JP2008155775A - Sound absorbing material for vehicle and method of manufacturing sound absorbing material for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sound absorbing material for a vehicle capable of integrating a skin layer and an intermediate layer without using an adhesive etc. and of easily adjusting air-flow amount, and a method of manufacturing the sound absorbing material for the vehicle. <P>SOLUTION: A vehicle insulator 100 is formed along the shape of a dash panel 10 and is a laminated structure formed by laminating and integrating the skin layer 20, the intermediate layer 30 and a sound absorbing layer 40 in this order from the inner side of a cabin R. The skin layer 20 and the intermediate layer 30 are laminated and integrated to be entangled with each other by an optionally controlled needle punch 50. Therefore, this structure can integrate the skin layer 20 and the intermediate layer 30, and can easily adjust air-flow amount. Moreover, since an adhesive etc. is not interposed between the skin layer 20 and the intermediate layer 30, the number of manufacturing processes can be reduced. Since predetermined air-flow amount to achieve well-balanced sound absorbing characteristics and sound insulating characteristics is set between the skin layer 20 and the intermediate layer 30, sound absorbing efficiency can be enhanced. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vehicle sound absorbing material and a method for manufacturing a vehicle sound absorbing material.

  The interior of an automobile is equipped with a sound absorbing material for a vehicle having sound absorbing performance and sound insulating performance in order to prevent the propagation of noise to the passenger compartment. Examples of the vehicle sound absorbing material include a floor carpet attached to the floor panel surface of the vehicle, a roof trim attached to the interior surface of the roof panel, and an insulator dash attached to the interior side of the dash panel.

  FIG. 1 is a cross-sectional view of a conventional insulator dash. As shown in FIG. 1, for example, the insulator dash 1 includes an outer skin layer 2 and a base material layer 3 that include sound-absorbing PET (polyester) fibers, and an intermediate portion interposed between the outer skin layer 2 and the base material layer 3. It is a laminated molded body with the layer 4.

  The intermediate layer 4 is composed of a PE (polyethylene) film, and an adhesive layer 5 of an unsaturated polyester film is laminated thereon. Moreover, the through hole is formed in the intermediate | middle layer 4 (for example, refer patent document 1). It is known that a hot roll apparatus having protrusions is used in the drilling process for opening a through hole in the intermediate layer 4.

  In addition, in the conventional insulator dash, it has been proposed to perform drilling using a needle punch in order to open a through hole (Patent Documents 2 to 4).

JP 2006-137160 A JP 2005-178030 A Japanese Patent Laid-Open No. 08-216312 Utility Model Registration No. 311898

  FIG. 2 is a diagram showing an example of a drilling process for opening a through hole in the intermediate layer 4 shown in FIG. 1, and FIG. 2 (a) is a diagram showing a process of processing an intermediate layer of a conventional insulator dash. (B) is an expanded sectional view of the heat roll apparatus shown to (a). As shown in FIG. 2, the PE film to be the intermediate layer 4 is installed on the supply roll 6A, and the low melting point resin film to be the adhesive layer 5 is installed on the supply roll 6B. And after PE film and low melting point resin film are supplied onto the belt conveyor 7 from the supply rolls 6A and 6B and heated by the hot air heating furnace 8, a through-hole is formed by the hot roll device 9 having the protrusions 9A. While being laminated and integrated. And as shown in FIG. 1, the skin layer 2 is laminated | stacked on the one side by which the adhesive layer 5 of the intermediate | middle layer 4 was laminated | stacked, and the base material layer 3 by which the adhesive agent was apply | coated to the surface is laminated | stacked on the other side. .

  However, in the insulator dash 1 shown in FIG. 1 and FIG. 2, since the through holes are formed in the PE film that becomes the intermediate layer 4 using the heat roll device 9, the air flow rate of the intermediate layer 4 cannot be freely adjusted. There was a problem. This is because the aperture ratio of the through hole cannot be freely adjusted according to the rotation speed of the hot roll device 9. For this reason, when changing the opening ratio of the through hole in order to adjust the air flow, it is necessary to change the number of protrusions 9A of the heat roll device 9. Further, since the intermediate layer 4 is disposed between the skin layer 2 and the base material layer 3, there is a problem that it is necessary to laminate the adhesive layer 5 on the intermediate layer 4 and the manufacturing cost is high.

  Therefore, the present invention has been made in view of the above problems, and it is possible to integrate the skin layer and the intermediate layer without using an adhesive or the like, and it is possible to easily adjust the air flow rate, and a vehicle sound absorbing material, and It aims at providing the manufacturing method of the sound-absorbing material for vehicles.

  In order to solve the above problems, a vehicle sound absorbing material according to the present invention is a sound absorbing material for a vehicle having a laminated structure including a skin layer, an intermediate layer, and a sound absorbing layer, and the skin layer and the intermediate layer are formed of a needle punch. The layers are integrated so as to be entangled with each other by processing. According to the present invention, the aperture ratios of the skin layer and the intermediate layer can be freely adjusted by needle punching, so that the optimum air flow rate can be easily controlled. Furthermore, since no adhesive or the like is interposed between the skin layer and the intermediate layer, the manufacturing cost can be reduced and the number of manufacturing steps can be reduced.

  The laminated skin layer and the intermediate layer are integrated with the sound absorbing layer by thermal welding. According to the present invention, the interface strength between the skin layer and the intermediate layer can be increased.

  The adhesive used in the heat welding is a thermoplastic resin powder. According to the present invention, the sound absorbing layer can be firmly laminated on the skin layer and the intermediate layer. Further, a sound insulating function can be provided between the intermediate layer and the sound absorbing layer.

  The sound absorbing layer is subjected to needle punching simultaneously with needle punching of the skin layer and the intermediate layer. According to the present invention, it is possible to omit the step of applying an adhesive and performing heat welding.

  The opening ratio of the skin layer and the intermediate layer by the needle punching process is any of 7 to 41 pieces / square centimeter. According to the present invention, the balance between the sound insulation performance and the sound absorption performance can be improved.

The skin layer and the intermediate layer formed by the needle punching are formed with through holes having an air flow rate in the range of 5 to 25 cc / cm ² / sec. According to the present invention, the skin layer and the intermediate layer can be set to a predetermined air flow rate in which both the sound absorption performance and the sound insulation performance are balanced, and the sound absorption efficiency can be improved. Further, since the through holes are formed by needle punching, the diameter and pitch of the through holes can be easily adjusted. For this reason, since the aperture ratio of the through hole can be adjusted, the optimum air flow rate can be easily controlled.

A method for producing a sound absorbing material for a vehicle having a laminated structure including a skin layer, an intermediate layer, and a sound absorbing layer,
And laminating and integrating the skin layer and the intermediate layer so as to be entangled with each other by needle punching. According to the present invention, since the aperture ratios of the skin layer and the intermediate layer can be freely adjusted by needle punching, the optimum air flow rate can be easily controlled. Furthermore, since no adhesive or the like is interposed between the skin layer and the intermediate layer, the manufacturing cost can be reduced and the number of manufacturing steps can be reduced.

  The method further includes the step of integrating the sound absorbing layer, the adhered skin, and the intermediate layer by heat fusion. According to the present invention, the interface strength between the skin layer and the intermediate layer can be increased.

  And needle punching the sound absorbing layer simultaneously with needle punching of the skin layer and the intermediate layer. According to the present invention, it is possible to omit the step of applying an adhesive and performing heat welding.

The step of laminating and integrating the skin layer and the intermediate layer by the needle punching process includes forming a through hole in the skin layer and the intermediate layer in a range of 5 to 25 cc / cm ² / sec. Forming. According to the present invention, the skin layer and the intermediate layer can be set to a predetermined air flow rate in which both the sound absorption performance and the sound insulation performance are balanced, and the sound absorption efficiency can be improved. Further, since the through holes are formed by needle punching, the diameter and pitch of the through holes can be easily adjusted. For this reason, since the aperture ratio of the through hole can be adjusted, the optimum air flow rate can be easily controlled.

  ADVANTAGE OF THE INVENTION According to this invention, while using an adhesive agent etc., while being able to integrate an outer skin layer and an intermediate | middle layer, the sound-absorbing material for vehicles which can adjust air flow volume easily, and the manufacturing method of a sound-absorbing material for vehicles are provided. be able to.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the accompanying drawings regarding a vehicle sound absorbing material and a vehicle sound absorbing material manufacturing method according to the present invention. In the present embodiment, a vehicle insulator dash will be described as an example of a vehicle sound absorbing material.

  A vehicle insulator dash 100 according to the present embodiment will be described with reference to FIGS. 3 to 6. FIG. 3 is a cross-sectional view showing the configuration of the vehicle insulator dash according to the embodiment of the present invention.

  As shown in FIG. 3, the vehicle insulator dash 100 includes a vehicle compartment R surface of the dash panel 10 that partitions the engine compartment E and the vehicle compartment R in order to prevent noise from propagating from the engine compartment E to the vehicle compartment R. Installed on the side. The vehicle insulator dash 100 is a laminated structure that is formed along the shape of the dash panel 10 and is laminated and integrated in the order of the skin layer 20, the intermediate layer 30, and the sound absorbing layer 40 from the inside of the passenger compartment R.

The skin layer 20 is a high-density nonwoven fabric that is disposed on the side of the passenger compartment R and fulfills functions of sound insulation performance and rigidity. The skin layer 20 is formed with a plurality of through holes so that the air flow rate is in the range of 5 to 25 cc / cm ² / sec by needle punching. Also, the basis weight of the skin layer 20 is suitable in the range of 50 to 300 g / m ^2, the skin layer in this embodiment has a basis weight of 200 g / m ^2. Examples of the nonwoven fabric include polyesters such as PET (polyethylene terephthalate), high-density synthetic fiber nonwoven fabrics such as PP (polypropylene), PE, and PA (polyamide), pinder-rich high-density paper nonwoven fabrics, glass and natural fiber nonwoven fabrics, or 2 Nonwoven fabrics in which more than one species are combined, or nonwoven fabrics in which these are impregnated with a resin. In this embodiment, the skin layer 20 uses PE nonwoven fabric.

The intermediate layer 30 is a porous PE film interposed between the skin layer 20 and the sound absorbing layer 40. The intermediate layer 30 is integrated with the skin layer 20 together with the skin layer 20 by needle punching, and has an air flow rate in the range of 5 to 25 cc / cm ² / sec so as to communicate with the through hole of the skin layer 20. A plurality of through holes are formed. In addition, the thickness of the intermediate layer 30 is preferably in the range of 15 to 50 μm. In the present embodiment, the intermediate layer 30 is set to a thickness of 20 μm. In addition, the intermediate | middle layer 30 is made into PE film which has air permeability from PE film which does not have air permeability by carrying out needle punch processing with the skin layer 20 so that it may mention later. In the present embodiment, a PE film is used for the intermediate layer 30, but a PET film, a PP film, a PA film, or the like may be used.

The sound absorbing layer 40 is a base material that is disposed on the dash panel 10 side and on which the skin layer 20 and the intermediate layer 30 are laminated. The sound absorbing layer 40 is a high melting point synthetic fiber having sound absorbing performance and vibration isolation performance. In this embodiment, the basis weight of the sound absorbing layer 40 is set to 1000 g / m ² . Examples of the high melting point synthetic fibers include polyester fibers such as PET, PP fibers, PE fibers, PA fibers, and the like, or fibers obtained by combining two or more of these. In the present embodiment, the sound absorbing layer 40 uses PET fibers.

  In order to adhere the intermediate layer 30 and the sound absorbing layer 40 between the intermediate layer 30 and the sound absorbing layer 40, thermoplastic PE powder (not shown) is added as a thermoplastic resin binder. The thermoplastic resin binder is not limited to PE powder, but is a single resin powder such as polyester such as PP and PET, PA, EVA (ethylene-vinyl alcohol copolymer), or a composite resin powder of a blend polymer obtained by combining these. It may be. The resin powder preferably has an average particle size in the range of 0.1 to 1.0 mm.

  Next, a method for manufacturing the vehicle insulator dash 100 described above will be described with reference to FIGS. First, each process of the manufacturing method of the insulator dash 100 for vehicles is demonstrated using FIG.

  FIG. 4 is a diagram for explaining a manufacturing process of the vehicle insulator dash according to the present invention. As shown in FIG. 4, a non-woven skin A serving as the skin layer 20, a PE film B serving as the intermediate layer 30, and a sound absorbing material C serving as the sound absorbing layer 40, which constitute the insulator dash 100 illustrated in FIG. 3, are prepared.

  In the needle punching process, as will be described in detail later, the nonwoven fabric skin A and the intermediate layer 30 which become the skin layer 20 are simultaneously subjected to needle punching with the nonwoven fabric skin A which becomes the skin layer 20 and the PE film B which becomes the intermediate layer 30. The PE film B to be stacked is integrated (step S1).

  In the adhesive application process, PE powder is applied to the surface of the sound absorbing material C to be the sound absorbing layer 40 (step S2). In the heating step, the surface of the sound absorbing material C to which the PE powder is applied is heated and softened to make the PE powder a resin binder (step S3).

  In the heating step, the non-woven skin A serving as the skin layer 20 and the PE film B serving as the intermediate layer 30 are laminated and integrated on the surface of the resin binder of the sound absorbing material C serving as the sound absorbing layer 40 by heat treatment using a heater. Step S4). At this time, since the PE film B functions as a resin binder, the interfacial strength between the non-woven skin A serving as the skin layer 20 and the PE film B serving as the intermediate layer 30B increases.

  In the press molding process, the inside of the cavity of the molding die is cooled, and the non-woven skin A to be the heat softened skin layer 20, the PE film B to be the intermediate layer 30, and the sound absorbing material C to be the sound absorbing layer 40 are formed into the required shapes. Cold press molding is performed (step S5). In the trim and piercing process, the molded product is taken out from the molding die, and cut processing for removing surplus on the outer periphery of the molded product or piercing processing for attaching a clip or the like is performed (step S6).

  Next, the needle punching process (step S1) briefly described above will be described in more detail with reference to FIGS. FIG. 5 is a diagram showing a needle punching process which is a process of manufacturing a vehicle insulator dash according to the present invention, and FIG. 6 is an enlarged sectional view of the needle punch used in the needle punching process shown in FIG.

  As shown in FIGS. 5 and 6, in the needle punching step (step S <b> 1), the non-woven skin A to be the skin layer 20 and the PE film B to be the intermediate layer 30 are arranged in a lattice shape to form through holes. A needle punch 50 including a plurality of needle portions 50A, a belt conveyor 60 that conveys an object to be processed in which a non-woven skin A serving as the skin layer 20 and a PE film B serving as the intermediate layer 30 are superimposed below the needle punch 50, and the skin layer 20 The supply roll 70A provided with the nonwoven fabric skin A serving as the skin layer 20 and the PE film B used as the intermediate layer 30 provided with the nonwoven fabric skin A and the PE film B serving as the intermediate layer 30 supplied onto the belt conveyor 60. The take-up roll 80 arranged in the discharge direction of the conveyor 60 on the side opposite to the roll 70B, the supply roll 70A and the supply roll 70B is necessary. To become.

  The plurality of needle portions 50A of the needle punch 50 have a diameter portion of 0.9 mm and are arranged at a density in the range of 7 to 41 pieces / square centimeter. Further, in the needle punching step (step S1), the lowering position of the needle punch 50 is changed so as to adjust the hole diameter of the through hole, and the lowering cycle speed and the line speed of the belt conveyor 60 are changed so as to adjust the pitch of the through hole. Processing is executed by a microcomputer (not shown) that controls the processing.

With the above-described configuration, the hole diameter and hole pitch of the through holes are adjusted by the plurality of needle portions 50A of the needle punch 50, so that the through holes communicated with the non-woven skin A serving as the skin layer 20 and the PE film B serving as the intermediate layer 30. Has a diameter of 0.9 mm and an aperture ratio in the range of 7 to 41 pieces / square centimeter. For this reason, the air flow rate of the skin layer 20 and the intermediate layer 30 is in the range of 5 to 25 cc / cm ² / sec.

  When the non-woven skin A to be the skin layer 20 and the PE film B to be the intermediate layer 30 are supplied onto the belt conveyor 60 from the supply rolls 70A and 70B, the non-woven skin A and the intermediate layer 30 to be the skin layer 20 are obtained. The PE film B is in an overlapping state. Then, when the non-woven skin A to be the skin layer 20 and the PE film B to be the intermediate layer 30 are arranged at predetermined positions below the needle punch 50, the needle punch 50 is controlled by a microcomputer as shown in FIG. Then, by moving downward to a predetermined lowered position, the plurality of needle portions 50A are pierced into the non-woven skin A serving as the skin layer 20 and the PE film B serving as the intermediate layer 30. At this time, the needle punch 50 is lowered by the plurality of needle portions 50A until a through-hole having a diameter of 0.9 mm is formed in the non-woven skin A serving as the skin layer 20 and the PE film B serving as the intermediate layer 30.

  The needle punch 50 reciprocates in the vertical direction at a high speed, so that the non-woven skin A serving as the skin layer 20 and the PE film B serving as the intermediate layer 30 communicate with each other while being entangled with each other. Is to be formed. And when a through-hole is formed in the nonwoven fabric skin A which becomes the laminated skin layer 20 and the PE film B which becomes the intermediate layer 30, the needle punch 50 rises and the belt conveyor 60 is driven in the discharging direction. .

  And the nonwoven fabric skin A used as the skin layer 20 in which the through-hole was formed, and PE film B used as the intermediate | middle layer 30 are discharged | emitted by the belt conveyor 60 in the discharge | emission direction, and are wound up by the roll 80 for winding. Thereafter, as described above, an adhesive application process (step S2), a heating process (step S3), a heating process (step S4), a press molding process (step S5), and a trim and piercing process (step S6) are obtained. A vehicle insulator dash 100 shown in FIG. 3 is formed.

  The vehicle insulator dash 100 formed by the above-described method will be described again with reference to FIG. 7 is an enlarged cross-sectional view of the vehicle insulator dash shown in FIG.

  As shown in FIG. 7, the vehicle insulator dash 100 includes a skin layer 20 and an intermediate layer 30 that are laminated and integrated so as to be entangled with each other by a needle punch 50, and a skin layer that is coated with PE powder on the surface and thermally welded. A sound absorbing layer 40 laminated and integrated with the intermediate layer is provided. Thereby, the skin layer 20 and the intermediate layer 30 can be integrated with each other without using an adhesive by being needle punched by the needle punch 50 that is arbitrarily controlled. The air flow rate of the skin layer 20 and the intermediate layer 30 can be easily controlled.

Further, since the vehicle insulator dash 100 has a ventilation rate of 5 to 25 cc / cm ² / sec in the skin layer 20 and the intermediate layer 30, the sound from the vehicle compartment R passes through the skin layer 20 and the intermediate layer 30. The sound absorbing material 40 can be reliably transmitted through. For this reason, since the sound absorption efficiency increases, the noise level of the passenger compartment R can be reduced (see FIG. 3). Further, the sound of the engine room E is propagated from the dash panel 10 and is absorbed by the sound absorbing material 40, but a part of the sound passes through the sound absorbing material 40 and is reflected by the intermediate layer 30 and the skin layer 20 to be absorbed again. Sound is absorbed by the material 40. That is, the skin layer 20 and the intermediate layer 30 exhibit sound insulation performance. In addition, since the PE powder is a resin binder between the intermediate layer 30 and the sound absorbing layer 40, a sound insulation function is working so that sound does not pass from the sound absorbing material 40 toward the intermediate layer 30 and the skin layer 20. For this reason, since the sound of the engine room E is surely absorbed by the sound absorbing material 40 without being transmitted through the skin layer 20 into the vehicle interior R, it is transmitted from the engine room E via the dash panel 10. Noise can be reduced (see FIG. 3).

As described above, the air flow rate range (5 to 25 cc / cm ² / sec) of the skin layer 20 and the intermediate layer 30 is a range in which sound absorption efficiency can be improved, and a range in which sound insulation performance can be exhibited. There is also. In other words, the skin layer 20 and the intermediate layer 30 are set with a range of airflow that balances both the sound absorption performance and the sound insulation performance. Therefore, the vehicle insulator dash 100 can cause the sound absorption layer 40 to absorb sound from both directions of the vehicle compartment R side and the engine room R side.

  Furthermore, since the skin insulator 20 and the intermediate layer 30 are laminated and integrated by the needle punch 50 without using an adhesive, the vehicle insulator dash 100 can reduce the number of manufacturing steps and reduce manufacturing costs. can do.

  Next, the modification of the manufacturing method of the vehicle insulator dash 100 mentioned above is demonstrated using FIG. FIG. 8 is a view showing a modification of the method for manufacturing a vehicle insulator dash according to the present invention.

  As shown in FIG. 8, in the needle punching process, the sound absorbing layer 40A is simultaneously laminated and integrated by the needle punch 50 in addition to the skin layer 20A and the intermediate layer 30A. At this time, the needle portion 50A of the needle punch 50 penetrates the skin layer 20A and the intermediate layer 30A and penetrates into the sound absorbing layer 40A.

  Thereby, since the sound absorbing layer 40A is integrated with the skin layer 20A and the intermediate layer 30A without using an adhesive or the like, the adhesive application step (step S2), the heating step (step S3), and the heating shown in FIG. The work process of the process (step S4) can be omitted. For this reason, manufacturing time and manufacturing cost can be reduced. In addition, after the needle punching step, a heating step may be performed to increase the interface strength between the skin layer 20A and the intermediate layer 30A, and the intermediate layer 30A and the sound absorbing layer 40A.

  The vehicle insulator dash 100 described above is an example of the vehicle sound absorbing material of the present invention, and other uses of the vehicle sound absorbing material according to the present invention include a floor carpet, a roof trim, and a trunk provided in the vehicle interior. There are trims, luggage trims, wheel house trims, dash front insulators and hood insulators in the engine room.

  The preferred embodiments of the present invention have been described in detail above. However, the vehicle sound absorbing material and the method for manufacturing the vehicle sound absorbing material according to the present invention are not limited to the above-described embodiments, but are within the scope of the claims. Various modifications and changes can be made within the scope of the gist of the present invention described.

It is sectional drawing which shows the conventional insulator dash. It is a figure which shows one process of the manufacturing process of the conventional insulator dash. It is sectional drawing which shows the structure of the insulator dash for vehicles by embodiment of this invention. It is a figure explaining the manufacturing process of the insulator dash for vehicles by this embodiment. It is a figure which shows the needle punch process which is one process of the manufacturing process of the insulator dash for vehicles by this embodiment. It is an expanded sectional view of the needle punch used in the needle punch process shown in FIG. It is an expanded sectional view of the insulator dash for vehicles shown in FIG. It is a figure which shows the modification of the manufacturing method of the insulator dash for vehicles of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Insulator dash for vehicles 10 Dash panel 20 Skin layer 30 Intermediate layer 40 Sound absorption layer 50 Needle punch 50A Needle part 60 Belt conveyor 70A, 70B Supply roll 80 Winding roll A Non-woven skin B PE film C Sound absorption material E Engine room R Car compartment

Claims (6)

A sound absorbing material for a vehicle having a laminated structure including a skin layer, an intermediate layer, and a sound absorbing layer,
The vehicle sound absorbing material, wherein the skin layer and the intermediate layer are laminated and integrated so as to be entangled with each other by needle punching. The sound absorbing material for a vehicle according to claim 1, wherein the sound absorbing layer is subjected to needle punching simultaneously with needle punching of the skin layer and the intermediate layer. The sound absorption for a vehicle according to claim 1 or 2, wherein an opening ratio of the skin layer and the intermediate layer by the needle punching process is any one of a range of 7 to 41 pieces / square centimeter. Wood. The skin layer and the intermediate layer formed by the needle punching process are formed with through-holes having an air flow rate in the range of 5 to 25 cc / cm ² / sec. Item 4. The vehicle sound absorbing material according to Item 3. A method for producing a sound absorbing material for a vehicle having a laminated structure including a skin layer, an intermediate layer, and a sound absorbing layer,
A method for producing a sound absorbing material for a vehicle, comprising the step of stacking and integrating the skin layer and the intermediate layer so as to be entangled with each other by needle punching. The step of laminating and integrating the skin layer and the intermediate layer by the needle punching process includes forming a through hole in the skin layer and the intermediate layer in a range of 5 to 25 cc / cm ² / sec. The method for manufacturing a sound absorbing material for a vehicle according to claim 5, comprising a step of forming the sound absorbing material.

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