JPH04115937A - Impact and vibration absorbing material - Google Patents

Abstract

PURPOSE:To obtain the impact absorbing material which may damp impact and vibration quickly and effectively by fixing the vibration-exciting member with specified weight and height to the object of impact and vibration-source so that minute vibration and rocking are excited by following up the vibration and impact transmitted from vibration source to one end of the member. CONSTITUTION:The impact and vibration generated in an object is transmitted to a vibration-exciting member 2. The vibration exciting member vibrates by following up the transmitted impact and vibration, but minute vibration and rocking are excited by the vibration amount generated by follow-up, while the minute shift of timing is actually generated. Any one of the vibrations shows the action which damps the transmitted vibration from the object 1 of original impact and vibration source, and its vibration energy is absorbed and reduced. Then, the vibration-damping of the body 1 of impact and vibration source is remarkably shortened by the existence of the vibration-exciting member 3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention absorbs and reduces vibrations of an object that is a source of impact vibration, and can be used as an impact vibration absorbing member in a wide variety of fields.

One suitable field of application is sports equipment with impact vibrations, and it is desirable to provide a member that can significantly suppress these impact vibrations.

[Prior Art] In recent years, sports equipment such as ball hitting equipment and other exercise equipment that involves impact vibrations have been made lighter, stronger, and more rigid. As aggregates for such tools, wood materials, lightweight alloys, plastics, FRP, various composite materials, etc. are used. Although some of these materials inherently have relatively good vibration damping properties, they can rapidly dampen shock vibrations.
In addition, the ability to reduce the amount effectively was not always sufficient. For example, in the case of tennis rackets, "stabilizers" have been proposed and commercially available for the purpose of reducing and mitigating impact vibrations when hitting a ball. The "stabilizer" is a rubber or soft synthetic resin molded product inserted between the racket guts or crimped onto the gut surface. This "stabilizer" is effective to a small extent in suppressing vibrations of the cut itself, but it is not sufficient.

Moreover, the vibration propagated from the guts to the frame is not damped by the function of the frame itself.

In addition, Japanese Patent Application Laid-Open No. 1-262877 discloses a racket in which a combination of elastic strings and a mass body is provided in the frame;
In the No. 88279, a small hole is formed near the grip of the racket frame, and a mass body is placed inside the hole through a gel layer. However, the former method transmits the vibrations of the racket body through a thin linear elastic string and attempts to link this to the mass body, but it is complicated to adjust the relationship between the mass body and the elastic string, and the regular effect cannot be achieved. It is estimated that the adjustment items are too complex to obtain this. In addition, since the latter is integrated by a combination of a gel layer and a mass body and is fixed inside the small hole, it is unclear whether it can sufficiently exhibit vibration damping ability, and even if damping ability can be obtained, it is limited. It is estimated that there is.

[Problems to be Solved by the Invention] In the case of the racket described above, in the conventional method, the impact vibration when hitting a ball with the racket is transmitted to the frame, then transmitted to the arm and elbow via the shaft and grip, and then to the wrist. This resulted in accumulated fatigue in the arms and elbows. In particular, disorders such as tennis elbow have been a troublesome problem for tennis enthusiasts. Furthermore, in the case of other sports, such as golf, the impact force when hitting a ball is often directly transmitted to the hand, and the impact is often applied to the wrist, arm, elbow, etc. In particular, if the ball is hit outside of the so-called sweet spot near the center of the club head, the result is an unpleasant vibration or tingling sensation, which not only prevents the player from enjoying the pleasure of hitting the ball, but can also cause sports injuries. . In addition, if players try to hit a large number of shots over a long period of time at a practice range, both beginners and experts may develop sports injuries.

In view of the drawbacks of conventional sports equipment, the present invention seeks to provide a shock absorbing material that can quickly and effectively attenuate impact vibrations. It is an object of the present invention to provide sports equipment that can reduce fatigue in the lower back, legs, etc.

[Means for Solving the Problems] The present invention employs the following means to achieve the above-mentioned object.

That is, the impact vibration absorbing material of the present invention is a vibration excitation member having a weight of at least 3 g or more and a height of 3 mm or more, and has a vibration excitation member at one end that absorbs vibrations and shocks propagating from a vibration source. On the other hand, it is characterized in that it is fixed to an object that is an impact vibration source so as to follow this and excite minute vibrations and oscillations.

Further, the impact vibration absorbing material of the present invention has a weight of at least 3
A laminate of a vibration excitation member having a height of 3 mm or more and a height of 3 mm or more, and a load material made of a material whose specific gravity for promoting free vibration of the member is greater than that of the vibration excitation member, The load material is incorporated into the tip side of the vibration excitation member, and one end of the laminate has a portion that is attached and fixed to an object that is an impact vibration source.

[Function] The present invention has discovered a mechanism that exhibits excellent vibration damping in sports equipment that causes impact vibrations, particularly in ball hitting tools such as rackets and golf clubs.

FIG. 1 is a model diagram for explaining the vibration absorption principle of the impact vibration absorbing material of the present invention, and FIGS. 2 to 6 are model diagrams showing embodiment examples of the impact vibration absorbing material of the present invention. 7 to 9 are schematic diagrams showing examples in which the impact vibration absorbing material of the present invention is applied to rackets and golf clubs. 10 to 13 are schematic diagrams showing examples in which the impact vibration absorbing material of the present invention is applied to skis, baseball bats, and fishing rods.

The principle of vibration absorption (vibration damping) by the impact vibration absorbing material of the present invention will be explained.

FIG. 1 shows an example of an impact vibration absorbing material comprising a vibration excitation member 2 and a load member 3 on the surface of an impact vibration source object 1. As shown in FIG. First, the impact vibration generated in the object 1 is propagated to the vibration excitation member 2. The vibration excitation member 2 vibrates following the propagating impact vibration, or actually excites minute vibrations and oscillations while causing a minute timing shift.

This vibration deviation exerts the effect of canceling the propagation vibration of the original impact vibration source object 1, and absorbs and reduces the vibration energy.

In this case, if another vibration excitation member 3 is stacked on the vibration excitation member 2 as shown in FIG. The impact vibration source object 1 has the effect of stimulating the vibration and canceling the vibration of the impact vibration source object 1.

Due to the presence of this vibration excitation member 3, the vibration damping of the impact vibration source object 1 is significantly shortened.

The shock vibration absorbing material of the present invention does not need to be a laminate as described above, and even a material composed only of the vibration excitation member 2 can sufficiently exhibit a vibration damping effect. Such vibration excitation member 2.3 may be made of various organic resins, such as natural resins such as natural rubber, polyvinyl chloride, polyurethane, polyamide, polystyrene, etc.
Synthetic resins such as ethylene vinyl acetate copolymer, ethylene ethyl acrylate, polyolefin, polyester, epoxy, phenol, fluorine, and urea, as well as synthetic rubber, such as styrene-butadiene rubber, nitrile rubber, and isoprene rubber. , hydrin rubber, chloroprene rubber, etc. can be used. moreover,
Foamed resins obtained by foaming these resins can also be preferably used.

It is important for the impact vibration absorbing material of the present invention that the height H from the impact vibration source object is 3M or more and the weight is 3g or more from the viewpoint of vibration damping effect.

In other words, in order to excite vibration, it depends on the size and weight of the impact vibration source object, but within the range of weight and balance, the higher the height, the better the excitation ability. As a result of experiments, it was determined that the minimum requirements are a height of 3 mm and a weight of 3 g.

FIG. 2 shows an embodiment of a combination of vibration excitation members 4.5 and 6 mounted directly on the impact vibration source object 1. FIG.

The shaded members in the drawings indicate that they are made of a single material, and those shown in FIGS. 2(b) and 2(c) are each made of a combination of two-component materials.

By configuring such a combination, it is possible to provide elastic performance as a vibration excitation member that cannot be obtained with a single material. In other words, a composite material made of a combination of multiple materials has the advantage that it is easier to adjust the performance of the ski to the target value than a single material.

In addition, the height H in the vertical direction with respect to the impact vibration source object 1 as shown in FIGS. Is it possible to function effectively even if the height H is reduced as in (c)? In both cases, the vertical height H is 3 mm.
It is important that the above is the case.

FIG. 3 shows a configuration in which vibration can be excited more efficiently than in the embodiment shown in FIG. Indicates that the part near the part that is connected is formed into a constriction or neck shape.

That is, FIG. 3(A) shows the lower end portion 8 of the vibration exciting member 7.
In FIG. 3(B), the lower end of the vibration excitation member 6 of a laminated body consisting of the vibration excitation members 6 and 9 is shaped into a thin column with three legs. Figure 3 (
In c), three thin connecting members ]-0 are provided at the lower end of the horizontally elongated vibration excitation member 6.

These impact vibration absorbers having a constricted or neck shape exhibit a function of more sensitively propagating and exciting vibrations from the impact vibration source object 1, and therefore provide an excellent vibration damping effect. I can do something.

Next, FIG. 4 shows another embodiment in which another configuration is added to the embodiment shown in FIGS. 2 and 3 above.

That is, it has a structure in which a slit-like or uneven-like protruding form is added to a part of the side surface or surface of the impact vibration absorbing material. Such a protrusion is a vibration exciting member 7.1.
6.17, which protrudes by at least 1 mm or more, forms two or more protrusions, and increases the surface area of the protrusions as much as possible, thereby increasing the ability to excite vibrations and damping vibrations more efficiently. It is.

That is, in FIG. 4(A), projections 11 and 12 are provided on the side surface of the vibration exciting member 7 of FIG. 3(A). In addition, as shown in FIGS. 4(b) and 4(c), the vibration excitation member body 1
6.17, vertically or horizontally slit-shaped members 1-3.14.1 made of materials with different elastic properties (such as 50% modulus) from these members.
5 may be incorporated, and the members 13.1-4.
By adjusting the length, thickness, surface area, weight, rigidity, protrusion length, etc. of 15 and increasing the surface area, it is possible to respond more sensitively to vibrations, thereby providing a more effective vibration damping function. can do.

Next, FIGS. 5 and 6 show another embodiment in which another configuration is added to the embodiment shown in FIGS. 2 to 4 described above.

First, as explained in FIG. 1, FIG. 5 shows vibration excitation members 18, 19, 20, which follow the vibrations and shocks propagating from the impact vibration source object 1 and are likely to excite minute vibrations and oscillations. 21
and a load material W connected thereto.

This load material W excites minute vibrations and oscillations with a slight timing shift in response to the vibrations of the vibration excitation member, and exhibits the effect of canceling out the vibrations of the vibration excitation member. Such a load material W is a vibration excitation member 18.19.20.21
It is preferable to use a material having a higher specific gravity than the material constituting the material. That is, if the load material W is made of a material with a light specific gravity, it will exhibit only an insensitive response to propagating vibrations, and the above-mentioned effects of the present invention cannot be achieved.

As the load material W, it is possible to use, for example, various metals, natural or synthetic resins, wood, and mixtures thereof, as well as composite materials of these materials and other reinforcing materials such as various fiber materials.

Such a load material W can be used in combination among the above-mentioned resins. For example, when polyethylene with a specific gravity of 0.91 to 0.96 is used as a vibration excitation member, AB
S resin (specific gravity = 1-.03 to 1.36), fluororesin (
Specific gravity -1.70 to 2.20) or the like can be used as the load material W.

Preferably, such a load material W is incorporated into the side of the tip end of the vibration excitation member 18, and furthermore, is laminated at the tip end.
This is good because it responds sensitively to vibrations.

That is, when the load material W is attached to the tip of the vibration excitation member 18, one end thereof is substantially unrestricted as shown in the figure, and the vibration of the vibration excitation member 18, 19, 20, 21 is This is to excite the vibration more effectively.

FIG. 6 shows a structure in which the vibration excitation members 22, 23, 24 are attached to the impact vibration source object 1 in such a manner that the vibrations are effectively tracked and excited.

That is, by attaching the vibration excitation members 22, 23, 24 made of various elastomers to the impact vibration source object 1 in a horizontal or circular arc shape, the impact vibration source object 1
It is possible to sensitively follow the vibrations from and effectively excite vibrations.

Next, FIG. 7 shows a specific structural example of the impact vibration absorbing material when applied to sports equipment such as tennis rackets and golf clubs shown in FIGS. 8 and 9. This example shows an elongated impact vibration absorber 30 having grooves 27, 28 in the head of the vibration excitation member 25, and legs supporting the vibration excitation member 26 made of the same material. .

Figure 7 (a) is a side view, (b) is a front view, and (c) is (
b) A sectional view taken along line xx' in the figure is shown.

FIG. 8 specifically shows the above-mentioned impact vibration absorbing material 30 attached to the shaft portion of a tennis racket 29. Here, the member 25 forming the upper end of the member is unrestricted and can be freely excited to vibrate. The figure shows an example in which the racket is fixed to the inside of the shaft in the frame of the racket. With this structure, the racket can function effectively without any problems during play.

FIG. 9 shows an example in which two of the above-mentioned shock vibration absorbers 30 are installed on the shaft portion 31 of a golf club.

The vibration excitation member of the present invention has a 50% modulus value of 0.5.
When constructed with various elasmers in the range of ~200 kg/cnf, it is possible to provide an element that responds sensitively even to minute vibrations and achieves excellent vibration damping effects.

Such vibration excitation members may be used by laminating or combining members having different values within the range of the above-mentioned 50% modulus value.

The method for measuring 50% modulus is JISK-630.
Measure according to the vulcanized rubber physical test method in 1-. In other words, the test piece had a No. 3 Danher shape (with a thickness of 4 mm).
), read the load when 50% elongation is applied to the test piece, and calculate the 50% modulus (stress) M2O using the following formula.

M. -F. /A M5o: Stress at 50% elongation (kgf/cnf) F,: 5
Load at 0% elongation (kg f) A: Cross-sectional area of test piece (c
II? ) Also, the method of measuring the vibration loss coefficient is, for example, by pasting the impact vibration absorbing material shown in Figure 7 on the inside of the racket shaft with a reactive putty-like material as shown in Figure 8, and then A micro-acceleration pickup is installed in the center of the grip, the tip of the frame is tapped with a hammer, the attenuation waveform of the vibration is measured with an FFT analyzer (manufactured by Ono Sokki), and the waveform is analyzed using a microcomputer (
The vibration loss coefficient (η) is determined by NEC ■) according to the calculation of tIL-P-22581B.

[Example code] The present invention will be explained in more detail with reference to Examples.

Example 1 An impact vibration absorbing material composed of vibration excitation members 32 and 33 made of the same material as shown in FIG. 10(A) was prepared.

In this case, the vibration excitation members 32 and 33 are Nα1 in Table 1.
Items made of various materials shown in ~6 were prepared. Its flexibility ability is expressed by the 50% modulus value in the table. The vibration excitation member 32 has a fixed shape (
The vibration excitation member 33 is made of the same material but has a different thickness, and the total weight of the members 32 and 33 is 3 g.

The amounts were adjusted to 6g, 12g and 20g.

The impact vibration absorbing material was attached to the shaft of a commercially available tennis racket, and the vibration loss coefficient of each racket was determined. The results are shown in Table-1.

As is clear from Table 1, N
Compared to α7, Nα1 to Nα6 equipped with this member all exhibited excellent shock vibration absorption properties with vibration loss coefficients of 0.009 or more.

Example 2 In Example 1, Table 1, Nα4 was used as the vibration excitation member.
The material was used. That is, impact vibration absorbing materials were formed by using polyurethane resins with various degrees of polymerization, each with a different 50% modulus. The total weight of these impact vibration absorbers was adjusted to 15 g.

This impact vibration absorbing material was attached to the shaft of a racket in the same manner as in Example 1, and the vibration loss coefficient was measured in the same manner as in Example 1.

The vibration loss coefficients of these rackets were measured in the same manner as in Example 1, and the results shown in Table 2 were obtained.

As is clear from Table 2, the 50% modulus value is 15
It was found that good impact vibration absorption performance was obtained at around 35 kg/al.

Example 3 Nα2 (specific gravity 1.24), Nα3 (specific gravity 0.99), Nα4 (specific gravity 1
．． Prepare the three types of materials shown in Figure 5 (a)
An impact vibration absorbing material having a cylindrical shape and a structure in combination with a load material W was manufactured.

Although the height (H) of the neck portion of the vibration excitation member 18 is changed,
The diameter used was 13 mm. The load material W was made of PBT resin and had a diameter of 16 mm and a specific gravity of 1.31. The weight of the entire vibration excitation member was adjusted to about 13 g.

The vibration loss coefficients of these impact vibration absorbers were measured in the same manner as in Example 1, and the results are shown in Table 3.

From Table 3, it can be seen that when the height (H) of the neck portion of the vibration excitation member is 3 or more cylinders, except for polyurethane, the vibration excitation member exhibits an excellent impact vibration absorption effect. In addition, it can be seen that polyurethane exhibits a good effect when the height is 4 anus or more.

Note that EPDM in Table 3 means an ethylene/propylene/diene terpolymer.

Example 4 The shock vibration absorber 30 shown in FIG. 7 was attached to the shaft below the grip of the golf club 31 shown in FIG.

There is one impact vibration absorber 30, and the material is polyurethane elastomer (50% modulus value = 15, 1 kg/
al), and the height of the vibration excitation part 26 is 3 mm.
, H=5 mm, and the total weight including that part was changed.

A micro acceleration pickup was attached to the center of the grip of these golf clubs 31, the center of the head was lightly hit with a hammer, and the vibration loss coefficient of the damping waveform was measured using the same measurement method as in Example 1. are shown in Table-4.

As is clear from Table 4, a good impact vibration absorption effect was obtained in a weight range of 3 g or more.

Example 5 The impact vibration absorbing material of the form shown in FIG. 7 used in Example 4 and having a weight of 20 g was used as shown in FIG. Shock vibration absorbers 35 are attached to the point and each position B near this point, a micro acceleration pickup 38 is attached to the center of the step, and the tip of the ski is tapped with a hammer 37 to measure the vibration loss coefficient. It was determined based on the measurement method of Example 1.

The results are shown in Table-5.

From Table 5, a good vibration damping effect was obtained whether the impact vibration absorbing material was installed at the position A or B. When we put these skis into practical use, we were able to experience the reduction in shock vibration transmission to the legs and the smoothness of the skis' sliding on the snow.

Example 6 A commercially available metal bat 39 having the form shown in FIG. 7 according to Example 5 was used as the impact vibration absorbing material 35 shown in FIG. It was attached at a distance of ~2 cm.

For these bats 39, an acceleration pickup was attached to the center 40 of the grip, and a point 41 14 an away from the tip of the bat was lightly hit with a hammer, and the vibration loss coefficient was measured using the same method as in Example 1. I measured it.

The results are shown in Table-6.

As is clear from Table 6, it was found that the impact vibration absorbing material of the present invention was 4 to 6 times more effective in absorbing impact than the impact vibration absorbing material not installed.

Example 7 A cast fishing rod and a lure fishing rod were prepared as commercially available fishing rods 42, and these fishing rods had the configuration shown in FIG.
A shock vibration absorbing material 30 weighing 20 g and made of nitrile rubber + EPDM is attached to a portion 46 below the grip as shown in FIG.
installed on.

For these fishing rods 42, an acceleration pickup 43 was attached as shown in FIG. 13, and the vibration loss coefficient was measured in the same manner as in Example 1 by lightly hitting the thread guide portion at the tip of the fishing rod with a hammer 44. The measurement was carried out by suspending the rod portion of the sample fishing rod at two locations using string hangers 45.

The results are shown in Table-7.

As is clear from Table 7, the products equipped with the shock vibration absorbing material of the present invention all had better vibration damping performance than those without the shock vibration absorber, and exhibited excellent impact vibration absorption effects. .

[Effects of the Invention] The present invention provides an impact vibration absorbing material that can rapidly and effectively attenuate impact vibrations. It can reduce fatigue.

[Brief explanation of the drawing]

Figure 1 is a model diagram for explaining the vibration absorption principle of the impact vibration absorbing material of the present invention, Figures 2 (A) to (C), Figures 3 (A) to (C), and Figure 4 ( A) to (C), Figure 5 (A)
~(c) and FIGS. 6(a) to (b) are model diagrams showing embodiments of the impact vibration absorbing material of the present invention, and FIG. 7(a)
~(c)~ FIG. 9 is a schematic diagram showing an example in which the impact vibration absorbing material of the present invention is applied to a racket and a golf club. 10(a) to 13(b) to 13 are schematic diagrams showing examples in which the impact vibration absorbing material of the present invention is applied to skis, baseball bats, and fishing rods. 1: Shock vibration source object 2-10.16-26.32-33: Vibration excitation member 11-15: Projection 27.28: Groove 29: Tennis racket 30.35.46: Shock vibration absorber 31: Golf club 34 Niski board 37.44: Hammer 38.43. Micro acceleration pickup 39: Baseball bat 40: Central part of bat grip 4 Light hitting part of bat 42: Fishing rod 45: String hanging hand Patent applicant Higashi Shi Co., Ltd. Figure 1 Figure Q Figure 1!91 'lI Building 41 Figure 5 Figure 6 (Lono tlsxo diagram

Claims (11)

[Claims] (1) The weight is at least 3g or more and the height is 3m
A vibration excitation member consisting of m or more, and at one end of the member,
An impact vibration absorbing material that is fixed to an object that is an impact vibration source so as to follow the vibrations and impact propagated from the vibration source and excite minute vibrations and rocking. (2) The weight is at least 3g and the height is 3mm.
A laminate of a vibration excitation member consisting of the above and a load material made of a material with a specific gravity greater than that of the vibration excitation member for promoting free vibration of the member, the load material being at the tip of the vibration excitation member. 1. An impact vibration absorbing material, characterized in that the material is incorporated into a side, and one end of the laminate has a portion that is attached and fixed to an object that is a source of impact vibration. (3) Claim (1) or (3) characterized in that a constricted or neck-shaped portion is provided at a constant volume ratio in a portion close to a fixed portion forming one end of the total volume constituting the vibration excitation member.
2) The impact vibration absorbing material described above. (4) The impact vibration absorbing material according to claim (1) or (2), wherein at least a part of the side surface or surface of the vibration excitation member is configured in a slit shape or an uneven shape. (5) The vibration excitation member has a 50% modulus value of 0.5 to
The impact vibration absorbing material according to claim 1 or 2, characterized in that it is composed of a single or multiple rubber-like elastic body having a tensile strength of 200 kg/cm^2. (6) The impact vibration absorbing material according to claim (1) or (2), wherein the vibration excitation member is attached to sports equipment. (7) The impact vibration absorbing material according to claim (6), wherein the sports equipment is a racket. (8) Claim (6) wherein the sports equipment is a golf club.
) shock vibration absorbing material. (9) Claim (6) that the sports equipment is a baseball bat.
Shock vibration absorber as described. (10) The shock vibration absorbing material according to claim (6), wherein the sports equipment is a fishing rod. (11) Claim (6) wherein the sports equipment is skis.
Shock vibration absorber as described.