JP2002213684A - Mounting method of soundproof cover - Google Patents

Abstract

PROBLEM TO BE SOLVED: To establish a soundproof cover mounting method which hardly leaks sound from the gap between each soundproof cover and a noise source. SOLUTION: According to the soundproof cover mounting method, the soundproof cover 11 has a sound-absorbing layer 1 on the side with a noise source 10; and when the cover 11 is to be installed on the noise source 10, a sealing material 21 is arranged at least between the peripheral edge 12 of the sound absorbing layer 1 and the noise source 10, and the peripheral edge 12 of the sound-absorbing layer 1 is made to tightly attach to the noise source 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for mounting a soundproof cover that covers a noise source and reduces noise, and more particularly to a method for mounting a soundproof cover used in an engine room of an automobile.

[0002]

2. Description of the Related Art Noise-generating equipment and structures, for example, in an engine room of an automobile, include equipment such as an engine.
A soundproof (sound insulation) cover is used for protection, vibration reduction, noise reduction, and the like. For example, a soundproof cover for an engine room (engine top cover (head cover), engine side cover, etc.) can absorb and block a certain amount of noise due to its shielding effect, and also has water resistance, oil resistance, and a certain heat resistance. Therefore, it can sufficiently fulfill the role of protecting the engine.

As shown in FIG. 3, a soundproof cover 31 for an engine room is formed by bonding a resin material (or an iron plate) 33 to a thermoplastic resin material (for example, urethane foam material) 32 into a desired shape. It covers a necessary part of the engine (the upper surface of the head cover 30 in FIG. 3). The cover 31 is fixed to the head cover 30 using fixing means such as bolts, screws, clips, and the like.
It is installed.

[0004] In recent years, there has been an increasing demand for reducing noise leaking from the automobile to the outside of the vehicle and for reducing noise and vibration transmitted to the interior of the automobile, so that further reduction of engine noise is required.

As a soundproof cover for further reducing the engine sound, a sound absorbing layer made of a felt material, a ventilation blocking layer made of a vulcanized rubber material, and a structural layer are laminated in this order from the noise source side, and A molded soundproof cover in which each layer is integrally molded is exemplified. Since the molded soundproof cover has a larger transmission loss than the cover 31, the molded soundproof cover has better sound absorbing and insulating properties when compared with the cover 31 shown in FIG.

[0006]

However, since this molded soundproof cover is a molded product, the cover itself is hard, and it is very difficult to bring it into close contact with the radiating surface of the engine, for example, the upper surface of the head cover 30. It is. For this reason, the engine sound leaks from the innermost layer of the molded soundproof cover, for example, a gap between the sound absorbing layer and the head cover 30, and as a result, the shielding (sealing) of the engine sound by the cover deteriorates.

An object of the present invention, which has been made in view of the above circumstances, is to provide a method of attaching a soundproof cover in which sound leakage from a gap between the soundproof cover and a noise source is small.

[0008]

In order to achieve the above object, a method of mounting a soundproof cover according to the present invention is directed to a method of mounting a soundproof cover that covers a noise source and reduces noise. When attaching the soundproof cover to the noise source,
At least a sealing material is arranged between the outer peripheral edge of the sound absorbing layer and the noise source, and the outer peripheral edge of the sound absorbing layer and the noise source are brought into close contact with each other.

On the other hand, a method of mounting a soundproof cover according to another embodiment is a method of mounting a soundproof cover that covers a noise source and reduces noise, wherein the soundproof cover having a sound absorbing layer on the noise source side is mounted on the noise source. The outer edge of the sound absorbing layer is attached in close contact with the noise source. Is filled with foamed rubber.

According to the above mounting method, by closing the gap between the soundproof cover and the noise source with the sealing material or the foamed rubber, it is possible to reduce sound leakage from the gap.

When a soundproof cover having a sound absorbing layer on the noise source side is attached to the noise source, a seal member is arranged at least between the outer peripheral edge of the sound absorbing layer and the noise source, and the outer peripheral edge of the sound absorbing layer is connected to the noise source. At the same time, the part inside the outer peripheral edge of the sound absorbing layer is installed away from the noise source, and the space between the inner part of the outer peripheral edge of the sound absorbing layer and the noise source is filled with foam rubber. You may.

Further, the sealing material is preferably formed of a material having a low spring constant, a sound absorbing property and excellent adhesion, and particularly preferably a foamed rubber.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a sectional view showing a state in which the soundproof cover is mounted on the upper surface of the engine head cover using the method for mounting the soundproof cover according to the present invention. FIG.
It is an enlarged view of the important section A of (a).

As shown in FIGS. 1 (a) and 1 (b), a soundproof cover 11 attached to a noise source (in FIG. 1, the upper surface of an engine head cover 10) includes a sound absorbing layer 1 and a ventilation layer from the upper surface side of the head cover 10. The barrier layer 2 and the structural layer 5 are laminated in this order. Further, the structural layer 5 has a two-layer structure of the shape retaining layer 3 on the inner layer side and the surface protective layer 4 on the outer layer side.
Further, the surface of the lowermost sound absorbing layer 1 on the noise source 10 side, that is, the back surface (the lower surface in FIG. 1B) of the soundproof cover 11 is provided in accordance with required water repellency, oil repellency, appearance, and the like. As appropriate
The nonwoven fabric layer 6 is formed by lamination.

Here, the soundproof cover 11 of FIG.
Although the sound absorbing layer 1 and the ventilation blocking layer 2 are laminated one by one, two or more layers of the sound absorbing layer and the ventilation blocking layer are alternately laminated, for example, a sound absorbing layer, a ventilation blocking layer, a sound absorbing layer, a ventilation blocking layer, They may be laminated in the order of the structural layers.

The sound absorbing layer 1 may be a single layer of a felt material, a nonwoven material, or a synthetic resin foam material, or a composite layer thereof.
Preferably, it is formed of a single layer of a felt material or a composite layer thereof, and since it is bulky and has air permeability, it must be made of a material having at least excellent sound absorbing properties. The felt material is obtained by temporarily opening a woven or non-woven fabric made of natural fiber, chemical fiber, or the like as a raw material, and processing it into a bulky material. Here, “spreading” refers to a process of turning a cloth-like material into a thread-like or fibrous shape. It goes without saying that not only the felt material formed through the fiber opening step but also an existing material may be used.

The felt material is a resin felt in which a thermosetting resin, for example, a phenol resin is sprayed on the surface and the fibers are adhered to each other by heating. ) Is stabbed with each other so that the fibers are entangled with each other and hardened. In particular, resin felt which can be thermoformed is preferable. Further, as the nonwoven fabric material, a material in which fibers of the nonwoven fabric are fixed with a binder resin may be used. Further, examples of the synthetic resin foam include polyurethane foam, polystyrene foam, polypropylene foam, polyethylene foam, vinyl chloride foam, vinyl acetate foam, and ethylene-vinyl acetate copolymer foam.

The ventilation blocking layer 2 is a single layer of a rubber material, an asphalt material, or a resin film or a composite layer thereof, preferably a single layer of a rubber material having a large specific gravity and being easily formed, or a single layer thereof. It is formed of a composite layer, and needs to be formed of a material that can block at least air permeability and can be molded.

Examples of the rubber material include synthetic rubber, natural rubber, vulcanized rubber and reclaimed rubber, preferably synthetic rubber such as butyl rubber, chloroprene rubber, butadiene rubber and styrene-butadiene rubber. Preferably, acrylonitrile butadiene rubber (NBR) having a high surface weight and excellent oil resistance is used. As the asphalt material, in addition to petroleum asphalt such as straight asphalt, prawn asphalt and semi-pron asphalt, natural asphalt can be applied. Further, examples of the resin film include those obtained by processing various known thermoplastic resins or thermosetting resins into thin films.

The shape-retaining layer 3 is formed by heating and pressing a single layer or a composite layer of a felt material or a non-woven material, preferably the same material used for the sound absorbing layer 1.

The surface protective layer 4 is made of a non-woven fabric or a felt material, preferably the same as that used for the sound-absorbing layer 1, and particularly preferably a single-layer or composite layer having good moldability, which is impregnated with a resin. It is formed by applying a resin coating treatment and a heat treatment to impart heat resistance, water resistance, and oil resistance. Examples of the resin to be impregnated or coated include conventionally known solvent-based resins, water-based resins, emulsion resins and the like, for example, phenol resins. The nonwoven fabric of the surface protective layer 4 and the nonwoven fabric layer 6 is, for example, polyethylene terephthalate (hereinafter “PET”).
Is shown).

A sound absorbing layer 1, a shape maintaining layer 3, a surface protective layer 4,
The felt or the nonwoven fabric constituting the felt material or the nonwoven fabric material of the nonwoven fabric layer 6 includes 3F felt formed of a mixed material of cotton, chemical fiber, and glass wool.

After each of the above-described layers 1 to 4 and 6 are formed, the non-woven fabric layer 6, the sound absorbing layer 1, the ventilation blocking layer 2, and the structural layers (shape maintaining layer 3 and surface protective layer 4) 5 are laminated in this order. Then, the soundproof cover 11 is obtained by integrally forming the layers 1 to 4 and 6 by vacuum forming. During this vacuum forming,
The ventilation blocking layer 2 prevents the sound absorbing layer 1 from being compressed, thereby ensuring the sound absorbing and sound insulating properties of the sound absorbing layer 1.

In this soundproof cover 11, the thickness T1 of the sound absorbing layer 1, which is an incompressible layer, is at least three times, preferably at least five times, the total thickness T2 of the ventilation blocking layer 2 and the structural layer 5. By increasing the thickness to about 10 times, excellent sound absorption / insulation and high rigidity can be obtained. As a result, noise generated from the engine can be greatly reduced, and noise leaking outside and inside the vehicle can be reduced. Here, as the thickness T1 of the sound absorbing layer 1 is increased, the weight (unit: g / m ² ) of the felt (or nonwoven fabric) of the felt material (or nonwoven fabric) constituting the sound absorbing layer 1 is reduced and the weight is reduced. Suppress increase.

A typical example of the felt constituting the felt material of the sound absorbing layer is a 1F felt formed of only cotton. Among them, the 1F felt using cotton having a small fiber diameter is particularly excellent. It has nature. However, since cotton is a natural fiber, its fiber diameter varies greatly depending on the place of origin, and stable sound absorption cannot be obtained. In addition, cotton having a small fiber diameter is high-grade cotton and is very expensive.

Therefore, in the soundproof cover 11, 3F felt formed by mixing cotton, chemical fiber, and glass wool is used as the felt. The 3F felt has substantially the same sound absorption as the 1F felt, and also has a stable sound absorption due to a small ratio of natural fibers. In addition, the 3F felt has a higher rigidity than the 1F felt particularly because glass wool is contained therein, and this rigidity can be freely adjusted by appropriately adjusting the mixing ratio of the glass wool. Furthermore, since the 3F felt contains chemical fibers and / or glass wool, the rate of stiffness reduction due to the influence of humidity and heat is smaller than that of the 1F felt, and as a result, it is possible to prevent shape deformation, for example, sagging. it can. The sound absorbing layer 1 and the shape maintaining layer 3 using the 3F felt are not at a rigidity level enough to hold the soundproof cover 11, but have a certain degree of rigidity. The vibration damping of the holding layer 3 can be improved.

Further, a material having a high density, for example, NBR, is used as a constituent material of the ventilation blocking layer 2 and its thickness is set to, for example, 2 to 4 mm, so that the ventilation blocking layer 2 is formed.
Weight can be increased. This ventilation blocking layer 2,
Since each of the sound absorbing layer 1 and the shape maintaining layer 3 acts as a weight layer, excellent sound insulation performance can be exhibited. As a result, even if the engine vibration is transmitted to the cover 11, the vibration is significantly reduced and attenuated in the ventilation blocking layer 2 and the shape maintaining layer 3 of the cover 11. Further, due to the vibration damping ability, the solid secondary radiation (radiated) sound radiated (radiated) from the cover 11 itself is significantly reduced. Thus, vibration and noise transmitted to the inside of the vehicle can be reduced.

The surface protective layer 4 is formed by impregnating (or coating) a thermosetting resin into a single layer or a composite layer of a nonwoven fabric material (or a felt material). For example, oil and water do not soak. Therefore, the soundproof cover 11 can be applied to an engine cover that is exposed to oil (engine oil, gear oil) or water.

Next, a method of attaching the soundproof cover according to the present invention will be described with reference to the accompanying drawings.

The method of mounting the soundproof cover according to the first embodiment is as follows. When the above-described soundproof cover 11 is mounted on a noise source such as an engine, for example, the upper surface of the head cover 10 shown in FIG. An annular sealing material 21 is disposed between the outer peripheral edge 12 of the sound absorbing layer 1 and the head cover 10, and the outer peripheral edge 12 of the sound absorbing layer 1 and the head cover 10 are
Are brought into close contact with each other.

The sealing material 21 has a low spring constant,
It is preferably formed of a material having sound absorbing properties and excellent adhesion, for example, foamed rubber or urethane.
In particular, among foamed rubbers or urethanes, those having closed cells, for example, expanded rubbers are preferable.

Since the above-mentioned soundproof cover 11 is a molded soundproof cover, the sound absorbing layer 1 of the cover 11 and the head cover 1 are formed.
In particular, the adhesion between the outermost peripheral portion (the position facing the boundary between the upper surface and the side surface of the head cover 10) 22 of the sound absorbing layer 1 and the head cover 10 is not very good. Therefore,
In the mounting method of the soundproof cover according to the present embodiment,
When attaching the cover 11 to the upper surface of the head cover 10,
Utilizing that the outer peripheral edge 12 of the sound absorbing layer 1 and the upper surface of the head cover 10 are respectively flat, an annular sealing material 21 is provided between the outer peripheral edge 12 of the sound absorbing layer 1 and the head cover 10.
Is arranged, the outer peripheral edge 12 of the sound absorbing layer 1 and the head cover 10 can be brought into close contact with each other via the sealing material 21. That is, the sealing material 21 allows the head cover 10
And the soundproof cover 11 can be closed.

As a result, the engine sound radiated (radiated) from the upper surface of the head cover 10 is shielded (sealed) by the sealing member 21, and as a result, the engine sound leaks from the gap between the head cover 10 and the cover 11. Is reduced. In other words, the problem of the molded soundproof cover, which was not so good in shielding the engine sound, is solved by disposing the seal material 21, and the sound absorbing and insulating performance of the molded soundproof cover can be fully exhibited.

In the present embodiment, FIG.
The description has been made using the soundproof cover 11 having the structure shown in FIG. 3B, that is, the molded soundproof cover.
May be used. Also in this case, it goes without saying that the leakage of the engine sound is reduced.

Next, another embodiment of the present invention will be described with reference to FIG.

In the method of mounting the soundproof cover according to the second embodiment, the soundproof cover 11 is replaced with the head cover 10.
When the sound absorbing layer 1 is mounted on the upper surface, the outer peripheral edge 12 of the sound absorbing layer 1
A portion 13 (hereinafter referred to as an inside portion) inside the outer peripheral edge portion 12 of the sound absorbing layer 1 is attached separately from the head cover 10, and a foam rubber (not shown) is provided in a space S between the inside portion 13 of the sound absorbing layer 1 and the head cover 10. ).

In this embodiment, it goes without saying that the same operation and effect as those of the method for mounting the soundproof cover according to the first embodiment can be obtained. In the case of the present embodiment,
Since the space S between the inner portion 13 of the sound absorbing layer 1 and the head cover 10 is filled with the foamed rubber, the adhesion between the outermost peripheral portion 22 of the sound absorbing layer 1 and the head cover 10 hardly matters.

Further, the method of mounting the soundproof cover according to the third embodiment is such that when the above-described soundproof cover 11 is mounted on the upper surface of the head cover 10, at least a portion between the outer peripheral edge 12 of the sound absorbing layer 1 and the head cover 10. Annular sealing material 2
1 and the outer edge 12 of the sound absorbing layer 1 and the head cover 1
0 is attached in close contact with the sealing material 21, and a portion 13 (hereinafter referred to as an inside portion) of the sound absorbing layer 1 inside the outer peripheral edge 12 is attached away from the head cover 10, and the inside portion of the sound absorbing layer 1 is attached. The space S between the head 13 and the head cover 10 is filled with foamed rubber (not shown).

In this embodiment, it is needless to say that the same operation and effect as those of the method for attaching the soundproof cover according to the first and second embodiments are obtained.

It is most effective to attach the soundproof cover 11 to the engine body, which is the largest sound source. However, the soundproof cover 11 is located in the engine room, and other devices serving as a sound source and a vibration source, such as a generator and an actuator. By further mounting it, the engine sound can be further reduced.

[0042]

EXAMPLES In order to facilitate understanding of the present invention, examples will be described below. Needless to say, the present invention is not limited to the following examples. (Example 1) A soundproof cover having a structure in which a resin layer is bonded to a thermoplastic resin material is mounted on the upper surface of the head cover by using the soundproof cover mounting method according to the first embodiment having the structure shown in FIG. Was. Here, the thermoplastic resin material has a thickness of 1
The resin layer is a nylon layer having a layer thickness of 1.5 mm. (Comparative Example 1) A soundproof cover having a structure in which a resin layer was bonded to a thermoplastic resin material was mounted on the upper surface of the head cover by using the conventional soundproof cover mounting method having the structure shown in FIG. Here, the same soundproof cover as in Example 1 was used.

Next, the engine was driven and the engine sound was measured. Here, the engine speed at the time of measurement is
720 rpm in the idling state and the sound measurement position were at the center of the engine at a position 1 m above the head cover surface.

As shown in FIG. 2, in the first embodiment,
1.7 d in all frequency range (OA) compared to Comparative Example 1.
As B (A), the measured sound level was lower.

That is, in the first embodiment using the method for mounting the soundproof cover according to the first embodiment, almost no engine sound leaks from the gap between the soundproof cover and the head cover. It can be seen that the sound shielding performance is improved as compared with Comparative Example 1 using the cover mounting method.

As described above, the embodiments of the present invention are not limited to the above-described embodiments, and it is needless to say that various other embodiments are also conceivable.

[0047]

In summary, according to the present invention, since there is almost no sound leakage from the gap between the soundproof cover and the noise source, an excellent effect of enhancing the sound shielding property is exhibited.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a state in which a soundproof cover is mounted on an upper surface of an engine head cover using the method for mounting a soundproof cover according to the present invention. FIG. 1B is an enlarged view of a main part A of FIG.

FIG. 2 is a diagram showing sound absorbing and insulating characteristics of each cover of Example 1 and Comparative Example 1.

FIG. 3 is a cross-sectional view showing a state in which the soundproof cover is mounted on an upper surface of an engine head cover using a conventional soundproof cover mounting method.

[Explanation of symbols]

 Reference Signs List 1 sound absorbing layer 10 head cover (noise source) 11 soundproof cover 12 outer peripheral edge 13 inner part (part inner than outer peripheral edge) 21 sealing material S space

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Mitsuo Nakano, Indo Tsunami, Fujisawa-shi, Kanagawa Prefecture Isuzu Central Research Laboratories Co., Ltd. Inside the Development Center Co., Ltd. (72) Inventor Masamichi Furusuge 8-16-15 Toshima, Kita-ku, Tokyo Inside Japan Development Co., Ltd. (72) Inventor Takeshi Watanabe 8-16-15 Toshima, Kita-ku, Tokyo Japan Special Paint Co., Ltd. Development Center F-term (reference) 5D061 AA04 AA26 CC11 DD07

Claims (5)

[Claims] 1. A method for mounting a soundproof cover that covers a noise source and reduces noise, wherein when the soundproof cover having a sound absorbing layer on the noise source side is mounted on the noise source, at least a portion between an outer peripheral portion of the sound absorbing layer and the noise source. A method of attaching a soundproof cover, characterized in that a sealing material is disposed on the sound absorbing layer, and a noise source is brought into close contact with an outer peripheral portion of the sound absorbing layer. 2. A method for mounting a soundproof cover that covers a noise source and reduces noise, wherein when the soundproof cover having a sound absorbing layer on the noise source side is mounted on the noise source, the outer peripheral edge of the sound absorbing layer is brought into close contact with the noise source. At the same time, the part inside the outer peripheral edge of the sound absorbing layer is attached away from the noise source, and the space between the part inside the outer peripheral edge of the sound absorbing layer and the noise source is filled with foam rubber. How to attach the soundproof cover. 3. When a soundproof cover having a sound absorbing layer on the noise source side is attached to the noise source, a sealing material is arranged at least between the outer peripheral edge of the sound absorbing layer and the noise source, and the outer peripheral edge of the sound absorbing layer and the noise source are arranged. At the same time, the part inside the outer peripheral edge of the sound absorbing layer is installed away from the noise source, and the space between the inner part of the outer peripheral edge of the sound absorbing layer and the noise source is filled with foamed rubber. A method for mounting the soundproof cover according to claim 2. 4. The method for mounting a soundproof cover according to claim 1, wherein the sealing material is formed of a material having excellent adhesion. 5. The method for mounting a soundproof cover according to claim 4, wherein the sealing material is formed of foamed rubber.