JPH07117121B2 - Restrained damping tubular body - Google Patents

Description

The present invention relates to a constrained vibration damping tubular body having excellent vibration damping performance. More specifically, the outer circumference of the tubular body is covered with a viscoelastic material layer, and a restraint material is further provided on the outer circumference thereof. The present invention relates to a constrained vibration damping tubular body in which a layer is provided to further improve the vibration damping characteristics of the tubular body against vibrations in a wide audible frequency range.

Since the tubular body has been lightweight and strong in the past, it has been widely used in various fields as an industrial member and the like. Further, the tube is an indispensable means for transferring gas, liquid, and solid while blocking them from the outside. However, the tubular body alone has no effect in preventing vibration. Therefore, for example, in a pipe for flowing a refrigerant or the like, a method of bending the pipe body several times is applied, and a load is applied to a portion where resonance is severe, so that the pipe body is prevented from vibrating greatly. is the current situation. However, according to the above method, the resonance point is displaced, and it is difficult to control the level of vibration itself. Therefore, it is necessary to determine the position at which the load for preventing resonance is to be applied each time. Was needed. On the other hand, on the other hand, it is necessary to bend the tube body to a length longer than necessary, which results in a large material loss and a large piping space.
In recent years, in order to overcome the above-mentioned drawbacks, a pipe-shaped product having a spiral shape and a pipe-shaped product having an uneven surface formed on the inner surface and / or the outer surface have appeared. Although these methods are improved in comparison with the straight pipe in terms of vibration in addition to the fact that the bending of the pipe is easy, the sufficient effect has not been obtained yet.
That is, although the vibration level is reduced by the amount that the rigidity of the tubular body is reduced, on the contrary, the damping property of vibration is inferior to that of the straight pipe, and there is a drawback that it vibrates forever. Due to this poor damping property, there is a drawback that metal fatigue easily occurs.

The inventors of the present invention overcome the above drawbacks and reduce the piping space by using only necessary members, aiming at a vibration damping tubular body excellent in vibration damping performance and resistant to metal fatigue. After this research, the present invention was completed.

That is, as shown in the drawings, the constrained vibration-damping tubular body of the present invention is a constrained vibration-damped tubular body in which a viscoelastic body layer is formed substantially coaxially on the outer periphery of a desired metal tubular body. The outer surface and / or the inner surface of the tubular body is uneven, and the viscoelastic body that is formed to surround the metal tubular body is crosslinked, and the binding material layer is formed around the outer periphery of the viscoelastic body layer. This is characterized by the fact that the restraining type provided a very excellent vibration damping effect. That is, the constrained type vibration damping tubular body of the present invention hardly resonates and exhibits a characteristic that the damping is very fast. That is, when the restraint material layer is vibrated, the restraint type damping pipe vibrates and a bending stress is applied, but when bending stress is applied to the pipe due to the vibration, the tension acts on the unexcited portion of the restraint material. As will be described later, since the viscoelastic body and the restraint material are in close contact with each other, shear stress is generated on the viscoelastic body.

Therefore, the vibrational energy is reduced, resulting in less bending due to vibration and a much faster damping.

Next, the constituent members of the present invention will be sequentially described.

The tubular body is made of a material having excellent malleability and ductility such as copper, aluminum, brass, stainless steel, etc., and as a shape, a straight tube, an inner surface and / or an outer surface having irregularities as illustrated, or It is possible to exemplify one in which a fine metal wire is wound on the uneven surface, or a finer uneven surface is arranged on the uneven surface itself, and the sectional shape of the hollow portion of the tubular body is a circle,
It may be an ellipse, a triangle, a quadrangle, or another polygon. or,
The intervals for forming the irregularities may be constant intervals or irregular intervals, but the desirable shape of the tubular body is that having an uneven cross-sectional shape on the outer surface that easily doubles the restraining effect. Those with reduced rigidity are desirable for damping characteristics.

Next, the viscoelastic body will be described.

The viscoelastic body is preferably a rubber-like viscoelastic body, and specific examples thereof include rubberized asphalt, butyl rubber, liquid rubber cured product, polynorbornene rubber, polyisobutylene, styrene-butadiene-styrene copolymer, styrene- Examples thereof include ethylene-styrene copolymers, styrene-isoprene-styrene copolymers, ethylene-vinyl acetate copolymers, natural rubbers, styrene-butadiene rubbers and nitrile-butadiene rubbers. Therefore, the present invention can be carried out by a hot melt type, a liquid reaction curing type, a type obtained by a press molding method, an emulsion or a solvent dispersion type, and the like. Among them, considering manufacturing man-hours, material loss, economic efficiency represented by work safety during manufacturing, vibration control performance of finished products, temperature characteristics, corrosion resistance of tubular body, long-term durability, etc., It can be said that a liquid polymer having a reactive functional group is a suitable material.

As an example of the combination of the reactive functional group of the liquid polymer having the reactive functional group and the reactive functional group of the curing agent, a combination of those having the functional groups as shown in Table I is suitable. More specifically, in particular, the combination of a telechelic polymer having a hydroxyl group at the molecular end and a curing agent having two or more isocyanate groups per molecule is excellent in vibration damping property, processing workability, economical efficiency, etc. It can be said that it is the most suitable material because it is easy to control the characteristics and reaction. Specific examples of the hydroxyl-terminated telechelic polymer include those having a hydroxyl group at the end and a main chain made of polybutadiene, hydrogenated polybutadiene, polybutadiene-nitrile, polybutadiene-stainless steel, isoprene, or the like, polyether polyol, polyester polyol, urethane. An acrylic polyol, an aniline derivative polyol, etc. can be mentioned. These may be used alone or in combination. Further, as the curing agent for the above-mentioned reactive substance, an isocyanate-based curing agent is suitable, and it is necessary to have two or more isocyanate groups per molecule. Specific examples thereof include toluylene diisocyanate, diphenylmethane diisocyanate,
Hexamethylene isocyanate, isophorone diisocyanate, prepolymer having a terminal isocyanate group, etc. can be exemplified. These curing agents can be used alone or in combination.

The viscoelastic body uses the above polymer as a basic component,
Considering performance, workability, etc., a plasticizer, a bituminous substance, a tackifier, a filler, an antiaging agent, a rust preventive agent, a flame retardant, a catalyst, a surfactant, a coupling agent, etc. are appropriately combined as necessary. It is desirable to add it. Specific examples of such typical additives include naphthene-based, aromatic-based, paraffin-based oils, castor oil, cottonseed oil, pine oil, tall oil, phthalic acid derivatives, isophthalic acid derivatives, and adipic acid derivatives as plasticizers. Examples include maleic acid derivatives and liquid rubbers containing no functional group. Further, for the purpose of imparting flame retardancy, a halogen compound type or phosphorus compound type plasticizer can be used. As bituminous materials, there are straight asphalt, blown asphalt, tar and the like, which can be modified with a pre-tackifying resin or a plasticizer in order to obtain a desired crosslinked viscoelastic material. As the tackifying resin, natural resin, rosin, modified rosin, rosin and / or modified rosin derivative, polyterpene resin, terpene modified product, aliphatic hydrocarbon resin, cyclopentadiene resin, aromatic petroleum resin, phenol resin ,
Alkylphenol-acetylene resin, xylene resin,
Coumarone indene resin, vinyltoluene-α-methylstyrene copolymer and the like can be used alone or in combination.

The filler is mica, graphite, flint, talc, scale-like inorganic powder such as clay, ferrite, metal powder, barium sulfate, high specific gravity filler such as lithopone, calcium carbonate,
A general-purpose filler such as finely divided silica, carbon, magnesium carbonate, aluminum hydroxide, and asbestos can be used alone or in combination. Further, antimony trioxide, borax, etc. can be used for the purpose of flame retardancy.

The above-mentioned viscoelastic body may be one that is in close contact with the tubular body and the restraint material and has a condition of exhibiting vibration damping performance when used as a restraint type. Further, it is natural that the surface treatment may be performed with a primer or the like to further improve the adhesion.

Next, the restraint material will be described.

The restraint material may be a viscoelastic body wrapped around the pipe body and further wound from the outside, and specific examples thereof include a metal made of a material such as copper, brass, aluminum, iron, and stainless steel. Thin film or metal mesh; synthetic resin film such as polyester, nylon, vinyl chloride, polyethylene, polypropylene, polyvinyl butyral, non-vulcanized or vulcanized sheet of butyl rubber, natural rubber, chloroprene, hypalon, ethylene-propylene copolymer, glass Nonwoven fabrics made of fibers, nylon, polypropylene, polyester, etc., natural fibers such as cotton, hemp, etc. and / or synthetic fibers such as nylon, urethane, polypropylene, acrylic, polyester, etc., cloths made of inorganic fibers such as asbestos, urethane, acrylic, Synthetic resin type such as epoxy and polyester, and inorganic type such as cement type It is possible to illustrate the fee.

Further, the restraint material may be a material having a surface coated with a paint in consideration of aesthetics and durability, or a laminate having a film or the like attached thereon.

The condition that the restraining material should have is that it should be in close contact with the viscoelastic body, but it may be used after improving the close contact property with a primer or the like. Further, the restraint material is preferably a material having higher rigidity, and a metal thin film or a metal net is suitable. In addition, the restraint material may be of a so-called double-tube structure in which a viscoelastic body is provided between the tubular body and the restraint material so that the restraint material is integrated with the tubular body in advance.
The viscoelastic body may be wrapped around the tube body and then wrapped or wrapped.

Next, the present invention will be described with reference to the drawings by examples and comparative examples.

Example 1 shows a case where the metal tube body is spirally processed to have a concavo-convex shape, the viscoelastic body is surrounded, and the restraining material is further wound.

Comparative Example 1 shows a case of a single straight metal tube body.

Comparative Example 2 shows a case of a single tube body in which the metal tube body used in Example 1 is processed to have an uneven shape in a spiral shape.

Comparative Example 3 shows a case in which a viscoelastic body is surrounded by the Comparative Example 2 and no restraint material is provided.

An example and a comparative example are shown in Table II, and an example of the relationship between the vibration damping property of the viscoelastic body and temperature is shown in FIG. 6 Graph I (relationship between the vibration damping property of the viscoelastic body and temperature). Furthermore, the vibration conditions are shown in FIGS. 7 to 9, that is, graphs II to IV. Graph
II is a copper straight tube alone, Graph III is a copper spiral tube + viscoelastic body, and Graph IV is a copper spiral tube + viscoelastic single body + restraint material.

In addition, Table III shows a compounding example (part by weight) of the viscoelastic body used in the examples.

Next, a test method showing the examples and comparative examples of the present invention will be described.

A copper pipe with a diameter of 15.88 mm, a wall thickness of 0.5 mm, and a length of 500 mm is a straight pipe or spiral pipe (both ends are 50 mm straight pipes, and the central portion is 400 mm).
It was used that was processed into a spiral shape. The difference in depth between the peaks and valleys of the uneven portion was set to 2 mm. ) Is prepared as a straight pipe, a spiral pipe alone, a spiral pipe with a viscoelastic body having a thickness of about 0.5 mm above the convex portion, and a concave portion with the entire surface enclosed, and the viscoelastic body with the viscoelastic body enclosed. Samples were prepared for a total of four types in which the elastic body was wrapped with an aluminum thin film having a thickness of 50 μm.

The viscoelastic body used in the test was as shown in Table III.

The cantilevered beam was prepared by attaching one end of each of the tubular bodies prepared as described above to an iron base having a thickness of 50 mm.

Next, each sample was subjected to a vibration test by the FFT method, and the results were converted into a computer and charted. As shown in the table or the graph of the drawings, it is understood that the first and second embodiments of the present invention dampen vibration very efficiently. Further, the damping due to the vibration damping is large, and as is clear from Graph IV in FIG. 9, the waveform of the peak showing the resonance is very wide and the vibration loss is also very large, and it can be seen that the large vibration damping property is exhibited.

Comparative Example 1 shows a single straight copper pipe. It is a very large vibration inertance and it is necessary to take measures to prevent vibration.

In Comparative Example 2, the copper tube is spiral. Although the inertance is reduced, it has a drawback that it has a poor damping capacity and is susceptible to metal fatigue.

Comparative Example 3 shows a case where a spiral copper tube is surrounded by a viscoelastic body. Although the vibration inertance is further lowered and the resonance frequency is also lowered, the waveform showing the resonance point is also sharp, and the phase shown at the top of the graph is also changing sharply, and a sufficient damping effect is obtained. Not a thing. Further, the damping speed is also slow, and as in Comparative Example 2, a device must be devised to avoid metal fatigue.

That is, by utilizing the present invention, it absorbs vibrations in a wide audible frequency range, and further attenuates quickly to alleviate fatigue of the tubular body itself or the joint surface between the tubular body and other members, The durability of the joint can be increased, the length of the tubular body can be shortened, the piping space can be made smaller, the resonance point need not be adjusted, and the man-hours can be greatly reduced. In terms of economic efficiency, it also has a great advantage in terms of durability and durability, and its utility value in industrial development is extremely high.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing an embodiment of the present invention, showing a case where the metal tube body has both inner and outer concave and convex shapes. FIG. 2 is a vertical sectional view showing another embodiment of the present invention,
The case where only the outer surface of the metal tube is uneven is shown. FIG. 3 is a vertical cross-sectional view showing still another embodiment of the present invention, showing a case where the inner surface of the metal tube body is uneven and the width of each convex portion of the concave portion is wide. FIG. 4 is a vertical cross-sectional view showing still another embodiment of the present invention, showing a case where the restraint member is spirally attached to the tubular body. FIG. 5 is a schematic diagram showing the measuring method according to the present invention. FIG. 6 is a diagram (graph I) showing the relationship between the vibration damping property and the temperature of the viscoelastic body according to the present invention. FIG. 7 is a diagram showing the vibration situation of a single copper straight tube (graph II). FIG. 8 is a diagram showing a vibration situation of the copper spiral tube + the viscoelastic body (graph III). Furthermore, Fig. 9 shows a copper spiral tube + viscoelastic body + restraint (graph
It is a diagram showing a situation of vibration of IV). DESCRIPTION OF SYMBOLS 1 ... Metal tube body, 2 ... Viscoelastic body layer 3 ... Restraint material layer, 4 ... Restraint material fixing material 5 ... Sample, 6 ... Pickup 7 ... Hammer, 8 ... Cord 9 ... FFT vibration measuring device, 10 ... Sample mounting base

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazutaka Sakano 29 Nishinomachi, Toyoba, Toyoyama-cho, Nishikasugai-gun, Aichi Prefecture (56) References JP-A-60-225744 (JP, A) JP-A-50- 35544 (JP, A)

Claims (4)

[Claims] 1. A viscoelastic material layer is substantially coaxially fixedly formed on the outer circumference of a desired metal tube body, and a restraint material layer is further provided on the outer circumference of the viscoelastic material layer so that vibration of a frequency in a wide audible range can be achieved. In the constrained vibration damping tubular body to be damped, the outer surface and / or the inner surface of the metal tube body is uneven, and a viscoelastic body that is fixedly formed on the outer periphery of the metal tube body is crosslinked, and the viscoelastic body layer is further formed. A restraint type vibration damping tubular body characterized in that a restraint material layer is wound around and formed on the outer circumference of the restraint type vibration restraint tubular body. 2. A liquid polymer in which the metal tube is made of copper, brass, aluminum or stainless steel, the outer surface and / or the inner surface of which is uneven, and the viscoelastic body fixed to the metal tube has room temperature reactivity. The constrained vibration-damping tubular body according to claim 1, wherein the constrained vibration-damping tubular body is cross-linked and hardened using the base polymer and the hardener. 3. The viscoelastic material is obtained by reacting a hydroxyl group-terminated liquid polybutadiene and an isocyanate curing agent at room temperature, and the viscoelastic material according to claim 1 or 2. Restraint type vibration control tubular body. 4. The binding material layer is a metal thin film having a film thickness of 200 μm or less, or a metal mesh made of wire having a diameter of 1 mm or less, according to any one of claims 1 to 3. The restraint type vibration-damping tubular body as described above.