JPS63250543A - Balance meter - Google Patents

Abstract

PURPOSE:To facilitate measuring operation by holding the grip of a swing instrument rotatably in a vertical plane, and forming a rotary vibration system of the swing instrument and an elastic member which is fixed to the grip at one end and to a fixed part at the other end. CONSTITUTION:The grip 12 of, for example, a golf club is clamped while its torque center is aligned with the center of rotation of a vibrating turntable 14, and the shaft part 14c of the turntable 14 is supported pivotally on a bobbin- shaped cylindrical body 21 fixed to a base 19. A torsion spring 24 is provided between the flange part of the turntable 14 and the flange part of the shaft part 17 of the cylindrical body to form the rotary vibration system on the turntable 14 for a receiving shaft 17. Then moment of inertia is found from the vibration frequency of a vibration indicator when the club is fitted on the turntable 14 to know dynamic balance and the club is fitted to the receiving shaft 17 while the club fitting part is horizontal to know static balance; and the club is dropped and fixed on the base and the head side of the club is vibrated to obtain the elastic vibration frequency of the instrument. Consequently, the dynamic balance, static balance, and elastic vibration frequency are easily found.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to the dynamic balance, static balance, and elastic frequency of instruments used by swinging by hand, such as golf clubs or baseball bats. Regarding a balance meter that measures.

(Prior Art) For instruments that are used by swinging with the hand, such as golf clubs and baseball bats (referred to as swing instruments for convenience in this specification), if you swing and feel that it is heavy or light, it is simply a swing instrument. In addition to the fact that the weight itself is heavy or light, there are other important factors.

The prior art will be explained below using a golf club as an example. Conventionally, important elements of the golf club have been determined using a balance meter as shown in FIG. This measures the moment of weight, and the response of the swing is determined by the magnitude of the moment of weight.

FIG. 6 is a schematic diagram for explaining the principle of measuring the moment of weight of a golf club, in which the length between the grip end 2 of the golf club 1 and the center of gravity 4 of the head 3 is The weight of Wl.

A weight 5 is suspended from the grip end 2, its weight is W, and the length from the grip end 2 to the fulcrum 6 (this fulcrum can be roughly considered to be at or near the front end of the grip of both hands of the user) is r. If the balance is maintained by supporting the fulcrum 6, then Wr=CQ-r)W), +/:(x-r)dm holds true, where dm is the unit length of the point at distance X from the grip end 2. It is the weight of the shaft of , and it changes depending on X. Generally, the shaft of a golf club is tapered from the grip end side to the head side. Conventionally, even if the club changes, if the above-mentioned Wr is constant, the response will be constant, and one set is made up of clubs with the same (or close) Wr.

(Problem to be solved by the invention) However, since swing equipment swings dynamically, it is necessary to consider the dynamic balance, and static balance alone does not satisfy the feeling when actually swinging. Can not do it.

(Means for Solving the Problems) The present invention provides at least a means for rotatably holding a grip of a swing instrument so that the swing instrument can swing in a vertical plane, one end of which is fixed to the grip, and the other end of which is fixed to the grip. and an elastic member which is fixed to the fixed part and forms a rotational vibration meter together with the swing instrument.

A rotation system consisting of a base, a hollow cylindrical base fixed to the base, a cylindrical shaft part that is rotatably fitted concentrically into the hollow part of the cylindrical base, and a flange part perpendicular to the cylindrical shaft part. "S"
A bearing shaft, and a member that fixes the rotary bearing shaft to a cylindrical base and releases it to enable rotation.

A vibrating rotary table consisting of a shaft part that rotatably fits concentrically into the cylindrical shaft part of the rotary bearing shaft, and a flange part perpendicular to this shaft part, and both ends of which are fixed to the rotary bearing shaft and the vibrating rotary table, respectively. is,
An elastic body that forms a rotating vibration system with respect to the rotary bearing shaft together with the vibrating rotary table.

A member that directly or indirectly fixes the vibration rotating table to the base.

A member for removably fixing a swing instrument to the vibrating rotary table; and a pointer fixed to the vibrating rotary table and swinging with the rotation of the vibrating rotary table.

It consists of a vibration meter installed near the swing path of the pointer.

(Function) At least, it is possible to measure the dynamic balance from the vibration frequency or vibration period by vibrating the swing device from a horizontal state. Set the vibrating rotary table so that it is held horizontally, rotate and vibrate the swing device together with the vibrating rotary table, measure the moment of inertia of the swing device from the frequency or period of vibration, and then find out the dynamic balance. , the vibration rotation table is set so that the swing apparatus is held horizontally with no moment applied to it, and then the rotation of the vibration rotation table when a moment of the weight of the swing apparatus is applied. Measure the moment of the weight of the swing equipment from the corner to find out the static balance, rotate the vibration rotary table so that the swing equipment hangs vertically, fix it to the base, vibrate the swing equipment, and adjust the swing equipment. You can know the elastic frequency of.

(Example) Examples will be described below using a golf club as an example.

FIG. 3 is an explanatory diagram of the M principle of balance measurement according to the present invention,
Specifically, it is a relationship diagram of the force applied to the golf club during the swing of the golf club.

When a right-handed person swings the club 1, for example, a force F is applied in the direction of the arrow φ about the center 7 at a distance xt from the grip end 2, but F is applied in the direction of the arrow 0, and the head 3 is rotated by the arrow S. try to move in the direction of The force F is applied mainly by the left hand, the force F is applied mainly by the right hand, and 7 is the center of the torque created by the forces F and F. This can be considered to be roughly between the grip of the right hand and the grip of the left hand. When force is applied to the grip end as described above, the head 3 is accelerated, and the force F is applied to the head 3 according to the principle of static inertia. occurs in Since force is mass x acceleration, F=-LxQ8i-! r g dt . However, g: acceleration of gravity = 9.8 m/s"
.

Q8: Distance between the center of torque 7 and the center of gravity 4 of the head 3 This is the torque FR, I that F creates around the center of torque 7
is F, 2, =W h x a, d” 0 x
, x = W h n , 2 d ” E1dtgdt Since this is equal to the torque T created by hand, Wb 2d2
0 T=--Q, TIT. WhIIIx' in this formula is the moment of inertia. The fact that the torque T produced by the left and right hands is constant can be considered to mean that the response is constant.

This requires that the moment of inertia 1 to 2Q WhQx2 is constant, and dIT is the resulting value.

Moment WhI2 measured by the balance meter shown in Figure 6
The measurement is performed with club 1 in a static state, and the first
The moments of inertia W, Q Needless to say, it is reasonable.

Since the moment of the club shirt 1 cannot be ignored, the moment of inertia of the entire club 1 must be calculated. Then, Ie=WhQx + / (x x,)”d
m.

Next, an example of a balance meter for measuring the moment of inertia IC of a club will be explained.

(Example 1) As shown in Figure 4, the length from the center of torque 7 to the center of gravity 4 of the head 3! Moment of inertia is lx.

When the club L is fixed with one end of the helical spring 8 at the center of torque 7, the other end of the spring 8 is fixed to a fixed object, and the club is held horizontally, the spring 8 and the club 1 form one vibration system. Form. This vibration equation is IC-! l! -i-! 2! −=
- 1θ-QxWht. θ is the deflection angle of the club shaft that rotates and vibrates around the torque center 7, and 1 is a known spring constant. From the general solution of this equation, the circular frequency p becomes 2・=h IC , and if n is the frequency, then p=2πn and the vibration period T a ” 1 / n, so the frequency n or the vibration period By actually measuring T., the moment of inertia Ic can be determined.

(Example 2) As shown in Fig. 5, the center of torque 7 is set as the fulcrum, and r from the fulcrum. If the club is suspended from the curved point using an elastic spring 9 (with a spring constant) and the club is held horizontally, a vibration system is created. This vibration equation is 1 cg=-k20 r,
X r, -Q, W.

dt, and as in the previous example, p2=, , 2/IC. Also, as in the previous example, p = 2πn and the vibration period T0 = 17n, so the vibration frequency is n or the vibration period is 1゛. By actually measuring, the moment of inertia IC can be obtained.

(Example 3) Furthermore, the balance meter of the present invention, which can also measure static balance and elastic frequency, will be explained first.

FIG. 1(a) is a front view of a balance meter according to an embodiment of the present invention, FIG. 1(b) is a side view of the balance meter seen from the right side of FIG. 1(a), and FIG. ) and (b) are enlarged views of the main parts of Fig. 1 (a) and (b), respectively, and (b) is (a).
) is a sectional view taken along line X-X of FIG. In the figure, reference numeral 11 denotes a golf club, and the front lower protrusion 14a of the vibrating rotary table 14 is arranged so that the center of torque 13 of the grip 12 coincides with the rotation center of the vibrating rotary table 14 that holds the grip 12;
14a, and an upper protrusion 14b.

It is clamped by a stopper 16.16 that moves up and down by a common stopper bolt 15.15 screwed into the stopper 14b. The shaft portion 14c of the vibration rotary table 14 is rotatably supported by a rotary bearing shaft 17 via a bearing 18, and the cylindrical shaft portion 17a of the rotary bearing shaft 17 is a pincushion fixed to the base 19 with bolts 20. A rotary bearing shaft set plate 23 is screwed to the rear end of the shaft portion 17a of the one-rotation bearing shaft 17 rotatably supported on the shaped cylindrical table 21 via a threaded portion 22. 17
When the rotary bearing shaft 17 and the rotary bearing shaft set plate 23 are rotated relative to each other using the handle L7b of the rotary bearing shaft set plate 23 and the handle 23a of the rotary bearing shaft set plate 23, the rotary bearing shaft set plate 23 moves forward and backward in the axial direction of the rotary bearing shaft 17 for one rotation. When the cylindrical base 21 is moved forward, both flanges Ia and 21b of the cylindrical base 21 are pinched between the flange 17c of the rotary bearing shaft 17 and the rotary bearing shaft set plate 23, and the rotary bearing shaft 17 is moved to the cylindrical base 21. Therefore, it can be fixed to the base 19, and can be freely rotated when it is retreated. Vibration rotary table 1
4 flange portion 14d and the flange portion 1 of the rotary bearing shaft 17
A torsion spring 24 is interposed between the torsion spring 24 and the flange 7c, and both ends thereof are fixed to the flange portion t4cl and the flange portion L7c, respectively, and the vibration rotary table 14 forms a rotational vibration system with respect to the rotary bearing shaft 17. A pointer 25 is vertically fixed in the center of the front lower part of the flange portion 14d of the vibration rotary table 14, and a vibration meter 26 is installed across the vibration passing surface of the pointer 25.The vibration meter 26 is a non-contact type. Whether electromagnetic or optical,
In short, it is sufficient that the pointer 25 outputs an output indicating that it has passed each time the pointer 25 passes near the vibration meter 26. Further, an angle meter 27 having an arcuate portion 27a drawn around the central axis of rotation of the vibration rotary table 14 is fixed to the front of the base 19, so that the rotation angle of the club 11 can be measured. 28 is a through bolt hole, which is used only when fixing the vibration rotation shaft.

Next, a method of measuring the inertia moment, static moment, and elastic frequency of a club using this balance meter will be described.

(Measurement of dynamic balance) First, as shown in FIG. 1, the golf club 11 is mounted on the vibration rotary table 14, and the connection between the one-rotation bearing shaft 17, the rotary bearing shaft set plate 23, and the cylindrical table 21 is released, and the rotation bearing axis 1
7 to firmly connect the rotary bearing shaft 17 and the rotary bearing shaft set plate 23 to the cylindrical base 21 at a position where the club 11 is kept horizontal as shown in FIG. 1(a). Then,
When the club 11 is caused to vibrate in a circular motion up and down, the vibration system continues to vibrate in a circular manner as shown by arrow A, and in synchronization with the circular vibration, the pointer 25
passes back and forth between the vibration meters 26, so the frequency or vibration synchronization of the vibration system can be determined.

In this case, the moment of inertia of the vibrating rotary table 14 is ■.

is also added, so the overall moment of inertia I including the club 11 is: I = Q x” W h + / : (x x t
)” d rn + r wa = I c + I m
However, I e'' II, ``W), 10f'(x −
t)" d m.■. is the moment of inertia of the club only.

If the circular frequency measured in this way is P, then p2=3/
I=3/IIe+,) Therefore Ic=(k,/P”
) I+w=ka/p"ka/Pa' However, k3
The constant Pa is the circular frequency when only the vibration rotary table 14 is vibrated circularly as before without the club 11 attached to the vibration rotary table 14, Pa2224/I-1However, k4 is from the constant , which is always constant, only needs to be calculated once.

In short, the moment of inertia of the club 11 can be determined by determining the circular frequency when the club 11 is attached to the vibration rotating table 14. This allows dynamic balance to be measured.

(Measurement of Static Balance) Without attaching the club 11 to the vibrating rotary table 14, the rotary bearing shaft 17 is set so that the club mounting portion of the vibrating rotary table 14 is horizontal. Next, the club 11 is moved to the vibrating rotary table 14.
Attach to. As a result, club 1
1 is θ together with the vibration rotary table 14. only rotates. Therefore, k, 0. =QxWh+/'(x-xt)dm, O
By measuring o, the static balance of the club 11 can be determined.

(Total elastic frequency: 81q) The golf club 11 is attached to the vibration rotary table 14, and rotated 90 degrees in the direction of arrow B, so that the golf club 11 matches the position of the vibration meter 26, that is, hangs vertically. The vibrating rotary table 14 is firmly fixed to the base 19 or a fixed part (not shown) by passing bolts through the bolt holes 28, for example. Since the club 11 has a cantilever shape, the elastic frequency and vibration period of the club 11 can be measured by vibrating the head side of the club 11 and measuring the frequency at that time.

(Effects of the Invention) As described above, 1. According to the device of the present invention, at least the dynamic balance of the swing equipment can be determined, and furthermore, the static balance and the elastic frequency can be determined extremely easily and accurately with one device. can be asked for.

[Brief explanation of the drawing]

Figures 1 (a) and (b) are front and side views of the balance meter of the present invention, and Figures 2 (a) and (b) are Figure 1 (a), respectively.
, (b) is an enlarged view of the main part of (b), (b) is a sectional view taken along the line X-X of (a), FIG. 3 is an explanatory diagram of the principle of measuring the dynamic balance of a golf club using the balance meter of the present invention, and FIG. 5 and 5 are diagrams showing an example of a balance meter of the present invention for measuring the dynamic balance of a golf club, and FIG. 6 is a diagram showing an example of a conventional balance meter. 1... Golf club, 2... Grip end. 3...Head, 4...Center of gravity of the head, 5...
Weight, 6...Fully point, 7...Center of torque, 8
... Helical spring, 9... Telescopic spring, 11...
Golf club, 12...grip, 13...center of torque, 14...vibration rotary table. 14a...lower protrusion, 14b...upper protrusion,
14c... Shaft portion of the vibration rotation shaft, 14d... Flange portion of the vibration rotation shaft, 15... Bolt for fastener, 16
... Fastener, 17... Rotating bearing shaft, 17a...
Cylindrical shaft portion of the rotary bearing shaft, 17b... Handle of the rotary bearing shaft, 17c... Flange portion of the rotary bearing shaft, 18...
・Bearing, 19... Base, 20... Port,
21...Cylindrical stand, 22...Threaded part, 23...
Rotating bearing shaft set plate, 23a... Rotating bearing shaft setting plate handle, 24... Torsion spring, 25... Pointer, 2
6... Vibration meter, 27... Angle meter, 27a...
Arc part, 28...Through bolt hole, W...Weight of weight, Wh...Weight of head.

Claims (2)

[Claims] (1) means for rotatably holding a grip of a swinging device so that the swinging device can swing in a vertical plane;
A balance meter comprising an elastic member having one end fixed to the grip and the other end fixed to the fixed part to form a rotational vibration meter together with the swing instrument. (2) A base, a hollow cylindrical base fixed to the base, a cylindrical shaft part that is rotatably fitted concentrically into the hollow part of the cylindrical base, and a flange part perpendicular to the cylindrical shaft part. a rotary bearing shaft, a member that fixes the rotary bearing shaft to the cylindrical base and allows the rotary bearing shaft to rotate when released; a shaft portion that is rotatably fitted concentrically to the cylindrical shaft portion of the rotary bearing shaft; A vibrating rotary table consisting of a flange section perpendicular to the shaft, and both ends fixed to the rotary bearing shaft and the vibrating rotary table, respectively.
An elastic body that forms a rotating vibration system with respect to the rotating bearing shaft together with the vibrating rotary table; A member that directly or indirectly fixes the vibrating rotary table to the base; and a swing device that is detachably fixed to the vibrating rotary table. A balance meter consisting of a member, a pointer that is fixed to a vibrating rotary table and swings as the vibrating rotary table rotates, and a vibration meter installed near the swing path of the pointer.