JPH03224577A - Shock cushioning material - Google Patents

Abstract

PURPOSE:To remarkably suppress the shock vibration by constituting the shock cushioning material of a vibration inhibiting material and a constraining material consisting of a raw material having higher strength and rigidity than those of the vibration inhibiting material. CONSTITUTION:As for a vibration inhibiting material, a damping resin material whose vibration damping capacity is high is used, and as for the damping resin material, a resin hardened matter consisting of a resin composite whose main component is at least one kind of inorganic filler selected from an epoxy resin having fluidity extending from a room temperature to 100 deg.C, a polyamide resin and graphite, etc., is desirable. As for a material for constituting a constraining material 3, a composite material, etc., of a base material having higher strength and rigidity than those of the vibration inhibiting material, for instance, a single matter, a composite matter, and a joint use matter of various metals, a thermoplastic resin, etc., and a reinforcing material of a carbon fiber, a glass fiber, etc., are used. Also, between the vibration inhibiting material 2 and the constraining material 3, a cushioning material 4 is interposed. In such a way, the vibration damping capacity of the vibration inhibiting material itself can be further improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a shock absorbing material that can significantly suppress impact vibrations generated by collisions between objects, impact operations, and the like.

(Prior art) In general, impact vibrations occur when objects collide.
There is currently no concrete solution to the technology for controlling such special vibrations.

(Problem to be solved by the invention) A batting tool that performs a desired work or play by performing a batting operation in the field where impact vibration is most problematic.
When a hitting operation is performed using such a hitting tool, the grip portion of the hitting tool receives strong impact vibrations.

If such impact vibrations are continued for a long period of time, a numbing sensation will remain in the wrists, arms, elbows, etc., and as the discomfort and fatigue caused by such numbing sensation accumulates, it will eventually cause damage to the human body.

The present invention is the result of careful consideration of the problems caused by the above-mentioned collisions and impacts.

That is, an object of the present invention is to provide a material that can significantly suppress impact vibrations caused by collisions between objects, impact operations, and the like.

Further, according to the present invention, for example, it is possible to solve the accumulation of discomfort and fatigue associated with the numbness that remains in the wrist, arm, elbow, etc. due to impact vibration when hitting, and to do so without worrying about injury.
The striking operation can be performed continuously for a long time comfortably.

(Means for Solving the Problems) The present invention employs the following means to achieve the above-mentioned objects.

That is, the shock absorbing material of the present invention is characterized by comprising a vibration suppressing material and a restraining material made of a material having higher strength and rigidity than the vibration suppressing material.

Furthermore, the shock absorbing material of the present invention includes a vibration suppressing material;
A restraining material made of a material having higher strength and rigidity than the vibration suppressing material, and a compression hardness of 5.0 kg/c at 25% compression measured according to JIS K-6787.
(Function) The present invention solves the problem of shock vibrations caused by collisions between objects, impact operations, etc. However, fields where such impact vibrations are causing problems are work and play that involve hitting operations.

That is, a typical example is one that uses a hitting tool (instrument, tool, instrument), and the present invention will be described below using this hitting tool as a representative example.

Examples of such hitting tools include tools, martial arts equipment, self-defense equipment, and general sports equipment.

Examples of tools include hammers, mallets, axes, etc.; examples of martial arts tools include nunchakus, wooden swords, sticks, etc.; examples of self-defense tools include batons, etc. Examples of general sports equipment include rackets for tennis, tennis and squash, sticks for hockey, ice hockey, cricket, gateball, etc., golf clubs, and ball-hitting tools such as baseball bats.

The present invention provides that, when a vibration suppressing material and a restraining material, or a combination material that combines these materials with a cushioning material, is attached to a part of the hitting tool, the impact vibration at the time of hitting can be unexpectedly significantly reduced. It was completed by investigating the fact that it can be suppressed.

FIG. 1 is a schematic diagram showing an example of a cross section of the impact cushioning material of the present invention. FIGS. 2 and 3 are examples showing cross sections of other impact cushioning materials of the present invention. FIG. 4 is a perspective view showing an example in which such a shock absorbing material is used in a hitting tool, and FIG. 5 is a perspective view showing an example in which the impact cushioning material is used as an aggregate in the handle of the hitting tool. It is.

First, the shock absorbing material 1 shown in FIG. 1 is a two-layer combination material having a structure in which a vibration suppressing material 2 is sandwiched between restraining materials 3.

Further, FIG. 2 shows a structure in which a buffer material 4 is interposed between the vibration suppressing material 2 and the restraining material 3 in addition to the structure shown in FIG. 1. The shock absorbing material 1 having this structure is preferable because it exhibits a higher impact vibration damping effect than the one shown in FIG.

3(A) to (D) are other typical cross-sectional structural examples of the impact cushioning material 1 of the present invention, but the impact cushioning material of the present invention is not limited to these structural examples. . Among these structural examples, (B) ~ has a structure in which the vibration suppressing material 2 and the cushioning material 4 are composited, and the composite material is integrated with the restraining material 3.
(D) is preferred because it exhibits a better impact vibration damping effect than (A).

Next, in FIG. 4, a hammer 6 is used as a striking tool, and the shock absorbing material 1 of the present invention is applied to a band 5 through a slit 7.
A perspective view of the installed state is shown. As in this example, when the shock absorbing material 1 of the present invention further interposes a shock absorbing material between it and the hitting tool, a particularly excellent impact vibration damping effect is exhibited.

That is, in FIG. 4, the shock absorbing material 1 made of a five-layer combination material having a structure in which a two-layer combination material of a vibration suppressing material and a cushioning material is sandwiched between restraining materials is used. The cushioning material may be combined in any number of layers within or around the vibration suppression material, and the combined structure may also be vertical,
The structure may be horizontal, bias, or a mixture thereof. The structure in which such vibration suppressing material and cushioning material are combined is the third
As shown in the figure, various modifications may be made, for example, a homogeneous or partial mixture of both materials may be used. Preferably composite-“
It is better if it is embodied. Further, in addition to such a shock-absorbing material, it is also preferable to further interpose a shock-absorbing material between the shock-absorbing material and the aggregate of the hitting tool from the standpoint of damping impact vibrations.

The vibration suppressing material referred to in the present invention is a material that mainly has the effect of damping impact vibrations, and examples of such materials include wood materials,
Elastic rubber, synthetic resin, cork, felt-like materials, etc., metals such as copper and lead, materials with high specific gravity such as ceramics, and mixtures thereof can be used. Among these vibration suppressing materials, it is particularly preferable to use a damping resin material with high vibration damping ability. Such vibration-damping resin materials can be processed into various desired shapes, such as protrusions, plates, and films, and can also be easily laminated and composited with materials such as restraining materials or cushioning materials. Therefore, it is preferable.

The above vibration damping resin material will be explained below.

That is, such vibration-damping resin materials include, for example,
Compounds of rubber and synthetic resins with relatively high specific gravity, compounds in which these resins are blended with metals with high specific gravity such as lead, inorganic fillers such as metal fibers, and even epoxies that have fluidity at room temperature to 100°C. A cured resin product consisting of a resin composition whose main components are a resin, a polyamide resin having fluidity at room temperature to 100° C., and at least one inorganic filler selected from graphite, ferrite, and mica is preferably used.

In other words, the above-mentioned cured resin product can be used from the stage of the resin composition before curing, so it has a high degree of processing freedom, is easy to stack and combine with restraining materials and cushioning materials, and the cured resin product itself can be used. It is also flexible and exhibits an extremely excellent vibration damping effect.

In the above-mentioned resin composition, the epoxy resin having fluidity at room temperature to 100°C is preferably a resin having at least two or more glycidyl ether groups, and more preferably has a viscosity of 1 to 300°C at 25°C. Poise, epoxy equivalent weight is 100-500, molecular weight is 200-100
0 is better. Specifically, for example, Epicote 82
8.827.834.807 (the above, Yuka Shell Chemical (
Co., Ltd.) etc. can be used.

In addition, as a polyamide resin having fluidity at room temperature to 100°C, preferably the viscosity at 25°C is 3 to 2000.
Those having a poise and amine value of 100 to 800 are suitable because they act effectively as a curing agent for the epoxy resin and as an agent for imparting flexibility to the resin after curing. Specifically, for example, Tomide #225-X, #215-X, #225 (
Above, manufactured by Fuji Kasei Co., Ltd.), Persamide 930.115
(manufactured by General Mills), Epon-V15 (
(manufactured by Shell) etc. can be used.

Such polyamide resin acts as a curing agent for epoxy resin, but in order to shorten the curing time and sufficiently progress the curing of the molded product, a commonly used curing agent for epoxy resin can be used in combination. . Such curing agents include aliphatic amines such as triethyltetramine, propatoolamine, aminoethylethanolamine, aromatic amines such as P-phenylenediamine, tris(dimethylamino)methylphenol, and benzylmethylamine; Carboxylic acids such as phthalic anhydride and maleic anhydride can be used. The amount of the curing agent to be added may be sufficient for curing, taking into consideration the epoxy equivalent, amine equivalent, and acid equivalent.

The inorganic filler filled in these resins is preferably at least one selected from graphite, ferrite, and mica. Among such inorganic fillers, graphite is preferably used because it has excellent impact vibration suppressing properties, and among these, those having an aspect ratio of 3 to 70 are preferable. The aspect ratio is a value obtained by dividing the diameter of a graphite particle by its thickness, and those in the above range may have excellent wettability and mixing characteristics with respect to resin.

The above components are preferably blended in the following proportions.

That is, the blending amount of polyamide resin with respect to 100 parts of epoxy resin is 100 to 800 parts, more preferably 2 parts.
00 to 500 parts, and the inorganic filler is 30 to 120 parts, more preferably 40 to 100 parts, based on 100 parts of the total amount of these resins (including monoglycidyl ether, which will be described later). .

Furthermore, by further blending a monoglycidyl ether compound with the above-mentioned resin composition, it is possible to provide a vibration-damping resin material that is extremely flexible and has excellent workability, and also has an excellent impact vibration damping effect. This is preferable because it allows Particularly preferably, the epoxy equivalent is 80 to 400. A monoglycidyl ether compound having a molecular weight of 80 to 400 is preferable. Specifically, octadecyl glycidyl ether, phenyl glycidyl ether, butylphenyl glycidyl ether, etc. can be preferably used.

The compounding amount of this compound is preferably 5 to 45 parts, more preferably 10 to 25 parts, per 100 parts of the epoxy resin.

Among such vibration-damping resin materials, the vibration loss coefficient in the frequency range of 50 Hz to 5 kHz at room temperature of 20° C. is preferably 0.01 or more, more preferably 0.
．． 0.02 or more, particularly preferably 0.04 or more, since it has a large impact vibration damping effect.

The above-mentioned vibration loss coefficient is measured as follows.

That is, after pasting a 10 mm thick sample resin onto a 5 mm thick steel plate using a two-component adhesive, the resin was left to stand for 24 hours to harden the adhesive, and then the M I of the US military standard was applied.
According to LP-22581B, the vibration damping waveform was measured under room temperature (20°C) conditions, and the vibration loss coefficient (η
).

a, Attenuation rate (DECAY RATE) Do (dB
/5et) = (F/N) 20 log (AI /All
) b, effective attenuation factor (EFFECTIVE DECA
Y RATE)De (dB/5ec)=Do-D
.

C1 critical attenuation rate (PERCENT CRITICA)
L DAMPING) C/Cc (%) = (183x
De)/F where, F: Natural frequency of the sample adhesive plate N: Number of calculated periods A,: Maximum amplitude A2 in N: Minimum amplitude Do in N: Damping rate D8 of the sample adhesive plate: Damping coefficient d of the original steel plate, vibration loss coefficient (η) η = (C/Cc) 150 When making a resin molded product made of a resin composition consisting of the above components, first the epoxy component (epoxy resin, monoglycidyl ether A method is used in which the compound) and the polyamide component (polyamide resin, curing agent, inorganic filler) are mixed in separate systems, and then the two are finally mixed. When mixing, it is preferable to use a mixer for high viscosity to mix gently and uniformly so as not to introduce air bubbles.

Curing of such a resin composition varies depending on the type of epoxy resin, curing agent, and polyamide resin used, but the curing temperature is between room temperature and
It can be cured and molded into a resin by coating or using a molding device into a desired shape under a temperature condition of 100°C. During such curing, the cushioning material described below is laminated (
By doing so, the impact cushioning material of the present invention can be easily combined.

The restraining material in the present invention has the function of stably fixing the vibration suppressing material or the combination material of the vibration suppressing material and the cushioning material, and also has the function of promoting and improving the function of the vibration suppressing material or the combined material. .

The material constituting the restraining material may include materials having higher strength and rigidity than the vibration suppressing material, such as various metals,
Thermoplastic resins, thermosetting resins, wood materials, etc. alone, or mixtures or combinations thereof, as well as these materials and other materials, such as high-strength fibers such as carbon fibers, glass fibers, and aramid fibers. Composite materials with reinforcing materials, etc. can be used. Among such materials, a material with higher wear resistance than the vibration suppressing material is preferable because it can provide a shock absorbing material with excellent durability.

It is preferable that such a restraining material be combined with and integrated with a vibration suppressing material, a shock absorbing material, etc., since this can further effectively exhibit the vibration damping function of the vibration suppressing material.

In the shock absorbing material of the present invention, by interposing a cushioning material between the vibration suppressing material and the restraining material, and further including one or more layers of the cushioning material in the inner layer of the vibration suppressing material, The vibration damping ability of the vibration suppressing material itself can be further improved.

Such a cushioning material has a function of improving and assisting the damping function of impact vibration by the vibration suppressing material.

Such cushioning materials have a compression hardness of 5.0 kg/ct or less at 25% compression as specified in JIS K6767,
Preferably materials below 3,0 kg/CJl are used.

Here, the compression hardness is measured using a compression hardness tester (manufactured by Daiei Kagaku Seiki Seisakusho) in a temperature-controlled room at 20°C.

The test piece used is a rectangular parallelepiped with a length of 50 mm, a width of 50 mm, and a thickness of about 25 mm.

The thickness of the central part of the test piece was measured, and then the test piece was placed in a predetermined position in the testing machine, and the compression speed was 10 mm/mi.
At n, the compressor is compressed by 25% of the initial thickness and then stopped. Then, the load (P) after being left in that state for 20 seconds is measured, and the compression hardness (■]) is calculated using the following formula.

11= P W @ 1 where P: Load after 20 seconds under 25% compression (kg
)W: Width of test piece (cm2) L: Length (cm2) As such a buffering material, the following can be used, but it is not limited to these.

Inorganic elastomers: rubber-like sulfur, silicon fluoride polymers, phosphorus-based, silicon-based (siloxane-based polymers,) phosphazene-based elastomers (phosphorus and nitrogen are the skeletons), etc.

Polymer gel type: polyvinyl alcohol hydrogel, sodium acrylate/acrylamide copolymer gel, etc.

Organic elastomers: Polyvinyl chloride, polyurethane, polyamide, polystyrene, ethylene vinyl acetate copolymer, ethylene ethyl acrylate, polyolefin, polyester, epoxy resins, etc.

Rubber elastomers: natural rubber, styrene-butadiene rubber, nitrile rubber, isoprene rubber, hydrin rubber, chloroprene rubber, etc.

Foamed plastics: Polyurethane-based, polystyrene-based, polyethylene-based, fluorine-based, EVA-based, phenol-based, PVC-based, polyurea-based resins, etc.

The impact cushioning material 1 of the present invention can be joined or fixed to the entire hitting tool or an appropriate portion thereof by various means.

Examples of joining or fixing methods include adhesion, lamination,
Methods such as composite, coating or mechanical fixation can be used. For example, when attaching the impact cushioning material to a hitting tool, an adhesive method, a mechanical fixation method, or a combination of these methods is highly effective. Practically speaking, it is preferable to use double-sided adhesive tape or to use a strong band, clip, or other type of fastener to fix the device, as it is simple and has a strong fixing force. In this way, when using the impact-absorbing material partially in the hitting tool, it is preferable to use it near the center of gravity (because it has a greater impact-vibration damping effect).

Further, in the impact buffering material 1 of the present invention, as shown in FIG. 5, for example, the aggregate constituting the hitting tool can be made of the impact cushioning material. In the case of FIG. 5, the impact cushioning material 1
The restraining material 3 is made of a composite material in which a thermosetting resin is combined with a matrix resin made of a thermosetting resin, and in this example, the thermosetting resin constitutes the restraining material 3.

In other words, the impact cushioning material of the present invention may be used in any way as long as it achieves the purpose of the present invention. In that case, the aggregate may be used as a restraining material.

The shock absorbing material of the present invention or a striking tool using the same preferably has an apparent vibration loss coefficient of 0.02 or more, more preferably 0.03 or more, particularly preferably 0.04 or more. It is preferable because it has an excellent impact vibration damping effect.

The method for measuring this apparent vibration loss coefficient is as follows.

That is, a micro-acceleration pickup is attached to one end of the sample or the center of the handle or grip of a hitting tool, and the head of the hitting tool is lightly hit with a hammer. The attenuated waveform of the vibration was measured using an FFT analyzer (manufactured by Ono Saiki), and the waveform was measured using a microcomputer (manufactured by NEC Corporation).
The vibration loss coefficient (η) is measured according to the formula of 2581B.

(Example) Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 A 0.5 mm steel plate was adhered to both sides of a 25x50x20 (mm) sized cork (vibration suppressing material) to form a shock absorbing material as shown in FIG.

This was fixed to the handle of the hammer with a rubber band as shown in Figure 4.

The apparent vibration loss coefficient of this hammer was 0.018.

For comparison, the apparent vibration loss coefficient of a hammer without the shock absorbing material of the present invention was measured and found to be 0.011.
Met.

The tingling feeling you get when you hit a wooden block with this hammer is
It was significantly smaller and better than a blank hammer without shock absorbers.

Example 2 Urethane rubber with a thickness of 3 mm (buffer material: compression hardness 0 at 25% compression,
389 kg/car), and 0.
A shock absorbing material as shown in FIG. 1 was formed by bonding 5 mm steel plates, and this was fixed to the handle of a hammer in the same manner as in Example 1.

The apparent vibration loss coefficient of this hammer was 0.123.

This hammer is much better than the one in Example 1,
I could barely feel the stinging sensation when I hit the wooden squares.

Example 3 A damping plate was made from a damping resin material made of epoxy resin, polyamide resin, and graphite by molding and hardening it into an equilateral triangle with a negative side of 40 mm and a thickness of 70 mm.

When the vibration loss coefficient of this damping plate was measured at a room temperature of 20°C using the method described above, it was found to be 5 KH from 50 Hz.
It was 0.12 in the frequency range of z.

A 3 mm thick soft polyethylene foam (buffer material: compression hardness at 25% compression: 0.015 kg/car) is laminated on the bottom and both sides of this damping plate (vibration suppressing material), and chloride foam is applied on both sides. The shock absorbing material shown in FIG. 3(A) was made by sandwiching it between vinyl resin molded plates (restraint material).

This impact cushioning material was fixed to the bat with the cushioning material side down using a rubber band in the same manner as in FIG. 4.

The apparent vibration loss coefficient of this bat was 0.116. The tingling sensation when hitting a hardball with this bat was much better than that of a blank bat with no shock absorbing material attached, and I did not experience any tingling sensation at all.

Example 4 Using the vibration suppressing material, cushioning material, and restraint material of Example 3, a shock absorbing material having the composite structure shown in FIG. 3(D) was produced.

This impact cushioning material was adhesively fixed to the inside (hollow interior) of an aluminum metal bat near the center of gravity by applying an epoxy resin adhesive to the urethane rubber side.

The apparent vibration loss coefficient of this bat was 0.072. On the other hand, the apparent vibration loss coefficient of the blank bat to which the shock absorbing material was not attached was 0.006.

The feeling of stiffness when hitting a hard ball with both bats was significantly different, and the shock absorbing material of Example 4 was attached. I was able to hit the ball comfortably with the bat without any stiffness.

(Effects of the Invention) The present invention significantly controls impact vibrations generated by collisions, impact operations, etc., and extremely effectively prevents the impact vibrations from being transmitted to the hands, body, or other parts of the body other than the part that received the impact. Since it is possible to provide a shock-absorbing material with a damping function, for example, a hitting tool using such a material is free from unpleasant vibrations and tingling, and can satisfactorily reduce arm and elbow fatigue caused by shock vibrations. You can work or play comfortably without accumulating fatigue in your wrists, arms, elbows, etc.

Furthermore, it is expected to be an extremely useful material for applications where shock vibrations are averse, such as in precision instruments.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a structural example of the impact cushioning material of the present invention. FIG. 2 shows a cross-sectional structure of another example of the impact cushioning material of the present invention. FIGS. 3(A) to 3(D) are sectional views of other structural examples of the impact cushioning material of the present invention. FIG. 4 is a perspective view showing an example of use in which the shock absorbing material of the present invention is attached to a hammer. FIG. 5 is a perspective view showing an example of a hammer having a handle made of the shock absorbing material of the present invention as an aggregate. : Shock cushioning material: Vibration suppression material: Restraint material: Cushioning material: Band: Hammer 7: Thrivet

Claims (7)

[Claims] (1) A shock absorbing material comprising a vibration suppressing material and a restraining material made of a material having higher strength and rigidity than the vibration suppressing material. (2) A vibration suppressing material, a restraining material made of a material having higher strength and rigidity than the vibration suppressing material, and JISK-6767
Compression hardness at 25% compression measured according to 5.0k
An impact cushioning material characterized in that it is a combination material with a cushioning material made of a material having a density of g/cm^2 or less. (3) The shock absorbing material according to claim (1) or (2), wherein the restraining material is made of a material having higher wear resistance than the vibration suppressing material. (4) The vibration suppression material has a vibration loss coefficient of 0 at room temperature.
The impact cushioning material according to claim 1 or 2, wherein the impact cushioning material is made of a material having a rating of 0.02 or more. (5) The shock absorbing material according to claim (2), wherein the cushioning material is interposed between at least the vibration suppressing material and the restraining material. (6) The shock absorbing material according to claim (2), wherein the vibration suppressing material is a composite material with a cushioning material. (7) The impact cushioning material according to claim (1) or (2), wherein the vibration suppressing material is a cured resin made of a resin composition comprising an epoxy resin, a polyamide resin, and an inorganic filler.