jig 24 Insertion hole 26 Action part 28 Load cell 30, 32 Laser displacement meter 34 Controller unit

Claims (8)

A golf club evaluation method for evaluating the impact performance of a golf club in which a golf club head is mounted on the tip of a golf club shaft,
Obtaining motion information of the golf club head immediately before hitting the golf ball by the golf club;
Based on the motion information, obtaining a deformation state at the tip of the golf club shaft;
Obtaining at least one of an effective loft angle and an effective lie angle of the golf club immediately before hitting the golf ball from the deformed state, and evaluating a hitting performance of the golf club from the effective loft angle and the effective lie angle. A method for evaluating a golf club.   The step of determining the deformation state of the golf club shaft obtains a force acting on the golf club head from the motion information, and a deflection angle at the tip of the golf club shaft from a moment acting on the golf club shaft caused by the force. The golf club evaluation method according to claim 1, wherein at least one of the deflection amount and the deflection amount is obtained as a deformation state of the golf club shaft.   The golf club evaluation according to claim 2, wherein the step of obtaining the deformation state of the golf club shaft is obtained by measuring at least one of the deflection angle and the deflection amount by applying the moment to a tip of the golf club shaft. Method.   The action of the moment on the front end of the golf club shaft includes an insertion hole for inserting and gripping and fixing the front end portion of the golf club shaft, and the action point for applying an external force is the central axis of the insertion hole for inserting the golf club. The golf club evaluation method according to claim 3, wherein the golf club evaluation method is performed using a measuring jig offset by a predetermined distance from the measuring tool. The moment acting on the golf club shaft is determined by the distance between the center of gravity in each of two different directions between the center of gravity of the golf club head and the center axis of the golf club shaft or an extension line of the center axis, and the golf club. Having moment components in two directions multiplied by the force acting on the head,
5. The golf club according to claim 2, wherein the step of determining the deformation state of the golf club shaft determines the deformation state of the golf club shaft in two directions using the moment component in the two directions. Evaluation methods. A golf club having a golf club head attached to the tip of a golf club shaft,
And a display means for displaying at least one information of a deflection angle and a deflection amount immediately before the golf ball is hit at the tip of the golf club shaft obtained based on the motion information of the golf club head immediately before the golf ball is hit. A golf club characterized by A golf club having a golf club head attached to the tip of a golf club shaft,
It has a display means for displaying at least one information of an effective loft angle and an effective lie angle of the golf club head immediately before hitting the golf ball obtained based on the motion information of the golf club head immediately before hitting the golf ball. A golf club characterized by A golf club set comprising a plurality of golf clubs having different numbers, with a golf club head mounted on the tip of a golf club shaft,
A group consisting of at least three golf clubs, wherein at least one of the deflection angle and the deflection amount at the tip of the golf club shaft immediately before hitting a golf ball changes substantially linearly in ascending or descending order of the count. A golf club set comprising:

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