JP4215146B2 - Automotive insulator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an automotive insulator mounted on the interior side of a vehicle body panel, and in particular, while reducing the weight of the skin layer, focusing on the ventilation structure and the non-venting structure in the skin layer, the frequency of noise to be absorbed The present invention relates to an insulator for an automobile that can control the area.
[0002]
[Prior art]
Normally, as shown in FIG. 2, an insulator dash 2 is mounted on the interior surface side of the dash panel 1 that partitions the engine room E and the vehicle compartment R, and the insulator dash 2 is shown in FIG. And a sound insulation layer 3 made of a high-density material such as a recycled rubber sheet and a recycled PVC sheet, and a sound absorbing layer 4 made of a fiber aggregate such as felt and polyester fiber nonwoven fabric laminated and integrated on the back side thereof. Yes.
[0003]
Further, a floor carpet 5 is laid in a wrap shape on the lower surface of the insulator dash 2, and the upper side of the insulator dash 2 is located in the instrument panel 6.
[0004]
The sound insulation mechanism of the conventional two-layer insulator dash 2 is such that the engine and auxiliary machinery noise in the engine room E is partially insulated by the dash panel 1 and transmitted through the dash panel 1 to the room. The transmitted noise propagating inward is absorbed in the sound absorbing layer 4 and a desired soundproofing performance is obtained by the double wall sound insulating function of the sound insulating layer 3.
[0005]
And as the sound insulation layer 3, since the material with weight increase in which the surface density is in the range of about ² to 10 kg / m ² is used, the product weight is about 2 to 12 kg.
[0006]
[Problems to be solved by the invention]
Thus, the conventional insulator dash 2 is composed of a two-layer laminate of the sound insulation layer 3 made of a high-density material and the sound absorption layer 4 made of a fiber assembly, and the weight of the sound insulation layer 3 is particularly large. Due to the increase in volume, the mounting workability when the product is mounted on the dash panel 1 is deteriorated, and the drawbacks are that the weight is increased and the fuel efficiency is adversely affected.
[0007]
Furthermore, since the sound insulation mechanism of the conventional insulator dash 2 depends mainly on the sound insulation and sound absorption function of the insulator dash 2 by the double wall sound insulation function, the sound absorption function in the instrument panel 6 is small and the target is the target. The frequency range of noise is limited, and it is not always effective for noise in a wide frequency range from a low frequency range to a high frequency range.
[0008]
The present invention has been made in view of such circumstances, and is an automotive insulator that is mounted on the interior side of a vehicle body panel, and in particular, eliminates a heavy sound insulation layer and promotes weight reduction. In addition, an object of the present invention is to provide an automotive insulator capable of obtaining desired soundproof performance.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, an invention according to claim 1 of the present application is an insulator for an automobile mounted on a vehicle compartment surface side of a vehicle body panel that partitions a sound source room and a vehicle compartment. A foam material comprising a laminate of a sound absorbing layer made of a fiber assembly molded along a shape and a skin layer made of a foam material integrated on the surface of the sound absorbing layer, and constituting the skin layer Is a single-layer non-ventilated structure, and is characterized by absorbing noise transmitted through the vehicle body panel from the sound source room side by means of membrane vibration of the skin layer, thereby reducing the noise level in the low and medium frequency ranges .
[0010]
Here, the material of the sound absorbing layer is made of felt, polyester fiber typified by PET (polyethylene terephthalate), non-woven fabric, wood, fiber aggregate made of paper (pulp, etc.), and 0.03-3. A material having an area density of 0 kg / m ² and an average sound absorption coefficient in the frequency range of 630 to 4000 Hz adjusted to 30 to 90% when the thickness is 20 mm is used.
[0011]
The foam material as the skin layer uses an olefin-based or porous material such as EPDM. As the material, synthetic resin such as polypropylene, polyurethane, polyethylene, polyester, etc. can be used, the surface density is suitably in the range of 0.05 to 0.3 kg / m ² , and the thickness is preferably in the range of 1 to 15 mm. , Set part or all.
[0012]
According to the invention described in claim 1, since the skin layer is made of a lightweight foam material, it is possible to reduce the weight of the product, and the skin layer allows the fibers to fray and fall off from the sound absorbing layer. Can be suppressed.
[0014]
Furthermore, according to the first aspect of the present invention, since the foam material constituting the skin layer has a non-venting structure, noise in the low / medium frequency range (500 to 2500 Hz) is effectively generated by the membrane vibration of the skin layer. Can absorb sound.
[0015]
The invention according to claim 2 of the present application is an automotive insulator to be mounted on a vehicle compartment surface side of a vehicle body panel that partitions a sound source room and a vehicle compartment, and is molded along the surface shape of the vehicle body panel. It is composed of a laminate of a sound absorbing layer composed of a fiber assembly and a skin layer composed of a foam material integrated on the surface of the sound absorbing layer, and the foam material constituting the skin layer is a ventilation structure, And surface density is 0.05-0.3kg / m < ² >. By changing the ventilation resistance, in addition to the sound absorption function at the mid and high frequency level due to the membrane vibration of the skin layer, the noise that is the target of sound absorption is provided. It is possible to tune in the frequency range.
[0016]
According to the second aspect of the present invention, the foam material, which is the material of the skin layer, increases the air permeability from a state where there is no air permeability. In addition to the sound absorbing function for absorbing 500 to 2500 Hz), the porous sound absorbing function for absorbing the noise in the middle / high frequency range (800 to 4000 Hz) can be achieved, so that the target frequency range can be tuned.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment in which an automobile insulator according to the present invention is applied to an automobile insulator dash will be described in detail with reference to the accompanying drawings.
[0018]
In FIG. 1, an automotive insulator dash 20 mounted on the interior surface side of a dash panel 10 that partitions an engine room E and a vehicle interior R is formed into a required shape in accordance with the surface shape of the dash panel 10. The layer 21 and the skin layer 22 laminated on the surface of the sound absorbing layer 21 are generally configured.
[0019]
More specifically, the sound absorbing layer 21 only needs to have a desired porous sound absorbing function. For example, felt, polyester fibers typified by PET (polyethylene terephthalate), and papers (pulp, etc.) are made fibrous. It consists of a fiber assembly, and in this embodiment, a heat-bonding fiber serving as a binder is mixed in a polyester fiber serving as a base, a fiber mat is formed, heat-softened in a hot air heating furnace, and then cold press-molded. Thus, the sound absorbing layer 21 having a desired shape is formed by appropriately changing the thickness of the thick part, the thin part, or the like. The surface density of the sound absorbing layer 21 is adjusted to 0.03 to 3.0 kg / m ² .
[0020]
On the other hand, the skin layer 22 uses a porous material (foaming material) such as a polyolefin resin or EPDM in place of the conventional high-density sound insulating layer that is heavy in weight, and is made of polypropylene, polyurethane, polyethylene, polyester, or the like. A synthetic resin can be used.
[0021]
The surface density of the skin layer 22 is not particularly limited. For example, 0.05 to 0.3 kg / m ² is appropriate, and a thickness of 1 to 15 mm is pasted on the entire surface or a part of the sound absorbing layer 21. It is the composition of wearing.
[0022]
A floor carpet 30 is laid in a wrap shape on the lower surface of the insulator dash 20, and an instrument panel 31 is disposed on the upper side of the insulator dash 20.
[0023]
Thus, since the insulator dash 20 for automobiles to which the present invention is applied adopts the lightweight skin layer 22 based on the foam material instead of the conventional sound insulation layer with a heavy weight, the weight can be reduced. There is an advantage that the fuel efficiency of the vehicle can be improved, the attachment work when attaching to the dash panel 10 can be performed smoothly, and the attachment workability can be improved.
[0024]
Furthermore, the sound absorption performance can be improved by variations of the skin layer 22 using a foam material. That is, when a non-breathable foam material made of an independent foam is used as the skin layer 22, transmitted noise transmitted through the dash panel 10 into the passenger compartment R is partially attenuated by the sound absorbing layer 21. In addition, since the skin layer 22 has a non-breathable foam structure, noise in the low / medium frequency range (500 to 2500 Hz) can be effectively absorbed by the membrane vibration of the skin layer 22.
[0025]
On the contrary, the skin layer 22 uses an open-cell foam material, and adjusts the air permeability, so that the sound absorption function in the low / medium frequency range (500 to 2500 Hz) due to the membrane vibration using the non-air-permeable foam material. In addition, it is possible to effectively absorb noise in the frequency range of the middle / high frequency range (800 to 4000 Hz) due to the porous sound absorption function.
[0026]
Therefore, by adjusting the air permeability of the skin layer 22 using the foam material, the work of tuning the frequency range of the target noise can be easily performed.
[0027]
Further, when foam material is used as the skin layer 22, noise propagating through the insulator dash 20 to the vehicle interior side is reflected in the instrument panel 31 and then enters the automobile insulator dash 20 through the skin layer 22 again. Since the sound is absorbed, it is possible to reduce the noise level in the vehicle interior, which leads to the improvement of the sound absorption performance in the vehicle interior.
[0028]
The present invention is not limited to the automobile insulator dash 20 described above, but can be applied to any automobile insulator mounted on a vehicle body panel.
[0029]
【The invention's effect】
As described above, the automotive insulator according to the present invention increases the fuel efficiency of the vehicle by using a foam material as the structure of the skin layer, thereby reducing the weight of the product by reducing the weight. In addition, there is an effect that the workability of attachment to the vehicle body panel can be improved.
[0030]
Furthermore, by making the skin layer based on foam material non-ventilated, the membrane layer's membrane vibration absorption function can effectively absorb noise levels in the low and medium frequency ranges, while the skin layer is vented from the non-ventilated structure. To achieve a well-balanced sound-absorbing performance by changing the ventilation structure and simplifying the tuning work in the target frequency range, such as by effectively changing the noise resistance in the mid- and high-frequency range by changing the ventilation resistance. Has the effect of being able to.
[Brief description of the drawings]
FIG. 1 is an explanatory view showing a configuration of an automobile insulator dash which is an embodiment of an automobile insulator according to the present invention.
FIG. 2 is an explanatory view showing an installation location of an insulator dash for an automobile.
FIG. 3 is an explanatory view showing a configuration of a conventional automotive insulator dash.
[Explanation of symbols]
10 Dash Panel 20 Insulator Dash 21 for Cars Sound Absorbing Layer (Fibrous Molded Body)
22 Skin layer (foaming material)
30 Floor carpet 31 Instrument panel E Engine room R Car compartment

Claims (2)

An automotive insulator (20) mounted on a vehicle compartment surface side of a vehicle body panel (10) that partitions a sound source room (E) and a vehicle compartment (R), along the surface shape of the vehicle body panel (10) The skin layer is composed of a laminate of a sound absorbing layer (21) made of a molded fiber assembly and a skin layer (22) made of a foam material integrated on the surface of the sound absorbing layer (21). The foam material constituting (22) is a single-layer non-ventilated structure, and absorbs sound transmitted through the vehicle body panel (10) from the sound source room (E) side by membrane vibration of the skin layer (22). An automotive insulator characterized by reducing noise levels in low and medium frequency ranges . An automotive insulator (20) mounted on a vehicle compartment surface side of a vehicle body panel (10) that partitions a sound source room (E) and a vehicle compartment (R), along the surface shape of the vehicle body panel (10) The skin layer is composed of a laminate of a sound absorbing layer (21) made of a molded fiber assembly and a skin layer (22) made of a foam material integrated on the surface of the sound absorbing layer (21). The foam material constituting (22) has a ventilation structure and an area density of 0.05 to 0.3 kg / m ^2. In addition to the sound absorption function at the mid and high frequency level by the membrane vibration of the skin layer (22) by varying the ventilation resistance, the sound absorption target is provided with the sound absorption function at the mid and high frequency range level. An automotive insulator characterized by enabling tuning of the frequency range of noise .

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