JPH1096448A - Vibration damping sound absorbing member and vibration damping sound absorbing-sound insulating member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide subject excellent in sound absorbing performance in a low frequency area by arranging through holes to connect hollow parts of these elastic hollow bodies in an elastic hollow body block which is composed of an elastic member having continuous bubbles and inside which plural elastic hollow bodies having the hollow parts are integrally formed. SOLUTION: Through holes 4 to connect hollow parts (t) of elastic hollow bodies 1, 2 and 3 are arranged in a block where the cylindrical elastic hollow bodies 1, 2 and 3 obtained by cutting a cylindrical continuous hollow body by performing continuous extrusion molding, are turned in the vertical (Y axis), horizontal (X axis), height (Z axis) respective directions, and are adhered together as one. A rubber type adhesive is used as an adhesive. Since it is thought that these through holes 4 or the hollow parts (t) function as slits and wall bodies of the elastic hollow bodies 1, 2 and 3 having continuous bubbles positioned at its back function as a sound absorbing body, they have a function close to a slit or a perforated plate resonator. Therefore, sound absorbing performance in a low frequency can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration damping sound absorbing material and a sound damping sound absorbing material used for reducing engine noise of a diesel vehicle such as a truck.

[0002]

2. Description of the Related Art Diesel engine noise is caused by, for example, vibrations of a cylinder block, a cylinder head, a crankshaft, a striking sound of a gear nozzle and a valve system, a striking sound of a piston and a cylinder block, and various lines. Such as the sound of flowing fluid.

[0003] In order to reduce such vibrations and the noise caused thereby, conventionally, for example, a sponge rubber or a urethane home molded product adapted to the shape of the mounting portion has been mounted around the above-mentioned various components.

[0004]

However, these molded articles have a certain function as a vibration damping material, but have a limited sound absorbing effect in a low frequency region as a sound absorbing material, and have a sufficient function. I couldn't say it did. This is considered to be due to the following reasons (1) and (2).

(1) The basic sound-absorbing characteristics of a porous material such as sponge rubber or urethane home are determined by a network of open-cell capillary channels. A portion of incident sound energy such as noise is converted into heat energy in these bubbles and absorbed by the porous material, and the remaining incident energy is reflected from the surface of the material. The sound absorbing effect of the porous material here increases as the thickness of the material increases. However, sound absorption by the porous material is larger in the high frequency region than in the low frequency region. Therefore, the conventional vibration damping sound absorbing material has poor sound absorbing performance in a low frequency region.

(2) As described above, the sound absorbing effect of the porous material increases as the thickness of the material increases. However, if there is an air layer between the materials, and as the thickness increases, as the thickness increases. It increases in the low frequency region. However, in the case of the conventional vibration damping sound absorbing material, this air space cannot be secured. For this reason, the sound absorption performance in the low frequency region is poor.

[0007] Further, since the molded product of sponge rubber or urethane home is molded in accordance with the shape of the space at the mounting location, the cost increases. In addition, for the same reason, the mounting location is limited, and lacks versatility.

Further, in the case of a sponge rubber or urethane foam molded article, by using it together with a molded steel sheet,
Some have a function as a sound insulating material, but in order to increase the sound insulating effect, it is necessary to increase the thickness of the steel plate, which increases the cost and weight. In addition, since a molded steel plate is used, mounting points are limited, and the versatility is lacking.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and is provided by forming a block made of a plurality of elastic hollow bodies made of synthetic rubber or the like, or by providing a through hole in the block. It is an object of the present invention to provide an inexpensive and versatile vibration-damping and sound-absorbing material which is excellent in vibration property and sound absorption in a frequency range from a low frequency range to a high frequency range.

[0010] The present invention also provides vibration-damping and sound-absorbing properties by laminating an elastic material having open cells such as sponge rubber or urethane foam and an elastic material having no air bubbles such as solid rubber or PVC material. It is an object of the present invention to provide an inexpensive and versatile vibration damping sound absorbing and sound insulating material having excellent sound insulating properties.

[0011]

[Means for Solving the Problems]

(1) The vibration-damping and sound-absorbing material provided by the present invention comprises a block of an elastic hollow body made of an elastic material having open cells and integrally formed with a plurality of elastic hollow bodies having a hollow portion therein. It is provided with a through-hole connecting the hollow portions of the elastic hollow body.

Another vibration-damping and sound-absorbing material provided by the present invention is an elastic hollow body made of an elastic material having open cells and integrally formed with a plurality of elastic hollow bodies having hollow portions therein. It consists of blocks.

The shape of the hollow portion of the elastic hollow body is as follows.
For example, a columnar shape, a pot shape, a ball shape and the like can be used.

The block may be formed by combining a plurality of elastic hollow bodies having the same shape and size into one, or a plurality of elastic hollow bodies having the same shape and at least partially different in size. They may be made together.

In addition, the block can be formed with a plurality of elastic hollow bodies each oriented in an arbitrary direction. That is, for example, a part may be formed in a different direction from other parts, all may be formed in the same direction, or all may be formed in a different direction.

(2) The vibration-damping sound-absorbing sound-insulating material provided by the present invention is referred to as an elastic material having open cells (hereinafter, referred to as a first elastic material) and an elastic material having no air bubbles (hereinafter, referred to as a second elastic material). ).

The first and second elastic materials may be provided with a hollow portion inside or a groove, unevenness or the like outside. The second elastic material may be a flat plate or a waveform.

The shape of the hollow portion is, for example, a cylindrical shape, an elliptic cylindrical shape, a pot shape, a ball shape, and the like. The shape of the groove is, for example, a V-shaped cross-section, a U-shaped cross-section, and the like. It has a crater shape or the like.

The laminate may have a two-layer structure of a first elastic material and a second elastic material (hereinafter, referred to as a unit laminate) or a laminate of a plurality of unit laminates (hereinafter, multiple laminates). Body). The shape and size of the unit laminate and the multiple laminate are arbitrary.

[0020]

[Action]

(1) Action of the vibration damping sound absorbing material The vibration damping sound absorbing material of the present invention has a thickness of the elastic material having open cells thinner by the volume of the hollow portion as compared with the conventional vibration damping sound absorbing material. Has sound absorbing performance. Conversely, the vibration-damping and sound-absorbing material of the present invention can have a large air space corresponding to the hollow portion. For this reason, the sound absorption performance in the low frequency region is improved accordingly.

In the vibration damping and sound-absorbing material of the present invention, the hollow portion functions as a sound wave propagation space, that is, a cavity (Helmholtz), and the through hole functions as a narrow opening communicating with the hollow portion, that is, as a neck. It is considered to have a function close to that of a Helmholtz resonator.

In the vibration-damping and sound-absorbing material of the present invention, the through hole or the hollow portion functions as a slit, and the elastic material having open cells located behind the hole or the hollow portion functions as the sound absorber. It is considered to have a function close to that of a resonator. Therefore, according to the vibration damping and sound absorbing material of the present invention, the sound absorbing performance in the low frequency region is improved.

Since the vibration-damping and sound-absorbing material of the present invention is made of an elastic material, for example, if it is mounted around a cylinder block of a diesel engine, the vibration of the cylinder block, the cylinder head, the crankshaft, etc. can be reduced at least by the conventional vibration damping material. It can be absorbed to the same degree as the vibration absorbing material.

The vibration-damping and sound-absorbing material of the present invention is a block made of an elastic hollow body which is made up of a single unit. If there is one type of block having a shape and size that is slightly larger than the space, it can be used for all the space in that range. Therefore, there is versatility. Also, the number of types of blocks to be prepared can be reduced, so that the cost can be reduced.

(2) Operation of the vibration-damping sound-absorbing sound-insulating material The sound-damping sound-absorbing sound-insulating material of the present invention can suppress sound transmission by an elastic material having no air bubbles.

In the vibration damping sound absorbing material of the present invention, the elastic material having open cells has sound absorbing performance in a high frequency range.
Further, the vibration-damping and sound-absorbing material of the present invention is such that, when an elastic material having open cells is provided with a hollow portion or a groove, unevenness, or the like, the hollow portion or the groove has an amount corresponding to a gap formed by the unevenness. The air layer can be large. For this reason, the sound absorption performance in the low frequency region is improved accordingly.

[0027] The vibration-damping sound-absorbing sound-insulating material of the present invention comprises a hollow portion,
Since the grooves and irregularities function as a sound wave propagation space, that is, a cavity (Helmholtz) and also function as a neck, it is considered that they have a function similar to a cavity (Helmholtz) resonator.

In the vibration-damping and sound-absorbing sound-insulating material of the present invention, a hollow portion, a groove, and a space formed by irregularities function as a slit,
Since the elastic material having open cells is considered to function as a sound absorber, it is considered that the elastic material has a function similar to a slit or perforated plate resonator. Therefore, according to the vibration damping sound absorbing and sound insulating material of the present invention, sound absorbing performance in a low frequency region is improved.

Since the vibration damping sound absorbing and sound insulating material of the present invention is made of an elastic material, if it is mounted around a cylinder block of a diesel engine, for example, the cylinder block,
Vibration of the cylinder head, crankshaft, etc. can be absorbed.

Since the vibration-damping and sound-absorbing sound-insulating material of the present invention is a laminated body, there is a slight difference in the size of the space at the mounting point.
If one kind is slightly larger than that space, it can be used for all of the space in that range. Therefore, there is versatility. In addition, since the number of types of the laminated body to be prepared is small, the cost is low.

[0031]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a plan view of an embodiment (hereinafter, referred to as Embodiment 1) of a vibration-damping and sound-absorbing material, FIG. 2 is a front view thereof, and FIG. It is.

In the drawing, K is the vibration damping sound absorbing material of the first embodiment. In this method, cylindrical elastic hollow bodies 1, 2, and 3 obtained by cutting a continuous extruded cylindrical elastic hollow body are vertically (Y-axis), horizontal (X-axis), and height (Z-axis). ) Are formed by providing through holes 4 for connecting the hollow portions t of the elastic hollow bodies 1, 2, 3 to a block of the elastic hollow body formed by bonding them together in each direction. As the adhesive, a rubber-based adhesive was used.

The elastic hollow bodies 1, 2, 3 are made of EPDM (ethylene-propylene-diene-terpolymer) having open cells. The length of each elastic hollow body 1, 2, 3 is 60 mm, 80 mm, 104 mm, respectively, and the outer diameter is 22 mm.
mmφ, the inner diameter is 16 mmφ, which is common to all three. Therefore, the size of the block is 204 mm long and 230 mm wide.
mm and a height of 124 mm.

The through hole 4 has a diameter of 9 mm, and has a vertical, horizontal,
50 mm intervals in each direction of height, ie, elastic hollow body 1
(2, 3) are provided at an interval of two lines. Through hole 4
Are radial holes of the elastic hollow bodies 1, 2, 3.

Next, the operation based on the above configuration will be described.

(1) The vibration damping sound absorbing material K is made of an elastic hollow body 1
EPD having open cells in the material used in 2 and 3
Since it is M, it has sound absorbing performance in a high frequency region.

(2) The vibration damping and sound absorbing material K is made of an elastic hollow body 1,
Since a structure in which an air layer corresponding to the hollow portion t is provided between the two or three walls, the sound absorbing performance in a low frequency region is good.

(3) In the vibration damping sound absorbing material K, the hollow portion t functions as a sound wave propagation space (cavity) and the through hole 4 functions as a narrow opening (neck) communicating with the hollow portion t. (Helmholtz) It is thought that it functions like a resonator.

The through holes 4 or the hollow portions t function as slits, and the walls of the elastic hollow bodies 1, 2, and 3 having open cells located behind the through holes 4 or the hollow portions t function as sound absorbers. It is considered to have a function similar to a perforated plate resonator.

Therefore, according to the vibration damping sound absorbing material K,
The sound absorption performance in the low frequency region is improved.

(4) The vibration damping and sound absorbing material K is made of EPDM and has elasticity. For example, by attaching it around a cylinder block of a diesel engine, the vibration of each part of the block is suppressed, and Generation of noise can be reduced.

(5) Since the vibration-damping and sound-absorbing material K has a simple shape in which only the through-hole 4 is formed in the block, the shape and size of the space in which it is mounted are typified, and By preparing several kinds of corresponding ones, most demands can be met. Therefore, it is cheap and versatile.

In Example 1, EPDM was used as the material of the elastic hollow body having open cells. In addition, synthetic rubber such as butyl rubber, acrylic rubber, nitrile butadiene rubber, silicone rubber, and thermoplastic elastomer were used. And other elastic materials can be used.

In the first embodiment, the elastic hollow body has a cylindrical shape. However, the elastic hollow body having a hollow portion such as a column, a pot, and a ball may be used. The shape and dimensions of the elastic hollow body may all be the same,
Different ones may be used, or partially different ones may be used.

In the first embodiment, the elastic hollow bodies in the block are arranged in the vertical, horizontal, and height directions, and are adhered. However, the elastic hollow bodies are adhered in any one or two directions. You may. Also, a unit block obtained by simultaneously extruding several elastic hollow bodies at the same time may be used as a unit block, and the unit block may be bonded to form a block.

Further, in Example 1, all layers of the elastic hollow body were made of EPDM having open cells. In addition to this, for example, the following materials were used and the following layer structure was adopted. be able to.

(1) Inner layer as sponge layer, outer layer as solid layer (2) Inner layer as solid layer, outer layer as sponge layer (3) Inner layer as non-oil resistant sponge layer, outer layer as oil resistant sponge layer (4) Inner layer as non The heat-resistant sponge layer and the outer layer are the heat-resistant sponge layer. (5) The inner layer is one layer selected from the above (1) to (4), and the outer layer is the one from the above (1) to (4). Another Selected Layer In the first embodiment, the through hole 4 is provided in the block of the elastic hollow body. However, the through hole 4 may be provided as needed. Even in the block in which the through-hole 4 is not provided, there is no significant difference in operation when the through-hole 4 of the first embodiment is provided.

(Embodiment 2) FIG. 4 is a side view of an embodiment (hereinafter, referred to as Embodiment 2) of a vibration damping sound absorbing and sound insulating material.

In the drawing, S ₁ is the vibration damping sound absorbing and sound insulating material of the second embodiment, which is formed by laminating four unit laminates U ₁ to form a multiple laminate.

The unit laminate body U _1, the surface is corrugated surface, and a solid plate 12 of EPDM having no sponge plate 11 and bubble EPDM having continuous air bubbles back surface has a planar, adhered in each of the planes It is formed by. A rubber adhesive was used for adhesion. The size of the damping sound absorbing sound insulator S ₁ is vertical 200 mm, horizontal 230 mm,
The height is 120 mm.

Next, the operation based on the above configuration will be described.

(1) The vibration-damping and sound-absorbing sound-insulating material S ₁ has sound insulating performance because the solid plate 12 suppresses sound transmission.

[0054] (2) vibration absorbing sound insulator S ₁ is, EPDM in which material used for the sponge plate 11 has an open cell
Therefore, it has a sound absorbing performance in a high frequency region.

(3) Since the vibration damping sound absorbing and sound insulating material S ₁ has a structure in which an air layer corresponding to the hollow portion 13 between the corrugated surface of the sponge plate 11 and the solid plate 12 is provided, the sound absorbing material S ₁ in the low frequency region is provided. Good sound absorption performance.

(4) The vibration damping sound absorbing and sound insulating material S ₁
Function as a slit and the sponge plate 11 functions as a sound absorber, so that it is considered to have a function similar to a slit or a perforated plate resonator. Therefore, sound absorption performance in a low frequency region is good.

(5) The vibration damping sound absorbing and sound insulating agent S ₁ is made of EPDM and has elasticity. For example, by attaching it around a cylinder block of a diesel engine, vibration of each part of the block can be suppressed. Generation of noise due to vibration can be reduced.

(6) Since the vibration damping sound absorbing and sound insulating agent S ₁ has a simple shape in which only the unit laminates U ₁ are laminated, the shape and size of the space in which the unit laminates U ₁ are mounted are categorized into various types. By preparing several types corresponding to the space, most demands can be met. Therefore, it is inexpensive and versatile.

(Embodiment 3) FIG. 5 is a side view of an embodiment (hereinafter, referred to as Embodiment 3) of a vibration damping sound absorbing and sound insulating material.

[0060] In view, in damping sound absorbing sound insulator of S ₂ Example 3, respectively the unit laminate U ₂ in the horizontal and vertical directions 4
These were laminated one by one to form a multi-layered body.

The unit laminate U ₂ is made of EP having open cells.
It is formed by bonding a hollow cylindrical sponge body 21 of DM and a solid plate 22 having no air bubbles on respective planes. The size of the damping sound absorbing sound insulator S ₂ is vertical 200 mm, horizontal 230 mm, a height of 140 mm.

The operation and effect of the third embodiment can be explained in the same manner as that of the second embodiment.

(Embodiment 4) FIG. 6 is a side view of an embodiment (hereinafter, referred to as Embodiment 4) of a vibration damping sound absorbing and sound insulating material.

In the figure, S ₃ is the vibration damping sound absorbing and sound insulating material of the fourth embodiment, which is formed by laminating four unit laminates U ₃ in the horizontal and vertical directions to form a multi-laminate.

The unit laminate U ₃ is made of EPD having no air bubbles.
An M-shaped square tubular solid hollow body 31 is integrally formed with an EPDM sponge tubular body 32 having open cells on the outer surface, so that the cross section is formed as a whole with a rounded square shape. The size of the multi-laminate S ₃ is the same as that S ₂ of Example 3.

The operation and effect of the fourth embodiment can be explained in the same manner as that of the second embodiment.

(Embodiment 5) FIG. 7 is a side view of an embodiment (hereinafter, referred to as Embodiment 5) of a vibration damping sound absorbing and sound insulating material.

In the drawing, S ₄ is the vibration damping sound absorbing and sound insulating material of the fourth embodiment, and the unit laminated body U ₄ is moved three times in the horizontal and vertical directions, respectively.
It is a multi-layered body obtained by laminating two pieces with each other.

The unit laminate U ₄ is made of EP having open cells.
A DM sponge cylinder 41 and four bubbles integrally formed on the inner surface side of the cylinder 41 at the time of molding the cylinder 41
It is formed by a PDM solid plate 42. 4
The solid plates 42 are arranged at intervals of 45 degrees.
The size of the multi-laminate S ₄ are vertically 150 mm, horizontal 150 mm,
The height is 100 mm.

The operation and effect of the fifth embodiment can be explained in the same manner as that of the second embodiment.

[0071] FIG. 8 (a), (b) show another embodiment of the unit laminate U ₄ of Example 5. Unit stack U ₅ in FIG. (A) is four solid plate 52 sponge cylinder 5
1 is an example in which it is arranged on the outer surface side. The unit laminate U ₆ shown in FIG. 4B is formed by combining four solid plates 62 into a sponge cylinder 61.
This is an example in which four solid plates 63 are arranged on the inner side of the outer side.

In Examples 2 to 5, EPDM was used as the material of the elastic hollow body having open cells. In addition to this, synthetic rubber such as butyl rubber, acrylic rubber, nitrile butadiene rubber, silicone rubber and the like were used. An elastic material such as a plastic elastomer can be used.

[0073]

As described above, the vibration-damping and sound-absorbing material of the present invention has the following effects because it has the above-described structure.

(1) The vibration damping effect is not inferior to that of the conventional vibration damping sound absorbing material.

(2) The sound absorbing effect is excellent not only in the high frequency region but also in the low frequency region.

(3) Inexpensive and versatile.

The vibration-damping sound-absorbing sound-insulating material of the present invention has the above-described structure, and thus has a sound-insulating effect in addition to the effects (1) to (3).

[Brief description of the drawings]

FIG. 1 is a plan view of a vibration damping sound absorbing material according to an embodiment.

FIG. 2 is a front view of the vibration damping sound absorbing material of the embodiment.

FIG. 3 is an enlarged cross-sectional view taken along line AA of FIG. 1;

FIG. 4 is a side view of the vibration damping sound absorbing and sound insulating material according to the second embodiment.

FIG. 5 is a side view of the vibration damping sound absorbing and sound insulating material according to the second embodiment.

FIG. 6 is a side view of a vibration damping sound absorbing and sound insulating material according to a fourth embodiment.

FIG. 7 is a side view of a vibration damping sound absorbing and sound insulating material according to a fifth embodiment.

FIG. 8 is a side view showing another mode of the unit laminated body in the fifth embodiment. K damping sound absorbing material 1, 2, 3 elastic hollow body 4 through hole t hollow portion S _{1 to} S ₄ damping sound absorbing sound insulating material U ₁ ~ U ₄ unit laminated body 11 Sponge board 12,22,42,52,62,63 Solid board 13 Hollow part 21 Sponge hollow body 31 Solid hollow body 32 Sponge cylinder 41,61 Sponge cylinder

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI G10K 11/172 G10K 11/16 E

Claims (9)

[Claims] 1. The hollow portion of an elastic hollow body is connected to a block of an elastic hollow body made of an elastic material having open cells and integrally formed with a plurality of elastic hollow bodies having a hollow portion inside. Vibration damping sound absorbing material with through holes. 2. A vibration-damping and sound-absorbing material comprising an elastic hollow block made of an elastic material having open cells and integrally formed with a plurality of elastic hollow bodies having hollow portions therein. 3. The elastic hollow body is a hollow body having a hollow portion such as a column, a ball, and a pot inside.
Or the vibration damping sound absorbing material according to 2. 4. The vibration damping sound absorbing material according to claim 1, wherein said plurality of elastic hollow bodies have the same shape and size. 5. The vibration damping and sound-absorbing material according to claim 1, wherein the plurality of elastic hollow bodies have the same shape, and at least a part thereof has a different size. 6. The block according to claim 1, wherein the plurality of elastic hollow bodies are respectively oriented in arbitrary directions.
2. The vibration damping sound absorbing material according to 2, 3, 4, or 5. 7. The plurality of elastic hollow bodies are at least partially made of different materials.
4. The vibration damping sound absorbing material according to 4 or 5. 8. A vibration damping sound absorbing and sound insulating material comprising a laminate of an elastic material having open cells and an elastic material having no air bubbles. 9. The control system according to claim 8, wherein at least one of the elastic material having open cells and the elastic material having no air bubbles has a hollow portion inside or a groove or an uneven portion outside. Vibration absorbing sound insulation material.