JP2002220009A - Insulator for automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an insulator for an automobile mounted on the indoor surface of a body panel to achieve weight reduction while increasing the efficiency of fuel consumption and workability for installation, without decreasing sound insulation characteristic. SOLUTION: An insulator dash 20 mounted on the indoor face of a dash panel 10 is composed of a single sound absorbing layer 21 formed of an assembly of fibers, so that in addition to providing the sound absorption and insulation performance of the insulator dash 20, the insulator provides sound absorption by causing noises reflected from the inner surface of the instrument panel 40 to be absorbed again into the sound absorbing layer 21 from the front side for increased sound insulation performance of the interior of the instrument panel 40. Thus by doing away with a conventional sound insulating layer, weight reduction can be achieved and an increase in sound pressure within the instrument panel 40 is avoided to enhance the silentness of the automobile's interior.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulator for a vehicle attached to the interior surface of a vehicle body panel, and more particularly, to eliminating a heavy sound insulation layer to reduce the weight and to achieve excellent sound insulation performance. The present invention relates to a ventilated automobile insulator obtained.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 17, an insulator dash 2 is attached to the interior surface side of a dash panel 1 for partitioning an engine room E and a passenger compartment R.
As shown in an enlarged view in FIG. 18, the insulator dash 2 has a sound insulating layer 3 made of a high-density material such as a recycled rubber sheet or a recycled PVC sheet, and a sound absorbing layer made of a fiber assembly laminated and integrated on the back side thereof. And layer 4;
On the lower surface of the insulator dash 2, a floor carpet 5 is laid in a wrap shape, and the upper side of the insulator dash 2 is located in the instrument panel 6.

The soundproofing mechanism of the conventional two-layer insulator dash 2 will be described with reference to FIG. 19. The noise f1 of the engines and accessories in the engine room E is partly reduced by the dash panel 1. The noise which is sound-insulated and remains is transmitted through the dash panel 1 and propagates to the indoor side, and f2
The noise indicated by enters the insulator dash 2.

A part of the noise f2 is absorbed by the sound absorbing layer 4 and partly by the sound insulating layer 3.
Part of the noise enters the instrument panel 6 as transmitted noise f3.

Further, the transmitted noise f3 entering the instrument panel 6 is reflected on the inner surface of the instrument panel 6, and this reflected noise f4 is reflected again by the sound insulation layer 3, resulting in reflected noises f4 and f5. Is a reverberation sound in the space of the instrument panel 6, and the reverberation sound is a major factor that hinders quietness in the vehicle interior.

In this conventional soundproofing (sound insulation / sound absorption) mechanism, the sound insulation / sound absorption ratio in the insulator dash 2 and the sound absorption ratio in the instrument panel 6 are approximately 9: 1.

[0007]

As described above, the conventional insulator dash 2 is composed of a two-layer laminate of the sound insulating layer 3 made of a high-density material and the sound absorbing layer 4 made of a fiber assembly. Therefore, it has been pointed out that the weight of the sound insulation layer 3 is increased, which goes against the reduction of the weight of the product, lowers the fuel efficiency and deteriorates the workability of mounting the insulator dash 2.

Further, in the conventional soundproof mechanism of the insulator dash 2, the insulator dash 2
Because the sound absorption function in the instrument panel 6 is very small compared to the sound insulation and sound absorption function mainly by the double wall sound insulation function, it is urgently necessary to eliminate the unattenuated transmitted sound in the instrument panel 6 And it was.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is directed to an automobile insulator to be attached to the interior surface of a vehicle body panel. It is an object of the present invention to provide an automotive insulator capable of promoting sound absorption performance.

[0010]

Means for Solving the Problems To achieve the above object, an invention according to claim 1 of the present application is an insulator for a vehicle attached to the indoor surface side of a vehicle body panel. It consists of a single layer of sound-absorbing layer based on fiber molded body, absorbs noise that enters the sound-absorbing layer through the vehicle body panel, and the transmitted noise that has passed through the sound-absorbing layer is reflected on the inner surface of the panel in the vehicle cabin, and the surface reappears. It is characterized in that it is configured as a ventilation type insulator that can return to the sound absorbing layer from the side and absorb the reflected noise.

Here, the material of the sound absorbing layer is felt, PE
T (polyester) fiber, paper (pulp or the like) or the like is formed into a fibrous aggregate, and has a surface density of 3.0 kg / m ² or less. Use a material adjusted to 30-90%.

According to the first aspect of the present invention,
Since the insulator is composed of a single sound absorbing layer, the conventional heavy sound insulating layer can be eliminated, and the insulator can be significantly reduced in weight.

[0013] Furthermore, since the non-breathable sound insulation layer has been eliminated,
The noise that propagates from the body panel to the cabin is transmitted through the sound absorbing layer into the cabin, and the reflected noise that is reflected on the inner surface of the cabin panel is again absorbed from the sound absorbing layer surface side, and the sound in the cabin is reduced. Pressure rise can be suppressed.

Next, the invention described in claim 2 of the present application is:
A skin layer comprising a high-density fiber aggregate set at a higher density than the surface density of the sound absorbing layer is laminated on at least one of the front and back surfaces of the sound absorbing layer.

Here, the material of the skin layer is felt, PE
T (polyester) fiber, paper (pulp or the like) or the like is formed into a fibrous fiber aggregate, and has an areal density of 0.005 to 0.3
At less than kg / m ² , the thickness of the skin layer is 15 mm, and the skin layer is set at a higher density than the sound absorbing layer.

The skin layer may be provided entirely or partially depending on the sound and vibration characteristics of the vehicle, and may be provided on either the front side or the back side of the sound absorbing layer, or on both sides. And a frequency range of 630 to 4000 Hz of an insulator dash composed of a sound absorbing layer and a skin layer.
The material whose average sound absorption coefficient is adjusted to 30 to 90% when the thickness is 20 mm is used.

The thickness of the entire insulator dash is in the range of 5 to 150 mm.

According to the second aspect of the present invention,
Both the sound-absorbing layer and the skin layer are composed of fiber aggregates, eliminating the need for a conventional heavy sound-insulating layer, enabling the product to be lighter. By setting the skin layer made of the fiber aggregate, the transmitted sound from the vehicle body panel can be cut off, and particularly, the transmitted sound can be efficiently absorbed.

Further, by disposing a sound absorbing layer made of a high-density fiber aggregate on the surface side of the sound absorbing layer, it is possible to effectively prevent dust and fibrous material from falling off the sound absorbing layer.

The invention according to claim 3 of the present application is characterized in that a skin layer obtained by laminating a hot melt film on the back surface of a nonwoven fabric is laminated on the surface of the sound absorbing layer, and the skin layer is formed into an uneven shape. The sound absorbing layer is bonded to the concave portion of the skin layer, and an air layer is formed at the convex portion of the skin layer.

Here, the nonwoven fabric as the skin layer is made of polyester fiber or the like, and has a basis weight of 10 to 100 g / m2.
² . The hot melt film is made of polyolefin, polyamide, polyester, ethylene-vinyl acetate copolymer or the like and has a thickness of 10 to 100 μm.

Further, as a means for forming the skin layer, the skin layer is heated and softened in an infrastructure heating furnace and the sound absorbing layer is heated and softened in a hot air heating furnace, and then both are stacked and put into a molding upper and lower mold. An air blow is applied to the sound absorbing layer side to perform cooling, and at the same time, apply a vacuum force from the upper mold to form an uneven shape on the skin layer.

Here, the area of the bonding portion between the skin layer and the sound absorbing layer is 0.5 to 100 cm ² and the area of the air layer is 1 to 100 c
m ² , the height of the air layer is 1 to 10 mm.

According to the third aspect of the present invention,
Because the product surface is formed in an uneven shape, wrinkles etc. are not noticeable, the skin layer is hard to tear due to the cushioning by the air layer,
The assemblability is improved, and the warpage caused by the difference in shrinkage can be prevented.

Further, the unevenness of the product surface allows irregular reflection of noise in the vehicle interior, and the increased surface area of the product improves the sound absorption coefficient.

The invention described in claims 4 to 10 of the present application is
A film layer is used as a skin layer to be laminated on the sound absorbing layer.

Here, the material of the film layer may be polyolefin resin, polyurethane resin, PET resin, paper, etc.
Alternatively, the film layer may be composed of a composite thereof, and the thickness of the film layer is preferably from 10 to 200 μm, and the presence or absence of air permeability does not matter.

Further, the arrangement of the film layer may be provided over the entire circumference of the sound absorbing layer, or may be provided on one or both of the front side and the back side of the sound absorbing layer. . Further, an opening may be provided in a part of the film layer and the sound absorbing layer may be partially laminated, or an air layer may be interposed between the sound absorbing layer and the film layer.

Further, as a configuration in which an air layer is provided between the film layer and the sound absorbing material layer, the sound absorbing layer and the film layer are integrated with the upper and lower molds, and a vacuum force is applied to the film layer from the upper mold. Alternatively, an uneven portion may be formed in the film layer, the film layer and the sound absorbing layer may be bonded to each other at the concave portion, and an air layer may be formed at the convex portion. In this case, if a hot melt film is laminated on the back surface of the nylon (polyamide resin) film as the film layer, good heat resistance and moldability can be ensured.

The area of the bonding portion between the film layer and the sound absorbing layer is 0.5 to 100 cm ² , and the area of the air layer is 1 to 100 c
m ² and the height of the air layer are preferably ¹ to 100 cm ² .

According to the present invention, since the film layer is laminated on at least one of the front and back surfaces of the sound absorbing layer, the conventional heavy sound insulating layer can be eliminated. , Can contribute to weight reduction.

Further, since the reflected noise reflected on the inner surface of the panel in the vehicle cabin can be absorbed inside the sound absorbing layer, an increase in the sound pressure in the vehicle cabin can be prevented, and the sound absorbing performance in the vehicle cabin can be improved.

Further, by adopting a structure in which a film layer is attached to the surface side of the sound absorbing layer, dust such as fibrous material of the sound absorbing layer can be prevented from scattering into the room.

Further, by adopting a configuration in which an air layer is formed between the film layer and the sound absorbing layer by forming the film layer into an uneven shape, the film layer is not broken due to the cushioning property of the air layer. In addition, generation of wrinkles and the like is not noticeable.

Further, in the air layer portion, since the film layer floats from the sound absorbing layer, membrane resonance occurs, the sound absorption coefficient is improved, and the air layer is located behind the air layer in response to transmitted noise from the vehicle body panel side. The sound absorption rate is improved.

Next, the invention described in claim 11 of the present application is
A skin layer made of a foamed resin sheet material is laminated on at least one of the front and back surfaces of the sound absorbing layer, or on a part thereof.

Here, as the foamed resin sheet material, an olefin-based foamed sheet, EPPM, or the like can be used. The area density is less than 0.005 to 0.3 kg / m ² and the thickness is 15 mm.
The following is good.

According to the eleventh aspect of the present invention, since the product weight of the insulator can be reduced, workability and fuel efficiency can be improved.

Further, when a foamed resin sheet having a closed cell structure is used as the skin layer, room noise can be reduced by blocking transmitted noise transmitted through the vehicle body panel and absorbing sound in the vehicle interior transmitted through the insulator.

Further, when the skin layer is used for a foamed resin sheet having a continuous foam structure, a sound absorbing effect in the vehicle interior through the insulator can be expected as compared with blocking of transmitted noise transmitted through the vehicle body panel.

Next, according to a twelfth aspect of the present invention, an undercover is provided below a panel in a vehicle cabin, and transmitted noise transmitted from a vehicle body panel through a sound absorbing layer is subjected to sound pressure in a closed space in the panel. It is characterized in that it is lowered.

According to the twelfth aspect of the present invention, the interior space of the panel in the vehicle interior can be made a closed space by attaching the under cover to the lower side of the panel in the vehicle interior. The noise transmitted through the vehicle does not leak into the cabin, and the sound pressure is attenuated in the cabin, so that the sound absorbing performance in the cabin can be further improved.

[0043]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an embodiment of a vehicle insulator according to the present invention.

FIGS. 1 to 4 show a first embodiment of the present invention. FIG. 1 is a sectional view showing a state where an insulator dash for a vehicle is attached to a dash panel, and FIG. 2 shows a sound absorbing mechanism of the insulator dash. FIG. 3 is a graph showing the soundproofing performance of the insulator dash, and FIG. 4 is an overall view showing a modified example of the insulator dash. 5 to 7 show a second embodiment of the present invention. FIG. 5 is a cross-sectional view showing a state where an insulator dash is attached to a dash panel. FIG. 6 is a graph showing a soundproof performance of the insulator dash. FIG. 7 is an explanatory view showing a modified example of the insulator dash.

8 to 10 show a third embodiment of the present invention. FIG. 8 is a sectional view showing a state where an insulator dash panel is attached to a dash panel, and FIG. 9 is a main part of the insulator dash. FIG. 10 is an explanatory view showing an outline of a forming process of the insulator dash.

FIGS. 11 to 15 show a fourth embodiment of the present invention. FIG. 11 is a sectional view showing a state where an insulator dash is attached to a dash panel.
2 is an explanatory view showing variations of a film layer in the insulator dash, FIG. 13 is a graph showing soundproof performance in the insulator dash, FIGS. 14 and 1
5 is an explanatory view showing a modified example of the insulator dash, and FIG. 16 shows a fifth embodiment of the present invention, and is a cross-sectional view showing a state where the insulator dash for a vehicle is attached to a dash panel.

First, a first embodiment of the present invention will be described with reference to FIGS.

In FIG. 1, an engine room E and a vehicle room R
The dash panel 10 is divided into a dash upper part 10a, a dash lower part 10b, and a toe board part 10c from the upper side, and an insulator dash 20 is attached along the interior surface of the dash panel 10,
On the front side of the insulator dash 20 mounted on the toe board portion 10c, a floor carpet 30 is laid in a wrap shape, and further mounted on the upper half portions of the dash upper portion 10a and the dash lower portion 10b of the dash panel 10. The upper half of the insulator dash 20
It is located in the instrument panel 40. Note that a crash pad (not shown) is mounted on the instrument panel 40.

Incidentally, the insulator dash 20 according to the present invention is configured so as to significantly reduce the weight of the product and to have sufficient soundproofing characteristics even if the weight is reduced, in order to enhance fuel efficiency and mounting workability. I have.

That is, the insulator dash 20
Has a single-layer structure of the sound absorbing layer 21 made of a fiber assembly. The sound absorbing layer 21 is made of felt, PET,
(Polyester) Fiber, a fiber aggregate made of paper (pulp or the like) or the like is formed into a fibrous shape, and is formed along the surface shape of the dash panel 10 using a thermoplastic resin or a thermosetting resin as a binder. Has a thickness of 5 to 150 mm
A material whose surface density is set to 3.0 kg / m ² and whose average sound absorption coefficient in the frequency range of 630 to 4000 Hz of the sound absorbing layer 21 is adjusted to 30 to 90% when the thickness is 20 mm is used.

In the present embodiment, the low-melting point PET resin is mixed with the recycled PET fiber as a binder, and what has been accumulated in a mat shape on a conveyor belt is subjected to a heat treatment, and then formed into a desired mat shape by press working. After the raw mat is softened by heating, it is formed into a desired shape along the surface shape of the dash panel 10 by a cold press forming die having a desired die shape.

In the case where the binder is impregnated with a thermosetting resin, the binder is formed into a required shape using hot press molding.

As described above, in the present invention,
As the binder, a thermoplastic resin or a thermosetting resin may be used, and the material and the molding method are not particularly limited as long as the binder is made of a fiber aggregate having excellent sound absorbing properties.

As described above, since the insulator dash 20 for an automobile according to the present invention is composed of a single layer of the sound absorbing layer 21, the conventional sound insulating layer such as a heavy rubber sheet or a PVC sheet can be eliminated. The product weight can be greatly reduced, and the fuel efficiency can be improved by this weight reduction, and the workability of attaching the insulator dash 20 to the dash panel 10 also becomes excellent.

Further, since the insulator dash 10 according to the present invention has a single-layer structure of the sound absorbing layer 21, it exhibits the sound absorbing mechanism shown in FIG.

That is, part of the noise (F1 in the figure) generated in the engine room E is interrupted by the dash panel 10, and the rest enters the sound absorbing layer 21 as noise (F2 in the figure).

Then, as a result of a part of the noise indicated by F2 being absorbed by the sound absorbing function of the sound absorbing layer 21, the remaining transmitted noise (F3 in the drawing) enters the instrument panel 40, and the inner surface of the instrument panel 40 is exposed. The reflected noise (F4 in the figure) is reflected again to become a recurring transmitted noise (F5 in the figure) transmitted through the sound absorbing layer 21 again, and is absorbed by the sound absorbing function of the sound absorbing layer 21.

As described above, by adopting the single-layer structure of the sound absorbing layer 21, the noise transmitted to the cabin through the dash panel 10 is partially absorbed, and the transmitted noise transmitted through the sound absorbing layer 21 and transmitted into the vehicle interior. Is reflected by the instrument panel 40, and the reflected noise is again attenuated by the sound absorbing layer 21 so that the instrument panel 40
The transmitted sound which is not attenuated can be effectively prevented.

As shown in the graph of FIG. 3, the sound insulating properties of the insulator dash 20 are shown in the graph of FIG.
Is the sum of the sound insulation performance (b) of the instrument panel 40, the sound absorption / sound insulation performance (c) of the sound absorbing layer 21, and the sound absorption performance (d) of the instrument panel 40.
It is clear from the graph that the noise in the frequency range level in the middle range and the high range can be effectively attenuated.

Next, FIG. 4 shows a modified example of the above-mentioned insulator dash 20. In order to enhance the sound absorption in the instrument panel 40, an instrument under cover 41 is installed below the instrument panel 40. It is a feature that the inside of the instrument panel 40 is a closed space, whereby the sound absorbing performance in the instrument panel 40 can be further improved, and further improvement in soundproofing properties can be expected.

FIGS. 5 to 7 show a second embodiment of the present invention. In the insulator dash 20 according to the second embodiment, a skin layer 22 made of a fiber aggregate is provided on the surface side of a sound absorbing layer 21. It is integrated.

The sound absorbing layer 21 may have the same structure as that of the first embodiment, and is characterized in that the skin layer 22 is set at a higher density than the sound absorbing layer 21.

The material of the skin layer 22 is felt, PET,
(Polyester) Fiber, paper (pulp or the like) or the like is formed into a fibrous fiber aggregate, and has an areal density of 0.005 to 0.3.
At less than kg / m ² , the skin layer 22 partially blocks and partially absorbs noise that enters the sound absorbing layer 21 from the engine room E through the dash panel 10. Then, the transmitted noise transmitted through the skin layer 22 is reflected on the inner surface of the instrument panel 40 and is again
Since the sound enters the sound absorbing layer 21 through 2 and is absorbed, it is possible to reliably prevent the muffled sound from being generated in the instrument panel 40.

In this embodiment, the sound absorbing layer 2
1, the skin layer 22 may be integrated with the dash panel 10 side, that is, on the back surface of the sound absorbing layer 21, depending on the sound and vibration characteristics of the vehicle. Layer 22 is laminated to part of sound absorbing layer 21,
The remaining portion may be a single layer of the sound absorbing layer 21.

The average sound absorption coefficient of the insulator dash 20 composed of the sound absorbing layer 21 and the skin layer 22 is 15 to
The material is set so as to be 95%, and the average sound absorption coefficient at normal incidence is 630 to 4000 Hz. The thickness of the skin layer 22 is set to 15 mm, and the thickness of the insulator dash 20 is set to between 5 and 150 mm.

Further, as a forming method of the sound absorbing layer 21 and the sound absorbing layer 22, fibrous materials are scattered in a conveyer shape by card ring and accumulated in a mat shape, and a raw mat of the sound absorbing layer 21 is formed. Heat treatment may be performed by attaching hot melt powder to the bonding surface of the layer 22, and the skin layer 22 previously formed in a mat shape may be laminated in a state where the hot melt is melted and integrated by cold press molding.

The soundproofing performance of the insulator dash 20 according to the second embodiment is shown in the graph of FIG.
Is a sum of the sound insulation (b) of the instrument panel 40, the sound absorption of the insulator dash 20, the sound insulation (c), and the sound absorption performance (d) of the instrument panel 40, and is 630 to 4000 Hz. It can be seen that good soundproofing performance was obtained in

The composition of the insulator dash used for this measurement was as follows: PET fiber 2.0 kg / m ² as the sound absorbing layer 21 and PET fiber 1.2
It was used in kg / ^{m 2.}

As described above, also in the insulator dash 20 in the second embodiment, since the conventional heavy sound insulating layer can be eliminated, the weight can be reduced, the fuel efficiency can be improved, and the mounting workability can be improved. In addition to the same operation and effect as the first embodiment,
As shown in the graph, excellent soundproof performance is obtained.

Further, as shown in FIG. 7, also in the second embodiment, the instrument panel 40 is provided with an instrument under cover 41 below the instrument panel 40 so that the inside of the instrument panel 40 is closed and the instrument panel is closed. The sound absorbing performance in the inside 40 can be improved.

FIGS. 8 to 10 show a third embodiment of the present invention. The same parts as those in the above-described first and second embodiments are denoted by the same reference numerals, and detailed description is omitted.

As shown in FIG. 8, an insulator dash 20 according to the present embodiment uses a laminate in which a hot melt film 23b is laminated on the back surface of a nonwoven fabric 23a as a skin layer 23 laminated on the surface side of a sound absorbing layer 21. I have.

The non-woven fabric 23a is made of polyester fiber and has a basis weight of 10 to 100 g / m ² .
The hot melt film 23b functions as an adhesive medium, and has a thickness of 10 to 100 μm.

Further, as shown in FIG. 9, the relationship between the sound absorbing layer 21 and the skin layer 23 is such that the skin layer 23 is formed in an uneven shape, and the concave portions of the skin layer 23 are formed at a plurality of positions. The bonding portion 24 is set as a bonding portion 24 between the base layer 21 and the skin layer 23, and the area S1 of the bonding portion 24 is 0.5 to 100 cm ² .

The convex portion of the skin layer 23 corresponds to the air layer 25, the area S2 of the air layer 25 is 1 to 100 cm ² , and the height h of the air layer 25 is 1 to 10 mm.

Then, as shown in the figure, the product surface is formed in an uneven shape, and the sound absorbing layer 21 and the skin layer 23 correspond to the projections.
Since the air layer 25 is formed between the air layer 25 and the air layer 25, the cushioning action of the air layer 25 makes it difficult for the skin layer 23 to be broken, thereby improving the workability of assembling the vehicle body panel.

Furthermore, warpage due to a difference in shrinkage between the sound absorbing layer 21 and the skin layer 23 is suppressed, and the fit to the panel is improved.

Further, since the product surface is uneven, wrinkles and the like are not conspicuous, the appearance performance can be improved, and the surface area of the skin layer 23 against the noise from the indoor side is increased, so that the sound absorption is achieved. Performance is improved.

Next, a method of forming the insulator dash 20 shown in FIGS. 8 and 9 will be described with reference to FIG. 10. The forming die 50 includes an upper forming die 51 and a lower forming die 52. The mold surface of the mold 51 has countless vacuum suction holes 51.
a is provided, a vacuum suction mechanism (not shown) is additionally provided, and the mold surface of the upper mold 51 is set to an uneven surface 53 corresponding to the product unevenness. On the other hand, countless blow holes 52a are formed in the mold surface of the lower molding die 52, and an air blow mechanism (not shown) is additionally provided.

When the molding die 50 is in an open state, the skin layer 23 is heated and softened in an infrastructure heating furnace, and the sound absorbing layer 21 is heated and softened in a hot air heating furnace. The molds 51 and 52 are clamped, the skin layer 23 is vacuum-sucked from the upper mold 51, and the lower mold 5 is closed.
By supplying air into the sound absorbing layer 21 from 2, the insulator dash 20 provided with the air layer 25 in which the skin layer 23 is floated from the sound absorbing layer 21 can be formed.

FIGS. 11 to 15 show a fourth embodiment of the present invention. As shown in FIG. 11, an insulator dash 20 according to this embodiment has a film layer 26 integrally formed on the surface side of a sound absorbing layer 21. Has been

Therefore, also in the present embodiment, the weight can be reduced and the mounting workability can be improved by eliminating the conventional sound insulating layer such as a heavy rubber sheet or a PVC sheet. Similarly, sound absorbing layer 2
The transmitted noise that penetrates into the instrument panel 40 after passing through the first and film layers 26 is reflected by the inner surface of the instrument panel 40 and re-enters the film layer 26 and the sound absorbing layer 21 to be subjected to sound absorption processing. The same effect of preventing the sound pressure from increasing in the instrument panel 40, preventing noise from reverberating, and improving the quietness in the vehicle cabin is provided. The structure is simple and easy to manufacture.

The integration of the film layer 26 and the sound absorbing layer 21 depends on the sound vibration characteristics of the vehicle and the sound absorbing characteristics of the sound absorbing layer 21.
Various variations shown in FIG. 12 are conceivable.

FIG. 12A shows a structure in which a film layer 26 is integrated on the surface side of the sound absorbing layer 21, and FIG. 12B shows a structure in which the sound absorbing layer 21 is surrounded by the film layer 26 over the entire circumference. FIG. 12C shows a configuration in which a film layer 26 is disposed on both the front and back surfaces of the sound absorbing layer 21 with a part of the air layer 25 interposed therebetween, and FIG. The film layer 26 is integrated, but an opening 26a is partially formed in the film layer 26, and the sound absorbing layer 21 is partially formed in the film layer 26.
It is a configuration covered with.

As a method for integrating the film layer 26 with the sound absorbing layer 21, when the sound absorbing layer 21 used in the first and second embodiments is used, the raw mat of the sound absorbing layer 21 is hot-coated. After coating the melt-based powder, heating and softening, the film layer 26 may be overlaid and integrated.

The film layer 26 may be made of a polyolefin resin film, a polyurethane resin film, a polyester resin film, paper, or a composite thereof.
Has a thickness of 10 μm to 200 μm. The film layer 26 also has the effect of preventing the fibers and the like of the sound absorbing layer 21 from falling off to the outside, regardless of the presence or absence of air permeability.

When a film layer 26 having air permeability is used as the film layer 26, a part of the sound transmitted from the engine room E can be cut off, and furthermore, the instrument panel 40 in the transmitted instrument panel 40 can be cut off. The transmitted noise can be taken into the sound absorbing layer 21 again to absorb the reflected noise.

FIG. 13 is a graph showing the soundproofing characteristics of the insulator dash 20 according to the fourth embodiment.

Also in this fourth embodiment, the total soundproofing characteristics (a) of the insulator dash 20
Is the sum of the sound insulation (b) of the instrument panel 40, the sound absorption of the insulator, the sound insulation (c), and the sound absorption (d) of the instrument panel 40. As shown in the graph of FIG. Good sound absorption at 630 to 4000 Hz can be expected.

Further, also in the fourth embodiment, as shown in FIG. 14, by providing an instrument under cover 41 below the instrument panel 40, the inside of the instrument panel 40 is closed, and the instrument panel 40 is closed. The sound absorption in the interior can be enhanced.

Further, as shown in FIG. 15, the air layer 25 may be provided by partially floating the film layer 26 from the sound absorbing layer 21. In this case, the film layer 26
In consideration of heat resistance and moldability, a material obtained by laminating a hot melt film as an adhesive layer on the back surface of a nylon (polyamide) resin film is suitable.

The molding method may use the molding die 50 shown in FIG. 10, and the configuration of the bonding portion 24 and the air layer 25 is the same as that of the skin layer 23 of the third embodiment.

Finally, a fifth embodiment of the present invention will be described with reference to FIG. In this embodiment, the skin layer 2
7, a foamed resin sheet material is used. For example, a foamed foam material such as an olefin foamed resin or EPDM having an area density of less than 0.005 to 0.3 kg / m ² and a thickness of 15 mm or less is suitable.

Also, in this embodiment, since the foamed resin sheet material is used as the skin layer 27, the insulator dash 20 can be reduced in weight, and workability and fuel efficiency can be improved.

When a foam material having a closed-cell structure is used as the skin layer 27, the indoor noise is blocked by the transmission of sound from the engine room E and the absorption of the sound in the instrument 40 through the insulator dash 20. Can be reduced.

On the other hand, when a foam material having a continuous foam structure is used as the skin layer 27, the sound absorption of the sound in the instrument 40 transmitted through the insulator dash 20 may be more important than the cutoff of the sound transmitted from the engine room E. it can.

As described above, the automotive insulator dash 2
Although the zeroth embodiment has been described, the present invention can be applied to all automotive insulators mounted on a vehicle body panel.

[0098]

As described above, the automotive insulator according to the present invention has a single-layer structure of a sound-absorbing layer made of a fiber assembly, or a skin layer made of a high-density fiber assembly on at least one side of the sound-absorbing layer. Or, it is a configuration in which film layers are laminated, and because it is a configuration in which the conventional heavy rubber sheet and a sound insulation layer such as a PVC sheet are eliminated, the weight reduction of the insulator can be greatly promoted, and the fuel efficiency can be improved. At the same time, there is an effect that the workability of attaching the insulator can be improved.

Further, since the insulator according to the present invention is of a ventilation type, a part of noise transmitted to the indoor side through the vehicle body panel is absorbed by the sound absorbing layer, while transmitted noise transmitted to the indoor side is: The sound is reflected by the panel in the cabin and returns to the sound absorbing layer again, and a part of the sound is absorbed, so that an increase in sound pressure in the cabin can be prevented, and the soundproofing properties in the cabin can be greatly improved. .

In the structure in which the skin layer or the film layer composed of the high-density fiber aggregate is laminated on the sound absorbing layer, the skin layer or the film layer has a protector function, so that the fibrous material of the sound absorbing layer is prevented from falling outside. This also has the effect of ensuring a clean environment in the vehicle interior.

In addition, when a skin layer such as a non-woven fabric or a film layer is adhered to the surface of the sound absorbing layer, if the skin layer is partly floated from the sound absorbing layer and laminated and integrated, the air layer will have a buffer action. In addition, since there is no breakage of the skin layer, the fit to the vehicle body panel is improved, and the surface of the product is uneven, so that noise is irregularly reflected in the vehicle interior, and the sound absorption efficiency can be improved.

[Brief description of the drawings]

FIG. 1 shows a first embodiment of the present invention, and is a cross-sectional view showing a state where an automobile insulator dash is attached to a dash panel.

FIG. 2 is an explanatory view showing a sound absorbing mechanism of the automotive insulator dash shown in FIG.

FIG. 3 is a graph showing soundproofing characteristics of the automotive insulator dash shown in FIG. 1;

FIG. 4 is an explanatory diagram showing a modified example of the insulator dash shown in FIG.

FIG. 5 shows a second embodiment of the present invention, and is a cross-sectional view illustrating a state where an insulator dash for a vehicle is attached to a dash panel.

FIG. 6 is a graph showing soundproofing characteristics of the insulator dash mounting structure shown in FIG. 5;

FIG. 7 is an explanatory view showing a modification of the automotive insulator dash shown in FIG. 5;

FIG. 8 shows a third embodiment of the present invention, and is a cross-sectional view illustrating a state where an automobile insulator dash is attached to a dash panel.

9 is a cross-sectional view showing a main part of the automotive insulator dash shown in FIG.

FIG. 10 is an explanatory view showing a molding die of the automotive insulator dash shown in FIG. 8;

FIG. 11 is a cross-sectional view showing a state where an automobile insulator dash according to a fourth embodiment of the present invention is attached to a dash panel.

12 is an explanatory diagram showing variations of a film layer in the automotive insulator dash shown in FIG. 11;

FIG. 13 is a graph showing the soundproofing characteristics of the automotive insulator dash shown in FIG.

FIG. 14 is an explanatory view showing a modified example of the automotive insulator dash shown in FIG. 11;

FIG. 15 is an explanatory view showing a modified example of the automotive insulator dash shown in FIG. 11;

FIG. 16 is a cross-sectional view showing a state in which an automobile insulator dash according to a fifth embodiment of the present invention is attached to a dash panel.

FIG. 17 is an explanatory diagram showing a configuration of a conventional insulator dash.

FIG. 18 is a cross-sectional view showing a configuration of a conventional insulator dash.

FIG. 19 is an explanatory view showing a soundproof mechanism in a conventional insulator dash.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Dash panel 10a Dash upper part 10b Dash lower part 10c Toe board part 20 Insulator dash 21 for automobiles 21 Sound absorption layer 22,23,27 Skin layer 24 Adhesion part 25 Air layer 26 Film layer 30 Floor carpet 40 Instrument panel 41 Instrument under cover 50 Molding mold 51 Molding upper mold 52 Molding lower mold

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Kuniaki Sasaki, 3316 Miyayama, Samukawa-cho, Koza-gun, Kanagawa Prefecture, Japan (72) Inventor Yuji Sakata 3316 Miyayama, Samukawa-cho, Koza-gun, Kanagawa, Japan (Kasai Kogyo Co., Ltd. 72) Inventor Shozo Yabushita 3316 Miyayama, Samukawa-cho, Koza-gun, Kanagawa Prefecture (72) Inventor Tomohiro Tachiki 3316 Miyayama, Samukawa-cho, Koza-gun, Kanagawa Prefecture F-term (reference) 3D023 BA02 BA03 BB17 BC01 BD12 BE04 BE20 BE22

Claims (12)

[Claims] An automobile insulator (20) provided on the indoor side of a vehicle body panel (10), wherein the insulator (20) is a single layer of a sound absorbing layer (21) based on a fiber molded body. And absorbs the noise that enters the sound absorbing layer (21) through the vehicle body panel (10), and the transmitted noise transmitted through the sound absorbing layer (21) is reflected on the inner surface of the panel (40) in the vehicle interior, and again. An insulator for a vehicle, wherein the insulator is configured as a ventilated insulator that can return to the sound absorbing layer (21) from the front side and absorb the reflected noise. 2. A skin layer (22) made of a high-density fiber aggregate set at a higher density than the surface density of the sound absorbing layer (21) is laminated on at least one of the front and back surfaces of the sound absorbing layer (21). The automotive insulator according to claim 1, wherein: 3. A nonwoven fabric (23) is provided on the surface of the sound absorbing layer (21).
a) A skin layer (23) in which a hot melt film (23b) is laminated on the back surface is laminated, and the skin layer (22) is formed in an uneven shape, so that a sound absorbing layer is formed in a concave portion of the skin layer (23). (21) and
The automotive insulator according to claim 1, characterized in that an air layer (25) is formed at the projections of the skin layer (23). 4. The automotive insulator according to claim 1, wherein a film layer (26) is attached to the sound absorbing layer (21). 5. A sound absorbing layer (21) comprising: a film layer (26);
The insulator for a motor vehicle according to claim 4, wherein the insulator is provided so as to cover the sound absorbing layer (21) over the entire circumference of the insulator. 6. The film layer (26) comprises a sound absorbing layer (21).
5. The automotive insulator according to claim 4, wherein the front and back sides of the insulator are laminated. 7. The sound absorbing layer (21) comprising a film layer (26).
5. The automotive insulator according to claim 4, wherein a surface of the insulator is laminated. 8. The sound absorbing layer (21) comprising a film layer (26).
The insulator for a vehicle according to claim 4, wherein the insulator is provided only on a part of the front and back surfaces of the vehicle. 9. An automotive insulator according to claim 4, wherein an air layer (25) is provided between the film layer (26) and the sound absorbing layer (21). 10. The unevenness of the film layer (26) allows the film layer (26) to adhere to the sound-absorbing layer (21) at the concave portion and to form the air layer at the convex portion of the film layer (26). The automotive insulator according to claim 9, wherein (25) is formed. 11. A skin layer (27) made of a foamed resin sheet material is laminated on at least one of the front and back surfaces of the sound absorbing layer (21), or on a part thereof. The automotive insulator as described in the above. 12. An under cover (41) is provided below a panel (40) in a vehicle compartment, and transmitted noise transmitted from a vehicle body panel (10) through a sound absorbing layer (21) is a closed space in the panel (40). The automotive insulator according to any one of claims 1 to 11, wherein the sound pressure is reduced in the interior.