JP6754724B2 - Soundproof coating and engine unit - Google Patents

Description

The present invention relates to a soundproofing covering material and an engine unit.

In recent years, the harmonization of standards for automobile noise has been examined at the World Forum for Harmonization of Automotive Standards of the United Nations Economic Commission for Europe (ECE), and rules regarding vehicle structure have been established and revised.
Conventionally, automobile manufacturers have been developing various soundproof specifications, and various soundproof covers for automobile engines have been proposed (see, for example, Patent Document 1 (Japanese Patent Laid-Open No. 2002-180845)). However, regarding the noise outside the automobile, the regulation value is set in the above ECE Rule 51 (ECE R51), and according to Regulation EU No. 540/2014 which set the regulation value, 72 dB (phase) by July 2016. 1), 70 dB (Phase 2) by July 2020, 68 dB (Phase 3) by July 2024, and stricter standards will be enforced, and the regulation level of outside noise will be finally set to 7 in 2016. There is a very strict requirement to reduce the sound pressure energy to about 1 / 2.5 by 4 dB against the standard up to the month.

By the way, the above-mentioned automobile noise is generated from the engine room because it is a sum of not only the noise generated from the drive system engine room such as the engine, motor, and transmission, but also the exhaust noise, wind noise, tire road noise, and the like. If the above target is to be achieved only by reducing noise, it is necessary to reduce noise by 5 to 6 dB in the engine room and 1/4 as sound pressure energy. Therefore, the conventional soundproof cover for an automobile engine is used. It is becoming difficult to deal with it.

JP-A-2002-180845

As described above, it is difficult for the conventionally proposed soundproof cover to obtain a sufficient noise suppression effect against the increasingly strict regulation level.

Under such circumstances, as a soundproofing specification, for example, soundproofing material is applied to almost the entire engine, that is, almost the entire surface of the engine wall surface, upper surface (bonnet) side, and lower surface (underbody) side, and the entire engine serving as a sound source is used. It is conceivable to use (near) engine encapsulation, which is covered with a soundproofing material to suppress noise leakage to the outside of the vehicle and at the same time reduce the noise level in the engine room by its sound absorbing effect.

However, since each part is highly integrated in the engine room of a recent downsized vehicle and the space is small, the thickness prepared for the soundproof material is about 10 to 20 mm even when the above encapsulation is performed. On the other hand, when trying to reduce noise by the sound absorption and sound insulation effect of the soundproof material, the noise on the relatively low frequency side of 1 kHz or less depends on the thickness and mass of the soundproof material, so the effect obtained. Will be very limited. Therefore, when the soundproofing material is installed, only the noise on the high frequency side exceeding 1000 Hz is absorbed, and the noise on the low frequency side becomes conspicuous.

If the soundproofing material cannot exhibit sufficient sound absorption performance, a large reverberant sound will be heard in the engine room, and if the sound insulation performance is not sufficient, the energy that cannot be attenuated will vibrate the wall surface, top surface, and bottom surface of the engine room. Even louder noise may be generated.

Therefore, there is a need for a soundproof cover that can suppress the sound pressure in the frequency band of about 800 to 2000 Hz and can also suppress the sound pressure in the frequency band of about 400 Hz or more and less than 800 Hz in order to further reduce the sound pressure.

Further, for example, in a soundproof cover for an automobile engine, a part of the exhaust side wall surface and the upper surface of the engine (near the exhaust manifold through which the combustion exhaust gas passes) is heated by the exhaust gas, so that the soundproof covering material is 150 ° C. Those having a certain degree of heat resistance are required.

Under such circumstances, it is an object of the present invention to provide a novel soundproofing covering material having heat resistance and sufficient soundproofing performance even if the thickness is thin, and an engine unit having such a soundproofing covering material. Is to be.

As a result of diligent studies by the present inventors in order to achieve the above object, one or more of the first porous film having an aperture ratio of 0.1 to 5.0% and an aperture diameter of 100 to 1000 μm. The elastic porous body layer and the second porous film having a pore ratio of 0.1 to 5.0% and a pore diameter of 100 to 1000 μm are laminated in this order by a soundproofing coating material. We have found that the above technical problems can be solved, and have completed the present invention based on this finding.

That is, the present invention
(1) A first porous film having a pore opening ratio of 0.1 to 5.0% and a pore diameter of 100 to 1000 μm, one or more elastic porous body layers, and a pore opening ratio of 0.1 to 0.1. pore size 5.0 percent and the second porous film is 100 to 1000 [mu] m, Ri Na are laminated in this order,
The elastic porous body layer
Fiber assembly or felt containing one or more selected from glass wool, rock wool, silica fiber, silica alumina ceramic fiber, alumina fiber and mullite fiber,
One or more felts selected from polyethylene terephthalate felt, nylon fiber felt, polypropylene fiber felt, aramid fiber felt, resin felt,
One or more resin foams selected from polyurethane foams, polypropylene foams, phenolic foams, nitrile butadiene rubber foams and silicone rubber foams.
Soundproofing coverings, characterized by being selected from
(2) The soundproofing coating material according to (1) above, which further has a skin material on at least one of the outer surface side of the first porous film and the outer surface side of the second porous film.
(3) The soundproofing coating material according to (1) or (2) above, wherein the ventilation resistance of the first porous film or the second porous film is 0.1 to 10 kPa · s / m.
(4) The soundproofing covering material according to any one of (1) to (3) above, wherein the soundproofing covering material is a soundproofing cover for an automobile engine.
(5) Accommodates the automobile engine and the soundproofing covering material according to any one of (1) to (4) above, which covers at least a part of the automobile engine, and the automobile engine and the soundproofing covering material. An engine unit having an engine room and having a gap of 0.1 to 30 mm between the automobile engine and the soundproofing covering material or between the soundproofing covering material and the engine room. It provides a characteristic engine unit.

According to the present invention, it is possible to provide a novel soundproofing covering material having heat resistance and sufficient soundproofing performance even if the thickness is thin, and an engine unit having such a soundproofing covering material.

It is a figure which shows the sound absorption characteristic in the Example of this invention. It is a figure which shows the sound absorption characteristic in the comparative example of this invention. It is a figure which shows the sound absorption characteristic in an Example and a comparative example of this invention.

First, the soundproofing covering material according to the present invention will be described.
The soundproofing coating material according to the present invention has a first porous film having an aperture ratio of 0.1 to 5.0% and an aperture diameter of 100 to 1000 μm, and one or more elastic porous body layers. It is characterized in that a second porous film having a pore ratio of 0.1 to 5.0% and an opening diameter of 100 to 1000 μm is laminated in this order.

In the soundproofing coating material according to the present invention, the first porous film and the second porous film have an aperture ratio of 0.1 to 5.0% and an opening diameter of 100 to 1000 μm.
In the soundproofing coating material according to the present invention, the first porous film and the second porous film may be the same or different.

In the soundproofing coating material according to the present invention, the constituent material of the first porous film or the second porous film is not particularly limited, and a material having a desired pore distribution may be appropriately selected.
As the first porous film or the second porous film, it is preferable that the first porous film or the second porous film has flexibility and does not cause significant heat shrinkage or the like in a use environment while sandwiching the elastic porous body layer described later.

Examples of such a porous film include a polyamide (nylon) film selected from a polyethylene film, a 6-nylon film, a 6,6-nylon film, an 11-nylon film, a 12-nylon film, and the like, and polyester. One or more selected from organic films such as films, short-fiber non-woven fabrics, long-fiber cloths, and paper-made papers can be mentioned.

In the soundproofing coating material according to the present invention, the first porous film or the second porous film may be composed of a multilayer film, and the multilayer film may be, for example, on both sides of a polyamide (nylon) film. Examples thereof include a co-extruded multilayer film manufactured so that a low-pressure polyethylene adhesive layer is arranged.
By using the above-mentioned multilayer film, it is possible to easily improve the adhesion to the elastic porous body layer described later.
Further, the first porous film or the second porous film may have a surface coated with an appropriate coating agent in order to control its air permeability.

In the soundproofing coating material according to the present invention, the first porous film or the second porous film has an aperture ratio of 0.1 to 5.0%, and is 0.1 to 1. It is preferably 0%, more preferably 0.1 to 0.5%.
Further, in the soundproofing coating material according to the present invention, the first porous film or the second porous film has a pore size of 100 to 1000 μm, preferably 300 to 800 μm, and preferably 500 to 800 μm. It is more preferably 700 μm.

In the present application documents, the aperture ratio (%) of the first porous film or the second porous film is determined when the surface of each porous film is observed with a microscope (Keyens Co., Ltd., VHX-500). It means the arithmetic mean value at any 50 points of the opening ratio calculated by (total area of holes / area of porous film) × 100.
The total area of the holes means a value measured by a microscope.

Further, in the present application documents, the opening diameter of the first porous film or the second porous film is the arithmetic mean value of the maximum diameters of 50 pores when the surface of the porous film is observed with a microscope. means.

Since the first porous film or the second porous film constituting the soundproofing covering material according to the present invention has the above-mentioned aperture ratio and opening diameter, sound passes through the covering material from the outside. The sound pressure of low-frequency sound at a desired frequency, particularly a frequency of 400 Hz or more and less than 800 Hz, can be easily reduced while exhibiting desired heat resistance by easily controlling the flow resistance.
That is, by arranging the micro-breathable film material (the first porous film and the second porous film) on both main surface sides of the soundproofing coating material, the flow resistance of the entire soundproofing laminated material is adjusted and sound absorption is performed. It is thought that the performance can be improved.

In the soundproofing coating material according to the present invention, the opening portion of the first porous film or the second porous film is formed by needle punching the film material constituting the porous film, passing a hot sword mountain roll, or the like. It can be formed by performing the pore-opening treatment, and the pore-opening ratio and the pore-opening diameter of the porous film can be easily controlled by controlling the treatment conditions at the time of the pore-opening treatment.

In the soundproofing coating material according to the present invention, the first porous film or the second porous film preferably has a ventilation resistance of 0.1 to 10 kPa · s / m, and is 0.5 to 5. The one having 0 kPa · s / m is more preferable, and the one having 0.5 to 1.5 kPa · s / m is further preferable.

In the present application documents, the aeration resistance of the first porous film or the second porous film is 0.4 cc / cm ² / s in the direction perpendicular to the main surface of the porous film. The difference (differential pressure) between the two when the pressure pressure on the inlet side and the outlet side at that time was measured with a flow resistance measuring instrument (product name: KES-F8-AP1, manufactured by Kato Tech Co., Ltd.) was divided by the flow velocity. Means.

Since the soundproofing coating material according to the present invention has the first porous film or the second porous film having the above-mentioned ventilation resistance, the flow resistance when sound passes through the covering material from the outside can be reduced. It can be easily controlled to easily reduce the sound pressure of low-frequency sound at a desired frequency, particularly a frequency of 400 Hz or more and less than 800 Hz.

In the soundproofing coating material according to the present invention, the Young's modulus of the first porous film or the second porous film is preferably 0.5 GPa or less, more preferably 0.1 GPa or less, still more preferably 0.05 GPa or less. , 0.01 GPa or less is more preferable.
When the Young's modulus of the porous film is within the above range, the porous film has desired flexibility, is excellent in flexibility and the like, and can easily provide a soundproofing coating material having excellent sound absorption. it can.

In the present application documents, the Young's modulus of the first porous film or the second porous film means a value measured in accordance with the provisions of JIS K7127.

In the soundproofing coating material according to the present invention, the thickness of the first porous film or the second porous film is preferably 10 to 100 μm, more preferably 10 to 80 μm, and 30 to 70 μm. It is more preferable to have.
When the thickness of the first porous film or the second porous film is within the above range, it is possible to have excellent flexibility and easily reduce the thickness (compactification) of the soundproofing coating material.

The soundproofing coating material according to the present invention has an elastic porous body layer in the central portion and has a first porous film and a second porous film on the outside thereof, so that the covering material can be sounded from the outside. The sound pressure of low-frequency sound at a desired frequency, particularly at a frequency of 400 Hz or more and less than 800 Hz, can be easily reduced by easily controlling the flow resistance when passing through.
This is because the sound waves that are about to pass through the coating material from the outside are not reflected by the surface of the porous film due to the pores provided in the porous film. Sound waves with low frequencies that are captured inside and have a frequency of 400 Hz or more and less than 800 Hz are blocked by the porous film and the sound energy propagating in the air is converted into vibration energy, which is absorbed by the vibration of the porous film and the entire covering material. It is thought that it will be done.

Since the soundproofing coating material according to the present invention has the first porous film and the second porous film on the upper surface side and the lower surface side of the elastic porous body layer, respectively, the soundproofing coating material of the present invention. The sound absorption characteristic can be exhibited not only for the sound passing from the lower surface side to the upper surface side but also for the sound passing from the upper surface side to the lower surface side.
Therefore, for example, when the soundproofing covering material according to the present invention is used as a soundproofing cover for an automobile engine, the sound emitted from the automobile engine passes from the lower surface side to the upper surface side of the soundproofing covering material from the automobile engine. Sound waves of low frequency sound with a frequency of 400 Hz or more and less than 800 Hz emitted are blocked by a porous film arranged under the covering material and absorbed, and a part of the low frequency sound with a frequency of 400 Hz or more and less than 800 Hz is covered with the above soundproofing material. Even when passing through the material, when it is reflected on the wall surface of the engine room accommodating the automobile engine and the soundproofing covering material and passes from the upper surface side to the lower surface side of the soundproofing covering material, the covering material is similarly applied. It is converted into vibration energy by the porous film placed on the upper side of the, and can effectively exhibit sound absorption performance.

The soundproofing coating material according to the present invention is characterized in that a first porous film, one or more elastic porous body layers, and a second porous film are laminated in this order. Is.

When a plurality of elastic porous body layers are provided in the soundproofing coating material according to the present invention, the sound pressure can be reduced more effectively.

In the soundproofing coating material according to the present invention, examples of the elastic porous body constituting the elastic porous body layer include one or more selected from fiber aggregates, felts and resin foams.

Examples of the fiber assembly include an assembly composed of inorganic short fibers such as glass wool (glass fiber), rock wool, silica fiber, silica-alumina ceramic fiber, alumina fiber, and mullite fiber.
Examples of the felt include those obtained by integrating one or more of the above-mentioned various short fibers by means such as needle punching, and specifically, an inorganic fiber composed of inorganic short fibers that already form an aggregate. Made of felt (for example, glass felt made of glass wool (glass fiber felt), polyester fiber felt such as polyethylene terephthalate felt, nylon fiber felt, polyethylene fiber felt, polypropylene fiber felt, acrylic fiber felt, aramid fiber felt, silica Alumina ceramics fiber felt, silic fiber felt, cotton, wool, wood wool, waste fiber and the like are processed into a felt shape with a thermosetting resin, and one or more selected from resin felt and the like can be mentioned.
The felt, inorganic fibers made felt is preferred, preferably has density of 10 to 50 kg / ^{m 3,} preferably than is 15~50kg / ^{m 3,} more preferably those which are 20 to 35 kg / ^{m 3,} Sprayed or molded products of artificial mineral fibers can be used.
The resin foam includes one or more selected from resin foams such as polyurethane foam, polyethylene foam, polypropylene foam, phenol foam, and melamine foam, and ditril butadiene rubber, chloroprene rubber, styrene rubber, silicone rubber, urethane rubber, and ethylene. -One or more selected from open cell bodies in which propylene, diene rubber, etc. are foamed in a continuous foam form or which is foamed by crushing after foaming can be mentioned.

When heat resistance is taken into consideration, the elastic porous body preferably contains inorganic fibers such as glass fibers or aramid fibers as constituent fibers, and more preferably contains inorganic fibers.

In the soundproofing coating material according to the present invention, the elastic porous body constituting the elastic porous body layer preferably contains glass fibers as constituent fibers, and the glass fibers have a fiber diameter of 0.1 to 1. It is preferably 4 μm, more preferably 0.1 to 2 μm, and even more preferably 0.1 to 1 μm.
The glass fiber having the above fiber diameter can be produced by a centrifugal method or a flame method.

In this application document, the fiber diameter of the glass fiber means the arithmetic mean value of the maximum diameter of the 20 glass fibers measured by the microscope.

In the soundproofing coating material according to the present invention, the elastic porous body constituting the elastic porous body layer contains the glass fiber having the above fiber diameter as the constituent fiber, so that the desired heat resistance and flame retardancy can be more easily obtained. Can be demonstrated.

In the soundproofing coating material according to the present invention, when the elastic porous body constituting the elastic porous body layer contains glass fibers having the above fiber diameter as constituent fibers as constituent fibers, the elastic porous body contains glass fibers. , For example, it may be fixed with a binder made of a phenol resin selected from, for example, novolak, resol, benzylic ether, etc., or a modified phenol resin such as urea modification, or by treatment such as needle punching. It may be manufactured by entwining glass fibers in the thickness direction.

In the soundproofing coating material according to the present invention, when the elastic porous body constituting the elastic porous body layer contains polyester fibers as constituent fibers, flame-retardant polyester fibers are preferable as the polyester fibers.

The main repeating unit of the flame-retardant polyester fiber is polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene isophthalate (PEI), polycyclohexylene dimethylene terephthalate (PCHDT), polyethylene naphthalate (PEN), or the like. Polyester can be mentioned.

Examples of the flame-retardant polyester fiber include known ones, and are described in, for example, JP-A-51-82392, JP-A-55-7888, JP-A-55-41610 and the like. I can mention things.

In the soundproofing coating material according to the present invention, when the elastic porous body constituting the elastic porous body layer contains polyester fibers as constituent fibers, the polyester fibers include flame-retardant polyester and heat-adhesive polyester. It may be a flame-retardant composite fiber made of a composite.

In the flame-retardant composite fiber formed by combining the flame-retardant polyester and the heat-adhesive polyester, examples of the flame-retardant polyester include the same as those constituting the flame-retardant polyester fiber described above. ..
Further, in the flame-retardant composite fiber, the heat-adhesive polyester functions as a binder for the flame-retardant polyester, has a melting point lower than the melting point of the flame-retardant polyester, and has a melting point of the flame-retardant polyester. Those having a melting point at least 20 ° C. lower than that are preferable.
If the difference in melting points is less than 20 ° C., the orientation of the flame-retardant polyester tends to decrease because high-temperature treatment is required when producing the flame-retardant composite fiber, and the reinforcing effect of the heat-adhesive polyester is reduced. As a result, the durability of the flame retardant inner fiber tends to decrease, and the physical properties of the flame retardant polyester, which is the base material, tend to decrease.

The heat-adhesive polyester preferably has a melting point of 110 ° C. to 220 ° C., and more preferably 130 ° C. to 200 ° C. When the melting point of the heat-adhesive polyester is within the above range, the reinforcing effect can be easily exerted.

In the documents of the present application, the melting point of the flame-retardant polyester and the melting point of the heat-adhesive polyester are oriented when the fibrous material is arranged in a cross shape on a hot plate and the temperature is raised from room temperature to 5 ° C./min. It shall mean the temperature at which the striped pattern generated by the above burns out.

The heat-adhesive polyester is not particularly limited, and for example, terephthalic acid, isophthalic acid, phthalic acid, p-hydroxybenzoic acid, 5-sodium sulfoisophthalic acid, naphthalenedicarboxylic acid, oxalic acid, adipic acid, sebatic acid, etc. One or more acid components selected from cyclohexylene dicarboxylic acid and the like, and one or more glycols selected from ethylene glycol, diethylene glycol, triethylene glycol, propanediol, butanediol, pentanediol, hexanediol, neopentyl glycol, polyethylene glycol and the like. Examples thereof include those obtained by ester-bonding a component.

In the soundproofing coating material according to the present invention, the elastic porous body constituting the elastic porous body layer has a flame-retardant composite fiber obtained by combining the flame-retardant polyester and the heat-adhesive polyester as a constituent fiber. In this case, the composite ratio of the flame-retardant polyester and the heat-adhesive polyester is not particularly limited, but the content ratio of the flame-retardant polyester is preferably 20 to 80% by mass, and 30 to 70% by mass. More preferably, it is more preferably 40 to 60% by mass.
When the content ratio of the flame-retardant polyester constituting the flame-retardant composite fiber is within the above range, the desired flame-retardant property can be easily imparted to the flame-retardant composite fiber.

As the composite form of the flame-retardant polyester and the heat-adhesive polyester, a sea score type having a flame-retardant polyester as a core component and a heat-adhesive polyester as a sheath component, a flame-retardant polyester and a heat-adhesive polyester are arranged adjacent to each other. Examples include a layered multi-layer structure type and a side-by-side type.

In the soundproofing coating material according to the present invention, the thickness of the elastic porous body layer is preferably 0.5 to 20 mm, more preferably 1.5 to 15 mm, and further preferably 3 to 10 mm. preferable.
In the soundproofing coating material according to the present invention, when the elastic porous body layer is composed of a plurality of layers, the total thickness of the plurality of elastic porous body layers may be within the above range.

In the soundproofing covering material according to the present invention, since the thickness of the elastic porous body layer is within the above range, the soundproofing covering material has excellent flexibility and sufficient sound absorption while reducing the thickness (compactification) of the soundproofing covering material. It can be easily exerted.

In the soundproofing coating material according to the present invention, the bulk density of the elastic porous body constituting the elastic porous body layer is preferably 0.001 to 1.2 g / cm ³ , preferably 0.01 to 0.5 g. / more preferably cm is ^3, further preferably 0.025～0.1G / cm ^3.
The bulk density is appropriately selected from those having a desired sound absorbing property, depending on the structure and thickness of the elastic porous body.

In order to achieve the above density, the basis weight of the elastic porous material constituting the elastic porous body layer is preferably from 10 to 1000 g / ^{m 2,} more preferably from 15~500g / ^{m 2,} 25 It is more preferably ~ 250 g / m ² .
When the basis weight of the elastic porous body is within the above range, it is possible to easily provide a soundproof covering material which is lightweight and has a desired shape.

The soundproofing covering material according to the present invention absorbs low-frequency sound having a frequency of 400Hz or more and less than 800Hz by converting it into vibration energy by a porous film with respect to the sound that is about to pass through the covering material from the outside. It is considered that high-frequency sound having a frequency of about 800 to 2000 Hz is absorbed by the elastic porous body layer arranged inside after passing through the pores of the porous film.

Since the soundproofing coating material according to the present invention has the first porous film and the second porous film on the upper surface side and the lower surface side of the elastic porous body layer, respectively, the soundproofing coating material of the present invention. The sound absorption characteristic can be exhibited not only for the sound passing from the lower surface side to the upper surface side but also for the sound passing from the upper surface side to the lower surface side.
Therefore, for example, when the soundproofing covering material according to the present invention is used as a soundproofing cover for an automobile engine, when the sound emitted from the automobile engine passes from the lower surface side to the upper surface side of the soundproofing covering material, the sound wave is emitted from the automobile engine. The sound waves with a frequency of 800 to 2000 Hz that are emitted pass through the porous film arranged under the covering material and are absorbed by the elastic porous body layer arranged inside, and a part of the sound waves with a frequency of 800 to 2000 Hz is described above. Even if it passes through the soundproofing covering material, it is reflected on the wall surface of the engine room accommodating the automobile engine and the soundproofing covering material, and when passing from the upper surface side to the lower surface side of the soundproofing covering material, the same applies. It is considered that sound is absorbed by the elastic porous body layer similarly arranged inside after passing through the porous film arranged on the upper side of the covering material, and the sound absorbing performance can be exhibited more effectively.

The soundproofing coating material according to the present invention may further have a skin material on at least one of the outer surface side of the first porous film and the outer surface side of the second porous film.
In the soundproofing coating material according to the present invention, the skin material is preferably provided on at least one of the outer surface side of the first porous film and the outer surface side of the second porous film, and is provided on both of them. It is more preferable that the film is used.

In the soundproofing coating material according to the present invention, when the skin material is provided on both the outer surface side of the first porous film and the outer surface side of the second porous film, even if both skin materials are the same. It may or may not be different.

As the skin material, if problems such as melting and significant shrinkage do not occur at a temperature of 150 ° C., a flame-retardant polyester fiber non-woven fabric, an inorganic long fiber cloth, an inorganic fiber sheet, or a metal foil resin subjected to perforation treatment One or more selected from sheets and the like can be arranged.

Examples of the flame-retardant polyester fiber constituting the flame-retardant polyester fiber non-woven fabric include polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene isophthalate (PEI), polycyclohexylene methylene terephthalate (PCHDT), and polyethylene. Examples thereof include polyester having naphthalate (PEN) or the like as a main repeating unit.
Examples of the flame-retardant polyester fiber include known ones, and are described in, for example, JP-A-51-82392, JP-A-55-7888, JP-A-55-41610 and the like. I can mention things.

Further, as the inorganic long fiber cloth, one or more selected from inorganic fibers such as glass fiber, silica fiber, basalt fiber, silica-alumina ceramic fiber, alumina fiber, and mullite fiber can be woven into a cloth shape. Examples of the sheet made of inorganic fiber include one or more selected from the above-mentioned inorganic fibers integrated by means such as needle punching.
Further, as the metal foil resin sheet that has been subjected to the hole-opening treatment, a metal foil such as an aluminum foil that has fine holes on the surface to suppress sound reflection can be used for designability and prevention of fiber scattering due to vibration. It is suitable from the viewpoint.

The ventilation resistance of the skin material may be within a range that does not hinder the effect of preventing fiber scattering, etc. in order to suppress the reflection of the incident sound wave on the surface side, and is 1.0 kPa · s / m or less. It is preferable that the content is 0.5 kPa · s / m or less, and more preferably 0.3 kPa · s / m or less.
The ventilation resistance can be appropriately adjusted depending on the knitting method of the fiber, the degree of opening of the metal foil, and the like.

In the present application documents, the ventilation resistance of the skin material is the flow resistance of the air pressure on the inlet side and the outlet side when air is passed at 0.4 cc / cm ² / s in the direction perpendicular to the main surface of the skin material, respectively. It means the difference (differential pressure) between the two when measured with a measuring instrument (product name: KES-F8-AP1, manufactured by Kato Tech Co., Ltd.) divided by the flow velocity.

Examples of the inorganic fiber sheet include glass fiber felt containing glass fiber and a resin binder, and examples of the resin binder constituting the glass fiber felt include novolak, resole, and the like having a content of less than 5% by mass. Examples thereof include phenolic resins such as benzylic ether and modified phenolic resins such as urea-modified having a content of 10 to 20% by mass.

When an inorganic fiber sheet is used as the skin material, it is possible to easily exhibit excellent heat resistance and heat insulating properties while exhibiting desired sound absorption.

When a metal foil is used as the skin material, the pore opening ratio is preferably 3% to 7%, more preferably 4% to 7%, in order to exhibit desired sound absorption. More preferably, it is 5% to 7%.
Further, in the soundproofing coating material according to the present invention, the metal foil preferably has a pore diameter of 1 μm or more, more preferably 5 μm or more, and 10 μm or more, as long as the liquid blocking property can be ensured. Those are more preferable.
The opening ratio and the opening diameter of the skin material can be measured by the same measuring method as the above-described method for measuring the opening ratio and the opening diameter of the porous film.

When the soundproofing covering material according to the present invention has a skin material, it becomes easy to secure shape stability and designability, and it is possible to suppress scattering of fibers and the like constituting the covering material at the time of use. Water repellency can be easily exhibited.

As the soundproofing covering material according to the present invention, a material having a thickness of 5 to 20 mm is suitable, a material having a thickness of 10 to 20 mm is more suitable, and a material having a thickness of 15 to 20 mm is more suitable.
The soundproofing covering material according to the present invention can exhibit sufficient soundproofing performance even if it is thin.

Since the soundproofing coating material according to the present invention has the above-mentioned ventilation resistance, the flow resistance can be easily controlled to obtain a sound pressure at a desired frequency, particularly a frequency of 400 Hz or more and less than 800 Hz, and a sound at a frequency of 800 to 2000 Hz. The pressure can be easily reduced.

The soundproofing covering material according to the present invention can be produced, for example, by hot-press molding into a predetermined shape in a state where all the forming materials corresponding to the constituent members of the soundproofing covering material to be obtained are sequentially laminated. ..
Further, the soundproofing covering material according to the present invention is, for example, a material obtained by hot-press molding into a predetermined shape in a state where only a part of all the forming materials corresponding to the constituent members of the soundproofing covering material to be obtained is sequentially laminated. It can be produced by sequentially laminating other forming materials corresponding to the constituent members of the soundproofing covering material to be obtained and hot-press molding them into a predetermined shape by appropriately fixing them with an adhesive or the like. ..

Specifically, as the soundproofing coating material according to the present invention, for example, (1) a first porous film, (2) an elastic porous body layer, and (3) a second porous film are sequentially arranged in this order. When forming a laminated soundproofing covering material, it can be produced by hot-press molding into a predetermined shape in a state in which the forming materials forming each of these are sequentially laminated in this order.
Further, for soundproofing, (1) the first skin material, (2) the first porous film, (3) the elastic porous body layer, and (4) the second porous film are laminated in this order in order. When forming a covering material, for example, it can be produced by hot-press molding into a predetermined shape in a state in which the forming materials forming each of these are sequentially laminated in this order.
Further, (1) the first skin material, (2) the first porous film, (3) the elastic porous body layer, (4) the second porous film, and (5) the second skin material are the same. When forming the soundproofing covering material which is sequentially laminated in order, for example, it can be produced by hot-press molding into a predetermined shape in a state where the forming materials forming each of these are sequentially laminated in this order.
In addition, (1) first skin material, (2) first porous film, (3) first elastic porous body layer, (4) second elastic porous body layer, (5) first. When forming a soundproofing coating material in which the second porous film and (6) the second skin material are sequentially laminated in this order, for example, a state in which the forming materials forming each of these are sequentially laminated in this order. It can be produced by hot-press molding into a predetermined shape.

The soundproofing covering material according to the present invention can be suitably used as, for example, a soundproofing cover for an automobile engine.
When the soundproofing covering material according to the present invention is used as a soundproofing cover for an automobile engine, for example, by arranging it on at least a part of the exhaust side wall surface and the upper surface of the engine, suitable sound absorbing characteristics can be easily exhibited. ..

According to the present invention, it is possible to provide a novel soundproofing covering material which has heat resistance and has sufficient soundproofing performance even if the thickness is thin.

Next, the engine unit according to the present invention will be described.
The engine unit according to the present invention has an automobile engine, a soundproofing covering material according to the present invention covering at least a part of the automobile engine, and an engine room accommodating the automobile engine and the soundproofing covering material. The engine unit is characterized in that it has a gap of 0.1 to 30 mm between the automobile engine and the soundproofing coating material or between the soundproofing covering material and the engine room. is there.

In the engine unit according to the present invention, the details of the soundproofing covering material according to the present invention are as described above.
Further, in the engine unit according to the present invention, known ones can be appropriately adopted as the automobile engine and the engine room.

In the engine unit according to the present invention, the distance between the automobile engine and the soundproofing coating material or between the soundproofing covering material and the engine room (the width of the gap formed between the automobile engine and the soundproofing covering material or The gap (gap formed between the soundproof covering material and the wall surface of the engine room) is 0.1 mm or more, preferably 5 mm or more, and more preferably 10 mm or more.

In the engine unit according to the present invention, the soundproofing coating material has a first porous film and a second porous film having a predetermined opening ratio and opening diameter, respectively, and the sound wave passing through the soundproofing covering material When a predetermined flow resistance is generated and the distance between the automobile engine and the soundproof covering material or between the soundproofing covering material and the engine room is within the above range, the soundproofing covering material is generated from the automobile engine. Not only the sound that passes through the engine room, but also the sound that is reflected on the wall surface of the engine room and passes through the soundproofing coating material is efficiently converted into vibration by the porous film, and the energy is attenuated, so that the engine room It is considered that the sound pressure inside can be suitably reduced.

According to the present invention, it is possible to provide a novel engine unit having a soundproofing covering material having heat resistance and sufficient soundproofing performance even if the thickness is thin.

Next, the present invention will be described in more detail with reference to examples, but this is merely an example and does not limit the present invention.

(Example 1)
(1) As the first skin material, polyester fiber felt (125H manufactured by Maeda Kosen Co., Ltd., fiber diameter 10 μm, density 125 kg / m ³ , basis weight 125 g / m ² , thickness 1 mm) and
(2) As a forming material for the first porous film, a 6-nylon film (Sperene 35N-LL manufactured by Ube Film Co., Ltd., density 900 kg / m ³ , thickness 0.07 mm) is passed through a hot swordsman roll. As a result, a film having an opening (opening ratio 4.1%, opening diameter 290 μm, flow resistance 0.10 kPa · s / m) and
(3) As the first elastic porous body forming material, polyester fiber felt (S250-HSGYN manufactured by Takayasu Co., Ltd., average fiber diameter of polyester fiber 10 μm, density 25 kg / m ³ , grain size 250 g / m ² , thickness 10 mm)
(4) As a material for forming the second elastic porous body, polyester fiber felt (S250-HSGYN manufactured by Takayasu Co., Ltd., average fiber diameter of polyester fiber 10 μm, density 25 kg / m ³ , grain size 250 g / m ² , thickness 10 mm)
(5) As a forming material for the second porous film, a 6-nylon film (Sperene 35N-LL manufactured by Ube Film Co., Ltd., density 900 kg / m ³ , thickness 0.07 mm) is passed through a hot swordsman roll. As a result, a film having a hole (opening ratio 4.1%, hole diameter 290 μm, flow resistance 0.10 kPa · s / m) and
(6) As the second skin material, polyester fiber felt (125H manufactured by Maeda Kosen Co., Ltd., fiber diameter 10 μm, density 125 kg / m ³ , basis weight 125 g / m ² , thickness 1 mm) was used.
The soundproof covers for automobile engines having a maximum thickness of 10 mm were obtained by sequentially arranging them in this order and hot-press molding at 185 ° C. for 30 seconds under a pressing force of 5 MPa.

(Example 2)
In Example 1, (2) the forming material of the first porous film and (5) the forming material of the second porous film had an aperture ratio of 1.7%, an opening diameter of 438 μm, and a flow resistance of 0. A soundproof cover for an automobile engine having a maximum thickness of 10 mm was obtained in the same manner as in Example 1 except that the thickness was changed to 57 kPa · s / m.

(Example 3)
In Example 1, (2) the forming material of the first porous film and (5) the forming material of the second porous film had an aperture ratio of 1.3%, an opening diameter of 690 μm, and a flow resistance of 1. A soundproof cover for an automobile engine having a maximum thickness of 10 mm was obtained in the same manner as in Example 1 except that the thickness was changed to 27 kPa · s / m.

(Example 4)
In Example 1, (2) the forming material of the first porous film and (5) the forming material of the second porous film had an aperture ratio of 0.4%, an opening diameter of 308 μm, and a flow resistance of 9. A soundproof cover for an automobile engine having a maximum thickness of 10 mm was obtained in the same manner as in Example 1 except that the thickness was changed to 99 kPa · s / m.

(Sound absorption evaluation)
Behind each automobile engine soundproof cover using the automobile engine soundproof covers obtained in Examples 1 to 4 and using a Bruel Care Japan 4206 type acoustic tube based on the provisions of JIS-A-1415. The vertical incident sound absorption coefficient at 500 to 6400 Hz was measured with an air layer of 10 mm provided in the air layer. The results are shown in FIG.

(Comparative Example 1)
An automobile having a maximum thickness of 10 mm in the same manner as in Example 1 except that (2) a first porous film forming material and (5) a second porous film forming material were not used in Example 1. I got a soundproof cover for the engine.

(Comparative Example 2)
In Example 1, (2) the first porous film forming material and (5) the second porous film forming material were not used, (3) the first elastic porous body and (4) the second. A porous film having a pore ratio of 1.2%, a pore diameter of 730 μm, and a flow resistance of 0.45 kPa · s / m was arranged between the forming materials of the elastic porous body of the above, and the maximum was the same as in Example 1. A soundproof cover for an automobile engine having a thickness of 10 mm was obtained.

(Sound absorption evaluation)
Using the soundproof covers for automobile engines obtained in Comparative Examples 1 to 2, and using a 4206 type acoustic tube manufactured by Bruel Care Japan based on the provisions of JIS-A-1415, behind each soundproof cover for automobile engines. The vertical incident sound absorption coefficient at 800 to 2000 Hz was measured with an air layer of 10 mm provided in the air layer. The results are shown in FIG.
In addition, in FIG. 2, the results obtained in Example 2 are also shown for comparison.

(Example 5)
The soundproof cover for an automobile engine obtained in Example 3 was cut out into a 1 m ² flat plate to be used as a measurement sample, and the side surface of the measurement sample was made of L-shaped aluminum by the reverberation room Ab-Loss manufactured by Nippon Acoustic Engineering Co., Ltd. The sound absorption coefficient (reverberation room method sound absorption coefficient) was measured in a state where a 10 mm spacer was used on the back surface of the measurement sample in a state of being sealed with an ankle and a back air layer of 10 mm was provided (Example 5). The sound absorption coefficient was measured in the range of 800 Hz to 2000 Hz using the impulse response integration method based on ISO354 (2003). The results are shown in FIG.

(Comparative Example 3)
In Example 5, the back air layer was used in the same manner as in Example 5 except that the automobile engine soundproof cover obtained in Comparative Example 32 was used instead of the automobile engine soundproof cover obtained in Example 3. The sound absorption coefficient (reverberation room method sound absorption coefficient) was measured in a state where 10 mm was provided. The results are shown in FIG.

From FIGS. 1 and 3, the soundproof covers for automobile engines obtained in Examples 1 to 4 have sufficient heat resistance made of a heat-resistant material and suppress sound pressure in a frequency band of about 800 to 2000 Hz. At the same time, it can be seen that the sound pressure in the frequency band of 400 Hz or more and less than 800 Hz can be sufficiently suppressed.

On the other hand, from FIG. 2 and FIG. 3, Comparative Examples 1 to 3 soundproof cover obtained automobile engines in 2 that the sound pressure in a frequency band of about 800~2000Hz are those not sufficiently suppressed I understand.

According to the present invention, it is possible to provide a novel soundproofing covering material having heat resistance and sufficient soundproofing performance even if the thickness is thin, and an engine unit having such a soundproofing covering material.

Claims (5)

A first porous film having a pore ratio of 0.1 to 5.0% and a pore diameter of 100 to 1000 μm, one or more elastic porous body layers, and a pore ratio of 0.1 to 5.0. % and a second porous film opening diameter is 100~1000μm in that, Ri Na are laminated in this order,
The elastic porous body layer
Fiber assembly or felt containing one or more selected from glass wool, rock wool, silica fiber, silica alumina ceramic fiber, alumina fiber and mullite fiber,
One or more felts selected from polyethylene terephthalate felt, nylon fiber felt, polypropylene fiber felt, aramid fiber felt, resin felt,
One or more resin foams selected from polyurethane foams, polypropylene foams, phenolic foams, nitrile butadiene rubber foams and silicone rubber foams.
A soundproofing coating material that is selected from <br />. The soundproofing coating material according to claim 1, further comprising a skin material on at least one of the outer surface side of the first porous film and the outer surface side of the second porous film. The soundproofing coating material according to claim 1 or 2, wherein the ventilation resistance of the first porous film or the second porous film is 0.1 to 10 kPa · s / m. The soundproofing covering material according to any one of claims 1 to 3, wherein the soundproofing covering material is a soundproofing cover for an automobile engine. The soundproofing covering material according to any one of claims 1 to 4, which covers at least a part of the automobile engine and the automobile engine, and an engine room accommodating the automobile engine and the soundproofing covering material. An engine having an engine having a gap of 0.1 to 30 mm between the automobile engine and the soundproofing coating material or between the soundproofing covering material and the engine room. unit.