JP3656232B2 - Sound absorbing material for vehicles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sound absorbing material for a vehicle suitable for a molded ceiling, a rear parcel shelf, a rear tray and the like for a vehicle, and more particularly, to a sound absorbing material for a vehicle excellent in sound absorbing performance capable of effectively absorbing noise in a high frequency range in a vehicle interior. .
[0002]
[Prior art]
For example, various vehicle sound absorbing materials are installed in the interior of the vehicle. 10 and 11 show a molded ceiling mounted on the interior surface of a vehicle ceiling panel. This seed-molded ceiling 1 is formed by laminating and integrating a skin 3 excellent in surface texture and the like on the surface of a base material 2 having shape retention and mounting rigidity to a vehicle body panel.
[0003]
And as a structure of the base material 2 and the skin 3 in the molding ceiling 1, various things are conventionally used. FIG. 12 schematically shows the conventional configuration of the substrate 2 and FIG. 13 schematically shows the conventional configuration of the skin 3.
[0004]
For example, as shown in FIG. 12, as the substrate 2, those of (1) to (5) are conventionally known.
[0005]
(1). Sound-absorbing nonwoven fabric As shown in FIG. 12 (a), a web-like hot melt 2b is laminated on both sides of a PET fiber 2a, and a backside nonwoven fabric 2c is laminated on the back surface via a venting film 2d. And since it is based on PET fiber, it is excellent in porous sound absorption performance.
[0006]
(2). PPO (polyphenylene oxide) base material As shown in FIG. 12 (b), a PPO resin skin layer 2f is laminated and integrated on both surfaces of a PPO foam layer 2e, and a back nonwoven fabric 2c is laminated via a hot melt 2b. When the PPO resin base materials 2e and 2f are used, the hard PPO resin skin layer 2f provides high rigidity, and the PPO resin foam layer 2e can reduce the weight.
[0007]
(3). Urethane base material As shown in FIG. 12 (c), glass mats 2h are bonded to both surfaces of hard urethane 2g, and back nonwoven fabric 2c is laminated on the back surface side through air vent film 2d. And in the case of these urethane base materials 2g and 2h, it is excellent in the dimensional stability at the time of shaping | molding.
[0008]
(4). As shown in FIG. 12 (d), an air blocking film 2d is laminated on the product surface side of the olefin resin substrate 2i mixed with glass fibers, and the back surface nonwoven fabric 2c is formed on the back surface. Laminated. And this olefin resin base material 2i with glass fiber is excellent in dimensional stability.
[0009]
(5). Olefin-based resin substrate with glass fiber (Sound absorption type)
As shown in FIG. 12 (e), the hot melt 2b is laminated on the front surface side of the olefin resin base material 2i mixed with glass fibers, and the air permeation stop film 2d is laminated on the back surface. When a ventilation stopper is provided on the back side of the product, a certain level of sound absorption can be expected.
[0010]
Next, as the skin 3 in the molded ceiling 1, as shown in FIG. 13, a thin slab urethane 3c is formed on the back surface of a non-woven skin 3a made of synthetic fiber such as polyester or polyolefin, or a cloth 3b such as tricot or knit. A laminate is used. This slab urethane 3c has a density of 0.02 to 0.05 g / cc, a thickness of 2.0 to 10.0 mm, and an air flow rate of 100 to 200 cc / cm ² / sec (according to a fragile air flow rate measuring device).
[0011]
Further, as a conventional configuration of interior parts such as a rear parcel shelf and a rear tray provided in the luggage room, the configuration of the rear parcel shelf 4 will be described with reference to FIGS. The rear parcel shelf 4 has a skin 3 attached to the surface of the substrate 2. In this case, as shown in FIG. 16, the variations of the base material 2 include (1) polyolefin resin base material 2j, (2) polyolefin composite resin base material 2k mixed with wood flour, and (3) PET fiber. The mixed polyolefin-based resin base material 2l, (4) The glass fiber-containing olefin-based resin base material 2i is laminated with a ventilation barrier film 2d on the product surface side, and the back surface is laminated with the back nonwoven fabric 2c, (5) In some cases, the backside nonwoven fabric 2c is laminated on the product backside of the glass fiber-containing olefin resin substrate 2i.
[0012]
Furthermore, the same material as the skin 3 of the molded ceiling 1 is used as the skin 3 in the rear parcel shelf 4.
[0013]
[Problems to be solved by the invention]
As described above, as the material of the conventional molded ceiling 1, the above-described structure is well known as the base material 2 and the skin 3, but as the base material 2, a sound-absorbing nonwoven fabric type using PET fibers 2 a, It has been pointed out that the cost is high and the fiber-based core material has low rigidity and poor shape retention.
[0014]
In addition, when PPO resin base materials 2e and 2f are used, the dimensional stability is low, it is difficult to use for large ceilings, and since there is no air permeability, the room noise is reflected and the sound absorption function cannot be expected. There is.
[0015]
Next, in the case of the urethane base materials 2g and 2h, it has a certain level of sound absorption performance. However, in order to obtain further sound absorption performance, it is necessary to perform needle hole processing, which increases the processing cost and increases the thickness. There is a disadvantage that the weight is increased and the weight cannot be reduced.
[0016]
Further, in the case of the glass fiber-containing olefin resin base material 2i, when the air-proofing film 2d is laminated on the product surface side, the sound-absorbing performance is deteriorated. Although the performance is slightly improved, the actual situation is that the sound-absorbing property of the sound-absorbing nonwoven fabric cannot be expected.
[0017]
Thus, the base material 2 in the conventional molded ceiling 1 does not satisfy all of the sound absorption performance, rigidity, dimensional stability, cost, and the like, and the conventional skin 3 has a configuration in which the sound absorption performance cannot be expected. .
[0018]
Similarly, in the case of the rear parcel shelf 4, when (1) to (3) are used as the base material 2, since the base material 2 has no air permeability, indoor noise is reflected, resulting in sound absorption performance. In addition, there is a disadvantage that it is inferior, and when the base material 2 uses (4) glass fiber-containing olefin resin base material (i.e., a structure having a ventilation stopper on the surface of the skin 3) 2i, it reflects indoor noise. Similar to the above-described configuration, there is a problem that the sound absorption performance is lowered. Furthermore, when (5) glass fiber-containing olefin-based resin base material (structure without ventilation) 2i is used, a certain level of improvement in sound absorption performance can be expected, but the desired sound absorption performance cannot be obtained unless the thickness is increased. For this reason, there is a drawback in that the weight is increased.
[0019]
This invention was made in view of such circumstances, and is a vehicle sound absorbing material suitable for a vehicle molded ceiling, a rear parcel shelf, a rear tray, and the like, and by imparting excellent sound absorbing performance to the skin, An object of the present invention is to provide a vehicle sound absorbing material having excellent sound absorbing performance.
[0020]
[Means for Solving the Problems]
In order to achieve the above object, an invention according to claim 1 of the present application is composed of a base material attached to the indoor side of a vehicle body panel, and a skin layer laminated and integrated on the surface of the base material. Further, a surface layer sheet made of a nonwoven fabric or a woven fabric is laminated on the surface of a low ventilation type slab urethane whose air permeability is set to 1 to 50 cc / cm ² / sec.
[0021]
Here, the use of the sound absorbing material for the vehicle can be applied to a molded ceiling attached to the inside of the roof surface of the vehicle body panel, a rear parcel shelf provided in the luggage room, a rear tray, or an interior panel installed in the trunk room. .
[0022]
Furthermore, as the base material, a glass fiber-containing olefin resin base material, a urethane base material, a PPO resin base material, a sound-absorbing non-woven base material such as a PET non-woven fabric, and the like can be applied. If laminating is performed, it is possible to prevent rubbing noise between the body panel. In addition, as a base material for interior parts such as a rear parcel shelf, an olefin resin base material containing glass fiber, an olefin resin base material, or an olefin resin base material mixed with wood flour or polyester fiber can be used. .
[0023]
Next, as the skin, low-breathing slab urethane is laminated on the back surface of a surface layer sheet such as nonwoven fabric or woven fabric.
[0024]
This low ventilation type slab urethane increases the resistance by reducing the size of the cell and decreases the air permeability, and increases the resistance by increasing the membrane between the cells and decreases the air permeability. Also good.
[0025]
The air permeability of the low air permeability type slab urethane is preferably in the range of 1 to 50 cc / cm ² / sec, and this measured value is obtained using a Frazier type air permeability measuring device. In this case, if the air flow rate is less than 1 cc / cm ² / sec, the indoor noise is reflected and the sound absorbing effect cannot be exhibited. If the air flow rate exceeds 50 cc / cm ² / sec, the desired porous Sound absorption performance cannot be expected.
[0026]
Further, the urethane density of the low-air-permeable slab urethane is 0.02 to 0.05 g / cc, the urethane thickness is 2.0 to 10.0 mm, and preferably 3.0 to 5.0 mm ensures a product uneven shape. Is preferable.
[0027]
According to the vehicle sound-absorbing material according to claim 1, since the low-breathing slab urethane is laminated on the back surface of the surface layer sheet as the structure of the skin, in particular, the medium / high frequency of 2.0 to 6.3 kHz Effectively absorbs noise in the frequency range.
[0028]
Therefore, it is used for substrates that cannot be expected to have sound absorption performance, such as glass fiber-containing olefin resin base materials, olefin resin base materials, wood flour, polyester fiber-containing olefin resin base materials, or PPO resin base materials. In other words, in addition to cost and physical properties, the sound absorbing material for a vehicle is excellent in sound absorbing performance. On the other hand, if a skin having low air permeability slab urethane is used for a base material having a certain level of sound absorption performance, such as a sound-absorbing nonwoven fabric base material or a urethane base material, a sound-absorbing material for vehicles having a higher sound absorption performance can be obtained.
[0029]
Next, the invention according to claim 2 of the present application is characterized in that an adhesive medium sheet is laminated on the surface of the low-breath slab urethane facing the substrate in the skin.
[0030]
As the adhesive medium film, a slit-containing hot melt film, a web-like hot melt film, or a nonwoven fabric (surface density of 10 to ²⁰⁰ g / m ² ) can be used.
[0031]
According to the vehicle sound-absorbing material according to claim 2, since a hot melt film with slits, a web-like hot melt film, a nonwoven fabric, and the like are laminated on the surface of the low air-permeable slab urethane facing the base material, The adhesion of the skin to the material is increased, and there is no peeling failure.
[0032]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of a sound absorbing material for a vehicle according to the present invention will be described in detail with reference to the accompanying drawings.
[0033]
1 to 6 show a first embodiment in which a vehicle sound absorbing material according to the present invention is applied to a molded ceiling. FIG. 1 is a front view of the molded ceiling to which the present invention is applied as viewed from the indoor side. Is a sectional view showing the structure of the molded ceiling, FIG. 3 is an explanatory diagram showing the structure of the base material and skin of the molded ceiling, and FIG. 4 shows the difference in sound absorption coefficient between the molded ceiling according to the present invention and the conventional molded ceiling. FIG. 5 is a schematic diagram showing variations of the base material in the vehicle sound absorbing material according to the present invention. FIG. 6 is a schematic diagram showing variations of the skin in the vehicle sound absorbing material according to the present invention. .
[0034]
7 to 9 show a second embodiment in which the vehicle sound absorbing material according to the present invention is applied to a rear parcel shelf. FIG. 7 is a perspective view showing the rear parcel shelf, and FIG. FIG. 9 is a schematic view showing a variation of a modification of the base material in the rear parcel shelf.
[0035]
First, a first embodiment of the present invention will be described with reference to FIGS. In FIG. 1, a molded ceiling 10 has an outer shape that covers the interior surface of a vehicle roof panel (not shown), a storage recess 10a that houses a sun visor at the front side edge, a lamp mounting hole 10b at the center, and an assist at both sides. The grip storage recess 10c is formed in a gently curved shape.
[0036]
As shown in FIGS. 2 and 3, the first embodiment of the vehicle sound absorbing material according to the present invention applied to the molded ceiling 10 is a surface of the base material 20 having shape retention and mounting rigidity to the roof panel. In addition, the skin 30 having excellent surface texture and feel is laminated and integrated.
[0037]
And in this embodiment, as shown in FIG. 3, as the concrete structure of the base material 20 and the skin 30, the base material 20 is the one side of the glass fiber containing olefin resin base material 21 (the skin 30 and the opposite side). An air-blocking film 22 such as an olefin resin film is laminated on the other side (the surface facing the vehicle body panel), and a back nonwoven fabric 23 is laminated on the other side (the surface facing the vehicle body panel).
[0038]
In addition, when the glass fiber containing olefin resin base material 21 is used, although it is inferior in sound absorption, it has the property excellent in cost, a moldability, dimensional stability, weight reduction, etc.
[0039]
On the other hand, the skin 30 uses a two-layer structure in which a low-breathing slab urethane 32 is laminated on the back surface of a surface layer sheet 31 such as a woven fabric sheet such as a nonwoven fabric sheet, tricot, or knit.
[0040]
By the way, especially this invention is characterized by providing the sound absorption performance excellent in the skin 30 by laminating the low ventilation type slab urethane 32 on the back surface of the surface layer sheet 31 as a structure of the skin 30.
[0041]
This low ventilation type slab urethane 32 has a density of 0.02 to 0.05 g / cc and a thickness of 2.0 to 10.0 mm (preferably a thickness of 3.0 to 5.0 mm for securing the product uneven shape). The composition of the low air permeability type slab urethane 32 may be ether type or ester type.
[0042]
What is more important is that the air flow rate of the low air flow type slab urethane 32 is set to 1 to 50 cc / cm ² / sec (using a Frazier type air flow rate measuring device). For example, if the air flow rate is less than 1 cc / cm ² / sec, the indoor noise is reflected and the sound absorption effect is not exhibited, and if it exceeds 50 cc / cm ² / sec, the porous sound absorption performance cannot be expected. by.
[0043]
In addition, as the work of adjusting the air flow rate of the low-air-permeable slab urethane 32, the resistance is increased by decreasing the cell size, and the resistance is increased by decreasing the air permeability or increasing the membrane between the cells. Therefore, it is conceivable to reduce the air permeability.
[0044]
Therefore, if the base material 20 adopting the glass fiber-containing olefin resin base material 21 is applied to the molded ceiling 10 using the skin 30 in which the low air-permeable slab urethane 32 is laminated on the back surface, the good dimensions of the base material 20 are obtained. In addition to advantages such as stability, increased rigidity, and weight reduction, the sound absorption performance of the skin 30 can be obtained, and it is possible to provide a molded ceiling 10 that can be reduced in weight and reduced in weight, and has excellent moldability and sound absorption performance. Can do.
[0045]
In this case, the graph of FIG. 4 is shown as a standard for improving the sound absorption performance. The solid line in this graph shows the correlation between the sound absorption coefficient in each frequency region of the molded ceiling (urethane density 0.035 g / cc, thickness 5.0 mm, air flow rate 20 cc / cm ² / sec) shown in FIG. In order to be able to contrast with this, a conventional example in the case of using a non-woven skin on the same substrate is shown by a dotted line.
[0046]
As can be seen from the graph of FIG. 4, it can be easily understood that the sound absorption rate of noise in the middle / high sound range at 2 to 6.3 kHz is improved in the present invention as compared with the conventional example. .
[0047]
Next, FIG. 5 shows a variation of the base material 20 in the molded ceiling 10, and as shown in FIG. 5 (a), the hot melt 24 with slits on the skin 30 side of the olefin resin base material 21 with glass fiber, the back surface An air-proofing film 22 such as an olefin-based resin film may be laminated on the side, and in this case, the air-proofing film 22 is placed on the back side of the glass-fiber-containing olefin-based resin base material 21, thereby The improvement of the sound absorption performance in the base material 21 can be expected.
[0048]
Next, FIG. 5 (b) uses a nonwoven fabric substrate 25 typified by PET (polyethylene terephthalate) as the substrate 20, and laminates hot melt 24 on both sides of this nonwoven fabric substrate 25, and further on the back side thereof. In this configuration, the back nonwoven fabric 23 is laminated and integrated through the air blocking film 22.
[0049]
And when this sound-absorbing nonwoven fabric base material 25 is used, the sound-absorbing performance of the base material 20 can be obtained, so it is better in synergy with the sound-absorbing performance of the skin 30 using the low air permeability type slab urethane 32. Sound absorption performance can be obtained.
[0050]
Next, as shown in FIG. 5 (c), a PPO resin skin layer 26b is laminated on both sides of the PPO resin foam layer 26a as the base material 20, and the hot melt 24 is placed on the front side and the hot melt 24 is placed on the back side. When the PPO resin base material 26 is used, the sound absorption performance of the base material 20 cannot be expected, but the shape retention is excellent, and the PPO resin foam layer 26a is Due to the foam structure, the weight can be reduced and the dimensional stability is excellent. In addition, regarding the sound absorbing performance that is insufficient, by applying the skin 30 having the low-air-permeable slab urethane 32, it is possible to provide a satisfactory molded ceiling 10 by covering the shortage of the sound absorbing performance in the base material 20.
[0051]
Moreover, as shown in FIG.5 (d), the urethane base material 27 which laminated | stacked the glass mat 27b on both surfaces of the hard urethane resin 27a can also be used, and the back surface nonwoven fabric 23 is integrated through the ventilation film 22. In this case as well, excellent dimensional stability and a certain level of sound absorbing performance can be imparted to the substrate 20, and by combining with the skin 30 having a good sound absorbing function, the dimensional stability and sound absorbing properties are excellent. Can provide a molded ceiling.
[0052]
Next, FIG. 6 shows a modification of the skin 30 used in the present invention. In order to increase the adhesive strength with the base material 20, as shown in FIG. A hot melt film 33 with slits is laminated on the surface facing the substrate.
[0053]
Further, as shown in FIG. 6B, a web-like hot melt 34 is laminated on the surface of the low air-permeable slab urethane 32 facing the substrate.
[0054]
As shown in FIG.6 (c), the nonwoven fabric (weight per unit area 110-200 g / m < ² >) is laminated on the base material opposing surface of the low ventilation | gas_flowing type | mold slab urethane 32. As shown in FIG.
[0055]
And by appropriately laminating the hot melt film 33 with slits, the web-like hot melt 34, and the nonwoven fabric 35, the adhesive strength between the base material 20 and the skin 30 can be increased, and since it is a layer having air permeability, Adhesive strength can be strengthened without lowering the sound absorption effect, there can be no peeling failure of the skin 30, and quality performance can be improved.
[0056]
Next, FIGS. 7 to 9 show a second embodiment in which the present invention is applied to the rear parcel shelf 40. 7 and 8, the rear parcel shelf 40 is composed of a two-layer laminate of a base material 20 and a skin 30 that are molded into a required shape, and has a shallow bottom shape so that the equipment can be securely placed and accommodated. The receiving recess 41 is formed.
[0057]
Further, as the base material 20, as in the above-described molded ceiling 10, a glass fiber-containing olefin resin base material 21 having a back surface nonwoven fabric 23 laminated on one surface is used, and the back surface of the surface layer sheet 31 is also used in the skin 30. It is a structural feature that the skin 30 excellent in sound absorbing performance obtained by laminating a low-ventilation type slab urethane 32 is used.
[0058]
Therefore, the interior noise can be effectively absorbed by the skin 30 especially in the middle and high frequency range, and the sound absorption performance can be obtained to some extent even in the base material 20. Therefore, the rear parcel shelf 40 having excellent overall sound absorption performance can be obtained. Can be provided.
[0059]
Furthermore, as the base material 20 of the rear parcel shelf 40, each structure of Fig.9 (a)-(d) is also employable.
[0060]
FIG. 9A shows a configuration in which a ventilation film 22 is laminated on the skin side of the glass fiber-containing olefin resin substrate 21, and FIG. 9B shows the olefin resin substrate 28, FIG. 9C. Is an olefin-based resin base material 28a containing wood flour, and FIG. 9 (d) is an olefin-based resin base material 28b containing polyester fibers.
[0061]
Therefore, since the base material 20 shown in FIGS. 9A to 9D has excellent properties such as cost, moldability, mechanical strength, etc., excluding the sound absorbing property, the skin 30 having the sound absorbing property is applied. The rear parcel shelf 40 which is inexpensive and excellent in sound absorbing performance can be manufactured.
[0062]
Note that the present invention can be applied to a rear tray and other interior panels instead of the rear parcel shelf 40.
[0063]
【The invention's effect】
As described above, the vehicle sound-absorbing material according to the present invention is a vehicle sound-absorbing material in which a skin is integrated on the surface of a base material having shape retention, and the structure of the skin is a low-breathing type on the back surface of the surface sheet. By laminating slab urethane, it is configured to improve the sound absorbing performance of the sound absorbing material for vehicles by giving high sound absorbing performance to the skin, especially in the middle and high frequency range of low ventilation type slab urethane. Since the sound absorbing property can be enhanced, there is an effect that it is possible to provide a vehicle sound absorbing material having excellent sound absorbing performance.
[Brief description of the drawings]
FIG. 1 is a front view of a molded ceiling to which a vehicle sound absorbing material according to the present invention is applied as viewed from the indoor side.
2 is a cross-sectional view taken along line II-II in FIG.
FIG. 3 is a schematic diagram showing a configuration of a base material and a skin in the molded ceiling shown in FIG.
FIG. 4 is a graph showing a comparison of sound absorption rates between a molded ceiling according to the present invention and a conventional molded ceiling.
FIG. 5 is a schematic diagram showing a modified example of a base material in a molded ceiling applied to a vehicle sound absorbing material according to the present invention.
FIG. 6 is a schematic view showing a variation of a modified example of the skin on the molded ceiling to which the vehicle sound absorbing material according to the present invention is applied.
FIG. 7 is an external view showing a rear parcel shelf to which the vehicle sound absorbing material according to the present invention is applied.
8 is a cross-sectional view taken along line VIII-VIII in FIG.
FIG. 9 is a schematic view showing a variation of a modification of the base material in the rear parcel shelf to which the vehicle sound absorbing material according to the present invention is applied.
FIG. 10 is a front view showing a conventional molded ceiling.
11 is a cross-sectional view taken along line XI-XI in FIG.
FIG. 12 is a cross-sectional view showing a configuration of a base material in a conventional molded ceiling.
FIG. 13 is a cross-sectional view showing the structure of the skin of a conventional molded ceiling.
FIG. 14 is an external view showing a conventional rear parcel shelf.
15 is a cross-sectional view taken along line XV-XV in FIG.
FIG. 16 is a cross-sectional view showing a configuration of a base material in a conventional rear parcel shelf.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Molded ceiling 20 Base material 21 Glass fiber containing olefin resin base material 22 Air vent film 23 Back surface nonwoven fabric 24 Hot melt 25 Sound absorption nonwoven fabric base material 26 PPO resin base material 26a PPO resin foam layer 26b PPO resin skin layer 27 Urethane base material 27a Hard urethane resin 27b Glass mat 28 Olefin-based resin substrate 28a Wood powder-containing resin substrate 28b Polyester fiber-containing resin substrate 30 Skin 31 Surface layer sheet 32 Low-breathing slab urethane 33 Slit hot melt film 34 Web-like hot melt 35 Non-woven fabric 40 Rear parcel shelf

Claims (2)

It is comprised from the base material (20) attached to the indoor side of a vehicle body panel, and the skin (30) laminated | stacked and integrated on the surface of a base material (20), and the said skin (30) has an air flow of 1-50 cc / A sound-absorbing material for vehicles, wherein a surface layer sheet (31) made of a nonwoven fabric or a woven fabric is laminated on a surface of a low-breathing slab urethane (32) set to cm ² / sec. 2. The vehicle according to claim 1, wherein an adhesive medium sheet (33, 34, 35) is laminated on a surface of the skin (30) facing the substrate of the low ventilation type slab urethane (32). Sound absorbing material.

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