JP3295912B2 - Swing torque measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring a swing torque of a hitting tool, for example, a golf club, a baseball bat, a tennis racket and the like. Here, the swing torque is a torque applied to the hitting tool by the player at the time of a swing, and means a torque that generates a bending moment in the hitting tool.

[0002]

2. Description of the Related Art In sports using a hitting tool such as a golf club, a baseball bat, and a tennis racket, the magnitude of a swing torque applied to the hitting tool by a player during a swing and its temporal change characteristic vary depending on each player. Even the same player differs depending on the physical condition and the like. Further, the temporal change characteristic of the swing torque is closely related to the natural vibration, the moment of inertia, and the like of the hitting tool. Therefore, examining the swing torque is very important in improving the skill of the player or in developing a hitting tool suitable for each player.

Conventionally, methods for measuring the swing torque of a hitting tool include: (1) a method based on the analysis of a video image of a swing, and (2) the motion acceleration of the hitting tool measured by an accelerometer attached to the hitting tool. A method of calculating a swing torque from a motion acceleration, and (3) a method of calculating a swing torque from a bending deformation amount of the entire impact tool detected by a strain gauge attached to the impact tool have been proposed.

[0004]

In the method of calculating the swing torque by analyzing the video image, the swing torque is calculated from the position of the hitting tool on the screen and the moment of inertia of the hitting tool. Since it largely depends on accuracy and requires complicated arithmetic processing, an expensive and large-scale device is required.

[0005] In addition, a complicated calculation process is required in the method of calculating the swing torque from the measured values of the motion acceleration and the amount of bending deformation of the hitting tool. Furthermore, in the method of measuring the motion acceleration of the hitting tool, the accelerometer is positioned at the center of gravity of the hitting tool,
In addition, in the method of measuring the amount of bending deformation, it is necessary to attach a plurality of strain gauges to each location in the length direction of the impact tool, so long or complicated wiring from the grip end to the accelerometer and strain gauge is required. And wiring is troublesome.
In addition, since these long wires affect the moment of inertia of the hitting tool, the characteristics of the practice hitting tool used for the measurement are significantly different from those of the hitting tool used in actual play, and the swing torque measurement value It may cause a decrease in usefulness.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a swing torque measuring device capable of easily and beneficially examining a magnitude of a swing torque applied to a hitting tool by a player during a swing and a temporal change characteristic thereof. .

[0007]

Means for Solving the Problems To achieve the above object, the present invention provides: (1) a base member fixedly connected to an end of a shaft with a screw or the like, and an outer peripheral surface of the base member. A hitting tool including a grip having a movable piece that fits in a recess and a cylindrical rubber grip attached to the outer periphery of the base body and the movable piece, and is provided on the grip and joins the grip during swing. A swing torque comprising: a load sensor for detecting a load; and a signal processing device for calculating a swing torque applied to the hitting tool by the player based on the load detection value of the load sensor and a predetermined multiplier, and displaying a temporal change thereof. Measuring device, (2) Recesses are formed symmetrically on both sides of a base body connected and fixed to the end of the shaft with screws or the like, and movable pieces are provided in both recesses via load sensors. And a signal processing device for calculating a swing torque applied to the hitting tool by the player based on a load detection value of the load sensor and a predetermined multiplier, and displaying a temporal change thereof. (3) a hitting tool including a base body connected and fixed to an end of the shaft with a screw or the like, and a grip portion having four movable pieces disposed on the base body via load sensors, respectively; And a signal processor for calculating a swing torque applied to the hitting tool by the player based on a load detection value of the load sensor and a predetermined multiplier, and displaying a temporal change thereof, wherein the load sensor has a central axis of the grip portion. X orthogonal to
The present invention provides a swing torque measuring device characterized by being arranged in the Y2 axis direction. In the invention of (1), the load sensor has a bending portion having a bending portion extending in the length direction of the base body. The bending portion has a leg at both ends of the bending portion, a bottom portion having a bottom surface in contact with the bottom surface of the concave portion, and a projection portion in contact with the movable piece at the center portion of the bending portion. It is suitable.

[0008]

In the swing torque measuring device having the above construction, the load sensor of the hitting tool outputs the load applied to the grip portion of the hitting tool. Therefore, the signal processing device simply multiplies the detected load value by a predetermined multiplier. The swing torque can be calculated immediately. Therefore, the apparatus becomes a very simple apparatus, and the magnitude of the swing torque and its temporal change characteristic can be examined with an inexpensive apparatus. Also,
Since the load sensor of the impact tool is provided on the grip of the impact tool, the wiring to the load sensor can be shortened, the wiring to the load sensor is simplified, and the impact on the moment of inertia of the impact tool etc. Can be kept small. Therefore, a hitting tool having characteristics similar to those of an actual playing hitting tool can be obtained, and a useful swing torque measurement value can be obtained.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 schematically shows an embodiment in which the present invention is applied to a golf club. In FIG. 1, reference numeral 1 denotes a golf club comprising a grip portion 2, a shaft 3, and a head 4. As shown in FIG. 2, the grip portion 2 of the golf club 1 is movable in a concave portion 6a formed on the outer peripheral surface of the base member 6 and fixedly connected to an end of the shaft 3 by a screw 5 or the like. A piece 7 and a cylindrical rubber grip 8 attached to the outer periphery of the base body 6 and the movable piece 7 are provided. Between the bottom surface of the concave portion 6a of the base body 6 and the movable piece 7, three load sensors 9, which will be described later, are arranged at intervals in the length direction.

As shown in FIG. 3 to FIG.
Has a flexure 10 having a flexure 10a extending in the longitudinal direction of the base body 6. At both ends of the flexure 10a of the flexure 10 are formed leg portions 10b whose bottom faces abut the bottom of the recess 6a. A protruding portion 10c that contacts the movable piece 7 is formed at the center of the bending portion 10a. Therefore, the movable piece 7
When a load is applied in the direction indicated by the arrow in FIG. 3, the central portion of the flexible portion 10a is pushed and flexes toward the base body 6. Therefore,
At this time, a compressive strain is generated on the outer side surface (upper surface in FIG. 3) of the bending portion 10a, and a tensile strain is generated on the inner side surface (lower surface in FIG. 3) of the bending portion 10a. Therefore, in this embodiment, the protrusion 10c
, A total of four strain gauges 11 to 14 are attached to the outer surface and the inner surface of the bending portion 10a.

As schematically shown in FIG. 6, the four strain gauges 11 to 14 schematically show a bridge circuit 15 for generating a load detection signal. In the bridge circuit 15, 16 is a bridge power supply, 17 is a variable balance resistor for balancing the bridge circuit, 18, 1
9 is an output terminal. In this embodiment, four strain gauges 11 are used.
14 constitutes a bridge circuit, so that one of the four bridge circuits using one strain gauge and the remaining three fixed resistors.
Double output can be obtained.

Further, in this embodiment, since each of the three load sensors 9 has four strain gauges 11 to 14, they all constitute a bridge circuit 20 shown in FIG. The four connection portions 22 to 2 of the bridge circuit 20
The wires connected to the cable 4 are combined into one cable 25 as shown in FIG. 2 and led out from the end of the grip portion 2 to the outside, and as shown in FIG. As a computer 27. The computer 27 calculates a swing torque by multiplying the output voltage value of the load sensor 9 by a preset multiplier value according to a program stored in the storage unit in advance, and displays a change in the swing torque value with time on the display 27a or the printer. (Not shown).

When the swing torque is measured by the swing torque measuring device having the above configuration, a multiplier value is determined in advance. As a method therefor, using a chuck device (not shown) or the like, the grip portion 2 of the golf club 1 (for example, 20 mm from the grip end).
(0 mm) is held with an appropriate force, and the golf club 1 is horizontally cantilevered. At this time, the output voltage of the load sensor 9 is reset to 0 value. Next, a weight (not shown) having a predetermined weight (for example, 1 kgf) is hung on the head 4 of the golf club 1. When the total length of the golf club 1 is 1.1 m, the length from the grip portion 2 (chuck portion) to the load application point is 0.1 mm.
Because it is 9 m, one cantilevered golf club 1
The reference torque Tr applied by the kgf weight is 0.9 kg
f · m. On the other hand, when the weight is hung on the head 4 of the golf club 1, the load sensor 9 outputs a load applied to the grip portion 2 of the golf club 1. Therefore, the output voltage Er is measured. Er / Tr is a multiplier value. This multiplier value is input to the computer 27.

Next, when the player swings with the grip portion of the golf club 1, a load detection signal is input from the load sensor 9 to the computer 27 via the amplifier 26, and the computer 27 outputs the output of the load sensor 9. By multiplying the voltage value by the multiplier value (Er / Tr), the swing torque can be calculated immediately. Therefore, it becomes a very simple measuring device, and the magnitude of the swing torque and its temporal change characteristic can be examined with an inexpensive device.

Since the load sensor 9 of the golf club 1 is provided on the grip portion 2 of the golf club 1,
The wiring to the load sensor 9 can be shortened, the wiring to the load sensor 9 is simplified, and the golf club 1
Influence on the moment of inertia and the like can be kept small. Therefore, the golf club 1 having characteristics similar to those of an actual play golf club can be obtained, and a useful swing torque measurement value can be obtained.

FIG. 8 shows an example of the actual measurement of the swing torque by the above-mentioned swing torque measuring device. In the figure, t ₁ is at the start of takeback, t ₂ is at the start of downswing, and t ₃ is at the time of ball impact.

The load sensor 9 configured as described above detects a grip force when the player grips the grip portion 2 of the golf club 1, and the detected value becomes an error component with respect to the measured swing torque. Therefore, it is preferable to reset the output of the load sensor 9 to a zero value at the time of addressing by, for example, operating a computer keyboard.

FIGS. 9 and 10 show another embodiment of the present invention. In the embodiment shown in FIG. 9, recesses 6a are formed symmetrically on both sides of a base body 6 so as to be bilaterally concave. Place 6
a is provided with a movable piece 7 via a load sensor 9. In the embodiment of FIG. 10, two sets of load sensors 9 are arranged in XY biaxial directions orthogonal to the central axis of the grip portion 2. Four movable pieces 7 are attached to the base body 6, respectively. It is arranged through. According to the embodiment of FIG. 9, it is possible to obtain a larger load detection output than the embodiment of FIG. Further, according to the embodiment of FIG. 10, the load in the swing direction, and hence the swing torque, can be measured more accurately.

Although the illustrated embodiment has been described above, the present invention is not limited to only the above embodiment.
For example, changes can be made to the number of load sensors 9 disposed between the base body 6 and the movable piece 7, the number of strain gauges used in each bridge circuit of each load sensor 9, the type of load sensor, and the like. Further, the present invention is similarly applicable to various hitting tools such as a baseball bat and a tennis racket in addition to a golf club.

[0021]

As is apparent from the above description, according to the present invention, the swing which allows the player to easily and beneficially examine the magnitude of the swing torque applied to the hitting tool and the temporal change characteristic thereof when swinging. A torque measuring device can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a hitting tool swing torque measuring device when the present invention is applied to a golf club.

FIG. 2 is a sectional view of a grip portion of the golf club of FIG.

FIG. 3 is an enlarged view of a main part of the cross-sectional view shown in FIG. 2;

FIG. 4 is a cross-sectional view of the golf club of FIG. 1 along the line AA in FIG. 2;

FIG. 5 is a perspective view of a load sensor.

FIG. 6 is a bridge circuit block diagram of one load sensor.

FIG. 7 is an overall bridge circuit block diagram of three load sensors.

FIG. 8 is a graph showing an actual measurement example of a swing torque.

FIG. 9 is a sectional view similar to FIG. 4 of a grip portion of a golf club showing another embodiment of the present invention.

FIG. 10 is a sectional view similar to FIG. 4 of a grip portion of a golf club showing still another embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 golf club (hitting tool) 2 grip 6 base body 6a recess 7 movable piece 8 rubber grip 9 load sensor 10 flexure piece 10a flexure 10b leg 10c protrusion 11-14 strain gauge 15,20 bridge circuit 25 cable 26 amplifier 27 Computer (signal processing device)

Claims (4)

(57) [Claims] 1. The shaft is connected and fixed to the end of the shaft with a screw or the like.
Base body and the recess formed on the outer peripheral surface of the base body
The movable piece that fits and the outer periphery of the base body and the movable piece
A grip portion having an attached cylindrical rubber grip
, A load sensor provided on the grip portion for detecting a load applied to the grip portion during a swing, and a swing applied to the hitting device by the player based on a load detection value of the load sensor and a predetermined multiplier. A swing torque measuring device comprising: a signal processing device that calculates torque and displays a temporal change thereof. 2. The load sensor has a flexure having a flexure extending in the longitudinal direction of the base body. At both ends of the flexure of the flexure, there are formed leg portions whose bottom faces abut the bottom of the recess. 2. The swing torque measuring device according to claim 1, wherein a protruding portion that contacts the movable piece is formed at a central portion of the bending portion. 3. The shaft is connected and fixed to the end of the shaft with a screw or the like.
Recesses are formed symmetrically on both sides of the base body.
A movable piece is provided in each recess via a load sensor.
A swing torque including a hitting tool including a lip portion, and a signal processing device that calculates a swing torque applied to the hitting tool by the player based on a load detection value of the load sensor and a predetermined multiplier, and displays a temporal change thereof. measuring device. 4. The shaft is connected and fixed to the end of the shaft with a screw or the like.
And the load sensor for the base body
Grip with four movable pieces arranged via
And a signal processing device that calculates a swing torque applied to the hitting tool by the player based on a load detection value of the load sensor and a predetermined multiplier, and displays a time change thereof, and the load sensor includes a grip. Orthogonal to the central axis of the part
The swing torque measuring device is arranged in two XY directions .