JPS59220436A - Engine room insulator - Google Patents

Abstract

PURPOSE:To improve sound absorption effect by sticking sound absorbing materials, allowing them to face to each other, on the internal wall surfaces facing to each other at substantially symmetrical positions while holding a sound source such as an engine and accessories, etc., therebetween. CONSTITUTION:A hood insulator 2 is stuck on the internal surface of a hood panel 1. Further, thin sound absorbing sheets 20, 21 each comprising felt, non- woven cloth made of glass fiber, etc., are provided facing to each other on the internal surfaces of a wheel house part 10 and a hood ridge 11 located on both side parts of an engine while putting the engine 5 therebetween. Hereby, it is possible to improve sound insulation effect.

Description

[Detailed description of the invention] (Field of invention) This invention relates to an engine room insulator.

(Background of the Invention) In general, an engine room insulator absorbs noise from the main engine and auxiliary equipment installed in the engine room, and reduces the level of noise transmitted to the passenger compartment or outside as much as possible. It was established for this purpose.

As this type of engine room insulator, the first
As shown in the figure, a so-called hood insulator is attached to the inner surface of a hood 1 that covers the upper opening of the engine compartment E, and a front panel is installed in front of the dash panel 3 that partitions the engine compartment E and the vehicle interior R. There is an insulator 4, and each of these insulators 2.4 is set in a planar shape along the surface shape of each panel as a product form.

However, the interior of the engine room E is extremely small and there is not enough space between the engine 5 and other parts and the vehicle body panel, so the thickness of each insulator 2.4 is limited. Otherwise, some parts may not be able to be attached to the panel at all.

In addition, especially the surface of the dash panel 3 is
The dash panel 3 has many parts that pass through it, so it is necessary to provide a large hole in the front insulator 4 to allow the parts to pass through. Its set area is extremely small relative to the surface of the dash panel 3.

By the way, as shown in FIG. 2, in a case where a sound source S is placed inside a box B with an opening on the top surface, and an acoustic measuring means M such as a microphone is opposed to the opening surface, the inner wall surface of the box B as shown in <a> A sound absorbing material Q1 having a predetermined thickness t is placed on one side, and a sound absorbing material Q2 having the same surface density and half the thickness of the sound absorbing material Q1 is placed in a box B as shown in (b). When comparing the sound absorbing material Q2 with a thickness of 1/2 t facing the sound absorbing material Q2, when comparing the sound absorbing material Q2 with a thickness of 1/2 t, when comparing the sound absorbing material Q2 with a thickness of 1/2 t, It has been confirmed that the volume (sound pressure) emitted to the outside is extremely low.

In other words, in this experimental example, the thickness of the panel facing the sound ms, that is, the one in which the sound absorbing material is attached to the inner wall surface of box B, is 2
The present inventors have confirmed that the sound absorption effect increases even if the amount is less than one-fold.

In other words, even if the sound absorbing material itself is thin, by arranging the sound sources in opposing positions sandwiching the sound source, a good sound absorbing effect can be achieved even if the sound absorbing material is extremely thin.

(Object of the Invention) The present invention was made in view of the above knowledge, and its purpose is to obtain a sufficient sound absorbing effect even if the thickness of the sound absorbing material is thin, thereby improving the quietness of the vehicle interior. The purpose is to maintain the noise level and prevent noise from leaking outside the vehicle.

(Structure and Effects of the Invention) In order to achieve the above object, the present invention provides an engine room insulator in which a sheet-like sound absorbing material is attached to the inner wall surface of a vehicle body panel constituting the engine room. It is characterized in that it is attached to the inner wall surface facing in a symmetrical position, sandwiching the sound source such as the engine and auxiliary equipment.

According to the above configuration, by arbitrarily selecting a position between the sound sources such as the engine or auxiliary equipment, and covering the panel surfaces thereof with sound absorbing materials facing each other, it is possible to reduce the thickness of each sound absorbing sheet. Even if the material is thin, sufficient and efficient sound absorption effects can be obtained.

(Description of Embodiments) FIGS. 3 to 5 show the structure inside the engine compartment of an automobile to which the present invention is applied.

In each figure, the hood panel and dash panel 1,
A hood insulator 2 and a dash insulator 4 are attached to the inner surfaces of the engine 5, respectively, as in the conventional case, and the inner surfaces of the wheel house portion 10.10 and the hood ridge 11.11 on both sides of the engine 5 are provided with felt.

Thin sound absorbing sheet 20 made of glass fiber nonwoven fabric, etc.
．． 20 and 21.21 are provided facing each other.

In addition, the hood insulator 2 is installed at the top of the engine.
A sound-absorbing sheet 22 is attached to face the hood and the engine, and face each other with an air cleaner 23 disposed between the hood and the engine in between.

Furthermore, a sound absorbing sheet 23 facing the front insulator 4 is arranged at the rear of the engine 5.

The front insulator 4 and the sound absorbing sheet 23 work together to reduce the sound pressure generated therebetween.

In the above embodiment, the sound absorbing sheet is basically provided at a position facing the engine 5.

Further, a sound absorbing sheet 22 is also provided on the upper surface of the engine 5.

In this case, the engine 5 is different from the panel, but as described above, an arena and other parts that generate noise are placed on the upper part of the engine 5, or there is a device that propagates vibrations from the engine. Since the parts are mixed, the insulator 2 of the hood 1
If it is arranged as a sound-absorbing sheet facing the hood insulator 2, as described above, it can sandwich the noise source and cooperate with the hood insulator 2 to produce a sound-absorbing effect.

Furthermore, in the present invention, it is possible to set sound absorbing sheets of various shapes not only on each of the above-mentioned panels, or on the top or rear of the engine, but also at positions facing other noise generating sources. can.

In this case, the sound absorption effect will be further improved compared to the conventional method of simply pasting a single sheet to the panel, but 11. Needless to say, the sound absorption effect is greater than the increase in volume.

[Brief explanation of the drawing]

Fig. 1 is a partial sectional view showing a conventional engine room insulator and its mounting structure, Figs. 2(a) and (b) are explanatory views showing the basic principle of the present invention, and Figs. 3 to 5 are FIG. 2 is an explanatory diagram of the inside of a J engine room showing an embodiment of the present invention. 2.4...Hood insulator 4...Dash insulator 20.2
1, 22, 23...Sound absorbing sheet 7- Figure 1 Figure 2

Claims (1)

[Claims] (1) In an engine room insulator in which a sheet-like sound absorbing material is attached to the inner wall surface of a vehicle body panel constituting the engine room, the sound absorbing material is approximately symmetrical with the sound source such as the engine and auxiliary equipment in between. An engine room insulator characterized in that the engine room insulator is affixed to an inner wall facing the position.