JPH0333565Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in insulators for automobiles.

Automotive insulators are installed on the front floor of the vehicle interior, that is, on the bulkhead that separates the engine room from the vehicle interior, to reduce vibrations and noise from the engine compartment and keep the interior quiet. It is something. In addition, its structure is generally such that a sound insulating layer made of a heavy sheet such as a vinyl chloride sheet or rubber mat is laminated in a sandwich pattern on top of a sound absorbing layer made of a porous sheet such as felt or polyurethane foam. This creates the effect of a wall.

In order to improve the sound insulation properties of such a double structure automobile insulator, the layer thickness of the sound absorbing material and the sound insulation material must be increased, and a heavy filler should be used as a filler to be mixed with the sound insulation material. It is desirable to form the mixture by mixing them.

However, increasing the thickness and weight of such layers is disadvantageous in terms of reducing the weight of automobiles, and for this reason, what is desired for automobile insulators is lighter weight and thinner shapes, as well as better sound insulation effects. Great materials are needed, but as expected,
These problems involve material selection and cost issues, and at present it is difficult to obtain materials that are essentially lightweight and thin and have sound insulation effects.

Therefore, the purpose of this invention is to make it possible to obtain an automobile insulator that can further improve the sound insulation effect if the thickness is the same by making structural improvements.This invention is described below. One embodiment will be described in detail with reference to the drawings.

Figure 1 shows the partition wall between the engine room E and the passenger compartment R in the body panel of an automobile to which this invention is applied. It consists of a darts lower 2, a darts upper 3 provided on the upper part, a cowl top 4, a cowl top grill 5, etc. that form a space between the darts upper 3 and the upper panel.

The insulator dart 7 is attached to the floor surface from the dart lower 2 to the dart upper 3.

As shown in Fig. 2, this insulator dart 7 consists of two sound-absorbing layers 8, 8 made of porous sheets made of felt, foamed polyurethane, etc., and a sound-insulating layer 8 made of a heavy material sheeter such as a chlorinated beer sheet or a rubber mat between them. It has a three-layer structure in which the layers 9 are laminated and adhered in a sandwich-like pattern, and the insulator 7 formed in this three-layer structure is trimmed to match the shape of the floor surface and attached to the floor surface. be.

The difference between this triple-layered insulator and conventional insulators is that while conventional insulators have a double structure of a sound-insulating layer and a sound-absorbing layer, this insulator has a double-layered sound-absorbing layer in the middle. The sound insulating layers are laminated in a sandwich-like structure, and the thickness of the sound absorbing layers 8, 8 is half the thickness of a single conventional sound absorbing layer, and the total thickness is greater than that of the conventional double structure. It is exactly the same as an insulator,
Also, its total weight is exactly the same as the conventional one. However, although the conventional insulator and the insulator according to the present invention have the same thickness and the same weight, the insulator according to the present invention has a higher sound insulation effect.

Next, a more detailed example will be described. First, in a conventional double-structured insulator, the thickness of the sound absorbing layer (felt) is 20 mm, and the weight of the sound insulating layer (rubber) is 5.0 kg/m ² .

On the other hand, in the three-layer structure according to the present invention, the thickness of each sound absorbing layer is 10 mm, and the weight of the sound insulating layer is also exactly the same. When we measured the transmission loss between the conventional double structure insulator formed in this way and the triple structure insulator according to the present invention, it was found that both the conventional and the present invention had a transmission loss of 1600 Hz.
Almost the same transmission loss values were shown below, but from 1600 to
In the high frequency range up to 10000Hz, the present invention is better than 2.
The values were generally high at ~4 dB, clearly showing a significant difference.

As is clear from the above explanation, the insulator according to the present invention has significantly improved sound insulation performance compared to the conventional double-layered insulator at the same thickness and weight. However, in the case of the present invention, after passing through the sound absorbing layer 8 and the sound insulating layer 9, it is further absorbed by the sound absorbing layer 8 on the upper surface, which leads to a reduction in the noise inside the vehicle interior. It is thought that this is true.

Therefore, according to this invention, since it has a three-layer structure in which the above-mentioned sound insulation layer is laminated in the shape of a sandwich with a sound absorption layer, it not only provides a double wall sound insulation function between the darts panel and the sound insulation layer, but also provides sound insulation. By attenuating vibrations, noise, etc. with the sound absorbing layers above and below the layer, the sound insulation properties can be further improved.

On the other hand, if the sound insulation performance is the same as the conventional one, the total thickness and weight of the material can be reduced accordingly, which has the advantage of being expected to reduce the weight of automobiles.

[Brief explanation of drawings]

FIG. 1 is an explanatory cross-sectional view of the vicinity of the floor of an automobile to which this invention is applied, and FIG. 2 is a cross-sectional view of an insulator according to this invention laid on the same floor. 2, 3... Bulkhead, 7... Insulator, 8,
8...Sound absorbing layer, 9...Sound insulating layer.

Claims (1)

[Scope of utility model registration request] An insulator is placed on the side of the vehicle interior of a darts panel that separates the engine room from the vehicle interior to block vibrations and noise propagated from the engine room to the vehicle interior, and the insulator is made of a porous sheet of felt, foamed polyurethane, etc. It has a triple-layered structure in which a sound insulation layer made of heavy sheets such as vinyl chloride sheets and rubber mats is laminated and pasted on the sander arch between the two sound absorption layers, and a double wall sound insulation layer is installed between the darts panel and the sound insulation layer. What is claimed is: 1. An insulator for an automobile, characterized in that it is provided with functions and attenuates vibrations, noise, etc. by sound absorbing layers above and below the sound insulating layer.