JPS624622A - Ventilating device for automobile - Google Patents

Abstract

PURPOSE:To keep the interior of a cabin silent by establishing a region where sound pressures is lowered, within a drafter box with the provision of an opening to the cabin in this region. CONSTITUTION:The plural number of louvers 4 is provided for an opening, which opens outside a car, of a drafter box 1. And the width of the louver 4 is widened as it goes downward so as to establish a region where the sound pressure of sounds which come into the drafter box 1 through each of the louvers 4, is lowered. And another opening 3 is provided inside the cabin in this region. Accordingly, even if the cabin is communicated to atmosphere with a one-way valve 5 opened, this configuration is capable of preventing outside noise from coming into the cabin, and of also keeping the interior of the cabin silent without impairing the effect of ventilation.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a ventilation system for a motor vehicle.

BACKGROUND TECHNOLOGY Figures 4 to 6 show a conventional ventilation system, where l is a drafter box (not shown) disposed on the rear fender R-F of the vehicle body.
It has an opening 2 on the outside of the vehicle that opens to the surface, and an opening 3 on the interior side that opens into the interior of the vehicle (including the luggage room). A plurality of louvers 4 having the same width in the vertical direction are arranged in the vehicle exterior opening 2 so as not to spoil the exterior appearance. Furthermore, the vehicle interior side opening 3 is divided into a plurality of parts, and each vehicle interior side opening 3 has rubber, resin, etc. that opens due to the negative pressure generated near the rear fender R-F surface during driving. A one-way valve 5 made of an elastic material is provided. According to this ventilation system, negative running pressure generated near the rear fender R-F surface when the vehicle is running acts on the one-way valve 5 through the vehicle exterior opening 2, opens the one-way valve 5, and directs the interior air to the outside of the vehicle. This is what is derived. This similar structure is, for example, Utility Model Application No. 57-81907
It is shown in the publication No.

Problems to be Solved by the Invention When the vehicle is running, as mentioned above, the one-way valve 5 is open and the inside and outside of the vehicle are in communication state, so that external noise is transmitted to each looper 4 of the outside opening 2 of the drafter box L. It has been pointed out that if the outside noise enters the drafter box 1 through the opening 3, the outside noise echoes into the cabin through the cabin side opening 3, impairing quietness.

SUMMARY OF THE INVENTION Accordingly, the present invention provides a ventilation system for an automobile that can prevent outside noise from directly entering the vehicle interior without impeding the ventilation effect, and can ensure quietness in the vehicle interior.

Means for solving the problem: The width of a plurality of loopers, which are vertically arranged at an angle diagonally downward in the outside opening of the drafter box, is gradually increased in either the upper or lower direction. A region is formed in the drafter box in which the sound pressure of sound passing from outside the vehicle passing between each looper and entering the drafter box is low, and an opening on the passenger compartment side is provided in the region where the sound pressure is low. It is formed.

The sound waves that enter between the louvers at the outside opening of the drafter box from outside the working vehicle have different path lengths between adjacent louvers, so that a phase difference occurs between the antinode and node of the sound wave in the path between the adjacent louvers. The sound emitted from these paths into the drafter box spreads out as a spherical wave, or the sound pressure is lowered by overlapping the antinodes or nodes of the sound waves in the direction in which the cabin side opening is set.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings, with the same reference numerals assigned to the same parts as in the conventional structure.

In Figs. 1 to 3, a plurality of loopers 4 are disposed vertically in the vehicle exterior opening 2 of the drafter box l, slanting diagonally downward, and the vehicle interior side opening of the drafter box l is shown. 3 is provided with a one-way valve 5 which is opened by the running negative pressure applied via the outside opening 2, and the basic structure is the same as that of the conventional one.

Here, the width dimension of the looper 4 is sequentially enlarged in either the upper or lower direction, for example, as it goes downward,
A region S-L is formed in the upper part of the drafter box 1, in which the sound pressure of sound that passes between the loopers 4 from outside the vehicle and enters the drafter box 1 is lowered, and
The above-mentioned vehicle interior side opening 3 is set in this area S/I.

By sequentially increasing the width of the looper 4 as it goes downwards, the length of the path 6 between each looper 4 increases as it goes downwards. The sound S from outside the vehicle that enters the opening 2 has a phase difference between the antinode S1 and the node S of the sound wave in the adjacent path 6, and the sound wave enters the drafter box 1 from the end of each path 6 with the phase being shifted. It spreads out as a spherical wave. Each of these routes 6
The sound waves that spread out as spherical waves interfere with each other due to the phase shift, and the direction A in which the antinodes SL and node S of the sound waves overlap is directed diagonally upward in the drafter box L, where the aforementioned sound pressure becomes low. A region SL is thus formed. In addition, the direction B in which the antinode and antinode St and the node S and S2 of the sound waves overlap is directed diagonally downward of the drafter box 1, and there is an area S where the sound pressure increases at the bottom of the drafter box 1.
Although the sound pressure increases in this region S•■], it remains at approximately the same level as the incident wave S due to the sound diffusion phenomenon.

Therefore, in this embodiment, in addition to setting the cabin side opening 3 in the region S-L where the sound pressure is low as described above, the drafter box is set in the region S-H where the sound pressure is high. A sound absorbing material 7 is provided on the inner surface.

According to the above-described embodiment, when the vehicle is running, the negative pressure generated near the rear fender R-F' surface acts on the one-way valve 5 via the vehicle exterior opening 2.
Open the door. As a result, as in the conventional case, the interior air flows from the cabin side opening 3 to the drafter box l due to the running negative pressure.
It is drawn out from the vehicle through a path 6 between each looper 4 of the vehicle exterior opening 2.

Here, noise from outside the vehicle enters the drafter box l through the vehicle exterior opening 2, but each path 6 between the loopers 4 is located in the upper part of the drafter box l that forms the vehicle interior side opening 3.
Since a region S-L is formed where the sound pressure is low due to sound wave interference that spreads as a spherical wave from the outside of the vehicle, the influence of outside noise into the vehicle interior through the vehicle interior side opening 3 is suppressed as much as possible. be able to. Moreover, since the sound absorbing material 7 is provided in the area S-H where the sound pressure increases in the lower part of the drafter box l, it is also possible that the noise traveling to the area S-H will be absorbed by the sound absorbing material 7. In this way, the quietness inside the vehicle can be further improved. Furthermore, as in this embodiment, a region S-L where the sound pressure is low is formed at the upper part of the drafter box l, and the cabin side opening 3 is set at the upper part of the drafter box l. Because it is a splash.

This is also very advantageous in terms of measures to prevent the intrusion of water such as car wash water.

In the above embodiment, the width of the louver 4 is widened toward the bottom to form a region S-L where the sound pressure is low at the upper part of the drafter box l. It does not depart from the spirit of the present invention even if a region where the sound pressure is low is formed in the lower part of the drafter box l, and an opening on the compartment side is provided in the lower part of the drafter box l.

Effects of the Invention As described above, according to the present invention, the width of the louver at the outside opening of the vehicle is gradually expanded in either the upper or lower direction, thereby reducing the sound pressure of outside noise inside the drafter box. Since the opening on the passenger compartment side is set in this region, it is possible to avoid noise from outside the vehicle from echoing directly into the passenger compartment, and it is possible to ensure quietness in the passenger compartment. This has a great practical effect.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing one embodiment of the present invention, and FIG. 2 is a perspective view showing one embodiment of the present invention.
Figure 3 is an explanatory diagram showing the sound transmission effect; Figure 4 is a perspective view showing the conventional device; Figure 5 is a cross-sectional view taken along line ■-V in Figure 4. The cross-sectional view, Figure 6, is Vl in Figure 4.
It is a sectional view along the -Vl line. ■...Drafter box, 2...Vehicle outside opening, 3
... Compartment side opening, 4 ... Louver, 5 ... One-way valve, S-L ... Area where sound pressure is low. Figure 1

Claims (1)

[Claims] (1) A plurality of louvers are disposed vertically in the vehicle exterior opening of the drafter box, slanting diagonally downward, and act on the vehicle interior side opening of the drafter box via the vehicle exterior opening. In a structure in which a one-way valve is installed that opens due to the negative running pressure, the width of the louver is gradually expanded in either the upper or lower direction, and a valve is inserted into the drafter box between the louvers from outside the vehicle. 1. A ventilation system for an automobile, characterized in that a region is formed in which the sound pressure of sound entering the drafter box after passing through the drafter box is low, and the opening on the vehicle interior side is set in the region in which the sound pressure is low.