JP2977146B2 - Sound insulation structure and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound insulating structure suitable for an automobile dash panel mounted on a dash panel and a method of manufacturing the same, and more particularly, to a sound insulating structure having improved soundproofing and a method of manufacturing the same. About.

[0002]

2. Description of the Related Art For example, as shown in FIG. 12, a dash panel 1 for partitioning an engine room E and a vehicle room R has a dash panel 1 on the vehicle interior surface to prevent noise from propagating from the engine room E to the vehicle room R. To do so, an insulator dash 2 is provided.

[0003] This insulator dash 2 is shown in FIG.
As shown in the figure, a laminated structure of a relatively high-density sound-insulating material layer 3 such as a PVC sheet or a rubber sheet mixed with a filler and a sound-absorbing material layer 4 made of a porous base material such as felt, polyurethane foam, or nonwoven fabric. The body is commonly used.

[0004] The sound absorbing material layer 4 absorbs noise from the engine room E, and the dash panel 1 and the sound insulating material layer 3 have a double-walled sound insulating effect, so that good soundproofing properties are obtained in addition to the sound absorbing effect. It is configured to exert.

By the way, recently, a molded sound absorbing material has been mainly used as the sound absorbing material layer 4 so as to accurately fit the surface shape of the dash panel 1. For example, in the case of a fiber-based material, a binder resin is added to synthetic fiber or cotton and molded by pressing. In this case, as the binder resin of the thermoplastic type, a heat-sealing fiber such as polyethylene resin or polypropylene resin is used, and as the binder resin of the thermosetting type, a phenol resin is often used.

[0006]

However, in the conventional insulator dash 2, in places where it is difficult to secure a setting space for the insulator dash 2 such as a dash upper portion, the sound absorbing material layer 4 is formed into a thin wall.
It becomes hard.

Also, general parts have surface rigidity from the viewpoint of shape-retaining property, and particularly, hot-press molded articles tend to have a hard surface.

As described above, if the sound absorbing material layer 4 is hard,
As shown in FIG. 2, the vibration of the dash panel 1 is easily transmitted to the sound insulating material layer 3 via the sound absorbing material layer 4, and the vibration of the sound insulating material layer 3 becomes noise, which hinders the quietness of the vehicle interior. It is pointed out.

The present invention has been made in view of such circumstances, and in a sound insulating structure such as an automobile insulator dash using a sound absorbing material layer made of a molded body, vibration from a vehicle body panel is applied to the sound insulating material layer. It is an object of the present invention to provide a sound insulation structure having significantly improved sound insulation performance by using a sound absorbing material layer having a function of suppressing transmission, and a method of manufacturing the same.

[0010]

To achieve the above object of the Invention The present invention, vibration, between the external noise or the like is incident by a partition, such as steel, a structure that is shielded, the
In the sound insulation structure which is provided in contact with the inside of the partition wall and is formed by laminating and integrating a sound insulation material layer and a molded sound absorption material layer provided for the purpose of sound insulation, the molded sound absorption material layer conforms to the surface shape of the partition wall. And a flexible sound absorbing material layer that attenuates vibrations from the partition walls.

[0011] Of the above-mentioned molded sound absorbing material layers, the flexible sound absorbing material layer may be set on the partition wall side or on the sound insulating material layer side. The sound absorbing material layer may be inserted in a sandwich shape.

Further, the method for producing a sound insulating structure according to the present invention comprises 50 to 80 parts by weight of a thermoplastic synthetic resin fiber and 50 to 20 parts by weight of a heat-fusible fiber, and has a basis weight of 250 to 50 parts.
A bulky nonwoven fabric mat of 1500 g / m ² , 100 to 70 parts by weight of thermoplastic synthetic resin fiber, 0 to 30 heat fusible fiber
Parts by weight, a bulky nonwoven fabric mat having a basis weight of 150 g / m ² or less, integrated by a needle punching step and a hot air heating step to form a laminated nonwoven fabric mat, preheated and softened, and then placed in a cold press molding die. And press forming the formed sound absorbing material layer into a required shape.

The material of the shape-retaining sound-absorbing material layer is 50 to 80 parts by weight of a thermoplastic synthetic resin fiber such as nylon, polyacrylonitrile, polyacetate, polyethylene terephthalate and the like, which has a higher melting point than the heat-fusible fiber. It is a nonwoven fabric mat composed of 50 to 20 parts by weight of a low melting point heat fusible fiber such as polyethylene, polypropylene, linear polyester, polyamide, etc., and formed in a bulky manner by a card method, and has a basis weight of 250 to 1500 g / m ² .

On the other hand, as the material of the flexible sound absorbing material layer, the same synthetic fibers used for the shape-retaining sound absorbing material layer can be used, and fibers 100 to 70 of nylon, polyacrylonitrile, polyacetate, polyethylene terephthalate and the like can be used.
Parts by weight, and 0 to 30 parts by weight of heat-fusible fibers such as polyethylene, polypropylene, linear polyester, polyamide, etc., and similarly formed as a bulky nonwoven mat by a card-type method, and the basis weight is 150 g / m ² or less.

The weight ratio of the binder component contained in the flexible sound absorbing material layer is desirably smaller than that of the shape retaining sound absorbing material layer, but is not particularly limited.

[0016]

As is apparent from the above configuration, the molded sound-absorbing material layer is composed of a laminated structure of a shape-preserving sound-absorbing material layer that retains the shape formed in accordance with the partition shape and a flexible sound-absorbing material layer. Therefore, the vibration from the partition is attenuated by the flexible sound absorbing material layer, and the vibration is not transmitted to the sound insulating material layer.

Further, by adjusting the mixing amount of the heat-fusible fibers serving as a binder, two layers of nonwoven fabric mats are laminated and integrated by needle punching and hot air processing.
A layer containing a large amount of heat-fusible fibers is used as a non-woven mat for the shape-retaining sound-absorbing material layer, and a layer containing no or slightly mixed heat-fusible fibers is used as a non-woven mat for the flexible sound-absorbing material layer. If the thus formed laminated nonwoven fabric mat is preheated and then subjected to cold press molding, a molded sound absorbing material layer having a required shape can be easily molded.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the sound insulation structure according to the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a sectional view showing the structure of a first embodiment of an insulator dash to which the present invention is applied, FIG. 2 is a schematic diagram showing a degree of freedom vibration system of the insulator dash, and FIG.
7 are explanatory views and cross-sectional views showing respective steps in the method of manufacturing the insulator dash shown in FIG. 1, FIG. 8 is a cross-sectional view showing a second embodiment of the insulator dash to which the present invention is applied, and FIG. FIG. 10 is a schematic view illustrating a vibration system of a degree of freedom of an insulator dash, and FIG. 10 is a cross-sectional view illustrating a third embodiment of the insulator dash to which the present invention is applied.
FIG. 11 is a schematic diagram showing a vibration system with a degree of freedom of the insulator dash shown in FIG.

In FIG. 1, an insulator dash 10 for an automobile is made of a PVC sheet mixed with a filler having a high specific gravity,
A sound insulating material layer 20 having a relatively large surface density, such as a rubber sheet, and a molded sound absorbing material layer 30 formed by molding a bulky nonwoven fabric mat that is pressure-bonded and integrated on the back side of the sound insulating material layer 20. .

The sound insulating material layer 20 and the formed sound absorbing material layer 30 are formed into required shapes by cold press forming described later, and are fixed on the side surface of the dash panel 40 as a partition by a fixing means such as a clip (not shown). Is done.

The feature of the present invention is that the shaped sound-absorbing material layer 30 has a shape-preserving sound-absorbing material layer 31 that retains a shape formed according to the shape of the dash panel 40, and a vibration from the dash panel 40. The point is that it is composed of a laminated body with the flexible sound absorbing material layer 32 that attenuates.

That is, in this embodiment, the flexible sound absorbing material layer 32 is provided on the dash panel 40 side, and the sound insulating material layer 20, the shape-preserving sound absorbing material layer 31, and the flexible sound absorbing material layer 32 are arranged from the indoor side. 2, vibration from the dash panel 40 is applied to the flexible sound absorbing material layer 3 as shown in FIG.
2, the vibration of the dash panel 40 side is not transmitted to the sound insulating material layer 20, which can greatly contribute to quietness in the vehicle interior, and the insulator dash 10 having excellent soundproof performance can be provided.

Next, each step of the method of manufacturing the insulator dash 10 will be described in detail with reference to FIGS.

(1) Manufacturing Process of Laminated Non-Woven Mat M FIG.

First, a synthetic fiber and a heat-fusible fiber, which are materials of the shape-preserving sound-absorbing material layer 31, are put into the first card 50. The synthetic fiber has a higher melting point than the heat-fusible fiber, and may be appropriately selected from synthetic resin fibers such as nylon, polyacrylonitrile, polyacetate, and polyethylene terephthalate.

The heat fusible fiber is made of polyethylene, polypropylene, linear polyester, polyamide, or the like, and has a ratio of 50 to 80 parts by weight of synthetic fiber and 50 to 20 parts by weight of heat fusible fiber. After the synthetic fiber and the heat-fusible fiber are put into the first card 50, the first card 50 supplies the first card 50 onto the conveyor 60 in a bulky manner. The basis weight of the nonwoven fabric mat 51 at that time is 250 to
It is set to 1500 g / m ² .

Similarly, the second card 52 is mixed with a small amount of synthetic fiber, which is a material of the flexible sound absorbing material layer 32 and, if desired, heat-fusible fiber. As the synthetic fiber and the heat fusible fiber, the same synthetic fiber and heat fusible fiber as in the case of the shape-preserving sound absorbing material layer 31 are used, but the proportion of both is 100 to 70 parts by weight of the synthetic fiber and the heat fusible fiber. Adhesive fiber 0
It is characterized in that no heat-fusible fiber is used or the weight is reduced, as in the case of 30 parts by weight. The basis weight is 3
The nonwoven fabric mat 53 is laminated on the upper surface of the nonwoven fabric mat 51 supplied from the first card 50 so as to be 0 to 200 g / m ² .

As shown in FIG. 14, the material of the shape-preserving sound-absorbing material layer 31 is supplied in a bulky manner onto a conveyor 60 by a card 50, and then a separately matted flexible sound-absorbing material layer 32 is formed.
May be laminated.

The nonwoven fabric mats 51 and 53 are punched by a needle punching machine 61 and heated by a hot air heating furnace 62 to melt the heat-fusible fibers. After being formed, it is cut to a predetermined size to form a sound absorbing material layer 3 used in the present invention.
The laminated nonwoven fabric mat M, which is a material of No. 0, is used.

(2) Pressing process of the laminated nonwoven fabric mat M Thereafter, as shown in FIG. 5, the laminated nonwoven fabric mat M is heated and softened by a hot air heating furnace 70, and then, as shown in FIG. The laminated nonwoven fabric mat M is placed on the mold 80, and as shown in FIG. 7, the dash panel 40 is shaped by engaging and pressing the lower mold 80 for cold press molding and the upper mold 81 for cold press molding. Then, the molding of the molded sound absorbing material layer 30 in the insulator dash 10 shown in FIG. 1 is completed.

At this time, in each of the nonwoven fabric mats 51 and 53 of the laminated nonwoven fabric mat M, one of the nonwoven fabric mats 51 contains many heat-fusible fibers,
Due to the binder effect of the heat-fusible fibers, moderate rigidity and shape-retaining properties are provided, but the non-woven fabric mat 53 on the other side has no heat-fusible fibers or is not so mixed. The synthetic fibers are not fused to each other, and are restored to the original thickness after the molding, to form the flexible sound absorbing material layer 32 having an appropriate cushioning property.

The sound insulating material layer 20 and the molded sound absorbing material layer 30 may be integrated with each other by forming the sound insulating material layer 20 and the formed sound absorbing material layer 30 in separate steps and bonding them together, or And a method of press-integrating the sound insulating sheet and the laminated nonwoven fabric mat M with a press die, but the method is not particularly limited.

As described above, the automotive insulator dash 10 to which the present invention is applied is constituted by a laminated structure of the shape-preserving sound absorbing material layer 31 and the flexible sound absorbing material layer 32 as the molded sound absorbing material layer 30, The sound absorbing performance is enhanced by utilizing the vibration damping characteristics of the elastic sound absorbing material layer 32. In the above-described embodiment, the flexible sound absorbing material layer 32 is provided on the dash panel 40 side.
In this embodiment, as shown in FIG. 7, a flexible sound absorbing material layer 32 may be provided on the sound insulating material layer 20 side. In this embodiment, as shown in FIG. 8, the vibration from the dash panel 40 is partially transmitted by the shape-retaining sound absorbing material layer 31, but between the shape-retaining sound absorbing material layer 31 and the sound insulating material layer 20. The vibration from the dash panel 40 in the sound insulating material layer 20 can be reduced by attenuating the vibration by the flexible sound absorbing material layer 32 located at the position shown in FIG.

Further, as shown in FIG. 9, even if two layers of the shape-preserving sound-absorbing material layer 31 are provided and the flexible sound-absorbing material layer 32 is provided therebetween, as shown in FIG. The transmission of the vibrations to the sound insulating material layer 20 can be reduced.

[0036]

As described above, the present invention has the following special functions and effects.

(1) The sound-insulating structure according to the present invention uses a molded sound-absorbing material layer having a good fit to the partition walls and a sound-absorbing material layer composed of a shape-retaining sound-absorbing material layer and a flexible sound-absorbing material layer. Composed of a laminated structure, the vibration from the partition walls is attenuated by the flexible sound absorbing material layer, so the transmission of vibration to the sound insulating material layer is reduced, the soundproofing performance is significantly improved, and it greatly contributes to the quietness in the vehicle interior It has the effect that can be done.

(2) In the sound insulating structure according to the present invention, the molded sound absorbing material layer is constituted by a laminated structure of the shape-preserving sound absorbing material layer and the flexible sound absorbing material layer. layer is forced to thin, even vibration transmission to or to Kunar site has the effect of vibration transmission can be reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a configuration of a first embodiment of an automotive insulator dash to which a sound insulating structure according to the present invention is applied.

FIG. 2 is a schematic view showing a vibration system of a degree of freedom of the insulator dash shown in FIG.

FIG. 3 is an explanatory view showing a manufacturing process of a laminated nonwoven fabric mat in the method of the present invention.

FIG. 4 is an explanatory view showing another embodiment of the manufacturing process of the laminated nonwoven fabric mat in the method of the present invention.

FIG. 5 is a sectional view showing a preheating step of the laminated nonwoven fabric mat in the method of the present invention.

FIG. 6 is a sectional view showing a step of setting a laminated nonwoven fabric mat in a press die in the method of the present invention.

FIG. 7 is a cross-sectional view showing a cold press molding step of a laminated nonwoven fabric mat in the method of the present invention.

FIG. 8 is a cross-sectional view showing a configuration of a second embodiment of an automotive insulator dash to which the sound insulating structure according to the present invention is applied.

FIG. 9 is a schematic diagram showing a vibration system of a degree of freedom of the insulator dash shown in FIG. 8;

FIG. 10 is a cross-sectional view showing a configuration of a third embodiment of an automotive insulator dash to which the sound insulating structure according to the present invention is applied.

FIG. 11 is a schematic diagram showing a vibration system with a degree of freedom of the automotive insulator dash shown in FIG. 10;

FIG. 12 is an explanatory view showing a place where an insulator dash for a vehicle is installed.

FIG. 13 is a cross-sectional view showing a configuration of a conventional automotive insulator dash.

FIG. 14 is a schematic diagram showing a degree of freedom vibration system of a conventional automotive insulator dash.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Insulator dash for motor vehicles 20 Sound insulation material layer 30 Molded sound absorption material layer 31 Shape retention sound absorption material layer 32 Flexible sound absorption material layer 40 Dash panel 50, 52 Card 51, 53 Nonwoven fabric mat 60 Conveyor 61 Needle punch machine 62, 70 Hot air heating Furnace 80,81 Mold for cold press molding M Laminated nonwoven fabric mat

Continued on the front page (72) Inventor Masahiro Ikuta 3316 Miyayama, Samukawa-cho, Koza-gun, Kanagawa Prefecture Inside the Samukawa headquarters and factory (72) Inventor Hiroshi Sugawara 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan Motor Co., Ltd. (72) Inventor Hiroki Nagayama 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan Motor Co., Ltd. (72) Inventor Yugoro Masuda 17-6-341 Bessho Honcho, Takatsuki-shi, Osaka (72) Inventor Shosuke Oku 5-5-32-808, Nanko-chu, Suminoe-ku, Osaka-shi, Osaka (56) References JP-A-55-94860 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B32B 1 / 00-35/00 B60R 13/02-13/04 B60R 13/08

Claims (4)

(57) [Claims] 1. A vibration by a partition wall such as steel plate between the external noise or the like is incident, a structure that is shielded, the
In the sound insulation structure which is provided in contact with the inside of the partition wall and is formed by laminating and integrating a sound insulation material layer and a molded sound absorption material layer provided for the purpose of sound insulation, the molded sound absorption material layer conforms to the surface shape of the partition wall. A sound insulation structure comprising: a laminated structure including a shape-preserving sound-absorbing material layer that retains a formed shape and a flexible sound-absorbing material layer that attenuates vibration from partition walls. 2. An insulator dash for an automobile, which is installed in contact with a dash panel for partitioning an engine room and a vehicle cabin on a vehicle interior surface, and is formed by integrally laminating a sound insulating material layer and a molded sound absorbing material layer. The sound-absorbing material layer is a laminated structure including a shape-retaining sound-absorbing material layer that retains a shape formed according to the surface shape of the dash panel and a flexible sound-absorbing material layer that attenuates vibration from the dash panel. The sound insulation structure according to claim 1, wherein: 3. The shape-retaining sound absorbing material layer is composed of synthetic resin fibers having an average fiber diameter of 3 denier or less.
The sound insulation structure according to claim 1, wherein the sound insulation structure is made of synthetic resin fibers having an average fiber diameter of 2 denier or more. 4. A bulky nonwoven mat comprising 50 to 80 parts by weight of a thermoplastic synthetic resin fiber and 50 to 20 parts by weight of a heat-fusible fiber, and having a basis weight of 250 to 1500 g / m ² .
Consists of 100 to 70 parts by weight of thermoplastic synthetic resin fiber and 0 to 30 parts by weight of heat-fusible fiber, and has a basis weight of 30 to 200 g.
/ M ² or less and a bulky nonwoven fabric mat are integrated by a needle punching process and a hot air heating process to form a laminated nonwoven fabric mat, preheat softened, and a molded sound absorbing material layer is required in a cold press molding die. A method for producing a sound insulation structure, comprising press-forming into a shape.