JPH0516345B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for manufacturing a constrained vibration damping tubular body for obtaining a tubular body with excellent vibration damping performance, and more specifically, the present invention relates to a method for manufacturing a restrained vibration damping tubular body to obtain a tubular body having excellent vibration damping performance. The present invention relates to a method of manufacturing a constrained vibration damping tubular body in which a layer is provided to further improve the vibration damping properties of the tubular body. BACKGROUND ART Traditionally, tubular bodies have been widely used in various fields as various industrial members due to their light weight and strong strength. Furthermore, it is an essential component when considering a means for transporting substances in all states of gas, liquid, and solid while separating them from the outside. However, the tubular body alone has the disadvantage that it is completely ineffective in preventing vibrations. In other words, when the support or shaft of a machine or structure is used as piping, when the machine etc. vibrates, it is likely to receive vibration and cause resonance, resulting in noise generation or amplification of vibration. There are drawbacks such as. Moreover, the pillars and shafts are functionally firmly connected to machines, etc., and it is functionally impossible to connect them to machines, etc. through vibration insulators such as rubber, that is, to prevent vibrations from being transmitted to the pillars and shafts. There are many cases.
There are only three ways to prevent vibration in structural members: increasing weight, increasing rigidity, avoiding resonance, and damping vibration, but in the case of tubular bodies, even if the thickness of the tubular body used increases, the resonance frequency will change. However, it has little effect, and conventional methods have been to avoid resonance. In other words, vibration amplification due to resonance is avoided by shifting the resonant frequency of steel pipes used for columns etc. to a point different from the frequency of the vibration source by increasing the local weight, but the frequency of the vibration source is narrow in the frequency spectrum. In this case, the effect may be lost or it may be impossible to shift the resonance point out of the audible range, so that practical effects cannot be obtained with all machines.
Furthermore, in this case, it is necessary to individually check the resonance points and determine the position where the weight is to be increased, which is very time-consuming. Against this background, the inventors of the present invention aimed to create a tube body that has high vibration mitigation ability and quickly damps vibrations, and after repeated trial and error, surrounded the tube body with a viscoelastic material and created a restraining layer. It was discovered that a tubular body obtained by wrapping and surrounding the viscoelastic body exhibited very excellent vibration damping properties, and also had very good damping ability, and the present invention was completed. The present invention relates to a desired pipe body made of vinyl chloride, polyethylene, polybutene, iron, stainless steel, brass, or copper, the outer surface and/or
Or a viscoelastic layer made by cross-linking a liquid polymer that is reactive at room temperature and its curing agent as a basic polymer on the outer periphery of a tube whose inner surface is uneven, and whose hardness is specified by the Japan Rubber Association standard SRIS0101. C
The present invention provides a method for manufacturing a constrained vibration damping tubular body, characterized by forming a surrounding viscoelastic layer having a mold hardness of 50 or less, and further forming a constraining material layer around the outer periphery of the viscoelastic layer. Next, the constituent members of the present invention will be described. The tubular body is made of iron, aluminum, brass, copper,
Metals such as stainless steel and various alloys; plastics such as vinyl chloride, polyethylene, and acrylic; metals lined with inorganic materials such as ceramics and cement, or plastics; combinations of the above materials may be used. things can be applied. Further, the shape of the tube may be a straight tube, the inside and/or the outside may be uneven, or the tube may have a wavy shape with a narrow portion and a wide portion.
The vertical cross-sectional shape of the tube may be any shape such as a circle, ellipse, triangle, square, or other polygon, but metal tubes or plastic tubes made of materials with high malleability and ductility are preferred. I can say that there is. Next, the viscoelastic body will be explained. The viscoelastic body is preferably a rubber-like viscoelastic body, and specific examples of polymers serving as main raw materials that achieve the purpose of the present invention include rubberized asphalt, butyl rubber, recycled butyl rubber, liquid rubber cured product, polynorbornene rubber, Polyisobutylene, styrene-butadiene-styrene copolymer, styrene-isoprene
Examples include styrene copolymer, ethylene-vinyl acetate copolymer, polyvinyl butyral, natural rubber, styrene-butadiene rubber, nitrile-butadiene rubber, etc.; The present invention can be achieved using a mold obtained by injection molding, a water-dispersed type or a solvent-dispersed type such as an emulsion or latex, and a type used after drying. They should be selected in consideration of the conditions under which they will be used, such as adhesion to pipes, temperature characteristics, combustibility, corrosion resistance, migration of plasticizers and compounding agents, economic efficiency, and workability. However, if we take into consideration manufacturing man-hours, material loss, durability of manufacturing equipment, working environment and safety during manufacturing, it can be said that liquid polymers with reactive groups are suitable materials. . In addition, many of them are applied and sprayed on-site, wrapped with a restraining material, or made into a double pipe and injected, which is convenient for the purpose of producing the pipe body of the present invention on-site. There is also the advantage of being. Another advantage is that by applying the method described above, the present invention can be easily applied to pipes currently in use. Examples of combinations of the reactive functional groups of the liquid polymer having the above-mentioned reactive functional groups and the reactive functional groups of the curing agent include those having functional groups as shown in the table. More specifically, a telechelic polymer having a hydroxyl group at the end of the molecule,
A combination of curing agents having two or more isocyanate groups per molecule can be said to be an optimal material because of its excellent vibration damping properties, workability, economy, etc., room temperature reactivity, and ease of reaction control. Specific examples of hydroxyl group-terminated telechelic polymers include those with hydroxyl groups at the ends and whose main chain is polybutadiene, hydrogenated polybutadiene, polybutadiene-nitrile, polybutadiene-styrene, isoprene, etc., polyether polyols, polyester polyols, etc. , urethane acrylic polyol,
Aniline derivative polyols, etc. can be shown.
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 that each molecule has two or more isocyanate groups. Specific examples thereof include toluylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate; isophorone diisocyanate, and prepolymers having terminal isocyanate groups. These curing agents can also be used alone or in combination.
The viscoelastic body uses the above polymer as a basic component,
Add plasticizers, bituminous substances, tackifiers, fillers, anti-aging agents, rust preventive agents, flame retardants, catalysts, surfactants, coupling agents, etc. as necessary, taking into account usage, performance, workability, etc. It is desirable to add them in combination. Specific examples of the above-mentioned typical additives include naphthenic, aromatic, and paraffinic oils, castor oil, cottonseed oil, pine oil, tall oil, phthalic acid derivatives, isophthalic acid derivatives, adipic acid derivatives, and maleic acid. Examples include derivatives and liquid rubbers that do not contain functional groups. Further, for the purpose of imparting flame retardancy, halogen compounds and phosphorus compound plasticizers can also be used.
Examples of bituminous materials include straight asphalt, blown asphalt, and tar, which can be modified in advance with a tackifying resin, plasticizer, etc. in order to obtain a desired viscoelastic body. Tackifying resins include natural resins, rosins, modified rosins, derivatives of rosins and/or modified rosins, polyterpene resins, modified terpenes, aliphatic hydrocarbon resins, cyclopentanediene resins, aromatic petroleum resins, and phenols. Resins, alkylphenol-acetylene resins, xylene resins, coumaroindene resins, vinyltoluene-α methylene styrene copolymers, etc. can be used alone or in combination. Fillers include scaly inorganic powders such as mica, graphite, vermiculite, talc, and clay, high-density fillers such as ferrite, metal powder, barium sulfate, and lithopone, calcium carbonate, finely divided silica, carbon, magnesium carbonate, and water. General-purpose fillers such as aluminum oxide and asbestos can be used alone or in combination. Moreover, antimony trioxide, borax, etc. can also be used for the purpose of flame retardation. The above-mentioned viscoelastic body is in close contact with the pipe body and the restraining material,
Any material may be used as long as it meets the conditions for exhibiting vibration damping performance when used as a restraint type. It goes without saying that the adhesion may be further improved by surface treatment with a primer or the like. In addition, the thickness of the viscoelastic material used is preferably 0.5 mm to 5 mm, and if the restraining material used for the metal tube is made of different metals, corrosion will progress significantly if they come into contact due to their tendency to ionize. There is a risk of impairing the durability of the tube, so it is better to make the viscoelastic body sufficiently thick.
In addition, since the viscoelastic material is used in a restrained type, the hardness is SRIS.
It is desirable that the material be a flexible and cross-linked viscoelastic material with a Type C hardness of 50 or less as defined in -0101. Next, the restraining material will be explained. The restraining material may be one that is further wrapped around or surrounding the viscoelastic body surrounding the pipe body from the outside, and specific examples thereof include materials such as copper, brass, aluminum, iron, and stainless steel. Metal thin films, metal mesh products, polyester, nylon, PVC,
Synthetic resin films such as polyethylene, polypropylene, and polyvinyl butyral, unvulcanized or vulcanized sheets such as butyl rubber, natural rubber, chloroprene, Hypalon, and ethylene-propylene copolymers; nonwoven fabrics made of glass fiber, nylon, polypropylene, polyester, etc.; cotton , natural fibers such as linen and/or
Or cloth made of synthetic fibers such as nylon, urethane, polypropylene, acrylic, polyester, etc., or inorganic fibers such as asbestos; examples include synthetic resin-based paints such as urethane, acrylic, epoxy, polyester, and inorganic paints such as cement-based paints. I can do it. Further, the restraining material may be a material whose surface is coated with paint in consideration of aesthetic appearance, durability such as corrosion resistance, or a laminate with a film or the like pasted thereon. The condition that the restraining material must meet is that it adheres closely to the viscoelastic body, but the adhesion may be improved using a primer or the like. Further, it is desirable that the restraining material be made of a material with high rigidity, and a metal thin film or a metal net is suitable.
Further, the restraining material may have a so-called double-tube structure in which a gap is provided between the tubular body and the restraining material in which a viscoelastic body is inserted, and the restraining material is integrated with the tubular body. In addition, the restraining material only needs to have a viscoelastic body between it and the pipe body, and when fibers or net-like materials are used as the restraining material, even if the restraining material is embedded in the viscoelastic body. It can fully perform the vibration damping function. Next, an example of one aspect of the manufacturing method will be shown. As an example of a method for producing a viscoelastic body, in the case of the viscoelastic body used in the examples described below, a mixture of straight asphalt 60/80 and tackifying resin is added to hydroxyl-terminated liquid polybutadiene rubber and heated and melted. While adding the prescribed ingredients and mixing, gradually add the plasticizer, anti-aging agent, and mica, and disperse thoroughly and uniformly. Next, the base material is prepared through an ink roll, and a predetermined amount is sufficiently mixed with the curing agent, and the mixture is surrounded by the tube. The method is to
This can be done by uniformly enclosing the viscoelastic body by a method such as spraying, and wrapping the restraining material after the viscoelastic body stops flowing due to curing or solidification. Furthermore, for the part where piping has already been installed, a restraining material that has been applied and hardened may be wrapped around it. Next, the present invention will be explained using examples and comparative examples with reference to the drawings. Example 1 shows a case where the metal tube is a straight tube, a viscoelastic layer is formed around it, and a restraining material layer is further wrapped around it. Embodiment 2 shows a case where a metal pipe body is processed into a spiral shape, a viscoelastic body is surrounded by the viscoelastic body, and a restraining material is further wrapped around the metal pipe body. Comparative Example 1 shows the case where the metal tube used in Example 1 was a single straight pipe. Comparative Example 2 shows the case of a single tube in which the metal tube used in Example 2 was processed to have irregularities in a spiral shape. Comparative Example 3 shows a case where a viscoelastic body was enclosed in Comparative Example 2 but no restraining material was used. Examples and comparative examples are shown in tables, and an example of the relationship between the damping properties of the viscoelastic body and temperature is shown in the graph of FIG. 7 (relationship between the damping properties of the viscoelastic body and temperature).
Furthermore, the vibration situation is shown in FIGS. 8 to 11, that is, graphs. The graph shows the copper straight pipe alone, the graph shows the copper spiral pipe + viscoelastic body, the graph shows the copper spiral pipe + viscoelastic body + restraint material, and the graph shows the copper spiral pipe + high hardness viscoelastic body + restraint material. In addition, the situation of vibration due to the difference in hardness of the viscoelastic body between the grab and the grab was shown.
In addition, the table shows formulation examples (in parts by weight) of the viscoelastic bodies used in the examples. Next, a test method showing examples of the present invention and comparative examples will be explained. Straight pipes and spiral pipes were used for copper pipes with a diameter of 15.88 mm, wall thickness of 0.5 mm, and thickness of 500 mm (50 mm on each end were straight pipes, and 400 mm in the center was processed into a spiral shape. Note that the uneven parts The difference in depth between the crests and troughs was set to 2 mm.
A thin aluminum film with a thickness of 50μ is pasted, a single spiral tube, a spiral tube with a viscoelastic material approximately 0.5 mm thick above the convex part, and a concave part surrounded on the entire surface.
Furthermore, the viscoelastic material of the spiral tube surrounding the viscoelastic material is wrapped with a thin aluminum film having a thickness of 50μ.Furthermore, a high-hardness viscoelastic material is wrapped around the spiral tube to a thickness of approximately 0.5 mm above the convex portion, and the entire surface of the concave portion is covered. It is surrounded by a 50μ thick aluminum film wrapped around its outer circumference. Samples were created for five types. The viscoelastic bodies used in the test were as shown in the table. One end of each of the tubes prepared as described above was attached to a 50 mm thick iron stand to create a cantilever beam. Next, each sample was subjected to a vibration test using the FFT method, and the results were converted into a chart using a computer. As shown in the table and graphs in the drawings, it can be seen that Examples 1 and 2 of the present invention suppress vibrations very efficiently.
Furthermore, the damping due to vibration suppression is large, and as is especially clear from the graph of FIG. 10, the waveform of the peak indicating resonance is also very wide, and the loss of vibration energy is also very large, indicating a large vibration suppression performance. Also the first
The graph in Figure 1 shows that although it is inferior to the case of the low hardness viscoelastic body shown in the graph, the vibration damping effect is large, the width of the waveform is wide, and the loss of vibration energy is large. Comparative Example 1 shows a single straight copper pipe. This is a very large vibration inertance, and it is necessary to take measures to prevent vibration. Comparative Example 2 is a copper tube made into a spiral shape. Although it reduces inertance, it has poor damping ability and is susceptible to metal fatigue. Comparative Example 3 shows a case where a viscoelastic body is surrounded by a spiral copper tube. Although the vibration inertance further decreases and the resonant frequency also decreases, the waveform indicating the resonance point also sharpens, and the phase shown at the top of the graph changes rapidly, indicating that a sufficient vibration damping effect has been obtained. isn't it. Also, the speed of deceleration is slow,
Similar to Comparative Example 2, some measures are required to avoid metal fatigue. In other words, by utilizing the present invention, vibrations are absorbed and quickly damped, reducing fatigue of the tube itself and the joint surface between the tube and other members, and improving the durability of the tube and joints. It is possible to increase the length of the tube and shorten the length of the tube.
It has great economical advantages in that it can be made smaller than the piping space, does not require adjustment of the resonance point, significantly reduces man-hours, and has increased durability. has very high utility value.

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【table】 [Brief explanation of drawings]

FIG. 1 is a longitudinal cross-section showing a tubular body according to an embodiment of the present invention, and shows a case where both the inner and outer surfaces of the metal tubular body are uneven. FIG. 2 is a longitudinal cross-sectional view showing a tubular body according to another embodiment of the present invention, in which the metal tubular body has straight inner and outer surfaces. Figure 3 shows
FIG. 7 is a longitudinal sectional view showing a tubular body according to still another embodiment of the present invention, in which only the outer surface of the metal tubular body is uneven. FIG. 4 is a longitudinal sectional view showing a tubular body according to still another embodiment of the present invention, in which the inner surface of the metal tubular body is uneven and the width of each concave and convex portion is wide. . FIG. 5 is a longitudinal cross-sectional view showing a tubular body according to still another embodiment of the present invention, and shows a case where the restraining material is attached to the tubular body in a spiral shape. FIG. 6 is a schematic diagram illustrating the measurement method according to the invention. FIG. 7 is a diagram (graph) showing the relationship between vibration damping properties and temperature of the viscoelastic body according to the present invention. FIG. 8 is a diagram showing the state of vibration of a single straight copper pipe (graph). FIG. 9 is a diagram showing the vibration state of the copper spiral tube + viscoelastic body (graph). FIG. 10 is a diagram showing the vibration state of the copper spiral tube + viscoelastic body + restraint material (graph). Furthermore, FIG. 11 is a diagram showing the vibration state of the copper spiral tube+high-hardness viscoelastic restraint material+restraint material (graph). DESCRIPTION OF SYMBOLS 1... Metal pipe body, 2... Viscoelastic body layer, 3... Constraint material layer, 4... Constraint material fixing material, 5... Sample, 6...
...Pickup, 7...Hammer, 8...Cord, 9...FFT vibration measuring device, 10...Sample mounting stand.

Claims (1)

[Claims] 1 Vinyl chloride, polyethylene, polybutene,
A liquid polymer that is reactive at room temperature and its hardening agent are applied to the outer periphery of a desired tube body made of iron, stainless steel, brass, or copper and having an uneven outer surface and/or inner surface. A viscoelastic layer that is crosslinked as a basic polymer and has a hardness of 50 or less in the C type hardness specified in the Japan Rubber Association standard SRIS0101 is formed around the viscoelastic layer, and a restraining material is further formed on the outer periphery of the viscoelastic layer. A method for producing a constrained vibration damping tubular body, which comprises forming layers in a wound manner.