Manufacturing method for custom-made golf shafts

Abstract

The object of the present invention is to efficiently provide a golf shaft that is likely to suit an individual golf player without spending a lot of time and effort. In the golf shaft manufacturing method of the present invention, 1) a second club having a second shaft having characteristics most similar to those of the first shaft of a first club is selected from a plurality of second clubs, 2) a flex of a shaft to be manufactured is provisionally determined based on a moving speed of a second head measured when test-hitting with the selected second club, 3) one second club is selected from the plurality of second clubs based on a trajectory of a second head specified when test-hitting with the plurality of second clubs having the provisionally determined flex, 4) characteristics of the shaft to be manufactured are determined based on the behavior of the second shaft specified when test-hitting with the selected one second club and characteristic information of the second club, and finally 5) a shaft to be manufactured is manufactured using information on the characteristics of the shaft to be manufactured that has been determined.

Description

[Technical field]

[0001] The present invention relates to a method of manufacturing golf shafts, and more particularly to a method of manufacturing custom made golf shafts. [Background technology]

[0002] In recent years, there are various models of golf shafts that change the way they bend. In addition, each model often has a lineup with different specifications (for example, flex, torque, weight, etc.). When a person who enjoys golf (hereinafter sometimes referred to as a "golf player") purchases a golf shaft or golf club, he or she goes to a store where a swing analysis device, a trajectory measurement device, etc. are installed and a fitter is present, and repeatedly tries out multiple golf clubs (multiple golf shafts of various models and specifications with grips and heads attached) prepared in the store, and purchases the one recommended by the fitter based on the measurement data of the swing analysis device, trajectory measurement device, etc. during the test hit. (For example, see JP 2022-023015 A, etc.) [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-023015 Summary of the Invention [Problem to be solved by the invention]

[0004] However, currently, there are a wide variety of golf shaft models and specifications, so if a golf player wants to find a golf club or golf shaft that is truly suited to him / her, he / she needs to try out a considerable number of clubs, which requires a great deal of effort and time on his / her part. In some cases, he / she may not be able to find a golf shaft that is suited to him / her, which may result in a great deal of effort and time being wasted.

[0005] An object of the present invention is to efficiently provide a golf shaft that is believed to suit each individual golf player, without requiring the aforementioned great deal of effort and time. [Means for solving the problem]

[0006] A manufacturing method of a custom-made golf shaft (hereinafter, sometimes simply abbreviated as "OMG shaft") according to a first aspect of the present invention includes a characteristic specifying step, a first selection step, an HS measurement step, a tentative flex determination step, a head trajectory specifying step, a second selection step, a shaft behavior specifying step, a first determination step, and a manufacturing step. In the characteristic specifying step, the characteristics of a first shaft of a first golf club having a first shaft are specified. In the first selection step, a second golf club having a second shaft having characteristics most similar to those of the first shaft is selected from a plurality of second golf clubs having second heads and second shafts having mutually different characteristics. In the HS measurement step, the moving speed of the second head when a golf ball is hit with the second golf club selected in the first selection step is measured. In the tentative flex determination step, the flex of a shaft to be manufactured is tentatively determined based on the moving speed of the second head measured in the HS measurement step. In the head trajectory specification process, the trajectory of the second head of each of the plurality of second golf clubs (hereinafter referred to as "21st golf clubs") having a flex corresponding to the flex provisionally determined in the flex provisionally determining process is specified when a golf ball is hit with each of the plurality of second golf clubs. In the second selection process, one 21st golf club (hereinafter referred to as "22nd golf club") is selected from the plurality of 21 golf clubs based on the trajectory of the second head specified in the head trajectory specification process. In the shaft behavior specification process, the behavior of the second shaft of the 22nd golf club (the trajectory of the second shaft with respect to time) when a golf ball is hit with the 22nd golf club is specified. In the first determination process, the flex, torque, three-point rigidity, weight, shape and center of gravity position of the shaft to be manufactured are determined based on the behavior of the second shaft of the 22nd golf club specified in the shaft behavior specification process and the characteristic information of the 22nd golf club. In the manufacturing process, the shaft to be manufactured is manufactured using the information on the flex, torque, three-point stiffness, weight, shape, and center of gravity position of the shaft to be manufactured determined in the first determination process.

[0007] With this OMG shaft manufacturing method, a golf shaft that is thought to suit each individual golf player can be manufactured through the above-mentioned steps. Therefore, by utilizing this manufacturing method, a golf shaft that is thought to suit each individual golf player can be efficiently provided without spending a lot of time and effort on test shots, etc.

[0008] A manufacturing method of an OMG shaft according to a second aspect of the present invention is the manufacturing method of an OMG shaft according to the first aspect, further comprising an input step. In the input step, information on the characteristics of the first golf club identified in the characteristic identification step is input to a computer. Then, in the first selection step, the information on the characteristics of the first shaft is approximate-matched against a first database that stores information on the characteristics of the second shaft in association with identification information of the second shaft, thereby outputting identification information of a second golf club having a second shaft with characteristics most similar to those of the first shaft.

[0009] In this method of manufacturing an OMG shaft, the first selection step is performed automatically by inputting information on the characteristics of the first golf club into a computer, so that the second golf club having the second shaft with characteristics most similar to those of the first shaft can be quickly and accurately identified.

[0010] A manufacturing method of an OMG shaft according to a third aspect of the present invention is a manufacturing method of an OMG shaft according to the first or second aspect, in which in the HS measurement step, information on the moving speed of the second head is stored in a storage device. Note that this storage device may be built into the computer described above, may be externally attached to the computer, or may be built into or externally attached to a computer connected to the computer via a network or the like. Then, in the tentative flex determination step, the moving speed information is collated with a second database that stores information on the range of moving speeds in association with flex information, and flex information of the shaft to be manufactured is output.

[0011] In this OMG shaft manufacturing method, the flex provisional determination step is performed automatically, which allows the provisional flex of the shaft to be manufactured to be determined quickly and accurately.

[0012] A manufacturing method for an OMG shaft according to a fourth aspect of the present invention is a manufacturing method for an OMG shaft according to any one of the first to third aspects, and in a second selection process, information on the three-point stiffness of the shaft to be manufactured is output by comparing the identification information of the 22nd golf club with a third database that stores information on the three-point stiffness of the second shaft in association with identification information of the second golf club.

[0013] In this method of manufacturing an OMG shaft, the identification information of the second shaft of the 22nd golf club is collated with the third database, and information on the three-point stiffness of the shaft to be manufactured is output. This makes it easy to know the information on the three-point stiffness of the shaft to be manufactured.

[0014] A manufacturing method of an OMG shaft according to a fifth aspect of the present invention is a manufacturing method of an OMG shaft according to any one of the first to fourth aspects, further comprising a third selection step and a second determination step. In the third selection step, information on the flex, torque, three-point stiffness, weight, shape, and center of gravity of the shaft to be manufactured is approximated against a fourth database that stores manufacturing information of the second shaft and an OMG shaft manufactured in the past (hereinafter referred to as "manufactured golf shaft") in association with information on the flex, torque, three-point stiffness, weight, shape, and center of gravity of the second shaft and the manufactured golf shaft, and manufacturing information of the second shaft or the manufactured golf shaft as an approximate model shaft of the shaft to be manufactured is output. In the second determination step, the manufacturing method of the shaft to be manufactured is determined using the manufacturing information of the second shaft or the manufactured golf shaft as an approximate model shaft of the shaft to be manufactured. Then, in the manufacturing step, the shaft to be manufactured is manufactured based on the manufacturing method of the shaft to be manufactured determined in the second determination step.

[0015] In this OMG shaft manufacturing method, manufacturing information of a second shaft or an already manufactured golf shaft as an approximation model shaft of the shaft to be manufactured is output in the third selection step, and the manufacturing method of the shaft to be manufactured is determined using the manufacturing information of the second shaft or the already manufactured golf shaft as an approximation model shaft of the shaft to be manufactured in the second determination step. This makes it possible to quickly and easily design the shaft to be manufactured.

[0016] A golf shaft manufacturing method according to a sixth aspect of the present invention includes an output step, a determination step, and a manufacturing step. In the output step, information on the flex, torque, three-point stiffness, weight, shape, and center of gravity of a golf shaft to be manufactured (hereinafter referred to as a shaft to be manufactured) is approximate-matched to a database that stores information on golf shafts manufactured in the past (hereinafter referred to as a "manufactured golf shaft") in association with information on the flex, torque, three-point stiffness, weight, shape, and center of gravity of the manufactured golf shaft, and manufacturing information on the manufactured golf shaft as an approximate model shaft of the shaft to be manufactured is output. In the determination step, the manufacturing method of the shaft to be manufactured is determined using the manufacturing information of the manufactured golf shaft as an approximate model shaft of the shaft to be manufactured. In the manufacturing step, the shaft to be manufactured is manufactured based on the manufacturing method of the shaft to be manufactured determined in the determination step.

[0017] In this golf shaft manufacturing method, in the output step, information on the flex, torque, three-point stiffness, weight, shape, and center of gravity position of the shaft to be manufactured is approximately collated against the database, and manufacturing information of the manufactured golf shaft as an approximate model shaft of the shaft to be manufactured is output, in the determination step, the manufacturing method of the shaft to be manufactured is determined using the manufacturing information of the manufactured golf shaft as an approximate model shaft of the shaft to be manufactured, and in the manufacturing step, the shaft to be manufactured is manufactured based on the manufacturing method of the shaft to be manufactured determined in the determination step. This allows a smooth flow from designing to manufacturing the shaft to be manufactured. [Brief description of the drawings]

[0018] [Figure 1] 1 is a schematic diagram showing a system according to an embodiment of the present invention; [Diagram 2] 1 is a schematic block diagram showing a configuration of a first computer according to an embodiment of the present invention; [Diagram 3] 2 is a conceptual diagram of programs, data, etc. stored in an auxiliary memory of a first computer according to an embodiment of the present invention. [Figure 4] 13 is an image diagram of a second golf club characteristic information management table constituting a first database of the first computer according to the embodiment of the present invention. FIG. [Diagram 5] 1 is an image diagram of a batter-specific head trajectory information management table constituting a first database of a first computer according to an embodiment of the present invention. FIG. [Figure 6] 13 is an image diagram of a manufacturing history table constituting a second database of a second computer according to an embodiment of the present invention. FIG. [Figure 7] 1 is a diagram showing the trajectory of a motion capture sensor when a golf club incorporating a second shaft to which a motion capture sensor is attached is swung, where trajectories P1 to P7 in the diagram represent the trajectories of each of the motion capture sensors. [Figure 8] This is a graph showing the change in the movement speed of the motion capture sensor when a golf club incorporating a second shaft with a motion capture sensor attached thereto is swung. Note that the horizontal axis of the graph is time, and the vertical axis is the movement speed of the motion capture sensor. [Explanation of symbols]

[0019] 110 First Computer (First Computer) DB 1st database (1st database, 2nd database, 3rd database) DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] -Method of manufacturing a custom-made golf shaft according to an embodiment of the present invention- The custom-made golf shaft according to the embodiment of the present invention (hereinafter, sometimes simply referred to as "OMG shaft") is manufactured through a characteristic specification process, a first selection process, an HS measurement process, a tentative flex determination process, a head trajectory specification process, a second selection process, a shaft behavior specification process, a shaft specification determination process (corresponding to the "first determination process" in claim 1), a manufacturing specification determination process (corresponding to the "second determination process" in claim 5), and a manufacturing process. These processes are described in detail below. It is preferable that the characteristic specification process to the shaft specification determination process are performed by a fitter accompanying a golf player (hereinafter, sometimes referred to as a "hitter"). It is preferable that the manufacturing specification determination process is performed by a person who determines the manufacturing specifications of the golf shaft, and the manufacturing process is preferably performed by a golf shaft manufacturer. Each process may be performed manually while taking notes of the measured values, etc., or may be performed semi-automatically by a computer by manually or automatically inputting the measured values, etc.

[0021] (1) Characteristic identification process In the characteristic specification step, the characteristics of the first shaft of the first golf club having the first shaft are specified. The first golf club is preferably a golf club that is mainly used by the prospective purchaser of the OMG shaft at that time, but may be another golf club. The characteristics of the first golf club are (a) the weight balance of the golf club, (b) the weight, flex, torque, flex, three-point stiffness, flex coefficient, C / B value, T / C value, and frequency of the first shaft, and (c) the weight, volume, and center of gravity position of the first head. The weight balance of the golf club indicates, for example, in which of the areas in which the head side is divided into five areas A, B, C, D, and E from the lightest side and each of the areas A, B, C, D, and E is divided into ten areas 0 to 9 from the lightest side, the weight balance point is located, and may be expressed, for example, as ···, C8, C9, D0, D1, D2, ···. The weight of the shaft is the weight after it is cut to the desired length. Flex indicates the stiffness of the shaft, and can be expressed as A, LL, L, R, SR, S, SX, X, XX, etc., in order from softest to softest. This flex may be relative within the same model. Torque is a numerical value that indicates the ease of rotation of the shaft in the axial direction, and is usually expressed as about 2.0 to 7.0. Knee is a rough specification of the position of the shaft that is most likely to bend, and can be expressed as tip, mid-tip, mid-knee, mid-knee, and knee, with the head side being the tip. This knee is also called the kick point. Three-point stiffness means the load required to push down (i.e. bend) each of three points 250 mm from the tip, center, and 250 mm from the rear end of the grip by fixing the shaft at positions 150 mm on both sides, and applying weight to each of the three points. For ease of explanation, the stiffness value of the shaft at a position 250 mm from the tip may be referred to as the "stiffness value of the tip side portion," the stiffness value of the shaft at the center position may be referred to as the "stiffness value of the center portion," and the stiffness value of the shaft at a position 250 mm from the rear end of the grip may be referred to as the "stiffness value of the butt side portion."The flex coefficient, C / B value, and T / C value can be calculated from the three-point stiffness. The C / B value is the ratio of the stiffness of the center part to the stiffness of the butt part. The T / C value is the ratio of the stiffness of the tip part to the stiffness of the center part. The flex coefficient is a numerical value of the flex, and is calculated by (stiffness of the tip part / stiffness of the center part) x (stiffness of the tip part / stiffness of the butt part) x 100. In general, a flex coefficient in the range of more than 0 and less than 15 is considered to be tip-mid flex, 15 or more and less than 20 is considered to be mid flex, 20 or more and less than 25 is considered to be mid flex, 25 or more and less than 30 is considered to be mid flex, and 30 or more is considered to be butt flex, but this is not limited to this. The vibration frequency is a value measured by vibrating the golf club with the grip side fixed and a weight (which may be the head) attached to the head side, and measuring how many vibrations it makes per minute. The characteristics of the first golf club may be specified by directly measuring the first golf club (particularly the first shaft) or by using catalog values. When directly measuring the first golf club, it is a prerequisite that permission from the owner or the like is obtained, but the first golf club may be disassembled into a head, shaft, and grip for measurement.

[0022] Incidentally, the characteristic values ​​of the first golf club may be input to a computer, and the input values ​​may be used for the automatic selection of the second golf club in the first selection step. The automatic selection of the second golf club will be described in the section "(2) First Selection Step" below.

[0023] (2) First selection process In the first selection step, a second golf club having a second shaft having characteristics most similar to those of the first shaft is selected from a plurality of second golf clubs having a second head and a second shaft having mutually different characteristics. The second golf clubs are a plurality of models of golf clubs that the OMG shaft provider has in stock at that time. The plurality of second shafts are different in at least flex, torque, three-point stiffness, and weight. The second shafts having different three-point stiffness are preferably stocked in three or more types, more preferably five or more types, and even more preferably seven or more types. For the second shafts having different three-point stiffness, it is preferable to stock four or more second shafts having different weights, more preferably seven or more, and even more preferably ten or more. For the second shafts having different three-point stiffness, it is preferable to stock four or more second shafts having different flexes, more preferably six or more, and even more preferably ten or more. For the second shafts having different three-point stiffness, it is preferable to stock three or more second shafts having different torques, and even more preferably six or more. The second head is preferably the same in the plurality of second golf clubs.

[0024] As a preferred example of the above-mentioned second shafts, three second shafts with different three-point stiffness are provided, four second shafts with different weights (e.g., 40g, 50g, 60g, 70g) are provided for the second shafts with different three-point stiffness, four second shafts with different flex (e.g., R, SR, S, X) are provided, and three second shafts with different torque (e.g., 3.0°, 4.5°, 6.0°) are provided. In this case, 144 (=3×4×4×3) second shafts are provided. As another preferred example, five second shafts with different three-point stiffness are stocked, seven second shafts with different weights (e.g., 40g, 45g, 50g, 55g, 60g, 65g, 70g) are stocked for each of the second shafts with different three-point stiffness, six second shafts with different flex (e.g., RR, R, SR, S, SX, X) are stocked, and six second shafts with different torque (e.g., 3.0°, 3.6°, 4.5°, 5.0°, 6.0°, 7.0°) are stocked. In this case, the number of second shafts stocked is calculated to be 1260 (=5×7×6×6). Another more preferable example is that five second shafts with different three-point stiffness are stocked, and for each of the second shafts with different three-point stiffness, ten second shafts with different weights (e.g., 35g, 40g, 45g, 50g, 55g, 60g, 65g, 70g, 75g, 80g) are stocked, ten second shafts with different flexes (e.g., L, RR, R, SR1, SR2, S1, S2, SX, X, XX) are stocked, and six second shafts with different torques (e.g., 3.0°, 3.6°, 4.5°, 5.0°, 6.0°, 7.0°) are stocked. In this case, 3000 (=5×10×10×6) second shafts are stocked. Note that the above example is merely an example, and some second shafts that are used less frequently may be thinned out based on the experience of the fitter, etc.

[0025] When the information on the characteristic values ​​of the first golf club is input to a computer in the characteristic identification step, it is preferable to install a first database that stores information on the characteristics of the second shaft in association with identification information of the second shaft, and a matching program in the computer or another computer that is communicatively connected to the computer. This is because by executing the matching program to approximate-match the information on the characteristics of the first shaft against the first database, it is possible to output identification information of the second golf club having a second shaft having characteristics most similar to those of the first shaft.

[0026] In addition, when the information on the characteristics of the first shaft is information on values ​​such as weight, torque, three-point stiffness, flex coefficient, C / B value, T / C value, and frequency, the allowable range of the values ​​is set in advance in the comparison program or the first database, and when the comparison program is executed, a numerical range is defined based on the numerical value of the same characteristic, and identification information of the second shaft having a numerical value that falls within the defined numerical range is output. In addition, when the information on the characteristics of the first shaft is information on index values ​​such as weight balance and flex, similarly to the above, the allowable index value of the index value is specified in advance in the comparison program or the first database, and when the comparison program is executed, identification information of the second shaft having the specified index value is output. In addition, when there are multiple numerical items, multiple index value items, or a mixture of numerical items and index value items, when the comparison program is executed, identification information of the second shaft having at least one of a numerical value and an index value that matches at least one of the numerical range and index value of all the items is output. In addition, when there are multiple comparison items like this, it is preferable to assign a priority to the comparison items.

[0027] (3)HS measurement process In the HS measurement step, the moving speed of the second head (i.e., head speed) is measured when the golf ball (hereinafter, may be simply referred to as "ball" or "sphere") is hit with the second golf club selected in the first selection step. Note that the moving speed of the second head can be measured, for example, by a commercially available head speed measuring device or a head speed measuring app on a portable computer such as a smartphone.

[0028] Incidentally, the head speed measuring device and the portable computer may be communicatively connected to the above-mentioned computer or the like, and information on the measured moving speed of the second head may be transmitted to the computer or the like and stored, and the information on the moving speed may be used for automatically provisionally determining the flex of the to-be-manufactured shaft in the provisional flex determining step. The automatic provisional determination of the flex of the to-be-manufactured shaft will be described in the section "(4) Provisional flex determining step" below.

[0029] (4) Flex tentative determination process In the provisional flex determination step, the flex of the shaft to be manufactured is provisionally determined based on the moving speed of the second head measured in the HS measurement step.

[0030] When the information on the moving speed of the second head is stored in a computer in the HS measurement process, it is preferable to install a second database that stores the information on the moving speed of the second head in association with the flex information of the second shaft, and a comparison program in the computer or another computer communicatively connected to the computer. This is because the flex information of the second shaft can be output by executing the comparison program to compare the information on the moving speed of the second head with the second database.

[0031] Normally, if the moving speed of the second head is within the range of 36 m / sec or more and less than 39 m / sec, it is appropriate to set the flex to R, if the moving speed is within the range of 39 m / sec or more and less than 42 m / sec, it is appropriate to set the flex to SR, if the moving speed is within the range of 42 m / sec to less than 45 m / sec, it is appropriate to set the flex to S, and if the moving speed is 45 m / sec or more, it is appropriate to set the flex to SX or X, but this is not limited to the above.

[0032] (5) Head trajectory identification process In the head trajectory identification process, the trajectory (club path (the approach angle of the club head just before impact. Usually, "+" indicates that the head is coming down from the inside and "-" indicates that the head is coming down from the outside), attack angle, launch angle (face angle just before impact), etc.) of the second head of each of the multiple second golf clubs (hereinafter referred to as "21st golf clubs") having a flex corresponding to the flex provisionally determined in the flex provisional determination process when a ball is hit with each of the 21st golf clubs is identified. Note that the tracking of the trajectory of the second head can be performed, for example, by a commercially available head trajectory tracker (for example, what are called swing / trajectory measuring devices such as Trackman, Flight Scope, and Skytrack) or a head trajectory tracking app on a portable computer such as a smartphone. In addition, the trajectories of the second heads of all the 21 golf clubs may be specified, or after specifying the trajectory of the second head of the first 21 golf club, the fitter may specify the trajectory of the second head of the other 21 golf clubs based on his / her own experience, etc., and may end the specification of the head trajectory when a relatively good head trajectory is obtained. For example, if the trajectory of the second head is inside-out, the fitter has the hitter hit the ball with the 21 golf club with either a medium flex, a medium back flex, or a back flex depending on the degree of the trajectory, and check the trajectory of the second head again, and repeat the process until a relatively good result is obtained. On the other hand, if the trajectory of the second head is outside-in, the fitter has the hitter hit the ball with the 21 golf club with either a front flex, a front-middle flex, or a middle flex depending on the degree of the trajectory, and check the trajectory of the second head again, and repeat the process until a relatively good result is obtained. In addition, an upper blow / down blow may be considered as the trajectory of the head.

[0033] Incidentally, the head trajectory tracker or the portable computer may be communicatively connected to the above-mentioned computer or the like, and the measured information on the trajectory of the second head may be transmitted to the computer or the like for storage, and the information on the trajectory may be used for automatic selection of the 22nd golf club in the second selection step. In such a case, it is necessary to associate the measured information on the trajectory of the second head with the identification information of the second golf club and store it in the computer. The automatic selection of the 22nd shaft will be explained in the section "(6) Second Selection Step" below.

[0034] (6)Second selection process In the second selection step, one 21st golf club (hereinafter referred to as the "22nd golf club") is selected from the plurality of 21st golf clubs based on the trajectory of the second head identified in the head trajectory identification step. That is, in this step, a second shaft having three-point stiffness (which may be replaced by flex point, flex point coefficient, T / C value, and C / B value) that is considered to suit the hitter is selected. In this step, the 22nd golf club may be selected by a fitter based on information on the trajectory of the second head, or may be automatically selected by a computer based on information on the trajectory of the second head.

[0035] When the 22nd golf club is selected by the fitter based on the information on the trajectory of the second head, it is preferable to install in the computer a third database that stores information such as the three-point stiffness of the second shaft of the second golf club in association with the identification information of the second golf club, and a matching program, because by executing the matching program and matching the information on the identification information of the 22nd golf club against the third database, the information on the three-point stiffness of the second shaft can be output.

[0036] On the other hand, when the 22nd golf club is automatically selected by a computer based on the information on the trajectory of the second head, as described above, it is necessary to store the information on the trajectory of the second head in the computer in association with the identification information of the second golf club in the head trajectory specification process. It is preferable to install a fourth database that stores the information on the trajectory of the second head in association with information on a priority (the priority of the ideal head trajectory is set high) and a matching program in the computer or another computer that is communicatively connected to the computer. This is because by executing the matching program and matching the information on the trajectory of the second head against the fourth database, it is possible to output the identification information of the second golf club, i.e., the 22nd golf club, which shows the trajectory of the second head that is considered to be the best.

[0037] (7) Shaft behavior identification process In the shaft behavior identification process, the behavior of the second shaft of the 22nd golf club (the trajectory of the second shaft over time) when the ball is hit with the 22nd golf club is identified. The behavior of the second shaft can be tracked, for example, by attaching a plurality of motion capture sensors to the second shaft, tracking the sensors during the swing, and subjecting the tracking data to FEM analysis (also called the finite element method. A method of subdividing a complex analysis target and predicting an approximate solution for the whole by finding a solution for each of the subdivided areas. It is applied in the fields of structural mechanics and fluid dynamics.). In this process, by carrying out the above-mentioned steps, a trajectory diagram (see FIG. 7) of the motion capture sensor (i.e., the second shaft) and a graph showing the moving speed of the motion capture sensor (i.e., the second shaft) over time (see FIG. 8) can be obtained. In the latter graph, a point where the moving speed of the motion capture sensor suddenly drops is observed, and this point is the impact point. From the tracking data of the behavior of the second shaft around the impact, (a) it is possible to specify whether the timing at which the second shaft reaches its maximum speed is before the impact point, at the impact point, or after the impact point (if the timing at which the second shaft reaches its maximum speed is before the impact point, the speed of the motion capture sensor located closest to the head in the graph (e.g., the motion capture sensor located directly above the head) reaches its maximum before the impact point and then slows down (i.e., the curve becomes mountain-shaped just before the impact point), and if the timing at which the second shaft reaches its maximum speed is after the impact point, the speed of the motion capture sensor located closest to the head (e.g., the motion capture sensor located directly above the head) at the impact point becomes slower than the speed of the second head measured in the HS measurement process). Also, from the former trajectory diagram, it is possible to specify whether the trajectory (i.e., the swing) indicates a body turn type swing or a wrist turn type swing.

[0038] (8) Shaft specification determination process In the shaft specification determination process, the specifications of the shaft to be manufactured, i.e., flex, torque, three-point rigidity, weight, shape (shape of the grip side) and center of gravity position, are determined based on the shaft behavior of the second shaft of the 22nd golf club identified in the shaft behavior identification process and the characteristic information of the 22nd golf club.

[0039] Specifically, if the second shaft reaches its maximum speed before the impact point, the design value is determined so that the flex is stiffer than the flex of the second shaft of the 22 golf club, taking into consideration the extent of this, and if the second shaft reaches its maximum speed at the impact point, the design value is determined so that the flex is the same as the flex of the second shaft of the 22 golf club, and if the second shaft reaches its maximum speed after the impact point, the design value is determined so that the flex is softer than the flex of the second shaft of the 22 golf club, taking into consideration the extent of this (specifically, the flex is adjusted by changing the overall rigidity without changing the flex coefficient, T / C value, and C / B value). Also, when the tracking data indicates a body-turn type swing, the design value is determined so that the torque is larger (loose) than the torque of the second shaft of the 22nd golf club in consideration of the degree of the body-turn type swing (for example, about 4.5 degrees when the weight of the second shaft is 60g or more, about 6 degrees when it is in the 50g range, and about 7 degrees when it is 40g or less). When the tracking data indicates a wrist-turn type swing, the design value is determined so that the torque is smaller (tight) than the torque of the second shaft of the 22nd golf club in consideration of the degree of the body-turn type swing (for example, about 3 degrees when the weight of the second shaft is 60g or more, and about 4.5 degrees when it is 50g or less). Also, when the tracking data indicates a body-turn type swing, the shape of the grip side (butt side) of the shaft may be tapered, and when the tracking data indicates a wrist-turn type swing, the shape of the grip side (butt side) of the shaft may be straight. This is because with a body turn swing, the batter hardly uses his wrists, so a thinner grip is used to better catch the ball, and with a wrist turn swing, the batter uses his wrists, so a thicker grip is used to prevent overuse of the wrists.

[0040] In addition, if the trajectory of the hit ball is observed or collected as data in the head trajectory specification step, the weight of the second shaft may be adjusted according to the trajectory of the hit ball. Specifically, when the degree of curvature of the hit ball is relatively large, the weight of the second shaft is increased to stabilize the direction of the hit ball, and when the degree of curvature of the hit ball is almost zero, the weight of the second shaft is decreased to improve the moving speed of the second head. In addition, the trajectory of the hit ball may be taken into consideration when selecting the shape of the grip side (butt side) of the shaft. Specifically, when the tracking data indicates a body turn type swing and the trajectory of the hit ball is a little slicing, the shape of the grip side (butt side) of the shaft is made tapered, and when the tracking data indicates a wrist turn type swing and the trajectory of the hit ball is a little hooking, the shape of the grip side (butt side) of the shaft is made straight.

[0041] In addition, the balance point of the shaft to be manufactured is adjusted according to the club head to be attached to the shaft to be manufactured. Specifically, if the head balance is lighter, the balance point of the shaft to be manufactured is brought to the tip side in the range of 47% to 49%, and if the head balance is heavier, the balance point of the shaft to be manufactured is brought to the butt side in the range of 50% to 54%.

[0042] As described above, in this process, the flex, torque, three-point rigidity, weight, shape (shape on the grip side) and center of gravity position of the second shaft of the 22 golf club are corrected based on factors such as the behavior of the second shaft of the 22 golf club and the trajectory of the ball, and the flex, torque, three-point rigidity, weight, shape (shape on the grip side) and center of gravity position of the shaft to be manufactured are determined.

[0043] Incidentally, the various characteristic values ​​of the shaft to be manufactured that have been determined may be input into a computer, and the input values ​​may be used to automatically output "manufacturing specification information of a second shaft or an already manufactured shaft as an approximate model shaft of the shaft to be manufactured" that is required in the manufacturing specification determination step. Such automatic output of manufacturing specification information of a second shaft or an already manufactured shaft will be described in the section "(9) Manufacturing specification determination step" below.

[0044] (9) Manufacturing specification determination process In the manufacturing specification determination process, the manufacturing specifications of the shaft to be manufactured are determined based on the flex, torque, three-point rigidity, weight, shape (shape on the grip side) and center of gravity of the shaft to be manufactured that were determined in the shaft specification determination process. Note that the "manufacturing specifications" referred to here include the specifications of the prepreg (for example, the type of fiber (e.g., carbon fiber, boron fiber, etc.) and resin (e.g., epoxy resin, etc.) that constitute the prepreg, the weight and shape of the prepreg, etc.), the type of core metal around which the prepreg is wound, the number of layers of the prepreg, the layering angle of the prepreg, the layering method of the prepreg, and the curing method of the prepreg (oven method, autoclave method, heating conditions, pressure conditions, etc.). Specifically, the information on the flex, torque, three-point rigidity, weight, shape (grip side shape) and center of gravity of the shaft to be manufactured determined in the shaft specification determination process is approximated against the information on the flex, torque, three-point rigidity, weight, shape (grip side shape) and center of gravity of the second shaft and the OMG shaft manufactured in the past (hereinafter referred to as "manufactured shaft") accumulated up to that point in time, and the manufacturing specification information, and the manufacturing specification information of the second shaft or the manufactured shaft as an approximate model shaft of the shaft to be manufactured, that is, information that serves as a standard (reference) for the manufacturing specification information of the shaft to be manufactured, is obtained, and then the manufacturing specification determiner corrects the manufacturing specification based on his experience and rules to determine the manufacturing specification of the shaft to be manufactured. Correcting the manufacturing specification means, for example, replacing the fibers that make up the prepreg, adjusting the flex and torque by the fiber orientation angle, etc. It is preferable that such manufacturing specification information is stored in a computer or the like as a manufacturing specification. However, if the result of the above-mentioned approximate comparison does not provide any information that can serve as a standard (reference) for the manufacturing specification information of the shaft to be manufactured, the person who decides on the manufacturing specifications will determine new manufacturing specifications based on the flex, torque, three-point rigidity, weight, shape (shape of the grip side) and center of gravity position of the shaft to be manufactured that were determined in the shaft specification determination process.

[0045] In order to easily obtain information that serves as a standard (reference) for the manufacturing specification information of the shaft to be manufactured, it is preferable to install in the computer a fifth database that stores the manufacturing specification information of the second shaft and the OMG shaft manufactured in the past (hereinafter referred to as the "manufactured shaft") in association with information on the flex, torque, three-point stiffness, weight, shape, and center of gravity of the second shaft and the manufactured shaft, and a comparison program. The manufactured shaft includes a model shaft for fitting (i.e., the second shaft) and a manufactured OMG shaft. Then, the comparison program is executed to approximately compare the information on the flex, torque, three-point stiffness, weight, shape, and center of gravity of the shaft to be manufactured with the fifth database, and the manufacturing specification information of the second shaft or the manufactured shaft as an approximate model shaft of the shaft to be manufactured, i.e., information that serves as a standard (reference) for the manufacturing specification information of the shaft to be manufactured, is output.

[0046] (10) Manufacturing process In the manufacturing process, the shaft to be manufactured is manufactured in accordance with the manufacturing specifications of the shaft to be manufactured determined in the manufacturing specification determination process.

[0047] The shaft to be manufactured, i.e., the golf shaft, can be manufactured, for example, through the following prepreg cutting process, prepreg molding process, bagging process, curing process, and demolding process. The following examples are merely examples and do not limit the present invention. In the prepreg cutting process, the prepreg is cut by a cutting machine based on the cutting data described in the manufacturing specifications (hereinafter, the cut prepreg may be referred to as "cut prepreg"). In the prepreg molding process, the cut prepreg is wound around a core metal specified in the manufacturing specifications and laminated according to the orientation design drawing described in the manufacturing specifications, to form a prepreg shaft with a core metal. In the bagging process, the prepreg shaft with a core metal is bagged. In the curing process, the bagged prepreg shaft with a core metal is placed in an autoclave or oven, and then the prepreg shaft with a core metal is heated and pressurized at least to cure the resin in the prepreg. In the demolding process, the core metal is removed from the cured shaft obtained by curing the resin in the prepreg, and resin burrs adhering to the cured shaft are removed.

[0048] The above-mentioned first database, second database, third database, fourth database, and fifth database may exist independently, or may be constructed as a single database.

[0049] <Example of a semi-automatic system using measuring instruments and a computer> As shown in FIG. 1, the system 100 according to this embodiment is mainly composed of a first computer 110, a swing / trajectory measuring device 130, a high-speed camera 140, and a second computer 150. As shown in FIG. 1, the swing / trajectory measuring device 130 and the high-speed camera 140 are communicatively connected to the first computer 110 via a communication line CB such as a USB cable. The first computer 110 is communicatively connected to the second computer 150 via a communication network NT. Here, the first computer 110, the swing / trajectory measuring device 130, and the high-speed camera 140 are installed in a measurement room, and the second computer 150 is installed at a shaft manufacturing site. The first computer 110, the swing / trajectory measuring device 130, the high-speed camera 140, and the second computer 150, which are components of the system 100, will be described in detail below.

[0050] 1. First Computer (1) Configuration of the first computer 2, the first computer 110 is mainly composed of a main body 110a, an input device 122, a display 123, and a communication device 124. Examples of the input device 122 include a keyboard and a mouse. Examples of the communication device 124 include a network router.

[0051] 2, the main body 110a is mainly composed of a central processing unit 111, a main memory 113, an auxiliary memory 114, a connection unit 112, an auxiliary memory interface 115, an input interface 116, a display interface 117, a communication interface 118, and a clock 125. In this main body 110a, the central processing unit 111 is connected to the connection unit 112 via a first bus line 119, the main memory 113 via a second bus line 120, and the various interfaces 115 to 118 and the clock 125 via a third bus line 121.

[0052] (1-1) Central Processing Unit The central processing unit 111 is, for example, a semiconductor chip called a microprocessor, and is mainly composed of a control unit 111a and a calculation unit 111b (it may also include a primary cache memory, a secondary cache memory, etc.). The control unit 111a reads a program temporarily stored in the main memory 113, and controls the units 111b to 114, 125 and the devices 122 to 124 according to the read program. The calculation unit 111b obtains necessary data from the main memory 113 according to instructions from the control unit 111a, and performs calculation processing (for example, arithmetic calculation processing, logical calculation processing, etc.).

[0053] (1-2) Main memory The main memory 113 is, for example, a semiconductor chip such as a RAM (random access memory). The main memory 113 temporarily stores programs, data, etc. obtained from the auxiliary memory 114, temporarily stores data inputted by the input device 122, and temporarily stores data transmitted from the calculation unit 111b, the communication device 124, etc. In addition, the main memory 113 transmits the temporarily stored data, etc. to each of the units 111b to 114 and each of the devices 122 to 124 in response to an instruction from the control unit 111a.

[0054] (1-3) Connection The connection unit 112 is a semiconductor chip such as a chipset, and connects the main memory 113 and the clock 125 to the central processing unit 111, and also connects the auxiliary memory 114, the input device 122, the display 123 and the communication device 124 to the central processing unit 111 via various interfaces 115-118.

[0055] (1-4) Auxiliary memory The auxiliary memory 114 is, for example, a hard disk drive or SSD. In the embodiment of the present invention, as shown in Fig. 3, the auxiliary memory 114 stores programs such as an operating system 114a, a device driver 114b, a swing / trajectory analysis application 114c, a motion capture application 114d, a first database application 114e, and a semi-automatic selection application 114f, as well as various data. The auxiliary memory 114 supplies programs, data, and the like to the main memory 113 in response to an instruction from the control unit 111a, and stores data and the like transmitted from the main memory 113. The auxiliary memory 114 may be an external type.

[0056] The operating system 114a is, for example, WINDOWS (registered trademark), MACOS (registered trademark), OS / 2, UNIX (registered trademark) (for example, Linux (registered trademark) or BeOS (registered trademark)) and performs hardware monitoring of the respective units 112-114, the various interfaces 115-118, the respective devices 122-124, etc., providing a user interface, monitoring various data, processing common parts of applications, etc. The device drivers 114b are dedicated programs prepared for the auxiliary memory 114, the connection unit 112, and the respective devices 122-124, respectively, and act as an intermediary for the operating system 114a to control the auxiliary memory 114, the connection unit 112, and the respective devices 122-124.

[0057] The swing / trajectory analysis application 114c analyzes the measurement data transmitted from the swing / trajectory measurement device 130 to the first computer 110, and outputs data on the moving speed of the golf club head (i.e., head speed) when the batter hits the golf ball with the golf club, data on the trajectory of the golf head (e.g., club path, attack angle, launch angle, etc.), data on the moving speed, spin amount, spin axis, etc. of the hit golf ball, data on the trajectory of the golf ball, and displays them on the display 123.

[0058] The motion capture application 114d analyzes a plurality of image data transmitted from the high-speed camera 140 to the first computer 110, outputs data on the movement of the motion capture sensor in the image data, and displays it on the display 123. Of course, here, a plurality of motion capture sensors are attached along the longitudinal direction of the shaft.

[0059] The first database application 114e mainly includes a first data matching module SP and a first database DB, as shown in Fig. 3. In this first database DB, mainly, a second golf club characteristic information management table TB0 (see Fig. 4) and a hitter-specific head trajectory information management table TB1 (see Fig. 5) are created.

[0060] The second golf club characteristic information management table TB0 is a so-called master table, and in this second golf club characteristic information management table TB0, as shown in Fig. 4, the club ID data, the weight balance data of the club, the weight data, flex data, torque data, flex data, three-point stiffness data, flex coefficient data, C / B value data, T / C value data, and vibration frequency data, the weight data, volume data, and center of gravity position data of the second head are stored in association with each other on a row basis. Note that these data are input in advance by the service provider. The club ID data is data of an identification number unique to the second golf club that is assigned to the second golf club by the service provider.

[0061] The batter-specific head trajectory information management table TB1 is a table group including a plurality of tables provided for each batter ID as shown in Fig. 5. In the batter-specific head trajectory information management table TB1, the club ID data, club path data, attack angle data, launch angle data, spin amount data, etc. of the second golf club are stored in association with each other on a row basis. The club ID data is input by a fitter or the like, and the other data is sent from the swing / trajectory measuring device 130.

[0062] The semi-automatic selection application 114f mainly includes a first selection module, a flex selection module, a second selection module, and a shaft specification determination module. These modules will be described in detail below.

[0063] The first selection module is started at the same time as the semi-automatic selection application 114f is started, and first, an input screen for inputting the characteristic data of the first shaft to the user of the first computer 110 (e.g., the employer of the fitter, etc.) is displayed on the display 123. Then, when the user finishes inputting the characteristic data of the first shaft with the input device 122 (e.g., when the fitter, etc., presses a button indicating the intention of completing the input), the first selection module performs approximate comparison of the characteristic data of the first shaft with the second golf club characteristic information management table TB0 via the first data comparison module SP, selects the club ID data of the second golf club having the second shaft having characteristic data most approximate to the characteristic data of the first shaft, and displays it on the display 123. This display allows the fitter, etc. to specify the second golf club to be used immediately after the first golf club. In this case, the approximate matching method may include, for example, a method in which character data such as flex and character data before and after the character data are set in advance, and the club ID data of the second golf club having a second shaft that perfectly matches the character data is selected, and for numerical data such as weight, torque, flex, three-point stiffness, flex coefficient, C / B value, T / C value, and frequency, (i) a method in which the difference between each characteristic data of the first shaft and each characteristic data of the second shaft is calculated, and the club ID data of the second golf club having the second shaft with the smallest difference is selected, or (ii) a method in which a matching range is set for each characteristic data, the matching range is applied to the characteristic data of the first shaft, and the club ID data of the second golf club having a second shaft that falls within the matching range is selected (if multiple second shafts are selected at the beginning of matching, the matching range is gradually narrowed until one second shaft is finally selected). In addition, when both character data and numerical data are the subject of approximate matching, the character data may be set to a perfect match, and the approximate matching method of (i) or (ii) above may be adopted for the numerical data. In the latter approximate matching method (ii), priorities may be set for the characteristic data, and matching may be performed in stages based on the priorities.Additionally, the match rate with respect to the first shaft and the like may be displayed on the display 123 together with the club ID data of the second golf club.

[0064] The flex selection module has a selection table that associates the flex data of the second shaft with the moving speed of the second head, and when the moving speed of the second head is determined in the swing / trajectory analysis application 114c, the flex selection module compares the moving speed of the second head with the above-mentioned selection table, outputs the flex data of the second shaft, and displays it on the display 123. This display enables the fitter or the like to specify a plurality of second golf clubs with the same flex that should be handed over to the hitter next.

[0065] When the required amount of second head trajectory data has been accumulated in the hitter-specific head trajectory information management table TB1 (for example, when a fitter or the like presses a button etc. after being convinced that all or a sufficient amount of the second head trajectory data has been collected), the second selection module compares each piece of trajectory data of the second head with the initially set ideal data, selects the club ID data of the second golf club having the second head having trajectory data that is closest to the ideal data, and displays it on the display 123. Examples of the approximate matching method include (i) calculating the difference between each trajectory data of the second head and the ideal data, and selecting the club ID data of the second golf club having the second head with the smallest difference, (ii) setting a matching range for the ideal data and selecting the club ID data of the second golf club having trajectory data that falls within the matching range (if multiple second golf clubs are selected at the beginning of matching, the matching range is gradually narrowed to finally select one second golf club), and (iii) if the trajectory data can be displayed as a line on a coordinate system, selecting the club ID data of the second golf club having trajectory data that is most linearly close to the ideal data among the trajectory data. In the approximate matching method of (ii), a priority order may be set for each of different types of trajectory data, and matching may be performed stepwise based on the priority order. In addition, the matching rate with respect to the ideal data may be displayed on the display 123 together with the club ID data of the second golf club.

[0066] The shaft specification determination module outputs the specifications of the shaft to be manufactured, that is, the flex, torque, three-point stiffness, weight, shape (shape of the grip side) and center of gravity position, from the tracking data of the behavior of the second shaft of the 22 golf club acquired by the motion capture application 114d and the characteristic data of the 22 golf club. Specifically, as described above, if the timing when the second shaft reaches its maximum speed is before the impact point, a positive flex correction value according to the difference is added to the flex of the second shaft of the 22 golf club to make it the flex of the shaft to be manufactured, if the timing when the second shaft reaches its maximum speed is the impact point, the flex of the second shaft of the 22 golf club is used as it is as the flex of the shaft to be manufactured, and if the timing when the second shaft reaches its maximum speed is after the impact point, a negative flex correction value according to the difference is added to the flex of the second shaft of the 22 golf club to make it the flex of the shaft to be manufactured. Also, when the tracking data matches a pattern indicating a body turn type swing, a positive torque correction value according to the degree of match is added to the torque of the second shaft of the 22nd golf club to set it as the torque of the shaft to be manufactured, and when the tracking data matches a pattern indicating a wrist turn type swing, a negative torque correction value according to the degree of match is added to the torque of the second shaft of the 22nd golf club to set it as the torque of the shaft to be manufactured. Also, when the tracking data matches a pattern indicating a body turn type swing, text data is output to the effect that the shape of the grip side (butt side) of the shaft should be tapered, and when the tracking data matches a pattern indicating a wrist turn type swing, text data is output to the effect that the shape of the grip side (butt side) of the shaft should be straight.

[0067] Incidentally, when the shaft specification determination module outputs the specifications of the shaft to be manufactured, that is, the data on flex, torque, three-point rigidity, weight, shape (shape on the grip side) and center of gravity position, the user of the first computer 110 transmits the output to the second computer 150. Note that when the shaft specification determination module outputs the specifications of the shaft to be manufactured, that is, the data on flex, torque, three-point rigidity, weight, shape (shape on the grip side) and center of gravity position, the output may be automatically transmitted to the second computer 150.

[0068] (1-5) Interface The auxiliary memory interface 115 connects the auxiliary memory 114 to the connection unit 112. The input interface 116 is an interface such as PS / 2, USB, IEEE1212, RS232, or IrDA (Infrared Data Association), and connects an input device 22 such as a keyboard or a mouse for inputting data to the main memory 113. The display interface 117 is an interface such as AGP (Accelerated Graphics Port), PCI (Peripheral Component Interconnect), or RS232, and connects a display 123 such as a CRT display, a liquid crystal display, or a plasma display for displaying data transmitted from the main memory 113 as characters or images. The communication interface 118 connects a communication device 124 for communication connection to the communication network NT.

[0069] (2) Swing and trajectory analysis using the swing and trajectory analysis application The swing / trajectory analysis application 114c processes various measurement signals and measurement data transmitted from the swing / trajectory measurement device 130, outputs data on the moving speed of the golf club head (i.e., head speed), data on the trajectory of the head (e.g., club path data, attack angle data, launch angle data, etc.), data on the moving speed of the hit golf ball, spin amount data, spin axis data, trajectory data of the golf ball, etc., and displays these data graphically on the display 123. In addition, this swing / trajectory analysis application 114c registers the head trajectory data for each of a plurality of second golf clubs in a batter-specific head trajectory information management table TB1 of the first database DB.

[0070] (3) Identifying shaft behavior using a motion capture application As described above, the motion capture application 114d analyzes the image data transmitted from the high-speed camera 140, outputs data on the movement of the motion capture sensor in the image data, and graphically displays it on the display 123 (see FIG. 7). The motion capture application 114d also analyzes the data and displays a graph of the movement speed of the motion capture sensor against time on the display 123 (see FIG. 8).

[0071] 2. Swing and Trajectory Measurement Device 130 The swing and trajectory measuring device 130 corresponds to the head speed measuring device and head trajectory tracking device described above, and is used to measure the moving speed of the head of the golf club (i.e., head speed) when the batter hits a golf ball with the golf club, to identify the trajectory of the head (e.g., club path, attack angle, launch angle, etc.), to measure the moving speed, spin amount, and spin axis of the hit golf ball, and to identify the trajectory of the golf ball. Examples of such swing and trajectory measuring devices 130 include products from Trackman, Flight Scope, and Skytrack.

[0072] The swing / trajectory measuring device 130 is usually placed behind the batter, i.e., on the opposite side to the direction in which the golf ball is hit. As described above, the swing / trajectory measuring device 130 is communicatively connected to the first computer 110 via the communication line CB, and transmits a measurement signal and the measurement data thereof to the first computer 110 for each measurement.

[0073] 3. High-speed camera The high-speed camera 140, also called a high-speed camera, is usually placed above, behind (i.e., the side opposite to the direction in which the golf ball is hit) and to the side (the side where the golf ball is when the batter addresses the ball) of the batter, and transmits image data to the second computer 150 for each image capture. Note that the still image data and video data transmitted from the high-speed camera are analyzed by the motion capture application 114d installed in the first computer 110, as described above. As described above, in order to analyze the movement of an object by the motion capture application 114d, it is necessary to attach a motion capture sensor to the object.

[0074] 4. Second Computer The second computer 150 is a computer similar to the first computer 110, and as described above, is communicatively connected to the first computer 110 via the communication network NT. The second computer 150 is identical to the first computer 110, except that a second database application (not shown) and a manufacturing specification derivation application (not shown) are installed in place of the swing / trajectory analysis application 114c, the motion capture application 114d, and the first database application 114e.

[0075] The second database application mainly includes a second data collation module (not shown) and a second database (not shown). In the second database, a manufacturing history table TB2 is mainly created.

[0076] As shown in FIG. 6, the manufacturing history table TB2 stores the manufacturing specification data of the second shaft and the manufactured shaft, and the data on the flex, torque, three-point rigidity, weight, shape and center of gravity position of the same shaft, in association with each other on a row basis.

[0077] The manufacturing specification derivation application approximates the specifications of the shaft to be manufactured output by the shaft specification determination module of the first computer 110, i.e., data on flex, torque, three-point rigidity, weight, shape (shape of the grip side) and center of gravity position, against the manufacturing history table TB2 via a second data matching module, selects a second shaft or an already manufactured shaft having specification data that is closest to the specification data of the shaft to be manufactured, and displays the manufacturing specification data on the display. In this case, examples of the approximate matching method include a method in which, for character data such as flex, the character data and character data before and after the character data are set in advance, and a second shaft or a manufactured shaft that perfectly matches the character data is selected, and for numerical data such as weight, torque, flex, three-point stiffness, flex coefficient, C / B value, T / C value, and frequency, (i) a method in which the difference between each specification data of the shaft to be manufactured and each specification data of the second shaft and the manufactured shaft are calculated, and a second shaft and a manufactured shaft with the smallest difference are selected, or (ii) a method in which a matching range is set for each specification data of the shaft to be manufactured, the matching range is applied to each specification data of the shaft to be manufactured, and a second shaft or a manufactured shaft that falls within the matching range is selected (if multiple second shafts or manufactured shafts are selected at the beginning of matching, the matching range is gradually narrowed until one second shaft or a manufactured shaft is finally selected). In addition, when both character data and numerical data are the subject of approximate matching, the character data may be set as a perfect match, and the above-mentioned approximate matching method (i) or (ii) may be adopted for the numerical data. In the latter approximate matching method (ii), a priority order may be set for the specification data, and matching may be performed stepwise based on the priority order. Also, the matching rate with respect to the to-be-manufactured shaft may be displayed on a display together with the manufacturing specification data of the second shaft or the manufactured shaft.

[0078] The manufacturing specification determiner checks the manufacturing specification data displayed on the display, and then corrects the manufacturing specification data based on the experience or rule to determine the manufacturing specifications of the shaft to be manufactured. If there is a technical general rule or rule of thumb that fills in the difference between the specification items of the shaft to be manufactured and the specification items of the second shaft or the shaft that has already been manufactured, the manufacturing specification data of the shaft to be manufactured can be automatically output from the specification data of the shaft to be manufactured by incorporating the general rule or rule of thumb into the manufacturing specification derivation application.

[0079] Incidentally, the flex (e.g., three-point stiffness) and flex mainly depend on the number of laminated prepregs, the elastic modulus of the fibers in the prepregs, and the like, while the torque mainly depends on the number of laminated prepregs, the elastic modulus of the fibers in the prepregs, and the orientation angle of the fibers between the prepregs (i.e., the flex (e.g., three-point stiffness) and flex can be adjusted by changing the elastic modulus of the fibers in the second shaft or the manufactured shaft, while the torque can be adjusted by changing at least one of the elastic modulus of the fibers and the orientation angle of the fibers in the second shaft or the manufactured shaft). For this reason, in the above-mentioned approximate comparison, the flex (e.g., three-point stiffness) and flex, and the torque may be compared separately, and different manufacturing specification data of the second shaft or the manufactured shaft may be selected for the above-mentioned two types of shaft specifications. However, even in such a case, since the mass of the shaft must be the same, it is preferable that in the above-mentioned approximate comparison, the "mass, flex (e.g., three-point stiffness), and flex of the shaft to be manufactured" and the "mass and torque of the shaft to be manufactured" are compared separately, and manufacturing specification data of the second shaft or the manufactured shaft having the same mass are selected. It is preferable to incorporate this general rule into a manufacturing specification derivation application so that the manufacturing specification data of the shaft to be manufactured is automatically output from the specification data of the shaft to be manufactured.

[0080] <Features of the system according to the above example> In the system 100 according to the above example, the specifications of a golf shaft (a shaft to be manufactured) that is thought to suit each individual golf player can be semi-automatically determined through the above-mentioned steps, and then the manufacturing specification data of the golf shaft can be derived from the specification data (i.e., characteristic data) of the golf shaft. Therefore, by using this manufacturing method, a golf shaft that is thought to suit each individual golf player can be efficiently manufactured without spending a lot of time and effort on test shots, etc., and without excessive trial and error in manufacturing the golf shaft.

[0081] <Modification> (A) In the system 100 according to the previous example, the first computer 110 and the second computer 150 are provided, but if a measurement room is provided at the manufacturing site, the second database application of the second computer 150 may be integrated into the first database application 114e and the second computer 150 may be removed. That is, in this system 100, a series of processes according to the previous example can be performed by a single computer.

[0082] (B) In the system 100 according to the previous example, the manufacturing history table TB2 of the second computer 150 stored the manufacturing specification data of the second shaft and the manufactured shaft, and the data of the flex, torque, three-point stiffness, weight, shape and center of gravity position of the shaft in association with each other on a row basis, but the manufacturing specification data of only the manufactured shaft, and the data of the flex, torque, three-point stiffness, weight, shape and center of gravity position of the shaft in association with each other on a row basis may also be stored. [Industrial Applicability]

[0083] The manufacturing method of the custom-made golf shaft according to the present invention has the characteristic of being able to efficiently provide golf shafts that are thought to suit individual golf players without spending a lot of time and effort on test hits, etc., and can contribute to the development of the golf club industry.

Claims

1. a characteristic identifying step of identifying a characteristic of a first shaft of a first golf club having the first shaft; a first selection step of selecting a second golf club having a second shaft having characteristics most similar to those of the first shaft from a plurality of second golf clubs having second heads and second shafts having characteristics different from each other; a HS measurement step of measuring a moving speed of the second head when hitting a golf ball with the second golf club selected in the first selection step; a tentative flex determination step of tentatively determining a flex of a shaft to be manufactured based on the moving speed of the second head measured in the HS measurement step; a head trajectory determining step of determining a trajectory of each of a plurality of second golf clubs (hereinafter referred to as "21st golf clubs") having a flex corresponding to the flex provisionally determined in the flex provisionally determining step, when the golf ball is hit with each of the 21st golf clubs; a second selection step of selecting one 21st golf club (hereinafter referred to as a "22nd golf club") from the plurality of 21st golf clubs based on the trajectory of the second head identified in the head trajectory identification step; a shaft behavior specification step of specifying a behavior of the second shaft of the second golf club when the second golf club hits a golf ball; a first determination step of determining flex, torque, three-point stiffness, weight, shape and center of gravity of the shaft to be manufactured based on the behavior of the second shaft of the second golf club specified in the shaft behavior specifying step and characteristic information of the second golf club; a manufacturing process for manufacturing the shaft to be manufactured using information on the flex, torque, three-point stiffness, weight, shape, and center of gravity of the shaft to be manufactured determined in the first determination process; A method for manufacturing a custom-made golf shaft comprising:

2. an input step of inputting information on the characteristics of the first golf club identified in the characteristic identification step into a computer, In the first selection step, information on the characteristics of the first shaft is approximated against a first database that stores information on the characteristics of the second shaft in association with identification information of the second shaft, and identification information of a second golf club having a second shaft having characteristics most approximate to those of the first shaft is output. A method for manufacturing a custom-made golf shaft according to claim 1.

3. In the HS measurement step, information on the moving speed of the second head is stored in a storage device, In the tentative flex determination step, the information on the moving speed is collated with a second database that stores information on the range of the moving speed in association with the flex information, and thereby the flex information of the shaft to be manufactured is output. A method for manufacturing a custom-made golf shaft according to claim 1.

4. In the second selection step, the identification information of the 22nd golf club is collated with a third database that stores information on the three-point stiffness of the second shaft in association with the identification information of the second golf club, and the information on the three-point stiffness of the shaft to be manufactured is output. A method for manufacturing a custom-made golf shaft according to claim 1.

5. a third selection step in which information on the flex, torque, three-point stiffness, weight, shape and center of gravity of the shaft to be manufactured is approximately collated against a fourth database in which manufacturing information on the second shaft and a custom-made golf shaft manufactured in the past (hereinafter referred to as a "manufactured golf shaft") is stored in association with information on the flex, torque, three-point stiffness, weight, shape and center of gravity of the second shaft and the manufactured golf shaft, thereby outputting manufacturing information on the second shaft or the manufactured golf shaft as an approximate model shaft of the shaft to be manufactured; a second determination step of determining a manufacturing method for the shaft to be manufactured by using manufacturing information of the second shaft as an approximate model shaft of the shaft to be manufactured or a manufactured golf shaft; Further equipped with In the manufacturing step, the shaft to be manufactured is manufactured based on the method of manufacturing the shaft to be manufactured determined in the second determination step. A method for manufacturing a custom-made golf shaft according to claim 1.

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