JPH09319379A - Noise reduction system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce actively noise wave level itself by displaying the noise reduction effect not only in a physically fixed area but also in a movable optional position, actively radiating a sound wave to a noise source and interfering with the noise wave. SOLUTION: By loading plural noise reducing devices 1, a low noise area is generated in the inside of them. The noise wave is collected from the noise source 4 by a sound collecting device such as a microphone, etc., in individual noise reducing device 1, and phase conversion is performed, and the same sound wave with the phase shifting by a half-wavelength with an arrival noise wave from the position parting from the sound concentrating device by a fixed length at the position is radiated from a speaker in the direction of the noise source 4, and the noise is reduced by interference. By reducing the noise in the area within respective 180 deg. opposite to each other by plural noise reducing devices 1, a local low noise area is generated inside.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a noise reduction device,
In particular, the present invention relates to a noise reduction system that reduces noise in the past, such as around airfields, railroads, conventional roads such as automobiles, downtown, or construction sites.

[0002]

2. Description of the Related Art As a conventional active noise reduction device, there has been proposed a noise reduction device having no detection means for detecting a sound wave after noise and its correction sound interfere with each other. Only by possessing it, the area where noise was reduced was directionally limited, and it was not possible to secure a space in which the user could fully enjoy the effect.

[0003]

The first problem is that, in the conventional active noise reduction system, the noise reduction region has directionality, and the reduction effect in a constant region space that is not influenced by the direction is It couldn't be realized.

The reason is that the noise reduction device in the reduction system is only one, and it is inevitable that the reduction effect has directionality. For example, it is unavoidable that the effect is significantly reduced for noises in different directions of 180 degrees.

The present invention has been made in view of the above-mentioned conventional circumstances. Therefore, the object of the present invention is also effective for a moving noise source, and the structure of a noise reduction device is also effective for detecting interference sound waves. It has no means, can be used outdoors, is light in weight and easy to move by human power, and is equipped with a plurality of the above noise reduction devices to reduce noise in a certain directional spatial area that does not have directionality. It is to provide a novel noise reduction system that can be demonstrated.

[0006]

In order to achieve the above object, a noise reduction system according to the present invention comprises a noise reduction device (reference numeral 1 in FIG. 1) having no interference wave detecting means, and noises thereof. It is equipped with a mechanism (2 in FIG. 1) to which a plurality of reduction devices can be attached, and a lightweight and self-supporting structure device (3 in FIG. 1) that can be used outdoors and can be moved manually.

[0007]

With a plurality of noise reducing devices (two in the embodiment shown in FIG. 1) mounted on the above-mentioned body structure device (3 in FIG. 1), the respective mounting directions (180 ° in FIG. 1). In order to exert the noise reduction effect in two different directions), a constant noise reduction effect appears in all overlapping directions in the overlapping area.

When a total of three noise reduction devices are installed at every 120 degrees, a spatial region with less directivity and a high reduction effect is secured.

Further, since the structure device is self-supporting and lightweight, it can be moved to any place outdoors, is excellent in portability, and is suitable for the position where the structure device is placed without selecting a place. A low noise area can be revealed.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to FIG.

1A and 1B show an embodiment of the present invention, wherein FIG. 1A is a plan view and FIG. 1B is a side view.

In FIG. 1, reference numeral 4 indicates a noise source. The noise reduction system according to the present invention reduces noise radiated from the noise source 4, and includes a plurality of noise reduction devices 1 (two in the embodiment shown in FIG. 1) and a plurality of noise reduction devices. Mechanism (mounting mechanism) 2 with which the reduction device 1 can be mounted
And a plurality of these noise reduction devices 1 and its mounting mechanism 2 are integrally connected to each other, and a self-supporting structure device 3. As an example of the mechanism 2 for mounting the noise reduction device 1, for example, a bolt, a nut, a screw or the like can be used, and as the structure device 3, for example, a skeleton as shown in FIG. 1 can be used. .

The structure device 3 has a lower horizontal rod mounted and fixed on a horizontal surface, a vertical rod provided at a substantially right angle to the horizontal rod, and an upper portion on which the noise reduction device 1 is mounted at an end thereof. It is composed of a rod. Further, the upper rod portion can be configured so that its connecting portion can change the angle with respect to the vertical rod portion so that the axial direction can be changed with respect to the vertical rod portion. In a normal state, the upper rod is substantially perpendicular to the vertical rod, but in FIG. 1B, the upper rod is obtuse with respect to the vertical rod.

The noise reduction system which is integrated as a whole can be installed at any position in a noise environment where noise is not limited to one direction.

The noise reduction device 1 is described in the specification and drawings of Japanese Patent Application No. 7-11344 (noise reduction device for noise), which is currently applied for by the same applicant as the present application. A device having the same function as the device is adopted (see FIGS. 3 and 4).

When the system according to the present invention is arranged as shown in FIG. 1, the area where noise is reduced is shown in FIG.
As shown in, the noise is generated with a constant diffusion angle in accordance with the directivity performance of the loudspeaker 6 (see FIGS. 3 and 4) constituting the noise reduction device 1 inward of the noise reduction device 1. As a result, the overlapping area of the two noise reduction areas (the hatched area in FIGS. 1A and 1B) is, in principle, a noise reduction area that does not depend on the direction.

Next, a usage example of the present invention will be described in detail with reference to FIG.

FIG. 2 is a perspective view showing an example of use of the present invention. 2, the noise reduction system according to the present invention reduces the noise radiated from the noise source 4, and mainly includes a sound collector as a noise detection unit and a correction sound generation unit. A loudspeaker, a control device that outputs a correction sound drive signal to the loudspeaker based on the output signal of the sound collector, and the sound collector and the loudspeaker including the control device are connected with a certain distance and direction. Noise reduction device 1 including a structure
A plurality of (two in the embodiment shown in FIG. 2) and a mechanism capable of mounting the plurality of noise reduction devices 1 (2 in FIG. 2)
And a lightweight and self-supporting structure device (3 in FIG. 2) that can be used outdoors and can be moved manually.

First, regarding the noise reduction device 1, these devices are equipped with the same function and performance (two in FIG. 2).

The loudspeaker is arranged at a position closer to the side (inside in FIG. 1) that receives more noise from the noise source 4 with respect to the sound collector, and is radiated from the noise source 4 by a drive signal from the control device. Generates a correction sound to cancel the noise.

Regarding the noise reduction device shown here,
The above-mentioned Japanese Patent Application No. 7-113 filed by the same applicant as this application
Prior art "noise reduction device for noise" described in specification No. 44
The same function as is adopted (see FIGS. 3 and 4).

As a mounting method, the two noise reduction devices are mounted at positions different by 180 degrees from each other at the same height from the ground and in a direction outward from the center.

This noise reduction system is wholly integrated and is set at any position in the noise environment.

When the noise reduction device 1 is arranged as shown in FIG. 2, the area in which the noise is reduced is, as shown in FIG. In particular, according to the directional diffusion angle), it occurs at an angle of 180 degrees with a constant diffusion angle. As a result, the overlapping area of the two opposing noise reduction areas (the area indicated by the diagonal lines in FIG. 1) is a noise reduction area that does not depend on the direction.

As shown in FIGS. 1 and 2, when there are a plurality of noise sources 4, one noise reduction device 1 can be provided for each noise source 4.

[0026]

The present invention is configured and operates as described above, and therefore the following effects can be obtained according to the present invention.

The first effect is that it is possible to secure a noise reduction region which is not affected by the direction which could not be achieved by the conventional technique.

The reason is that by providing a plurality of noise reducing devices (any number of two or more), a plurality of reduction regions are overlapped with each other, and the noise reducing effect is exhibited for noise sources from all directions. Will be issued.

The second effect is that the noise reduction area can be realized at any position in various noise environments regardless of whether it is indoors or outdoors.

The reason for this is that the noise reduction system of the present invention is self-supporting and is composed of a lightweight structure device, so that it can be manually moved to any place.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of a noise reduction system according to the present invention, in which (a) is a plan view and (b) is a side view.

FIG. 2 is a perspective view showing an example of use of the present invention and showing a noise reduction region in FIG.

FIG. 3 is a principle diagram showing an example of a prior art.

FIG. 4 is a block diagram showing a configuration example of a control device in the prior art shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Noise reduction device 2 ... Mechanism (mounting mechanism) for mounting the noise reduction device 3 ... Construction device that can be used outdoors and is independent 4 ... Noise source 5 ... Sound collector 6 ... Loudspeaker 7 ... Control device 8 ... Connecting rod 10 ... Amplifier 11 ... Frequency detector 12 ... A / D converter 13 ... Delay circuit 14 ... D / A converter 15 ... Amplifier 17 ... Table 18 ... Chair 19 ... Parasol

Claims (4)

[Claims] 1. A noise source is provided with a plurality of noise reduction devices for reducing the noise, and the entire device can be easily moved by human power to be self-supporting. Noise reduction system. 2. The noise reduction device includes noise information detection means for detecting information on noise radiated from the noise source, and correction sound generation for generating a correction sound for canceling noise radiated from the noise source. And a drive signal for causing the correction sound generation means to generate a correction sound having an opposite sound phase and the same sound pressure with respect to the noise radiated from the noise source based on the signal from the noise information detection means. The noise reduction system according to claim 1, further comprising a control unit. 3. The noise according to claim 1, further comprising a plurality of the noise sources, wherein one noise reduction device is provided for each of the noise sources. Reduction system. 4. A plurality of noise reduction devices having no interference wave detection means, a mounting means for mounting the plurality of noise reduction means, and a lightweight body which can be used outdoors and can be moved manually. Moreover, a noise reduction system comprising a self-supporting structure device.