JPH10293072A - Impact force measuring apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a measuring apparatus whose position can be changed easily, in which an impact in a hitting operation is not applied directly to a body such as an arm or the like and by which an impact force can be measured precisely. SOLUTION: The measuring apparatus is provided with a target object 2 which is suspended so as to be rockable by a first wire group 3 and a second wire group 4 and with an accelerometer 13 which is attached to the target object 2. Acceleration which is generated at a time when the target object 2 is subjected to an impact is detected by the accelerometer 13, and the impact force of the target object 2 is found on the basis of the detected acceleration and on the basis of the mass of the target object 2. Consequently, since the measuring apparatus adopts a structure in which the target object 2 is suspended, its position such as its height or the like can be changed easily. In addition, since the target object 2 is suspended so as to be rockable, an impact in a hitting operation is not applied directly to a body such as an arm or the like. In addition, the acceleration which is generated at a time when the target object 2 is subjected to the impact is detected by the accelerometer 13, and the impact force of the target object 2 is found. As a result, the impact force can be measured precisely.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an impact force measuring device for measuring an impact in sports such as martial arts.

[0002]

2. Description of the Related Art Conventionally, as an impact force measuring device used in the field of sports science, for example, there is a flat force platform for measuring a landing impact in running. This four platform has a structure in which a plurality of piezoelectric elements using quartz are sandwiched between metal plates, and is fixed to the ground or floor at a landing position in running. In this case, if the four-platform is not fixed properly, the four-platform may shift horizontally or vibrate vertically due to the impact at the time of landing, generating noise and accurately measuring the impact force. Therefore, it is necessary to fix the four platform firmly. It is also important that the ground or floor on which the four-platform is fixed has sufficient strength and does not vibrate.Therefore, it is generally necessary to secure the four-platform on a concrete-paved ground or concrete floor. Has adopted.

[0003]

By the way, when using this four-platform to measure the impact force by the striking technique of martial arts, it is necessary to fix the four-platform vertically in order to suppose an opponent in a standing posture. It is necessary to fix the height so that the height can be changed according to the height of the opponent and the difference in the hitting technique. However, such four platforms have a weight of 10
Because of its heavy weight of Kg or more, it can be firmly fixed to a wall such as concrete, but there is a disadvantage that the height cannot be easily changed. There is also the inconvenience of directly adding to the body such as arms.

An object of the present invention is to make it possible to easily change the position, and to accurately measure an impact force without applying an impact upon impact to a body such as an arm.

[0005]

According to the present invention, there is provided a target object suspended swingably and an acceleration sensor attached to the target object, and the acceleration generated when the target object receives an impact is detected. It is characterized by detecting with an acceleration sensor and obtaining the impact force of the target from the detected acceleration and the mass of the target. Therefore, according to the present invention, since the target is suspended, the position such as the height can be easily changed, and the target is suspended swingably. The impact of the target is not directly applied to the body such as an arm, and the acceleration generated when the target receives the impact is detected by the acceleration sensor to determine the impact of the target. Can be.

In this case, if the acceleration sensor has a structure formed of a piezoelectric element that bends in the horizontal direction, the acceleration generated when the target object receives an impact can be accurately measured. . Further, if the weight of the target is configured to be variable as described in claim 3, it is possible to change the weight of the target according to the difference in the hitting technique, whereby the evaluation of the hitting technique can be further improved. It becomes possible to know more accurately.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an impact force measuring apparatus according to the present invention will be described below with reference to FIGS. 1 is a front view of the impact force measuring device, FIG. 2 is a side view thereof, and FIG. 3 is a top view thereof. This impact force measuring device
A cage 1 such as a cage is provided. The cage 1 is made of a metal pipe such as iron or steel.
It is formed in a substantially cube having a width and a height of 3 m each. A target 2 is suspended in the cage 1 by first and second wire groups 3 and 4. As shown in FIG. 4, the target 2 is a circular plate body 5 such as iron or steel, and a support pipe made of metal such as steel provided on the back surface (the right side surface in the figure) of the plate body 5. (Support member) 6, a plurality of weight plates 7 detachably attached to the support pipe 6, and fixing bolts (fixing members) 8 for fixing the plurality of weight plates 7 to the plate body 5.

The plate 5 is, for example, a disk having a diameter of about 15 cm and a thickness of about 0.5 cm. The support pipe 6 has a diameter of, for example, about 5 cm and a length of about 20 cm. It is fixed to the center by welding or the like. The weight plate 7 has a configuration in which a pipe insertion hole 7a through which the support pipe 6 is inserted is provided at a center portion thereof, and a bolt insertion hole 7b through which a fixing bolt 8 is inserted is provided at three locations around the center portion. Has become. The fixing bolts 8 are fixed to three places of the plate body 5 corresponding to the bolt insertion holes 7b of the weight plate 7.
That is, the head 8a of the fixing bolt 8 is embedded in the front surface (the left side surface in the figure) of the plate 5 and the screw portion 8b projects from the back side of the plate 5 in parallel with the support pipe 6. Accordingly, the fixing bolt 8 has a tip portion of the screw portion 8b protruding through each of the bolt insertion holes 7b of the plurality of weight plates 7, and a nut 9 is attached to the inserted tip portion.
Thus, the plurality of weight plates 7 are fixed to the plate body 5. In addition, an impact buffer 10 is provided on the front surface (the left side surface in the figure) of the plate body 5. A wire fitting 11 is detachably mounted on the rear end of the support pipe 6 by a screw 12.

An acceleration sensor 13 is provided in the support pipe 6 of the target 2. Acceleration sensor 13
As shown in FIG. 5, in a state where two rectangular plate-shaped piezo elements 15 are laid one on top of the other in the center of the cylindrical case 14, the short side at the lower end thereof is attached to the bottom 14 a of the cylindrical case 14. Fix the lead wires on both lower surfaces of the two piezo elements 15
6a and 16b are connected by solders 17a and 17b, and the lead wires 16a and 16b are drawn out of the cylindrical case 14. When acceleration is applied in the thickness direction of the piezo element 15, the acceleration sensor 13 vibrates and bends in the thickness direction of the piezo element 15, and the bending generates a voltage on the surface of the piezo element 15. It is configured to output via the lead wires 16a and 16b. The arrow shown in FIG. 5 indicates the same direction as the arrow shown in FIG. 4, that is, the direction in which the target 2 moves by receiving an impact, and this direction has the highest sensitivity of the acceleration sensor 13. Direction.

On the other hand, the first and second wire groups 3 and 4 for suspending the target 2 can be moved in the front-rear direction while the front surface of the plate 5 of the target 2, that is, the surface receiving the impact is substantially vertical. The object 2 is stretched around a cage 1 for suspending the object 2 so as to prevent the object 2 from rotating by receiving an impact. That is, as shown in FIGS. 1 to 3, the first wire group 3 includes two front wires 20 and 21 each having one end attached to the left and right ends of the plate 5 of the target 2.
Consists of In this case, one of the front wires 20 is
The other end is provided on the far side in the cage 1 via an upper pulley 22 provided in the upper left corner in the cage 1 and a lower pulley 23 provided substantially in the middle of the lower rear side in the cage 1. It is attached to a winding device (winding means) 24. Further, the other front wire 21 has the other end, the upper pulley 25 provided at the upper right corner in the cage 1 and the lower pulley 2 provided substantially at the middle of the lower rear side in the cage 1.
6, a winding device 2 provided on the back side in the cage 1
4 attached. Therefore, the front wire 2
Numerals 0 and 21 suspend the target 2 at an angle of about 45 ° from obliquely above.

As shown in FIGS. 1 to 3, the second wire group 4 includes two rear wires 27 and 28 each having one end attached to a wire fitting 11 at the rear end of the target 2. Consists of In this case, one rear wire 27 is connected to the upper pulley 2 provided at the other end at the upper left corner in the cage 1.
9, and via a lower pulley 23, is windably attached to a winding device 24. Also, the other rear wire 2
The other end 8 is rotatably attached to the winding device 24 via an upper pulley 30 and a lower pulley 26 provided at the upper right corner in the cage 1. Therefore, the rear wires 27 and 28 also hang the target 2 obliquely from above at an angle of about 45 °.

As shown in FIGS. 1 and 2, the winding device 24 is provided with a winch 31 suspended substantially in the middle of the upper part on the rear side in the cage 1, and a winch 31 wound around the winch 31.
And four turnbuckles 32 to 35 attached to the wires 31a to 31d.
Wires 20, 21, 27, 28 of the first and second wire groups 3, 4 are attached to the other ends of the wires 2 to 35, respectively. When the winder 31 is manually turned to wind up each of the wires 31a to 31d, the target 2 moves upward, and the winch 3 is turned in the opposite direction to rotate the respective wires 31a to 31d.
When the target 31 is extended, the target 2 moves downward. In this case, the height adjustment range of the target 2 by the winch 31 is set in the range of 50 cm to 200 cm. In addition, four turnbuckles 32-35
By turning these appropriately, the length of the first wire group 3 and the length of the second wire group 4 are adjusted respectively,
Is configured to adjust the horizontal balance.

In such an impact force measuring device, when a striking force is applied to the target 2 from the front, the target 2
Is generated in the acceleration sensor 13 according to the acceleration.
By bending the piezo element 15 and outputting an electric signal in accordance with the bending, the acceleration sensor 13 detects the acceleration, and the impact force can be obtained from the acceleration and the mass of the target 2. That is, the force F acting on the target 2
Is known as a physical law of F = ma. When the mass m of the target 2 is constant, the product of the acceleration a generated in the target 2 and the mass m of the target 2 is By corresponding to the impact force, the impact force can be calculated.

That is, in this impact force measuring device, the target 2 is suspended by taking out a specific force, that is, a force acting in the horizontal direction, from among various forces acting on the target 2. Other forces acting on the target 2 can be eliminated, the static force acting horizontally on the target 2 can be reduced to almost zero, and in a dynamic situation where a force acts on the target 2, Since the target 2 is suspended by the first and second wire groups 3 and 4 in order to set the inertia resistance of the target 2 itself, the resistance of the mounting portion of the target 2 is suppressed as small as possible. As a result, the impact force can be more accurately determined, and the impact at the time of the impact is not directly applied to the body such as the arm, so that the body can be prevented from being damaged.

Also, in this impact force measuring device, when the suspended target 2 vibrates by receiving a striking force, the tension in the wire and the gravitational force applied to the target 2 increase the amplitude in the horizontal direction. In order to prevent the force from gradually increasing, the length L of suspension of the target 2 by the first and second wire groups 3 and 4 (the length from the substantially upper surface of the cage 1 to the target 2) L is made as long as possible. be able to. That is, the suspension length L is determined by the action time of the impact force when the target 2 is actually hit and the angle at which the target 2 vibrates during the action time, For example, in the case of a hit with an arm fist, the duration of the impact is about 10 msec, and the angle at which the target 2 vibrates during this time is such that the suspension length L of the first and second wire groups 3 and 4 is 100 cm. If so, it can be considered almost zero.

Accordingly, in this impact force measuring apparatus, when a partner with a height of 200 cm is assumed, the height of the cage 1 is 3 m, and the target 2 has a height corresponding to the head of the partner.
Of the first and second wire groups 3 and 4 for positioning the target object 100 can be secured 100 cm, whereby the target 2 can be accurately measured at a height in the range of 50 cm to 200 cm. it can. In this case, since the target object 2 is suspended by the first and second wire groups 3 and 4, the winch 31 of the winding device 24 is manually turned to wind up or unwind the wires 31a to 31d. It is very easy to change the height of the target 2 from 50 cm to 20 cm.
The horizontal balance of the target 2 can be adjusted extremely easily by adjusting the four turn buckles 32 to 35 as appropriate and adjusting the four turn buckles 32 to 35 appropriately.

Further, in this impact force measuring device, when the suspended target 2 receives a striking force, there is a problem when the center of the front surface of the target 2, that is, the center corresponding to the center of gravity, receives the striking force. No, but when off the center, target 2
At this time, the target object 2 is moved from the first and second wire groups 3, 4 to the respective wires 20, 21, 27,
28, it is suspended obliquely from above at an angle of about 45 °, so that it is possible to minimize the left-right vibration that is about to rotate, and therefore, the center corresponding to the center of gravity on the front side of the target 2 Even if the player hits a position outside the part, the hitting force can be measured almost exactly.

Further, in this impact force measuring device, the weight of the target 2 can be easily changed by appropriately replacing the weight plate 7 of the target 2, thereby making the evaluation of the impact technique more accurate. You can know. That is, the evaluation technique of the batting technique in martial arts such as karate differs depending on the target area to be hit. This varies depending on the magnitude of the mass of the hit site (that is, the difference in the mass of the head, trunk, limbs, etc.), the buffer structure on the surface of the hit site, and the like. Assuming a specific impact target, after reproducing a state close to the mass of the impact target site and the buffer characteristics of the surface, by applying an impact to this and examining the reaction, accurate evaluation close to the actual case can be accurately performed Can be measured. In addition, as for the buffer characteristics of the front surface, the buffer member 10 provided on the front surface of the target 2 may use a material close to the buffer characteristics of the target portion.

[0019]

As described above, according to the present invention, since the target is suspended in a swingable manner, the position such as the height can be easily changed.
Accurately measures the impact force because the impact at the time of impact does not directly apply to the body such as an arm and the acceleration sensor detects the acceleration generated when the impact is applied to the target object and calculates the impact force of the target object can do.

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of an impact force measuring device according to the present invention.

FIG. 2 is a side view of FIG. 1;

FIG. 3 is a top view of FIG. 1;

FIG. 4 is an enlarged sectional view of the target shown in FIG. 2;

FIG. 5 is a diagram showing an internal structure of the acceleration sensor of FIG.

[Explanation of symbols]

 Reference Signs List 1 cage 2 target 3 first wire group 4 second wire group 5 plate 6 support pipe 7 weight plate 8 solid bolt 13 acceleration sensor 15 piezo element 20, 21 front wire 22, 25, 29, 30 upper pulley 23, 26 Lower pulley 24 Winding device 27, 28 Rear wire

Claims (6)

[Claims] A target object suspended swingably and an acceleration sensor attached to the target object, wherein an acceleration generated when the target object receives an impact is detected by the acceleration sensor; An impact force measuring device, wherein an impact force of the target is obtained from the detected acceleration and a mass of the target. 2. An impact force measuring apparatus according to claim 1, wherein said acceleration sensor is formed of a piezoelectric element which is bent in a horizontal direction. 3. The impact force measuring apparatus according to claim 1, wherein the target has a variable weight. 4. The target object includes a substantially circular plate, a support member provided on a back surface of the plate, a plurality of weight plates detachably mounted on the support member, and the plurality of weight plates. The impact force measuring device according to any one of claims 1 to 3, further comprising: a fixing member for fixing the plate member to at least one of the plate member and the support member. 5. The target object receives an impact by a first wire group having one end attached to a front portion of the target object and a second wire group having one end attached to a rear portion of the target object. The impact force measuring device according to any one of claims 1 to 4, wherein the receiving surface is suspended in a substantially vertical state. 6. The first wire group comprises two wires each having one end attached to the left and right end of the front part of the target, respectively, and the other end of each of the two wires is connected to the first wire group. A winding provided on the rear side of the cage via two front upper pulleys provided at each of the left and right upper portions in the cage and two lower pulleys provided substantially at the middle of the rear lower portion of the cage. The second wire group is composed of two wires each having one end attached to a rear portion of the target object.
Each other end of the book wire is removably attached to the winding means via two rear upper pulleys and two lower pulleys respectively provided at left and right upper portions in the cage. The impact force measuring device according to claim 5, wherein the impact force is measured.