JPH0719282A - Vibration insulating noise absorbing body - Google Patents

Abstract

PURPOSE:To provide a vibration insulating noise absorbing body which is manufactured at low cost and constituted to have excellent durability and effectively reduce the generation of traffic vibration and noise of a railroad and a road. CONSTITUTION:In a vibration insulating noise absorbing body formed of a binder and an aggregate, rubber particles are used as an aggregate and the vibration insulating noise absorbing body has porosity of 15-40%. A mixture of rubber particles and a rigid aggregate is used as the aggregate when occasion demands.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration damping and sound absorbing body, and more specifically to a vibration damping and noise reducing body mainly for railways, roads, etc. by using a specific aggregate and having a specific porosity. Vibration absorbers.

[0002]

2. Description of the Related Art Vibrations and noises include traffic vibrations and noises on railways, roads, etc., vibrations and noises emitted from machine tools and manufacturing machines, office automation equipments such as office equipments, and household electric appliances at homes. , Etc., which all cause daily discomfort and cause stress.

Railway noise is transmitted by sounds radiated from the vehicle such as pantograph noise, aerodynamic noise, and rolling noise, and vibrations from the vehicle.
Sound is radiated from structures such as viaducts.

To reduce the sound radiated from the vehicle, a soundproof wall is provided, and a sound absorbing material such as glass wool or foamed aluminum is attached to the inside of the soundproof wall. Further, in order to reduce the sound emitted from the structure, a grooved rubber is used between the rail and the structure, for example, between the rail and the sleepers, between the sleepers and the concrete track, and between the concrete track and the viaduct. A method of performing vibration insulation by installing a vibration-proof mat, etc. was used. In addition, ballast is also used to simultaneously obtain vibration insulation and sound absorption.

Further, as a method of reducing road traffic noise,
It is widely practiced to install soundproof walls and soundproof planting on both sides of the road, but these are mainly used around automobile roads because they require a large area around the road.
In recent years, as a noise countermeasure near a noise source, a sound absorbing pavement material having an asphalt pavement having many voids as a surface layer has been developed.

As a method of preventing vibration and noise of office automation equipment such as printers and copying machines of personal computers, home appliances such as refrigerators and washing machines, a measure such as laying a thin rubber vibration-proof mat is used. It's just done.

[0007]

However, the glass wool as the sound absorbing material is inferior in durability such as scattering when exposed to wind and rain, and the metal porous body such as foamed aluminum is expensive as a material. There are drawbacks. Anti-vibration mats such as grooved rubber are useful for reducing vibration, but do not have a sound absorbing effect. The method of obtaining vibration insulation and sound absorption effect by ballast has a problem that the weight becomes very large, and deterioration due to wind and rain vibration is severe, and repair is required once every several months, so durability, It also has problems such as complexity of maintenance.

Further, the sound absorbing pavement material used for reducing road traffic noise is mainly intended for drainage, and since hard crushed stone is used as the aggregate, the effect of blocking vibration cannot be obtained.

Further, it has been the current situation that a rubber mat for preventing vibration due to a machine or the like cannot effectively prevent vibration and noise.

The object of the present invention is inexpensive, excellent in durability,
Moreover, vibrations and noise, especially traffic vibrations of railways, roads, etc.
It is an object of the present invention to provide a vibration damping and sound absorbing body capable of effectively reducing noise.

[0011]

According to a first aspect of the present invention, in a vibration damping and sound absorbing body comprising a binder and an aggregate, rubber particles are used as the aggregate, and the porosity is 15 to 40%. Is characterized by.

A second aspect of the present invention is the vibration damping and sound absorbing body according to the first aspect, wherein a mixture of rubber particles and hard aggregate is used as the aggregate.

A third aspect of the present invention is the vibration-damping and sound-absorbing body according to claim 1, wherein the vibration-damping and sound-absorbing body has a thickness of 20 mm or more, and is laid on the roadbed of a railroad track. To do.

[0014]

[Function] In the vibration absorbing and sound absorbing body, the aggregate is rubber particles, or
Uses a mixture of rubber particles and hard aggregates and has a porosity of 15 to 4
When the content is 0%, vibration and sound waves are effectively attenuated by the elasticity of the rubber particles and the effect of individual voids existing around the rubber particles, which is useful for reducing vibration and noise. In addition, since rubber particles and binders, which are generally used for pavements and the like, are used in general, excellent effects can be obtained, so that a vibration-proof sound absorbing body that is inexpensive and has excellent durability even when used for transportation is obtained. Is something that can be done.

[0015]

The present invention will be described in detail below with reference to specific examples.

The present invention is a vibration damping and sound absorbing body comprising a binder and an aggregate, wherein rubber particles are used as the aggregate, and
The present invention relates to a vibration damping and sound absorbing body having a porosity of 15 to 40%.

The rubber particles used for the aggregate in the present invention include rubber particles molded by a conventional method, powdered rubber,
It is possible to use spews generated during tire vulcanization, crushed products of used tires, grinding scraps of tire treads generated during manufacturing of recycled tires, crushed products of used rubber products such as rubber belts and anti-vibration rubber. As described above, the rubber particles do not necessarily have to be spherical and may have any shape, but the average particle diameter is preferably about 2.5 mm to about 15 mm. vibration·
For noise, it is preferably about 2.5 mm to about 6 mm.

As a binder for a vibration and sound absorbing body, asphalt is generally used, and other binders include:
For example, epoxy-based, urethane-based, acrylic-based, and polyester-based polymer resins are listed, and in consideration of durability and the like, these polymer resins may be used, or these may be mixed with asphalt and used. Also, during asphalt,
Rubbers such as SBR (styrene-butadiene rubber) and CR (chloroprene rubber), or rubber-like polymers such as EVA (ethylene-vinyl acetate copolymer) and SBS (styrene-butadiene-styrene block copolymer) alone or in a mixture. Modified asphalt to which is added as a modifier can be used for improving durability.

The hard aggregates used by mixing with the rubber particles generally include natural aggregates made of natural stone such as river gravel and river sand, and artificial aggregates made of slag, crushed stone, etc., and are not particularly limited. However, for example, crushed stone No. 5 (particle size range 20 to 13 mm) and No. 6 (13 to 5 m) specified in JIS
m), No. 7 (5-2.5 mm), silica sand No. 4 (0.3-
0.6 mm), No. 5 (0.15-0.3 mm) or equivalent size of natural aggregate such as river gravel, mountain gravel, river sand and sea sand. In addition to these crushed stones and gravel, any hard material such as fiber reinforced plastic (FRP) waste material, crushed resin waste material, and steel slag can be arbitrarily used. The shape of the hard aggregate is arbitrary, but those having an average particle size of about 2.5 mm to about 15 mm are preferably used.

By mixing the aggregate and the binder, the aggregate partially adheres to each other through the binder, and the voids are retained after the binder is hardened.

In the present invention, the porosity of the vibration damping and sound absorbing body is
It is necessary to be 15 to 40%, especially 25 to 30
% Is preferable. If the porosity is less than 15%, the damping rate of vibrations and sound waves in the vibration damping sound absorbing body is small, and the vibration damping sound absorbing effect is insufficient, and if it exceeds 40%, the durability of the vibration damping sound absorbing body becomes problematic. Therefore, it is not preferable.

In the present invention, the porosity is represented by the following formula. 1- (apparent density / theoretical density) [where the apparent density is (total weight / apparent volume),
The theoretical density is obtained from (total weight of raw material mixture / total volume of mixture obtained from the density of each mixture). As an example of the method for producing the vibration-damping sound absorber, after mixing the rubber particles or the mixture of the rubber particles and the hard aggregate with a mixer for several minutes to homogenize the mixture, the asphalt serving as the binder is added and mixed to form an asphalt mixture. , A method of charging into a molding die to cure the binder, and molding into a plate shape. As the asphalt mixture, any of a heating mixture used by heating asphalt and a room temperature mixture using liquid asphalt at room temperature can be used. Also,
When the vibration-damping sound absorber of the present invention is used for roads, a mixture of an aggregate such as rubber particles and a binder such as asphalt is put on the base road base layer, tightened and hardened, and may be directly laid. it can.

The composition of the vibration absorbing and sound absorbing body is preferably 2 to 15 parts by weight of binder with respect to 100 parts by weight of aggregate which is rubber particles or a mixture of rubber particles and hard aggregate. The desired porosity can be obtained by adjusting the ratio of the binder to the. The amount of the hard aggregate mixed with the rubber particles is preferably about 0 to 60% by weight.

A sheet-shaped rubber composition generally has a very large spring constant, so that it is not possible to obtain a desired vibration damping performance. Therefore, the vibration-proof mat has a space for allowing the rubber to escape at the time of compression, such as a grooved rubber, so as to have a suitable spring constant, thereby improving the vibration-proof performance. In the present invention, a desired spring constant is easily achieved by providing a void around the rubber particles.

FIG. 1 is a graph showing the relationship between the frequency of the sound waves of the vibration absorbing and sound absorbing body and the normal incidence sound absorbing coefficient when the porosity is changed.

The normal incident sound absorption coefficient in FIG. 1 was measured by 100 parts by weight of rubber particles obtained by freeze-grinding a used tire having a particle diameter of 3 mm to 5 mm and straight asphalt 10
By mixing parts by weight with heating, the porosity is 10%, 15%, 20
%, 25%, 30% and molded and solidified to a diameter of 86 mm and a thickness of 40 mm as a sample.
Based on A1405.

The horizontal axis represents the frequency (Hz) of the sound wave and the vertical axis represents the normal incident sound absorption coefficient, and a graph of the sound absorption coefficient of the vibration-damping sound absorbing body having each porosity is displayed. Generally, it is known that a normal incident sound absorption coefficient of 0.3 or more at any frequency can provide a sufficient noise prevention effect. As for the sample No. 3, a sufficient sound absorbing performance was obtained, but it can be seen that a sample having a porosity of 10% cannot obtain a clear sound absorbing performance.

FIG. 2 is a graph showing the relationship between the frequency of sound waves and the normal incident sound absorption coefficient of a vibration absorbing and sound absorbing body in which a mixture of rubber particles and hard aggregate is used as the aggregate.

The vertical incident sound absorption coefficient in FIG. 2 was measured by a mixture of 60 parts by weight of rubber particles obtained by freeze-pulverizing a used tire having a particle diameter of 3 mm to 5 mm and 40 parts by weight of No. 6 crushed stone and straight asphalt 10. Parts by weight by heating,
A sample having a porosity of 25% and having a diameter of 86 mm and a thickness of 40 mm and solidified is used as JIS A1405.
Based on. From FIG. 2, it can be seen that even if a mixture of rubber particles and hard aggregate is used as the aggregate, almost the same sound absorbing performance as that obtained by using only the rubber particles can be obtained.

FIG. 3 is a graph showing the relationship between the frequency of a sound wave and the normal incident sound absorption coefficient when the thickness of the vibration absorbing and sound absorbing body is changed.

The normal incident sound absorption coefficient when the thickness is changed is shown for the sample shown in FIG. When the vibration frequency of each sound wave is measured, the sound absorption coefficient has a peak at 1 KHz at a thickness of 40 mm, and the sound absorption coefficient has a peak at 2 KHz at a thickness of 20 mm. Considering that the main frequency of railway noise is in the range of 250 Hz to 2 KHz, when used to prevent railway noise vibration, the thickness is 20 mm.
It turns out that the above is necessary. Also, from the viewpoint of sound absorbing performance, it is understood that the thicker the thickness, the better.

FIG. 4 is a graph showing the relationship between the ratio of hard aggregate in the aggregate and the spring constant of the vibration absorbing and sound absorbing body.

Among those shown in FIG. 1, the porosity is 25%.
The samples in which the ratio of the rubber particles of the aggregate to the hard aggregate to be mixed was changed were measured according to the static spring constant test of JIS K6385. As is apparent from FIG. 4, in the vibration damping and sound absorbing body of the present invention, it is understood that the desired spring constant can be obtained by adjusting the ratio of the hard aggregate to be mixed. The spring constant is a parameter for anti-vibration performance. For example, it is necessary that at least 2 kgf / cm ³ is used as a vibration isolator for OA equipment and home appliances, and used as a vibration isolator for railways. Generally, the spring constant is 5 kgf / cm ^{3 to} 48, depending on the part.
Those of kgf / cm ³ are preferably used. It can be seen that the spring constants of all the samples are within the range of this preferable vibration damping material.

(Examples 1 to 4) The formulations shown in Table 1 below,
With a porosity, a vibration-damping sound absorbing body having a thickness of 40 mm was prepared, and the sound absorbing coefficient and the spring constant were measured as Examples 1 to 4, respectively.
The sound absorption coefficient measurement results are shown in FIG. 5, and the spring constants are shown in Table 1.

[0035]

[Table 1]

FIG. 5 is a graph showing the relationship between the frequency of the sound waves of the vibration absorbing and sound absorbing bodies of Examples 1 to 4 and the normal incidence sound absorbing coefficient.

The horizontal axis represents the frequency of sound waves, and the vertical axis represents the normal incident sound absorption coefficient. As is clear from FIG. 5, all of the examples have a normal incident sound absorption coefficient of 0.5 or more for sound waves having a frequency that is a problem for traffic noise, and it is clear that they have excellent sound absorption performance. In addition, from the spring constants in Table 1, all of Examples 1 to 3 show excellent performance as a vibration isolator for preventing traffic vibration, and Example 4 is a vibration isolator used for machines such as OA equipment and home appliances. It is clear that it shows suitable performance as a material. That is, in each of Examples 1 to 4,
It also had a sound absorbing effect.

As a method of using the vibration damping and sound absorbing body of the present invention,
When creating a vibration-damping absorber with the desired mix, thickness, and porosity required by the noise source and using it as a measure against railway noise and vibration, for example, by laying it between a concrete roadbed and sleepers And vibration isolation. When used as a measure against road traffic noise / vibration, for example, by attaching the anti-vibration sound absorbing body of the present invention to the surface layer of the pavement, or by laying it directly on the base layer of the pavement,
The sound generated from the contact surface between the tire and the pavement is reduced, and the vibration when the vehicle passes through is blocked from propagating along the road through the ground. Further, when used for machines such as office automation equipment and home electric appliances, it is possible to easily obtain a vibration absorbing and sound absorbing effect by forming it into a sheet and laying it under the machine.

The vibration-damping and sound-absorbing body of the present invention is used as rubber particles which are essential components and hard aggregates used as desired as described above, as recovered rubber products such as used tires, crushed FRP waste materials, and steel slag. Since such recycled resources can be suitably used, not only can the manufacturing cost of the vibration-damping and sound-absorbing body be reduced, but also environmentally-friendly and resource-saving advantages are obtained.

[0040]

EFFECTS OF THE INVENTION Since the vibration-damping and sound-absorbing body of the present invention has the above-mentioned structure, it has an excellent effect that it is inexpensive, has excellent durability, and reduces vibration and noise caused by traffic and the like.

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between the frequency of sound waves of a vibration-damping sound absorber and the normal incidence sound absorption coefficient when the void ratio is changed.

FIG. 2 is a graph showing the relationship between the frequency of sound waves and the normal incident sound absorption coefficient of a vibration-damping sound absorbing body using a mixture of rubber particles and hard aggregate for the aggregate.

FIG. 3 is a graph showing the relationship between the frequency of sound waves and the normal incident sound absorption coefficient when the thickness of the vibration absorbing and sound absorbing body is changed.

FIG. 4 is a graph showing the relationship between the ratio of hard aggregate in the aggregate and the spring constant of the vibration absorbing and sound absorbing body.

FIG. 5 is a graph showing the relationship between the frequency of the sound waves of the vibration-damping sound absorbers of Examples 1 to 4 and the normal incident sound absorption coefficient.

Claims (3)

[Claims] 1. A vibration-damping sound-absorbing body comprising a binder and an aggregate, wherein rubber particles are used as the aggregate and the porosity is 15 to 40%. 2. The vibration damping and sound absorbing body according to claim 1, wherein a mixture of rubber particles and hard aggregate is used as the aggregate. 3. The vibration damping and sound absorbing body according to claim 1, wherein the vibration damping and sound absorbing body has a thickness of 20 mm or more and is laid on the roadbed of a railroad track.