JPS5819599Y2 - noise control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a noise control device, and particularly to a noise control device that can more effectively reduce noise by using a soundproof wall or the like.

Commonly used noise prevention methods include installing barriers such as a soundproof wall between the sound source and the sound receiver to block the propagation of sound, or completely surrounding and shielding the sound source. .

However, with the former type of barrier, it is natural that the soundproofing effect is limited because noise can overcome the barrier, and with the latter type of barrier, the structure becomes complicated when considering other factors such as heat and exhaust, and in some cases, The disadvantage is that it is difficult to implement.

These problems are common to soundproofing measures for railway noise, automobile noise on roads, machine noise in factories, etc.

In order to eliminate the above-mentioned drawbacks, the applicant filed a patent application filed in 1986-66.
As disclosed in No. 157, etc., a plurality of hollow passages are provided, and at the same time, the noise passing through the hollow passages is refracted downward, and at the same time, the phase is shifted from the direct propagation sound that propagates over the upper part, and the direct propagation sound that crosses over the upper part is generated. We proposed a noise control device that creates a sound reduction area at the boundary between directly propagated sound and refraction propagated sound by interfering with sound.

The present invention is an improvement on the above-mentioned noise control device, in which a part of the noise propagating from the noise source passes through the hollow passage, and is refracted and out of phase. In a noise control device in which a plurality of hollow bodies having pipe length differences that can produce a sound reduction area by interfering with sound are arranged in the noise propagation direction, the noise incident surface and the noise emission surface of the device are The device is characterized in that at least one side thereof is formed with a hollow passage extension that matches the hollow passage of the device and has a different angle.

Embodiments of the present invention will be described below with reference to the drawings.

Figures 1 and 2 were filed in Japanese Patent Application No. 50-661 by the present applicant.
57 and Japanese Patent Application No. 50-84412.

The noise control device 1 in FIG. 1 shows an example in which the angle α of the control element 2 with respect to the substrate 5 is less than or equal to the perpendicular angle.

The hollow passageway 3 formed by the control element 2 in this example is therefore oriented at an angle less than perpendicular to the substrate 5.

The noise control device 1 shown in FIG. 2 is an example in which the control element 2 is oriented approximately perpendicularly to the substrate 5, and the hollow passage 3 formed by the control element 2 is approximately perpendicular to the substrate 5. Orient vertically.

In either case, the pipes are arranged so as to form a difference in pipe length.

When noise passes through the plurality of hollow passages 3 of the noise control device 1 of FIGS. 1 and 2, it is refracted downward and at the same time is out of phase with the directly propagating sound that propagates over the top.

As a result of the interference between the refraction propagated sound and the directly propagated sound, a sound attenuation area is formed between these two propagated sound areas.

FIG. 3 shows an example in which the noise control device 1 shown in FIG. 2 is provided with a hollow passage extension 6 according to the present invention.

In the example shown in the drawings, an extension part 6 is provided on the noise incidence surface 7 of the noise control device 1, and the hollow passage 4 of the hollow passage extension part 6 is provided with an extension part 6.
and the angle of the hollow passage 3 of the noise control device 1 are made different, and the positions and cross-sectional shapes of the hollow passages 3 and 4 are matched, respectively.

The hollow passage extension 6 may be formed integrally with the noise control device 1, or may be attached separately.

Further, the hollow passage extension 6 may be provided only in a part of the hollow passage 3 of the noise control device 1.

4 to 7 diagrammatically show various examples of hollow passage extensions 6. FIG.

FIG. 4 shows an example in which a hollow passage extension 6 is provided on the noise incidence surface of the noise control device 1 shown in FIG. This is different from the main body.

b is an example in which the hollow passage extension 6 is formed separately from the main body and later provided in the main body.

It is a feature of the present invention that the angle of the hollow passage 4 of the hollow passage extension 6 is not different from the angle of the hollow passage of the main body.

FIG. 5 shows an example in which a hollow passage extension 6 is provided in the noise control device 1 shown in FIG. It's a lie.

1)-c shows an example in which the hollow passage extension 6 is formed separately from the main body and later provided in the main body of the noise control device 1, and b shows an example in which the hollow passage extension 6 is formed in a part of the hollow passage 3 in the main body of the noise control device 1. This is an example in which a hollow passage extension is provided, and the angles between the main body and the hollow passage are different.

While a to b described above are examples in which the hollow passage extension 6 is provided on the noise incidence surface 7, C shows an example in which the hollow passage extension 6 is provided on the noise emission surface 8 side.

FIG. 6 shows an example in which the hollow passage extensions 6 are provided in a double-sided type noise control device used when the noise control devices 1 shown in FIG. 2 are placed facing each other and noise sources are located on both sides.

a is a hollow passage extension part 6 for the entire hollow passage of the noise control device 1;
b shows an example in which hollow passage extensions 6 are provided in two parts of the hollow passage of the noise control device 1.

b is a difference between the angle of the hollow passage of the noise control device 1 and the angle of the hollow passage of the hollow passage extension part 6.

FIG. 7 shows an example in which the present invention is applied to a noise control device 1 having a curved hollow passage 3, and a shows a hollow passage extension 6 formed by forming straight hollow passages 9 with different passage lengths to the noise control device 1. An example is shown in which the hollow passage extension 6 having the curved hollow passage 10 is provided in a part of the noise control device 1.

In order to confirm the effect of providing the hollow passage extension 6 according to the present invention, the noise control device 1 shown in FIG. 2 was installed on the board 5 as shown in FIGS. 8a and 8b, and the speaker S was placed, white noise was generated from the speaker S, and the volume reduction at the sound receiving point O was measured.

The reduced volume here indicates the difference in sound ratio level between the case where the noise control device 1 is installed and the case where the noise control device 1 is not installed.

The sound receiving point O is 02 on the extension of the speaker S and 01 on the extension of the line connecting the speaker S and the tip of the noise control device.
It is the midpoint between

In b, a separately formed hollow passage extension 6 is provided on the noise incidence surface of the noise control device 1 in a.

Figure 9 shows the measurement results of the reduced sound volume.

As can be seen from this result, by providing the hollow passage extension 6, the volume reduction can be increased.

Under the conditions of this experimental example, the sound reduction was significantly improved, especially in the low frequency range of 500 Hz or less. According to the present invention, the sound reduction effect of the noise control device can be improved, and it is effective. Soundproofing measures can be taken.

[Brief explanation of the drawing]

1 and 2 are diagrammatic perspective views of a known type of noise control device, FIG. 3 is a diagrammatic perspective view of a noise control device according to the invention, and FIGS. 4 to 1 are diagrammatic perspective views of a noise control device according to the invention. A route map of a noise control device provided with a hollow passage extension, Fig. 8 is an explanatory diagram of a comparison experiment of the noise reduction of the noise control device according to the present invention and a conventional noise control device, and Fig. 9 is a diagram showing the noise reduction according to Fig. 8. It is a graph showing the results of a volume comparison experiment. 1... Noise control device, 2... Control element, 3, 4... Hollow passage, 5... Substrate,
6...Hollow passage extension part, 7...Noise incidence surface, 8...Noise emission surface.

Claims (1)

[Scope of utility model registration request] A pipe in which a part of the noise propagating from a noise source is refracted by passing through a hollow passage, causing a phase shift, and creating a sound reduction area by interfering with the propagating sound and directly propagating sound from the noise source. In a noise control device 1 in which a plurality of hollow bodies having different path lengths are arranged in the noise propagation direction, a hollow passageway is provided in at least one of the noise incidence surface 7 and the noise emission surface 8 of the device 1. 3. A noise control device characterized in that the hollow passage extensions 6 are formed at different angles in accordance with No. 3.