JP2009018746A - Sound insulation material for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sound insulation material for a vehicle mounted at an indoor surface side of a vehicle body panel, which reduces the weight and inexpensively performs sound insulation to noise with high sound pressure level. <P>SOLUTION: The insulator dash 20 mounted at the vehicle indoor surface side of a dash panel 10 uses a laminated sound absorption layer 30 formed by laminating a base sound absorption layer 31 with porous absorption function and a plastic foam sheet 32 integrated with the indoor surface side of the base sound absorption layer 31. A sound insulating layer 40 having a sound insulating function is attached to a part of a surface of the laminated sound absorption layer 30 by corresponding to a portion high in a sound pressure level permeating a dash panel 10, and mainly consisting of noise in a low frequency area. Accordingly, the effective sound absorption processing is performed on the noise in a wide range level from the low frequency area to a high frequency area, and especially the sound insulation of the part high in the sound pressure level is inexpensively performed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicle sound insulating material attached to the interior side of a vehicle body panel. In particular, the sound pressure level of noise transmitted through the vehicle body panel to the vehicle interior side can be reduced with an inexpensive structure, and excellent sound insulation. The present invention relates to a vehicle soundproofing material capable of exhibiting performance.

  Usually, in order to enhance the quietness of the vehicle interior, various soundproof materials are attached to the interior side of the vehicle body panel as the soundproof structure of the vehicle. As an example of this soundproof material, there is an insulator dash attached to the interior side of a dash panel that partitions an engine room and a vehicle interior. A conventional example of this insulator dash will be described with reference to FIG. In the drawing, an insulator dash 2 is attached to the interior surface side of the dash panel 1 that partitions the engine room E and the vehicle compartment R, and this insulator dash 2 is enlarged as shown in FIG. A sound absorbing layer 3 for absorbing noise transmitted through the dash panel 1 into the vehicle interior R by a porous sound absorbing function and a skin layer 4 laminated on the surface of the sound absorbing layer 3 are configured.

  As the material of the sound absorbing layer 3 in the insulator dash 2, a material capable of obtaining a porous sound absorbing function such as felt, nonwoven fabric mat, or foam can be used. As the skin layer 4, the sound insulating type shown in FIG. When applied to the insulator dash 2, a sound insulating material 4A made of a high-density material such as a recycled rubber sheet or a recycled PVC sheet is used. In addition, when applied to the vent type insulator dash 2A of FIG. 8B, a lightweight and breathable high-density breathable layer 4B such as a nonwoven fabric mat is used. The configuration of the conventional example of the sound insulation type insulator dash 2 is described in Patent Document 1, and the configuration of the conventional example of the ventilation type insulator dash 2A is described in Patent Document 2.

Japanese Utility Model Publication No. 7-5966

Special Table 2002-505209

  Thus, conventionally, for example, as shown in FIG. 8 (a), in the sound insulation type insulator dash 2, a heavy material such as a recycled rubber sheet and a recycled PVC sheet is used as the sound insulating material 4A. However, this increases the weight of the product and reduces the fuel efficiency and the mounting workability. Further, in terms of sound absorption performance, it has been pointed out that the sound absorption effect of high frequency range noise is not sufficient, and satisfactory soundproof performance cannot be obtained.

  On the other hand, the breathable insulator dash 2A shown in FIG. 8B uses a high-density breathable layer 4B such as a nonwoven fabric in place of the heavy sound insulating material 4A. As the fibers used are mainly recycled products, the specifications of the fibers differ depending on the season, and the resistance to airflow tends to fluctuate due to variations in thickness, etc., making it difficult to achieve uniform sound absorption performance. . In addition, the filaments are likely to fall off due to long-term use, leading to a decrease in sound absorption performance, and not preferable from the environmental aspect of the passenger compartment. Furthermore, as a method of reducing the noise level in the low frequency range, it has been dealt with by increasing the weight per unit area of the sound absorbing layer 3, but in this case, the material cost and the molding processing cost will rise, leading to an increase in cost. At the same time, there is a problem that the molding cycle is prolonged and productivity is greatly reduced.

  The present invention has been made in view of such circumstances, and is a vehicle soundproofing material that is mounted on the interior side of a vehicle body panel, and transmits through the vehicle body panel to the indoor side while achieving weight reduction. An object of the present invention is to provide a vehicle soundproofing material that can reliably reduce the sound pressure level of noise with an inexpensive structure.

  In order to solve the above-mentioned problems, the present invention provides a vehicle soundproofing material mounted on the interior side of a vehicle body panel, wherein the vehicle soundproofing material is formed along the surface shape of the vehicle body panel. A sound-absorbing layer comprising a laminate of a base sound-absorbing layer having a porous sound-absorbing function for absorbing noise transmitted through the room through the interior, and a foamed resin sheet integrated on the surface side of the base sound-absorbing layer, and a vehicle body panel The sound-insulating layer is attached to a part of the surface side of the laminated sound-absorbing layer so as to correspond to a portion where the sound pressure level of the noise transmitted through the room is large.

  Here, the installation location of the soundproofing material can be applied to the interior side of the vehicle body panel, the interior side of the engine room, the interior side of the luggage room, the interior side of the trunk room, and the like. Product forms include insulator dash, roof trim, engine room insulator, luggage trim, and trunk trim.

In the present invention, a laminated sound-absorbing layer obtained by laminating a base sound-absorbing layer and a foamed resin sheet is employed. As the base sound-absorbing layer, felt, synthetic fiber nonwoven fabrics such as PET (polyester) fibers, papers (pulp) Etc.) is usually formed into a fiber, and after the heat-softening treatment of the original fabric mat in which the fiber aggregate is accumulated in a mat shape, it is press-molded by a cold press mold having a mold surface of a required shape. Molded. The sound absorbing layer has physical properties of a density of 0.01 to 0.6 g / cm ³ , a surface density of 200 to 2400 g / m ² , and a thickness of 4.8 so that the average thickness of the entire soundproofing material is 5 to 60 mm. -50 mm, preferably 5-10 mm, air flow rate 0.1-30 cc / cm ² · sec, preferably 1-20 cc / cm ² · sec.

In addition, as the foamed resin sheet, a polyolefin resin foam sheet such as polypropylene foam and polyethylene foam, a polyurethane foam sheet, and the like can be used, and a preferable surface density range is 0.005 to 0.3 kg / m ² , and the thickness is The maximum is set to 15 mm. As the foamed resin sheet, either a closed cell type foamed resin sheet or an open cell type foamed resin sheet may be used. When a closed cell foam resin sheet is used, it is non-breathable, so it effectively absorbs noise in the entire area, especially in the low and medium frequency ranges, using the membrane vibration absorbing function for noise that passes through the body panel. Can do. On the other hand, when an open-cell foamed resin sheet is used, it is possible to expect a porous sound absorbing function that can reduce the noise level in the middle and high frequency range in addition to the membrane vibration absorbing function by adjusting the air flow rate. .

Next, a part of the surface of the laminated sound-absorbing layer composed of a laminate of the base sound-absorbing layer and the foamed resin sheet, for example, a sound insulation layer attached corresponding to a portion having a high sound pressure level transmitted through the vehicle body panel, EPDM, A relatively high density sheet material such as PVC (polyvinyl chloride resin) or PU (polyurethane resin) is used, and the basis weight is set to 500 to 7000 g / m ² .

  Next, resin powder such as polyethylene powder, a hot melt film, or a hot melt web can be used as a means for bonding between the base sound absorbing layer and the foamed resin sheet and bonding the sound insulating layer to the sound absorbing layer. When using resin powder, spray the resin powder on the raw mat that is the material of the base sound-absorbing layer, and melt the resin powder when heating the raw mat with hot air to apply the resin powder on the original mat The foamed resin sheet may be superimposed on the surface and integrated with the press mold. Resin powders, hot melt films, and hot melt webs can be similarly used for adhesion between the laminated sound absorbing layer and the sound insulating layer. It can be easily integrated by applying or laminating one of the bonding surface adhesive layers and press-bonding both.

  As is clear from the above configuration, the vehicle soundproofing material according to the present invention has a configuration in which a sound insulating layer is attached to a part of the surface of a laminated sound absorbing layer composed of a laminate of a base sound absorbing layer and a foamed resin sheet. Therefore, if a closed cell type sheet is used as the foamed resin sheet in the laminated sound absorbing layer, a membrane vibration absorbing function can be expected, and if an open cell type sheet is used, a porous sound absorbing function can be provided in addition to the membrane vibration absorbing function. As a result, it is possible to effectively absorb noise in the middle / high frequency range.

  Furthermore, since the sound insulation layer is arranged corresponding to the part where the sound pressure level of the noise transmitted through the vehicle body panel to the indoor side is high, centering on the noise in the low frequency range, when performing sound absorption treatment with the sound absorption layer, Since sound insulation can be effectively performed even for noise that cannot be processed without increasing the plate thickness, it is possible to effectively perform sound insulation treatment for noise in the entire range from the low frequency range to the high frequency range. Compared to the meat structure, the structure with the sound insulation layer can be implemented at a lower cost, so the cost can be reduced.

  Next, in a preferred embodiment of the present invention, the sound insulation layer is arranged as a sound insulation layer divided on the surface of the laminated sound absorption layer at two or more places with respect to noise transmitted through the vehicle body panel. It is characterized by being.

  In this embodiment, the noise transmitted through the vehicle body panel to the indoor side is not uniform, and the sound pressure level varies such as a part with a high noise level and a part with a low noise level. The sound pressure level can be reduced more efficiently by affixing sound insulation layers to two or more locations corresponding to the pressure level, and the surface density can be changed according to the difference in sound pressure level. In addition, since a sound insulating layer can also be employed, weight reduction can be further promoted, and it can be manufactured at a low cost.

  As described above, the vehicle soundproofing material according to the present invention includes a base sound-absorbing layer having a porous sound-absorbing function formed along the surface shape of the vehicle body panel, and a foam integrated on the surface side of the base sound-absorbing layer. A laminated sound absorbing layer consisting of two layers with a resin sheet is used, and in correspondence with the sound pressure level of the noise transmitted through the vehicle body panel, it is laminated corresponding to the high sound pressure level transmitting part where the noise in the low frequency range is concentrated. Adopting a structure in which a sound insulating layer is attached to the surface of the sound absorbing layer, the sound absorbing layer can effectively absorb noise in the middle and high frequency range. Especially, the foamed resin sheet is like the closed cell type or the open cell type. In addition, the sound-absorbing mechanism, such as the porous sound absorption type and the membrane vibration sound absorption type, can be used to effectively absorb mid- and high-frequency noise and transmit high sound pressure levels centered on low-frequency noise. For parts, since it was applied by partially arranging a sound insulation layer, the effect is that it can be implemented at low cost compared to the conventional form in which the sound absorption layer is thick and the noise in the low frequency range is absorbed. Have

  Furthermore, the sound pressure level of the noise that passes through the vehicle body panel varies from part to part, but the sound pressure level can be reduced more efficiently by arranging sound insulation sheets at two or more places. Therefore, the weight can be reduced and the effect can be achieved at low cost.

  Hereinafter, an embodiment of a soundproofing material for a vehicle according to the present invention will be described in detail with reference to the accompanying drawings, which is applied to an insulator dash mounted on a vehicle interior side of a dash panel. Note that the gist of the present invention is as described in the scope of claims, and the contents of the embodiments described below are merely examples of the present invention.

  1 to 5 show an embodiment of the present invention. FIG. 1 is a cross-sectional view showing a configuration of an insulator dash attached to a dash panel, FIG. 2 is a front view showing the insulator dash, and FIG. 3 is the insulator. FIG. 4 and FIG. 5 show a modified example of the insulator dash according to the present invention, FIG. 4 is a front view, and FIG. 5 is a cross-sectional view.

  In FIG. 1, a dash panel 10 that partitions an engine room E and a vehicle compartment R is partitioned into a dash upper portion 10 a, a dash lower portion 10 b, and a toe board portion 10 c from the upper side, and an insulator along the interior surface of the dash panel 10. A dash 20 is attached. Further, a floor carpet 11 is laid on the surface side of the insulator dash 20 mounted on the toe board portion 10c, and is further mounted on the upper half 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 is located in the instrument panel 12. A crash pad (not shown) is attached to the instrument panel 12.

  By the way, the insulator dash 20 according to the present invention is configured such that the product weight is significantly reduced in order to improve fuel efficiency and mounting workability, and further, sufficient soundproofing characteristics are provided even if the weight is reduced. ing.

  As is apparent from FIGS. 1 to 3, the insulator dash 20 is disposed on the side facing the dash panel 10, and has a base sound absorption layer 31 that can effectively absorb noise in the middle and high frequency ranges by a porous sound absorption function. The laminated sound absorbing layer 30 composed of a two-layer laminate of the base sound absorbing layer 31 and the foamed resin sheet 32 integrated on the indoor surface side, and a part of the surface of the laminated sound absorbing layer 30, particularly the dash lower portion 10b, etc. The sound insulation layer 40 is generally configured from a portion having a high sound pressure level where transmitted noise in the frequency range is concentrated. In addition, between the base sound-absorbing layer 31 and the foamed resin sheet 32 which comprise the laminated sound-absorbing layer 30, both are firmly integrated with the adhesive layer which is not shown in figure, Similarly, the laminated sound-absorbing layer 30 and the sound-insulating layer 40, As for the integrated structure between them, the adhesive layer is applied or laminated on either side, and the laminated sound absorbing layer 30 and the sound insulating layer 40 are firmly integrated via the adhesive layer.

Next, the material structure of the laminated sound absorbing layer 30 and the sound insulating layer 40 will be described sequentially. First, the base sound-absorbing layer 31 in the laminated sound-absorbing layer 30 is made of felt, polyester fiber typified by polyethylene terephthalate, synthetic fiber nonwoven fabric such as polypropylene fiber, fiber aggregate made of paper (pulp or the like), or polypropylene, A synthetic resin material such as polyurethane, polyethylene, or polyester can be used as a foamed resin material in which an inorganic foaming agent such as sodium bicarbonate or a foaming agent selected from organic foaming agents such as azodicarbonamide is mixed. The base sound-absorbing layer 31 only needs to have a porous sound-absorbing function capable of absorbing noise in a high frequency range. The surface density is 200 to 2400 g / m ² , and the thickness of the insulator dash 20 is 5 to 5 mm. It is set between 4.8 and 50 mm so as to be 60 mm.

Next, the foamed resin sheet 32 is a thermoplastic resin foamed resin sheet such as polypropylene foam, polyethylene foam, polyurethane foam, etc., and the preferred area density is 0.005 to 0.3 kg / m ² , and the maximum thickness is 15 mm. Is set to In addition, the foamed resin sheet 32 has a membrane vibration sound absorbing function when using a closed cell type foamed resin sheet. In particular, the foamed resin sheet 32 can effectively absorb noise in the low / medium frequency range, and is also open-celled. When the foamed resin sheet is used, the form is different by adjusting the air flow rate. For example, if the air flow rate is low, only the membrane vibration sound absorbing function can be expected. If the air flow rate is gradually increased, the porous sound absorbing function increases in inverse proportion to the decrease in the membrane vibration sound absorbing function.

  Therefore, in the foamed resin sheet 32, whether to use a closed cell type foamed resin sheet or an open cell type foamed resin sheet may be appropriately adopted in consideration of the frequency distribution of noise to be controlled. As for the adhesion between the base sound absorbing layer 31 constituting the laminated sound absorbing layer 30 and the foamed resin sheet 32, a resin powder such as polyethylene powder is used as a hot melt, or a thermoplastic such as a hot melt film or a hot melt web. An adhesive layer made of a resin material is interposed between the two.

Next, in the present embodiment, the sound insulation layer 40 provided corresponding to the dash lower portion 10b in the dash panel 10 has a relatively high density such as EPDM, PVC (polyvinyl chloride resin), PU (polyurethane resin), or the like. Although a resin material is used, the basis weight is 500 to 7000 g / m ² , and this basis weight can also be appropriately selected according to the noise level in the low frequency range that passes through the dash panel 10. . And about the adhesion | attachment means of this sound insulation layer 40 and the laminated sound absorption layer 30, resin powder, such as polyethylene powder, a hot melt film, a hot melt web, etc. similarly to the adhesive structure of the base sound absorption layer 31 and the foamed resin sheet 32, etc. Can be used.

As described above, the insulator dash 20 in this embodiment has a configuration in which the sound insulating layer 40 is attached to a part of the surface of the laminated sound absorbing layer 30 in which the base sound absorbing layer 31 and the foamed resin sheet 32 are laminated. Therefore, as shown in FIG. 3, as the function of the laminated sound absorbing layer 30, as described above, in addition to the porous sound absorbing function of the base sound absorbing layer 31, the foamed resin sheet with respect to the noise level in the middle / high frequency range A synergistic effect of the membrane vibration absorbing function and the porous sound absorbing function of 32 can be expected. For example, with respect to the noise transmitted through the dash upper portion 10a, it is possible to effectively perform the sound absorption processing for the noise level in the middle / high frequency range as f → f ₁ → f ₂ in FIG.

Next, the sound insulation layer 40 performs noise insulation processing on the sound with a high sound pressure level centering on low frequency noise (F, F _{1 in} FIG. 3) that passes through the dash lower portion 10b. Therefore, it is cheaper to arrange the sound insulation layer 40 than the conventional structure in which the sound absorption layer is thick and the low frequency noise is shut out. In addition, it is very advantageous in terms of cost, such as a small molding load.

  Next, FIGS. 4 and 5 show a modified example of the present invention. As shown in FIG. 4, the insulator dash 20A has two or more locations on the surface of the laminated sound absorbing layer 30 (in this modified example, Are provided with sound insulation layers 40A, 40B and 40C, respectively. As described above, the sound insulation layers 40A, 40B, and 40C are more dispersedly arranged, and can further reduce the weight as compared with the above-described embodiment, and compared with the sound insulation layers 40A and 40B on the left and right sides of the dash lower portion 10b. Although the weight per unit area of the sound insulation layer 40C of the dash upper portion 10a is reduced, the weight per unit area of each of the sound insulation layers 40A, 40B, and 40C can be changed to reduce the weight and reduce the cost, and more efficient sound insulation. Measures can be taken.

  Next, FIG. 5 shows still another modified example of the present invention. In the structure of the laminated sound absorbing layer 30, the foamed resin sheet 32 is omitted in the portion where the sound insulating layer 40 is applied. This is because when the foamed resin sheet 32 and the sound insulation layer 40 are polymerized, the membrane vibration sound absorbing function of the foamed resin sheet 32 alone cannot be obtained. Thus, if desired, the foamed resin sheet 32 can be omitted from the laminated sound absorbing layer 30 to simplify the configuration.

  In the above-described embodiment, the present invention is applied to the insulator dash 20 attached to the interior surface side of the dash panel 10. However, the dash panel 10 is installed in the engine room, the luggage room, or the trunk room as well as the roof trim attached to the interior of the vehicle interior. It can be applied to various soundproofing materials. Further, regarding the integration of the laminated sound absorbing layer 30 and the sound insulating layer 40, individually molded ones may be integrated by a pressure-bonding die, or the laminated sound absorbing layer 30 and the sound insulating layer 40 are pressed with the same die. It may be integrated.

It is sectional drawing which shows one Example which applied the soundproof material for vehicles which concerns on this invention to the insulator dash. It is a front view which shows the insulator dash shown in FIG. It is explanatory drawing which shows the soundproofing mechanism in the insulator dash shown in FIG. It is a front view which shows the modification of the insulator dash shown in FIG. It is sectional drawing which shows the further modification of the insulator dash shown in FIG. It is explanatory drawing which shows the installation location of the conventional insulator dash. It is sectional drawing which shows the structure of the conventional insulator dash. It is explanatory drawing which shows schematic structure of the sound insulation type | mold insulator dash and ventilation type | mold insulator dash in the conventional insulator dash.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Dash panel 10a Dash upper part 10b Dash lower part 10c Toe board part 11 Floor carpet 12 Instrument panel 20, 20A, 20B Insulator dash 30 Laminated sound absorption layer 31 Base sound absorption layer 32 Foamed resin sheet 40 Sound insulation layer

Claims (4)

  A vehicle soundproofing material (20) mounted on the interior side of the vehicle body panel (10), wherein the vehicle soundproofing material (20) is formed along the surface shape of the vehicle body panel (10). (10) a base sound-absorbing layer (31) having a porous sound-absorbing function that absorbs noise transmitted through the room, and a foamed resin sheet (32) integrated on the surface side of the base sound-absorbing layer (31) And a part of the surface side of the laminated sound absorbing layer (30) corresponding to a portion where the sound pressure level of the noise transmitted through the vehicle body panel (10) to the indoor side is large. A sound insulation material for a vehicle, characterized by comprising a sound insulation layer (50) affixed to the vehicle.   The foamed resin sheet (32) is a closed-cell foamed resin sheet, which absorbs noise transmitted through the vehicle body panel (10) by membrane vibration of the foamed resin sheet (32), thereby reducing the level of the low / medium frequency range. The soundproof material for a vehicle according to claim 1, wherein the noise is reduced.   As the foamed resin sheet (32), an open-cell foamed resin sheet is used, and in addition to the sound absorption function at the low / medium frequency level due to the membrane vibration of the foamed resin sheet (32), the noise at the medium / high frequency range level The soundproof material for a vehicle according to claim 1, wherein the sound is reduced by a porous sound absorbing function.   The sound insulation layer (40) is divided into the sound absorption layer (40A, 40B, 40C) divided into the surface of the laminated sound absorption layer (30) at two or more places with respect to noise transmitted through the vehicle body panel (10). The soundproofing material for a vehicle according to any one of claims 1 to 3, wherein the soundproofing material is arranged as follows.

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