JPH0667678A - Soundproofing device - Google Patents

Abstract

PURPOSE:To provide the soundproof device which can effectively prevent sound even with constitution disposed with a soundproof cover in relatively proximity to a noise generating source. CONSTITUTION:This soundproofing device is constituted by mounting the soundproofing cover 9 to the outside surface of the noise generating source 1 apart a slight spacing held therebetween to suppress and relieve the pressure fluctuation of the air generated between the noise generating source 1 and the soundproofing cover 9 by escaping a part of the air to the outside. The oscillation of the sound shielding plate 11 of the soundproofing cover 9 by the pressure fluctuation is thus prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soundproof device provided with a soundproof cover, and more particularly to a soundproof device which can be used in a state of being relatively close to a noise source.

[0002]

2. Description of the Related Art Conventionally, for example, when noise generated from a machine tool or the like may adversely affect the surroundings, the noise source of the machine tool or the like is sometimes covered with a soundproof cover. In this case, soundproofing can be performed more effectively by interposing a vibration-proof rubber or the like between the noise source and the installation surface or between the soundproof cover and the installation surface.

When the noise source is covered with a soundproof cover, when the distance between the noise source and the soundproof cover is considerably narrower than the wavelength of the sound to be soundproofed, the air pressure due to the vibration of the surface of the noise source is increased. Most of the fluctuation is transmitted to the soundproof cover as it is, and the soundproof cover is vibrated to transmit the sound to the outside, so that the soundproofing is not effectively performed.

Therefore, conventionally, a structure in which a relatively large distance is provided between the noise generating source and the soundproof cover is generally used.

[0005]

As described above, in the case of a structure in which the entire noise generating source of a machine tool or the like is covered with a soundproof cover, for example, the soundproof cover interferes with the operation of the machine tool and the like. By providing a relatively large distance between the noise source and the soundproof cover, there is a problem that an occupied area in a small factory becomes large, for example.

The present invention has been made in view of the conventional problems as described above.

[0007]

SUMMARY OF THE INVENTION The present invention provides a soundproofing device comprising a soundproof cover for covering a part or the whole of a noise generating source, the air being located between the noise generating source and the soundproof cover. When pressure fluctuation occurs due to the vibration of the surface of the noise generating source, in order to reduce the pressure fluctuation as much as possible, when the wavelength of sound to be soundproofed is λ, about λ / 2
The noise cover is provided with pressure relief portions at intervals.

Further, the soundproof device is provided with a noise cover for covering a part or the whole of the noise source, and vibration of the surface of the noise source is caused by the air located between the noise source and the soundproof cover. When a pressure fluctuation is caused by, the size of the soundproof cover from the center to the edge is about λ / The pressure relief portion is provided at the fourth position and a slight gap is provided between the respective soundproof covers arranged adjacent to each other.

[0009]

In the above structure, when the noise source vibrates,
Since the distance between the noise source and the soundproof cover is narrow, pressure fluctuations occur in the air between the noise source and the soundproof cover, tending to vibrate the soundproof cover. However, assuming that the wavelength of the target noise is λ,
Since the pressure relief portions are provided at intervals of / 2, a part of the air escapes from the pressure relief portion to the outside, and the pressure fluctuation of the air is alleviated.

Therefore, although noise leaking directly from the pressure relief portion to the outside cannot be sound-proofed, it is possible to prevent the sound-proof cover from vibrating due to the pressure fluctuation of the air between the noise source and the sound-proof cover. is there.

That is, even when the soundproof cover is relatively close to the noise generating source, the soundproofing effect is greater than in the conventional case.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 and 2, for example, a noise source 1 such as a press, a machine tool, other machines or a drive device is
It is installed on the installation surface 5 via the anti-vibration rubber 3. The antivibration rubber 3 does not necessarily have to be interposed, but it is preferable to interpose it.

A soundproof cover 9 is provided on the entire outer surface or a main part of the noise generating source 1 through a vibration isolator 7 such as a vibration isolating rubber, which is considerably narrower than the wavelength of sound to be soundproofed. It is installed with a space maintained. Soundproof cover 9
Is a structure in which a sound absorbing material 13 made of, for example, glass wool or urethane foam is appropriately fixed inside a sound insulating board 11 made of, for example, a vibration-damping steel plate.

In this embodiment, the size of the soundproof cover 9 is about λ / 4 from the center to the edge, where λ is the wavelength of the sound to be soundproofed. An appropriate gap S is held between the plurality of soundproof covers 9 attached to the noise source 1.

In the above structure, when the noise generating source 1 emits noise, the vibration due to the noise generation is transmitted to the air located between the soundproof cover 9 and the noise generating source 1, so that the pressure fluctuation is caused in the air. Will occur. Since this pressure fluctuation is inversely proportional to the distance between the noise generating source 1 and the sound insulating plate 11 of the soundproof cover 9, when the distance between the noise generating source 1 and the soundproof cover 9 is narrow, the pressure fluctuation of air is large. Therefore, the force of vibrating the sound insulating plate 11 of the soundproof cover 19 is increased and the sound insulating plate 11 tends to be vibrated. When the sound insulating plate 11 is vibrated in this way, noise is transmitted to the outside, and the soundproof effect is lost.

However, in this embodiment, the size of the soundproof cover 9 is about λ / 4 from the center to the edge with respect to the wavelength λ of the sound to be soundproofed, and the soundproof cover 9 is adjacent to the soundproof cover 9. Since a gap S is appropriately provided between the noise generating source 1 and the soundproof cover 9, when pressure fluctuation occurs in a narrow gap, a part of the gap S escapes to the outside. Fluctuations are mitigated and the sound insulation plate 1 of the soundproof cover 9
The tendency of vibrating No. 1 is suppressed.

That is, according to this embodiment, the gap S
Although it is difficult to prevent noise directly leaking from the outside to the outside, the soundproof cover 9 of the soundproof cover 9 is not vibrated, and the soundproof cover 9 is arranged close to the noise source 1. However, the soundproofing is effectively performed.

By the way, when the gap S between the adjacent soundproof covers 9 is large, the internal pressure fluctuation can be alleviated more effectively. However, if the gap S is too large,
Since the noise that passes through the gap S and leaks directly to the outside becomes large, the size of the gap S differs depending on the frequency and strength of the target sound, the structure of the soundproof cover 9, and the like, so it is desirable to obtain it on a test basis. It is a thing.

Now, in the above-mentioned construction, various tests were carried out with the longest dimension of the soundproof cover 9 in the range of 400 mm to 1200 mm, this time 400 mm, the thickness of the soundproof cover 9 was 70 mm, and urethane foam was used as the sound absorbing material 13. , Its thickness is 30 mm, and the dimension from the surface of the noise generating source 1 to the surface of the sound insulating plate 11 of the soundproof cover 9 is 75 mm.
(The dimension from the inner edge of the outer peripheral edge of the soundproof cover 9 to the noise generating source 1 is 5 mm), and the gap S is 5 mm, and 1.5 m from the installation surface 5 at a position 1 m away from the noise generating source 1.
When the microphone was installed at the height of the
The noise was reduced by about 8 dB as compared with the case where the soundproof cover 9 was not provided, and the effect was recognized.

1 and 2, the noise generating source 1 is illustrated as a rectangular parallelepiped, and a rectangular noise cover 9 is attached to the outer side surface of the noise generating source 1. Since the soundproof cover 9 has various shapes,
Corresponding to the appearance of the noise generating source 1, for example, a triangular shape, a hexagonal shape, or other various shapes are formed, and various shapes of soundproof covers are appropriately combined.

FIG. 3 shows a pipe as the noise source 1.
When noise is generated by the vortex of the fluid flowing in the pipe, a plurality of soundproof covers 9 are attached to the pipe via the vibration isolator 7 as shown in FIG. It can be effective.

In the above embodiment, a description has been given of the case where a plurality of soundproof covers 9 are attached to the noise generating source 1 with the gap S held therebetween, but the soundproof cover 9 does not necessarily have to be divided into a plurality of parts. It is a thing.

That is, as shown in FIG. 4, even if the soundproof cover 9 is relatively large and the gap S is provided at intervals of about λ / 2 with respect to the wavelength λ of the sound to be soundproofed. The same effects as those of the above embodiment can be obtained.

5 to 6 show still another embodiment of the present invention.

In FIG. 5, a soundproof cover 9 is attached to the noise source 1 via a vibration isolator 7A having an appropriate length.
A pressure relief portion 15 such as a slit or a hole is provided on the flange portion of the sound insulation plate 11 in order to reduce the pressure fluctuation of the air between the noise source 1 and the soundproof cover 9.

FIG. 6 shows the sound insulation plate 11 of the sound insulation cover 9.
9 shows a structure in which the pressure relief portion 15 is provided in the vibration isolator 7B instead of the above.

In FIG. 7, a pressure relief portion 15 is formed in the central portion of the soundproof cover 9, and a part of air is escaped through a sound absorbing material 19 interposed between the auxiliary sound insulation plate 17 and the soundproof cover 9. It is what

FIG. 8 shows a structure in which the path of the slit portion serving as the pressure relief portion 15 is made relatively long to improve the soundproof effect of noise leaking directly from the pressure relief portion 15 to the outside.

[0029]

As will be understood from the above description of the embodiment, in short, the present invention is not limited to the noise source 1 even if the soundproof cover 9 is arranged relatively close to the noise source 1. Since a part of the air between 1 and the soundproof cover 9 is released to the outside, the pressure fluctuation of the air between the noise source 1 and the soundproof cover 9 is suppressed and relaxed. The soundproof plate 11 of the soundproof cover 9 is not vibrated, and the soundproof effect is improved.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention.

FIG. 2 is a side view of the above.

FIG. 3 is a sectional view showing another embodiment of the present invention.

FIG. 4 is an explanatory view showing another embodiment of the soundproof cover.

FIG. 5 is an explanatory diagram showing another embodiment of the present invention.

FIG. 6 is an explanatory diagram showing another embodiment of the present invention.

FIG. 7 is an explanatory diagram showing another embodiment of the present invention.

FIG. 8 is an explanatory diagram showing another embodiment of the present invention.

[Explanation of symbols]

 1 Noise Source 9 Soundproof Cover 15 Pressure Relief Section S Gap

Claims (3)

[Claims] 1. A soundproof device comprising a soundproof cover for covering a part or the whole of the noise source, wherein vibrations of the surface of the noise source are caused by the air located between the noise source and the soundproof cover. When the pressure fluctuation is caused by the pressure fluctuation, the pressure is released to the noise cover at intervals of about λ / 2 when the wavelength of the sound to be soundproofed is λ so as to minimize the pressure fluctuation. A soundproof device comprising a section. 2. A soundproof device comprising a noise cover for covering a part or the whole of the noise source, wherein vibration of the surface of the noise source is caused by the air located between the noise source and the soundproof cover. When a pressure fluctuation is caused by, the size of the soundproof cover from the center to the edge is about λ / A soundproofing device, characterized in that it is provided at the fourth position and a small gap is provided between the soundproofing covers arranged adjacent to each other to serve as a pressure relief portion. 3. The soundproof device according to claim 1, wherein the soundproof cover is attached to the noise source through a vibration isolator.